Cytotoxicity, acute and sub-chronic toxicities of the leaves of Bauhinia thonningii (Schumach.) Milne-Redh. (Caesalpiniaceae).

BACKGROUND: Bauhinia thonningii is a plant traditionally used against many human diseases such as gastric ulcers, fever, inflammations, coughs, dysentery, diarrhea, and malaria. In the present investigation, the cytotoxicity of methanol extract of Bauhinia thonningii leaves (BTL), fractions and the isolated phytoconstituents was determined in a panel of 9 human cancer cell lines including drug sensitive and multidrug-resistant (MDR) phenotypes. The acute and sub-chronic oral toxicity of BTL was investigated as well. METHODS: Compounds were isolated using chromatographic techniques while their chemical structures were determined using spectroscopic methods. The resazurin reduction assay (RRA) was used to evaluate the cytotoxicity of samples, propidium iodide (PI) for apoptosis, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining for mitochondrial membrane potential (MMP) analysis, 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFH-DA) staining for the quantification of reactive oxygen species (ROS), whereas Caspase Glo assays were combined by means of flow cytometry. Furthermore, the toxicological investigations were performed as recommended by the Organization for Economic Cooperation and Development (OECD). RESULTS: The botanicals as well as 6-C-methylquercetin-3,7-dimethyl ether (2), quercetin-3-O-L-rhamnopyranoside (5), quercetin-3-O-ß-glucopyranoside (6), 6,8-C-dimethylkaempferol 3,7-dimethyl ether (7), and 6,8-C-dimethylkaempferol-3-methyl ether (8) had promising cytotoxic effects in the 9 tested cancer cell lines. The IC50 values below 20 µg/mL (botanicals) or 10 µM (compounds) on at least 1/9 tested cancer cell lines were considered. The best cytotoxic effects with IC50 values below 5 µM were achieved with compounds 7 against CEM/ADR5000 leukemia cells (2.86 µM) and MDA-MB-231-pcDNA breast adenocarcinoma cells (1.93 µM) as well as 8 against CCRF-CEM leukemia cells (3.03 µM), CEM/ADR5000 cells (2.42 µM), MDA-MB-231-pcDNA (2.34 µM), and HCT116 p53-/- cells (3.41 µM). BTL and compound 8 induced apoptotic cell death in CCRF-CEM cells through caspase activation, alteration of MMP, and increased ROS production. BTL did not cause any adverse effects in rats after a single administration at 5000 mg/kg or a repeated dose of 250 mg/kg body weight (b. w.). CONCLUSION: Bauhinia thonningii and its constituents are sources of cytotoxic drugs that deserve more in-depth studies to develop novel antiproliferative phytomedicine to fight cancer including resistant phenotypes.

Cytotoxicity of the methanol extracts and compounds of Brucea antidysenterica (Simaroubaceae) towards multifactorial drug-resistant human cancer cell lines.

BACKGROUND: Cancer remains a global health concern and constitutes an important barrier to increasing life expectancy. Malignant cells rapidly develop drug resistance leading to many clinical therapeutic failures. The importance of medicinal plants as an alternative to classical drug discovery to fight cancer is well known. Brucea antidysenterica is an African medicinal plant traditionally used to treat cancer, dysentery, malaria, diarrhea, stomach aches, helminthic infections, fever, and asthma. The present work was designed to identify the cytotoxic constituents of Brucea antidysenterica on a broad range of cancer cell lines and to demonstrate the mode of induction of apoptosis of the most active samples. METHODS: Seven phytochemicals were isolated from the leaves (BAL) and stem (BAS) extract of Brucea antidysenterica by column chromatography and structurally elucidated using spectroscopic techniques. The antiproliferative effects of the crude extracts and compounds against 9 human cancer cell lines were evaluated by the resazurin reduction assay (RRA). The activity in cell lines was assessed by the Caspase-Glo assay. The cell cycle distribution, apoptosis via propidium iodide (PI) staining, mitochondrial membrane potential (MMP) through 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining, and the reactive oxygen species (ROS) via 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFH-DA) staining, were investigated by flow cytometry. RESULTS: Phytochemical studies of the botanicals (BAL and BAS) led to the isolation of seven compounds. BAL and its constituents 3, (3-(3-Methyl-1-oxo-2-butenyl))1H indole (1) and hydnocarpin (2), as well as the reference compound, doxorubicin, had antiproliferative activity against 9 cancer cell lines. The IC50 values varied from 17.42 µg/mL (against CCRF-CEM leukemia cells) to 38.70 µg/mL (against HCT116 p53-/- colon adenocarcinoma cells) for BAL, from 19.11 µM (against CCRF-CEM cells) to 47.50 µM (against MDA-MB-231-BCRP adenocarcinoma cells) for compound 1, and from 4.07 µM (against MDA-MB-231-pcDNA cells) to 11.44 µM (against HCT116 p53+/+ cells) for compound 2. Interestingly, hypersensitivity of resistant cancer cells to compound 2 was also observed. BAL and hydnocarpin induced apoptosis in CCRF-CEM cells mediated by caspase activation, the alteration of MMP, and increased ROS levels. CONCLUSION: BAL and its constituents, mostly compound 2, are potential antiproliferative products from Brucea antidysenterica. Other studies will be necessary in the perspective of the discovery of new antiproliferative agents to fight against resistance to anticancer drugs.

Cytotoxicity, acute and sub-chronic toxicities of the fruit extract of Tetrapleura tetraptera (Schumm. & Thonn.) Taub. (Fabaceae).

BACKGROUND: Tetrapleura tetraptera is a medicinal spice traditionally used to treat cancer, diabetes, and several other ailments. This study analyzed the cytotoxicity of the dichloromethane methanol extract of T. tetraptera fruits (TTF) and its constituents. The toxicity profile of the TTF extract was also evaluated in rats. METHODS: The Cytotoxicity of this extract was evaluated using the resazurin reduction assay (RRA). Acute and sub-chronic toxicity studies were performed according to the protocol described by the Organisation for Economic Cooperation, and Development (OECD). Hematological, serum, and urine biochemical parameters, as well as histological sections of the liver and kidney, were also evaluated based on standard methods. RESULTS: The TTF extract, compound 5, and the reference drug doxorubicin were active in all 9 tested cancer cell lines. The recorded IC50 ranged from 18.32 µM (against B16-F1 murine melanoma cells) to 36.18 µM (against SKMel-505 BRAF wildtype melanoma cells) for TTF, from 10.02 µM (towards MaMel-80a BRAF-V600E homozygous mutant melanoma cells) to 31.73 µM (against SKMel-28 BRAF-V600E homozygous mutant melanoma cells) for compound 5, and from 0.22 µM (against B16-F1 cells) to 9.39 µM (against SKMel-505 cells) for doxorubicin. The study of acute toxicity test showed that the lethal dose (LD50) of this extract was greater than 5000 mg/kg body weight. In the sub-chronic toxicity studies, variations were observed in some biochemical parameters, especially at higher doses. CONCLUSION: TTF and its most active compound (5) are found to be potential cytotoxic agents, meanwhile, TTF was safe when given a single oral dose of 5000 mg/kg. However, caution is necessary in case of prolonged oral administration due to potential alterations of renal function at high doses (> 1000 mg/kg).

Antibacterial and antibiotic-potentiation activities of the hydro-ethanolic extract and protoberberine alkaloids from the stem bark of Enantia chlorantha against multidrug-resistant bacteria expressing active efflux pumps.

ETHNOPHARMACOLOGICAL RELEVANCE: Enantia chlorantha is traditionally used to treat various ailments including rickettsia fever, cough and wounds, typhoid fever, infective hepatitis, jaundice, and urinary tract infections. AIM OF THE STUDY: To isolate the antibacterial constituents of the hydro-ethanolic extract of the stem bark of E. chlorantha (ECB) and to evaluate the antibacterial and antibiotic-modifying activities of ECB and its constituents against the multidrug-resistant (MDR) phenotypes. MATERIALS AND METHODS: Chromatographic methods were used to isolate the constituents of ECB and Spectroscopic methods were used to elucidate the chemical structures of the isolated compounds. The antibacterial activity of samples was determined by the broth microdilution method while spectrophotometric methods were used to evaluate the effects of ECB and its most active constituent on bacterial growth. Their effects on bacterial proton-ATPase pumps was assessed through the acidification of the bacterial culture medium. RESULTS: Six protoberberine alkaloids were isolated and identified as columbamine (1), pseudocolumbamine (2), jathrorrhizine (3), palmitine (4), 4,13-dihydroxy-3,9,10-trimethoxyprotoberberine (5), and 13-hydroxy-2,3,9,10-tetramethoxyprotoberberine (6). The crude extract (ECB) inhibited the growth of all the tested MDR bacteria, with the minimal inhibitory concentration (MIC) values below 100 µg/mL obtained against Escherichia coli ATCC 10536, AG 102, Enterobacter aerogenes EA 27, Klebsiella pneumoniae ATCC 11296 and KP 55, Providencia stuartii NEA 16, and Staphylococcus aureus MRSA3 and MRSA6. Compound 1 had the best antibacterial effects with MIC values ranging from 16 to 64 µg/mL. The efflux pump inhibitor (EPI), phenylalanine-arginine-ß naphthylamide (PAßN) significantly improved the activity of compounds 1-6. Compounds 1-3 significantly potentiated the antibacterial activity of antibiotics such norfloxacin (NOR), ciprofloxacin (CIP), and doxycycline (DOX) against the tested MDR bacteria. CONCLUSION: The crude extract (ECB) and its isolated compounds 1-6 are potential antibacterial products from Enantia chlorantha. They could be explored more to develop the antibacterial agents that could be used alone or in combination with antibiotics to overcome MDR phenotypes.

Antibacterial and antibiotic-potentiation activity of the constituents from aerial part of Donella welwitshii (Sapotaceae) against multidrug resistant phenotypes.

BACKGROUND: The rise of multidrug-resistant (MDR) bacteria is a real public health problem worldwide and is responsible for the increase in hospital infections. Donella welwitschii is a liana or shrub belonging to the family Sapotaceae and traditionally used to cure coughs. OBJECTIVE: This study was conducted with the objective to validate the medicinal properties of this plant, the aerial part was studied for its phytochemical composition using column and PTLC chromatography and exploring its antibacterial and antibiotic-modifying activity as well as those of its phytochemicals. METHODS: The structures of the compounds were elucidated from their physical and spectroscopic data in conjunction with literature. The antibacterial activity of the isolated metabolites was performed toward a panel of MDR Gram negative and Gram-positive bacteria. The broth micro-dilution method was used to determine antibacterial activities, efflux pump effect using the efflux pump inhibitor (EPI) (phenylalanine-arginine-ß-naphthylamide (PAßN)), as well as the modulating activity of antibiotics. Monitoring the acidification of the bacterial growth medium was used to study the effects of the samples on the bacterial proton-ATPase pumps and cellular ATP production. RESULTS: Eleven compounds were isolated including pentacyclic triterpenes, C-glucosyl benzophenones. With a MIC value < 10 µg/mL, diospyric acid (7) significantly inhibited the growth of Escherichia coli AG102, Enterobacter aerogenes ATCC13048, Klebsiella pneumoniae KP55, Providencia stuartii NEA16 and Staphylococcus aureus MRSA3. 28-hydroxy-ß-amyrin (8) significantly impaired the growth of Enterobacter aerogenes EA27, Klebsiella pneumoniae ATCC11296 and Staphylococcus aureus MRSA6; and oleanolic acid (9) strongly impaired the growth of Escherichia coli AG 102, Enterobacter aerogenes EA27 and Providencia stuartii PS2636. Diospyric acid (7) and 28-hydroxy-ß-amyrin (8) induced perturbation of H+-ATPase pump and inhibition of the cellular ATP production. Moreover, at MIC/2 and MIC/4, compounds 7, 8, and 9 strongly improved the antibacterial activity of norfloxacin, ciprofloxacin and doxycycline with antibiotic-modulating factors ranging between 2 and 64. CONCLUSION: The overall results of the current work demonstrate that diospyric acid (7), 28-hydroxy-ß-amyrin (8) and oleanolic acid (9) are the major bioactive constituents of Donella welwitschia towards Gram-negative bacteria expressing MDR phenotypes.

Botanical from the Fruits Mesocarp of Raphia vinifera Displays Antiproliferative Activity and Is Harmless as Evidenced by Toxicological Assessments.

Raphia vinifera is widely used to treat several diseases including digestive disorders, dysentery, and genitourinary infections. In this study, the mineral contents, the cytotoxicity, and the toxicological effect of the crude CHCl3/MeOH extract (RVM) from the mesocarp of Raphia vinifera were evaluated. The mineral contents were evaluated using the method described by the Association of Official Analytical Chemists (AOAC). The cytotoxicity of both extract and chemical compounds from the plants was determined by a resazurin reduction assay (RRA). The toxicological studies were carried out using the experimental procedure of the Organization for Economic Cooperation and Development (OECD). After killing the rats, biochemical, histopathological, and hematological studies were performed. The result indicated that RVM is rich in zinc (6.52 mg/100 g of DM) and sodium (194.5 mg/100 g of DM). RVM had a cytotoxicity effect with IC50 values lower than 30 µg/mL in 18/18 cancer cell lines tested. These recorded IC50 values were between 12.35 µg/mL (toward CCRF-CEM leukemia cells) and 26.66 µg/mL (toward SKMel-505 BRAF wild-type melanoma cells). Raphvinin 4 displayed good cytotoxicity against MaMel-80aBRAF-V600E homozygous mutant with the IC50 of 10.42 µM. RVM was relatively nontoxic to rats, the median lethal dose (DL50) being above 5000 mg/kg body weight. However, during the oral administration period extending for 28 days, precautions should be taken due to the increase in urinary creatinine level and decrease in spleen weight in the male rats given the highest dose (1000 mg/kg) of extract. Conclusively, the extract of Raphia vinifera is weakly toxic in rats and could be further used in the development of anticancer phytomedicines.

Antibacterial secondary metabolites from Vernonia auriculifera Hiern (Asteraceae) against MDR phenotypes.

Purification of the aerial parts of Vernonia auriculifera Hiern afforded steroids (1-2), flavonoids (3-5), and polyalcohol (6). Their structures were determined using spectral evidences as well as by comparison with reported data. Iodonitrotetrazolium chloride (INT) colorimetric assay was used to assess the antibacterial activity of the extract and isolates against 13 pathogenic strains. The crude extract showed strong antibacterial activity (MIC < 100 µg/mL) against the tested bacterial strains. When combined with an efflux pump inhibitor phenylalanine beta naphthylamide (PAßN), the inhibition potency of the extract was substantially enhanced with the lowest MIC value at 4 µg/mL. Compounds 5 and 6 showed moderate activity (MIC < 100 µg/mL) against 12/13 (92.3%), and 8/13 (61.5%) bacterial strains, respectively. A minimal bactericidal concentration (MBC)/minimal inhibitory concentration (MIC) ratio ≤ 4 indicated their bactericidal effect against Escherichia coli, Enterbacter aerogenes, Klebsiella pneumoniae, Providencia stuartii, Pseudomonas aeruginosa, and Staphylococcus aureus.

In Vitro Anticancer Activity of Imperata cylindrica Root's Extract toward Human Cervical Cancer and Identification of Potential Bioactive Compounds.

Imperata cylindrica is traditionally used to cure several diseases including cancer, wounds, and hypertension. The present study was designed to investigate the anticancer activity of the methanolic root extract of I. cylindrica (IC-MeOH). The water-soluble tetrazolium-1 and colony formation assays were used to check the proliferation ability of the cells. Cell apoptosis and cell cycle were measured by flow cytometry-based fluorescence-activated cell sorting. The ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) analysis was used for the metabolites profiling of IC-MeOH. Based on high-mass accuracy, spectral data, and previous reports, tentative compound identifications were assigned. Our findings revealed that IC-MeOH inhibited the proliferation of HeLa and CaSki cells. The plant extract was also found to induce a concentration- and time-dependent apoptosis and cell cycle arrest in the G0/G1 phase (IC50 value) in CaSki cell line. Analysis of IC-MeOH permitted the identification of 10 compounds already reported for their anticancer activity, epicatechin, curcumin, (-)-yatein, caffeic acid, myricetin, jatrorrhizine, harmaline, cinnamaldehyde, dobutamine, and syringin. In conclusion, IC-MeOH is a rich source of cytotoxic metabolites that inhibits human cervical cancer proliferation via apoptosis and cell cycle arrest.

Botanicals and phytochemicals from the bark of Hypericum roeperianum (Hypericaceae) had strong antibacterial activity and showed synergistic effects with antibiotics against multidrug-resistant bacteria expressing active efflux pumps.

ETHNOPHARMACOLOGICAL RELEVANCE: Infections due to multidrug-resistant (MDR) bacteria constitute a real problem in the public health worldwide. Hypericum roeperianum Schimp. ex A. Rich (Hypericaceae) is used traditionally for treatment of various ailments such as abdominal pains, constipation, diarrhea, indigestion, nausea, and bacterial diseases. AIM OF THE STUDY: This study was aimed at investigating the antibacterial and antibiotic-modifying activity of the crude methanol extracts (HRB), ethyl-acetate soluble fraction (HRBa), residual material (HRBb), and 11 compounds from the bark of Hypericum roeperianum against multi-drug resistant (MDR) bacteria expressing active efflux pumps. MATERIALS AND METHODS: The antibacterial activity, the efflux pump effect using the efflux pump inhibitor (EPI), phenylalanine-arginine-ß-naphthylamide (PAßN), as well as the antibiotic-modifying activity of samples were determined using the broth micro-dilution method. Spectrophotometric methods were used to evaluate the effects of HRB and 8,8-bis(dihydroconiferyl) diferulate (11) on bacterial growth, and bacterial membrane damage, whereas follow-up of the acidification of the bacterial culture was used to study their effects on bacteria proton-ATPase pumps. RESULTS: The crude extract (HRB), HRBa, and HRBb had selective antibacterial activity with MICs ranging from 16 to 512 µg/mL. Phytochemical 11 displayed the best antibacterial activity (0.5 ≤ MIC ≤ 2 µg/mL). The activity of HRB and 11 in the presence of EPI significantly increased on the tested bacteria strains (up to 32-fold). The activity of cloxacillin (CLO), doxycycline (DOX), and tetracycline (TET), was considerably improved (up to 64-fold) towards the multidrug-resistant Enterobacter aerogenes EA-CM64 strain. The crude extract (HRB) and 11 induced the leakage of bacterial intracellular components and inhibited the proton-ATPase pumps. CONCLUSIONS: The crude extract (HRB) and 8,8-bis(dihydroconiferyl)diferulate from the bark of Hypericum roeperianum are good antibacterial candidates that deserve further investigations to achieve antibacterial drugs to fight infections involving MDR bacteria.

Botanical from Piper capense Fruit Can Help to Combat the Melanoma as Demonstrated by In Vitro and In Vivo Studies.

Piper capense belongs to Piperaceae family and has long been used as a traditional medicine to treat various diseases in several parts of Africa. The present study aims to investigate the effect of Piper capense fruit extract (PCFE) alone and in combination with dacarbazine on metastatic melanoma cell line B16-F10 and in vivo in C57BL/6J mice. Cytotoxic effects of PCFE alone and in association with dacarbazine on B16-F10 cells were studied by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and colony formation assay. Wound healing assay, immunofluorescence staining, and western blot analysis were performed to evaluate the individual and combined effect of PCFE and dacarbazine on epithelial-mesenchymal transition (EMT). For in vivo studies, C57BL/6J mice were subcutaneously injected with B16-F10 cells (5 × 105 cells/mL), and the effect of PCFE and dacarbazine was studied on tumor development. The alteration of EMT was evaluated by targeting E-cadherin, vimentin, and CD133 in PCFE alone and in combination with dacarbazine-treated tumor tissues by western blot analysis. Phytochemical screening of PCFE reveals the presence of certain secondary metabolites. Our results showed that PCFE alone and in association with dacarbazine has a good activity in preventing B16-F10 melanoma cell progression and clonogenicity. This extract also regulated EMT. In vivo results showed that PCFE (100 mg/kg body weight) reduced tumor size in C57BL/6J mice along with the decrease in the expression of vasculogenic mimicry (VM) tubes as well as an improvement in the qualitative and quantitative expression of markers involved in EMT. Our study suggests that PCFE may be useful for managing the growth and metastasis of melanoma.

An Efflux Pumps Inhibitor Significantly Improved the Antibacterial Activity of Botanicals from Plectranthus glandulosus towards MDR Phenotypes.

Bacterial multidrug resistance causes many therapeutic failures, making it more difficult to fight against bacterial diseases. This study aimed to investigate the antibacterial activity of extract, fractions, and phytochemicals from Plectranthus glandulosus (Lamiaceae) against multidrug-resistant (MDR) Gram-negative phenotypes expressing efflux pumps. The crude extract after extraction was subjected to column chromatography, and the structures of the isolated compounds were determined using spectrometric and spectroscopic techniques. Antibacterial assays of samples alone and in the presence of an efflux pump inhibitor (phenylalanine-arginine ß-naphthylamide, PAßN) were carried out using the broth microdilution method. The phytochemical study of P. glandulosus plant extract afforded seven major fractions (A-G) which lead to the isolation of seventeen known compounds. The ethanol extract of P. glandulosus was not active at up to 1024 µg/mL, whereas its fractions showed MICs varying from 32 to 512 µg/mL on the studied bacteria. Fraction C of P. glandulosus showed the lowest MIC (32 µg/mL) on E. coli ATCC8739 strain. Fraction D presented the highest activity spectrum by inhibiting the growth of 90% (9/10) of the studied bacteria. The presence of PAßN has improved the activity of extract and all fractions. Overall, the tested phytochemicals showed low activity against the studied bacteria. The overall results obtained in this study show that some fractions from P. glandulosus, mainly fractions C and D, should be investigated more for their possible use to fight against MDR bacteria.

CD24 gene inhibition and TIMP-4 gene upregulation by Imperata cylindrica's root extract prevents metastasis of CaSki cells via inhibiting PI3K/Akt/snail signaling pathway and blocking EMT.

ETHNOPHARMACOLOGICAL RELEVANCE: Imperata cylindrica (L.) Raeusch (Gramineae) is a medicinal spice traditionally used in the treatment of hypertension and cancer. AIM OF THE STUDY: To assess the anti-metastatic potential of the methanol extract of I. cylindrica roots and determined its mechanisms of action. MATERIAL AND METHODS: The growth inhibition activity of I. cylindrica root extract in vitro and in vivo in human cervical cancer. The scratch assay and Boyden Chamber assay were used to determine the anti-migrative and anti-invasion actions of the plant extract. The whole-genome gene expression profiling using RNA-Seq was performed to determine the differentially expressed genes in CaSki cells after exposure to I. cylindrica to identify its targeted genes related to metastasis. Using protein analysis (western blotting) and gene expression analysis (RTqPCR), the targeted pathways of the key genes that were initially identified with RNA-Seq, were evaluated. RESULTS: I. cylindrica extract showed dose-dependent cytotoxicity in vitro and in vivo in mice bearing tumors. Furthermore, I. cylindrica root extract significantly inhibited cell migration and cell invasion. After the genome-wide transcriptome analysis, we found that important genes involved in cancer progression and metastasis of cervical cancer, that is, CD24 and TIMP-4 were significantly downregulated and upregulated, respectively. Moreover, I. cylindrica root extract significantly inhibited the PI3/AKT/Snail signaling pathway and blocked the EMT of CaSki cells. CONCLUSION: These findings provide an anti-metastatic mechanism of action of I. cylindrica root extract toward the human cervical cancer suggesting that this plant maybe developed into selective chemotherapy.

Bioactivity of fractions and constituents of Piper capense fruits towards a broad panel of cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper capense is a medicinal spice whose fruits are traditionally used as aqueous decoction to heal several ailments such as trypanosomiasis, helminthic infections, and cancer. AIM OF THE STUDY: (1) To perform phytochemical investigation of the methanol extract of Piper capense; (2) to evaluate the cytotoxicity of botanicals (PCF, fractions PCFa-e), isolated phytochemicals on a broad panel of animal and human cancer cell lines; (3) to evaluate the induction of apoptosis of the most active samples. MATERIAL AND METHODS: Resazurin reduction assay (RRA) was used to determine the cytotoxicity of the studied samples. Cell cycle distribution (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1) and reactive oxygen species (ROS; H2DCFH-DA) were measured by flow cytometry. Column chromatography (CC) was used for the purification of PCF, whilst nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric (MS) analyses were applied for structural elucidation. RESULTS: The phytochemical investigation of PCF led to the isolation of 11 compounds: licarin B (1), licarin A (2), 7-(1,3-benzodioxol-5-yl)-7,8-dihydro-8-methyl-5-(2-propenyl)-furo[3,2-e]-1,3-benzodioxole (3), nitidine isocyanate (4), 5-hydroxy-7,4'-dimethoxyflavone (5), cardamomin (6), sitosterol (7) and stigmasterol (8), ß-sitosterol 3-O-ß-D-glucopyranoside (9), oleanolic acid (10) and lupeol (11). Fraction PCFb, compound 2 and doxorubicin (as positive control drug) revealed cytotoxic effects towards the 18 tested cancer cell lines. The IC50 values ranged from 6.1 µg/mL (against CCRF-CEM cells) to 44.2 µg/mL (against BRAF-V600E homozygous mutant melanoma cells) for PSCb; from 4.3 µM (against CCRF-CEM cells) to 21.8 µM (against HCT116 p53-/-) for compound 2 and from 0.02 µM (against CCRF-CEM cells) to 123.0 µM (against CEM/ADR5000 cells) for doxorubicin. PCFb and compound 2 induced apoptosis in CCRF-CEM cells mediated by activation of caspase 3/7, 8 and 9, MMP alteration and increased ROS production. CONCLUSION: Piper capense is a source of potent cytotoxic botanicals and phytochemicals that could help to fight various types of cancer including multidrug resistance phenotypes. PCFb and compound 2 should further be explored to develop new drugs to fight malignancies.

Cytotoxic phytochemicals from the crude extract of Tetrapleura tetraptera fruits towards multi-factorial drug resistant cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Tetrapleura tetraptera is an African medicinal spice used in traditional medicine to treat several ailments including cancer. AIM OF THE STUDY: The present study was designed to evaluate the cytotoxicity of the dichloromethane-methanol (1:1) extract of the fruits of Tetrapleura tetraptera (TTF) and its constituents: (3R, 4S)-3,4-dimethyloxetan-2-one (1), luteolin (2), stigmasterol (4), 3-O-[6'-O-undecanoyl-ß-D-glucopyranosyl]stigmasterol (6), olean-12-en-3-ß-O-D-glucopyranoside (7), 3-O-ß-D-glucopyranosyl-(1 â†’ 6)-ß-D-glucopyranosylurs-12-en-28-oic acid (8), 3-O-ß-D-glucopyranosyl-(1 â†’ 3)-ß-D-glucopyranosyl-27-hydroxyolean-12-ene-28-oic acid (9), methyl-O-ß-D-glucopyranoside (10), ß-D-fructofuranosyl-(2 â†’ 1)-ß-D-glucopyranoside (11) towards a panel of cancer cell lines including MDR phenotypes. The cellular mode of induction of apoptosis by TTF and compound 7 was further investigated. MATERIALS AND METHODS: The resazurin reduction assay (RRA) was applied to determine the cytotoxicity of the studied samples. The cell cycle (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1) and reactive oxygen species (ROS; H2DCFH-DA) were measured by flow cytometry. Column chromatography was used for the purification of TTF, whilst nuclear magnetic resonance (NMR) spectroscopic analysis was applied for structural elucidation. RESULTS: The botanical, TTF and the phytochemicals, 2, 7, 8 and 9 as well as doxorubicin exerted cytotoxicity against 9 cancer cell lines including drug-sensitive and drug resistant phenotypes. TTF, compound 7 and doxorubicin were the most active samples, and displayed IC50 values ranging from 10.27 µg/mL (in CCRF-CEM leukemia cells) to 23.61 µg/mL (against HCT116 p53-/- colon adenocarcinoma cells) for TTF, from 4.76 µM (against CCRF-CEM cells) to 12.92 µM (against HepG2 hepatocarcinoma cells) for compound 7, and from 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against CEM/ADR5000 cells) for doxorubicin. TTF induced apoptosis in CCRF-CEM cells through MMP alteration and increased ROS production while compound 7 induced apoptosis mediated by caspases activation, MMP alteration and increased ROS production. CONCLUSION: Tetrapleura tetraptera and some of its constituents, mostly compound 7 are good cytotoxic natural products that should be explored in depth to develop new drugs to fight cancers.

Cytotoxicity of botanicals and isolated phytochemicals from Araliopsis soyauxii Engl. (Rutaceae) towards a panel of human cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Araliopsis soyauxii Engl. (Rutaceae) is a Cameroonian medicinal plant traditionally used to treat lung diseases, malaria, and gonorrhea. It has been demonstrated that infectious disease contribute to about 20% of all human tumours. AIMS OF THE STUDY: (1) To perform a phytochemical investigation of the dichloromethane-methanol 1:1 extracts of the bark (ASB), roots (ASR), and leaves (ASL) from Araliopsis soyauxii; (2) to evaluate the cytotoxicity of extracts and isolated compounds; (3) to determine the mode of induction of apoptosis of ASB and kihadanin B (12). MATERIALS AND METHODS: Fourteen constituents of the crude extracts were isolated by column chromatography, while spectroscopic techniques were used for structural elucidation. The resazurin reduction assay (RRA) was applied to determine the cytotoxicity of samples towards a panel of 9 cancer cell lines. For caspases activity, the Caspase-Glo assay was used; flow cytometry was applied to investigate the cell cycle distribution (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1 staining), and the reactive oxygen species (ROS; H2DCFH-DA staining). RESULTS: Phytochemical investigations of botanicals (ASB, ASR, and ASL) led to the isolation of 14 compounds. Extract ASB, obacunone (11), kihadanin B (12) as well as doxorubicin (control drug) revealed cytotoxicity towards the 9 cancer cell lines tested. The IC50 values ranged from 11.11 µg/mL (against CCRF-CEM leukemia cells) to 28.18 µg/mL (against HCT116 p53+/+ colon adenocarcinoma cells) for ASB; from 28.25 µM (against MDA-MB-231-pcDNA breast adenocarcinoma cells) to 65.13 µM (against HepG2 hepatocarcinoma cells) for compound 11, and from 5.77 µM (against CCRF-CEM cells) to 43.56 µM (against U87.MGΔEGFR glioblastoma cells) for compound 12. ASB and compound 12 induced apoptosis in CCRF-CEM cells. ASB induced the apoptotic process mediated by MMP alteration and enhanced ROS production, while compound 12 induced apoptosis by caspases activation, MMP alteration, and enhanced ROS production. CONCLUSION: This study demonstrated that Araliopsis soyauxii is a potential source of cytotoxic phytochemicals such as kihadanin B and that ASB and compound 12. Extract and compounds will be explored further to develop anticancer drugs.

Botanicals from the leaves of Acacia sieberiana had better cytotoxic effects than isolated phytochemicals towards MDR cancer cells lines.

The efficiency of cancer chemotherapy is seriously hampered by the development of resistance of neoplastic cells to cytotoxic agents. In the present investigation, the cytotoxicity of the dichloromethane-methanol (1:1) extract of Acacia sieberiana (ASL), fractions (ASLa-c) from the leaves and isolated compounds: chrysoeriol-7-O-rutinoside (1), luteolin-7-O-rutinoside (2), chrysoeriol-7-O-ß-D-glucopyranoside (3), Apigenin-7-O-ß-D-glucopyranoside (4), luteolin-3',4'-dimethoxylether-7-O-ß-D-glucoside (5) and luteolin (6) was investigated. The study was extended to the assessment of the mode of induction of apoptosis by ASL. The resazurin reduction assay (RRA) was used for cytotoxicity studies. Assessments of cell cycle distribution, apoptosis, and reactive oxygen species (ROS) were performed by flow cytometry. A caspase-Glo assay was used to evaluate caspase activities. Botanicals ASL, ASLb and ASLc as well as doxorubicin displayed observable IC50 values towards the nine tested cancer cell lines while ASLa and compounds 1-7 had selective activities. The IC50 values ranged from 13.45 µg/mL (in CCRF-CEM leukemia cells) to 33.20 µg/mL (against MDA-MB-231-BCRP breast adenocarcinoma cells) for ASL, from 16.42 µg/mL (in CCRF-CEM cells) to 29.64 µg/mL (against MDA-MB-231-pcDNA cells) for ASLc, and from 22.94 µg/mL (in MDA-MB-231-BCRP cells) to 40.19 µg/mL (against HCT116 (p53-/-) colon adenocarcinoma cells) for ASLb (Table 1), and from 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against CEM/ADR5000 cells) for doxorubicin. ASL induced apoptosis in CCRF-CEM cells, mediated by ROS production. Acacia sieberiana is a good cytotoxic plant and should be further explored to develop an anticancer phytomedicine to combat both sensitive and drug resistant phenotypes.

Cytotoxic Constituents of the Bark of Hypericum roeperianum towards Multidrug-Resistant Cancer Cells.

The global cancer burden remains a serious concern with the alarming incidence of one in eight men and one in eleven women dying in developing countries. This situation is aggravated by the multidrug resistance (MDR) of cancer cells that hampers chemotherapy. In this study, the cytotoxicity of the methanol extract (HRB), fractions (HRBa, HRBb, and HRBa1-5), and compounds from the bark of Hypericum roeperianum (HRB) was evaluated towards a panel of 9 cancer cell lines. The mode of action of the HRB and trichadonic acid (1) was also studied. Column chromatography was applied to isolate the constituents of HRB. The cytotoxicity of botanicals and phytochemicals was evaluated by the resazurin reduction assay (RRA). Caspase-Glo assay was used to evaluate the activity of caspases, and reactive oxygen species (ROS) (H2DCFH-DA) were assessed by flow cytometry. Phytochemicals isolated from HRB were trichadonic acid (1), fridelan-3-one (2), 2-hydroxy-5-methoxyxanthone (3), norathyriol (4), 1,3,5,6-tetrahydroxyxanthone (5), betulinic acid (6), 3'-hydroxymethyl-2'-(4″-hydroxy-3″,5″-dimethoxyphenyl)-5',6':5,6-(6,8-dihydroxyxanthone)-1',4'-dioxane (7), and 3'-hydroxymethyl-2'-(4″-hydroxy-3″,5″-dimethoxyphenyl)-5',6':5,6-(xanthone)-1',4'-dioxane (8). Botanicals HRB, HRBa, HRBa2-4, HRBb, and doxorubicin displayed cytotoxic effects towards the 9 tested cancer cell lines. The recorded IC50 values ranged from 11.43 µg/mL (against the P-glycoprotein (gp)-overexpressing CEM/ADR5000 leukemia cells) to 26.75 µg/mL (against HCT116 (p53+/+) colon adenocarcinoma cells) for the crude extract HRB. Compounds 1, 5, and doxorubicin displayed cytotoxic effects towards the 9 tested cancer cell lines with IC50 values varying from 14.44 µM (against CCRF-CEM leukemia cells) to 44.20 µM (against the resistant HCT116 (p53-/-) cells) for 1 and from 38.46 µM (against CEM/ADR5000 cells) to 112.27 µM (against the resistant HCT116 (p53-/-) cells) for 5. HRB and compound 1 induced apoptosis in CCRF-CEM cells. The apoptotic process was mediated by enhanced ROS production for HRB or via caspases activation and enhanced ROS production for compound 1. This study demonstrated that Hypericum roeperianum is a potential source of cytotoxic phytochemicals such as trichadonic acid and could be further exploited in cancer chemotherapy.

A botanical from the antiproliferative Cameroonian spice, Imperata cylindrica is safe at lower doses, as demonstrated by oral acute and sub-chronic toxicity screenings.

BACKGROUND: The cytotoxicity of the root's methanol extract of Imperata cylindrica (ICR). was previously reported in a panel of human cancer cell lines, including multi-drug resistant phenotypes. The aim of this study was to assess the acute and sub-chronic oral toxicity of methanol root extract of Imperata cylindrica. METHODS: The acute toxicity was carried out according to the experimental protocol of OECD. The plant extract was administered orally to female rats at a single dose of 5000 mg/kg for 14 days and the animals were observed for any behavioral changes or mortality. For sub-chronic toxicity study, ICR was orally administered daily to male and female rats at different doses (250, 500 and 1000 mg/kg per b.w.) for 30 days. During these treatment days the animals were observed for any appearance of toxicity symptoms; following the treatment period, animals were sacrificed for hematological, biochemical and histopathology analysis. RESULTS: From the results of the acute oral toxicity assay, ICR was found to be non-toxic at the dose of 5000 mg/kg b.w. During the period of sub-chronic toxicity test, observation of signs, behavior and health status of the animals showed no abnormality in the groups of animals treated with ICR as compared to the controls. Significant variation of the relative body weights of heart and kidney were observed at dose a 1000 mg/kg b.w. Significant decrease of aspartate aminotransferase, creatinine level, low density lipoprotein concentration, triglyceride and total cholesterol were observed. In males, we noticed a significant decrease of the level of granulocytes with an increase of lymphocytes and mean corpuscular hemoglobin concentration levels. Histological examinations performed on kidney and liver showed a normal kidney architecture and liver also presented a normal hepatic architecture with slight degeneration at a dose 1000 mg/kg b.w. CONCLUSION: ICR is safe for acute oral administration; however, for long-term oral administration, safety measures should be taken. Thus, oral sub-chronic exposure of ICR at lower doses are recommended while higher doses around 1000 mg/kg b.w. should be discouraged.

N-acetylglycoside of oleanolic acid (aridanin) displays promising cytotoxicity towards human and animal cancer cells, inducing apoptotic, ferroptotic and necroptotic cell death.

BACKGROUND: The discovery of novel phytochemicals represents a reasonable approach to fight malignancies, especially those which are resistant to standard chemotherapy. PURPOSE: We evaluated the cytotoxic potential of a naturally occurring N-acetylglycoside of oleanolic acid, aridanin, on 18 cancer cell lines, including sensitive and drug-resistant phenotypes mediated by P-glycoprotein, BCRP, p53 knockout, deletion-mutated EGFR, or BRAF mutations. Furthermore, metastasizing B16/F10 cells, HepG2 hepatocarcinoma and normal AML12 hepatocytes were investigated. The mechanisms of aridanin-induced cell death was further investigated. METHODS: The resazurin reduction assay (RRA) was applied to evaluate the cytotoxicity, autophagy, ferroptotic and necroptotic cell death. CCRF-CEM leukemia cells were used for all mechanistic studies. A caspase-Glo assay was applied to evaluate the caspase activities. Flow cytometry was applied for the analyses of cell cycle (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1) and reactive oxygen species (ROS; H2DCFH-DA). RESULTS: Aridanin and doxorubicin (positive control) inhibited the proliferation of all cancer cell lines tested. The IC50 values for aridanin varied from 3.18 µM (CCRF-CEM cells) to 9.56 µM (HepG2 cells). Aridanin had considerably lower IC50 values than that of doxorubicin against multidrug-resistant CEM/ADR5000 cells and melanoma cell lines (MaMel-80a, Mel-2a, MV3, and SKMel-505). Aridanin induced apoptosis in CCRF-CEM cells through increase of ROS levels and MMP breakdown, and to a lesser extent via caspases activation. Aridanin also induced ferroptotic and necroptotic cell death. CONCLUSION: The present study opens good perpectives for the use of this phytochemical as an anticancer drug to combat multi-facorial resistance to established chemotherapeutics.

8,8-bis-(Dihydroconiferyl)-diferulate displayed impressive cytotoxicity towards a panel of human and animal cancer cells.

BACKGROUND: Recalcitrant cancers appear as a major obstacle to chemotherapy, prompting scientists to intensify the search for novel drugs to tackle the cell lines expressing multi-drug resistant (MDR) phenotypes. PURPOSE: The purpose of this study was to evaluate the antiproliferative potential of a ferrulic acid derivative, 8,8-bis-(dihydroconiferyl)-diferulate (DHCF2) on a panel of 18 cancer cell lines, including various sensitive and drug-resistant phenotypes, belonging to human and animals. The mode of induction of cell death by this compound was further studied. METHODS: The antiproliferative activity, autophagy, ferroptotic and necroptotic cell death were evaluated by the resazurin reduction assay (RRA). CCRF-CEM leukemia cells were used for all mechanistic studies. A caspase-Glo assay was applied to evaluate the activity of caspases. Cell cycle analysis (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H2DCFH-DA) were assessed by flow cytometry. RESULTS: DHCF2 demonstrated impressive cytotoxic effects towards the 18 cancer cell lines tested, with IC50 values all below 6.5 µM. The obtained IC50 values were in the range of 1.17 µM (towards CCRF-CEM leukemia cells) to 6.34 µM (towards drug-resistant HCT116 p53-/- human colon adenocarcinoma cells) for DHCF2 and from 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against multidrug-resistant CEM/ADR5000 leukemia cells) for the reference drug, doxorubicin. DHCF2 had IC50 values lower than those of doxorubicin, against CEM/ADR5000 cells and on some melanoma cell lines, such as MaMel-80a cells, Mel-2a cells, MV3 cells and SKMel-505 cells. DHCF2 induced autophagy as well as apoptosis in CCRF-CEM cells though caspases activation, MMP alteration and increase of ROS production. CONCLUSION: The studied diferulic acid, DHCF2, is a promising antiproliferative compound. It deserves further indepth investigations with the ultimate aim to develop a novel drug to fight cancer drug resistance.