Anthelmintic efficacy of Holarrhena pubescens against Raillietina spp. of domestic fowl through ultrastructural, histochemical, biochemical and GLCM analysis.

Globally, traditional knowledge systems are a powerhouse of information which can revolutionise the world, if decoded accurately and logically. Plant-based ethno-traditional and folklore curatives/medicines has a firm basis in the psyche of the common masses of West Bengal and Holarrhena pubescens is a representative example of it. This article communication on depicting the anthelmintic efficacy of ethanolic extract and Ethyl acetate fraction of the stem bark of Holarrhena pubescens against the cestode Raillietina spp. through efficacy studies, ultra-structural observations, histochemical and biochemical analysis on some tegumental enzymes i.e., Acid Phosphatase (AcPase), Alkaline Phosphatase (AlkPase), Adenosine Triphosphatase (ATPase) and 5'-Nucleotidase (5'-Nu) along with Gray Level Co-occurrence Matrix (GLCM) analysis of histochemical study. Praziquantel was used as the reference drug. Investigations revealed 10mg/ml dosage of crude extract was the most efficacious dose and amongst the fractions the ethyl acetate fraction showed the most anthelmintic property. Ultrastructural studies through Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) clearly depicted the damage in head, sucker, proglottids, proximal and distal cytoplasm (DC), microtriches (MT), basal lamina (BL), nuclear membrane (NM), and, nucleolus (NL) in the treated worms. Histochemical studies revealed decrease in staining intensity for all the tegumental enzymes in the treated worms compared to control. The GLCM analysis strongly supported the result of histochemical studies. Biochemical studies revealed marked reduction in enzyme activity in the treated worms with maximum reduction in the activity of 5'- Nu (77.8%) followed by ATPase (63.17%).

MicroRNAs from Holarrhena pubescens stems: Identification by small RNA Sequencing and their Potential Contribution to Human Gene Targets.

Holarrhena pubescens is an effective medicinal plant from the Apocynaceae family, widely distributed over the Indian subcontinent and extensively used by Ayurveda and ethno-medicine systems without apparent side effects. We postulated that miRNAs, endogenous non-coding small RNAs that regulate gene expression at the post-transcriptional level, may, after ingestion into the human body, contribute to the medicinal properties of plants of this species by inducing regulated human gene expression to modulate. However, knowledge is scarce about miRNA in Holarrhena. In addition, to test the hypothesis on the potential pharmacological properties of miRNA, we performed a high-throughput sequencing analysis using the Next Generation Sequencing Illumina platform; 42,755,236 raw reads have been generated from H. pubescens stems from a library of small RNA isolated, identifying 687 known and 50 new miRNAs led. The novel H. pubescens miRNAs were predicted to regulate specific human genes, and subsequent annotations of gene functions suggested a possible role in various biological processes and signaling pathways, such as Wnt, MAPK, PI3K-Akt, and AMPK signaling pathways and endocytosis. The association of these putative targets with many diseases, including cancer, congenital malformations, nervous system disorders, and cystic fibrosis, has been demonstrated. The top hub proteins STAT3, MDM2, GSK3B, NANOG, IGF1, PRKCA, SNAP25, SRSF1, HTT, and SNCA show their interaction with human diseases, including cancer and cystic fibrosis. To our knowledge, this is the first report of uncovering H. pubescens miRNAs based on high-throughput sequencing and bioinformatics analysis. This study has provided new insight into a potential cross-species control of human gene expression. The potential for miRNA transfer should be evaluated as one possible mechanism of action to account for the beneficial properties of this valuable species.

Holanamine, a Steroidal Alkaloid from the Bark of Holarrhena pubescens Wall. ex G. Don Inhibits the Growth of Leishmania donovani by Targeting DNA Topoisomerase 1B.

Leishmaniasis is a group of neglected tropical diseases (NTDs) caused by about 20 species of obligate intracellular protozoan parasites of the genus Leishmania, which occurs in cutaneous, mucocutaneous, and visceral forms. Many researchers have sought to utilize natural products for novel and effective treatments to combat many infectious diseases, including leishmaniasis. Holarrhena pubescens Wall. ex G. Don (Apocynaceae) bark is a rich source of bioactive steroidal alkaloids. The total alkaloidal extract (IC50 6.12 ± 0.117 µg/mL), and the isolated alkaloid, holanamine, showed significant antileishmanial activity (IC50 2.66 ± 0.112 µM against AG83 and 3.80 ± 0.126 µM against BHU-575) against the Leishmania donovani parasite, better than miltefosine (IC50 19.61 ± 0.093 µM against AG83 and 23.20 ± 0.094 µM against BHU-575). Holanamine inhibited the L. donovani topoisomerase 1B (LdToP1B) in a non-competitive manner (IC50 2.81 ± 0.105 µM), indicating that it interacts with the free enzyme and enzyme-DNA complex without inhibiting human topoisomerase. Hydrogen bonding and hydrophobic interactions of holanamine with the N-terminal and hinge region of the large subunit of LTop1B is responsible for its potent antileishmanial activity, as shown by docking studies. Treatment with holanamine causes apoptotic-like cell death by generating cellular and mitochondrial reactive oxygen species, disrupting the mitochondrial membrane potential and inducing ultrastructural alterations in the promastigotes. Holanamine effectively clears intracellular amastigotes but minimally affects host macrophages with no significant cytotoxicity in HEK 293 and L929 cell lines. Thus, our studies show that holanamine can further be used to develop effective antileishmanial agents against evolving drug-resistant parasites.

Induction of apoptosis in human bladder cancer cells by triterpenoids isolated from Holarrhena antidysenterica through differential reactive oxygen species generation.

A novel triterpenoid, holarol(1),3ß-lup-20(31)-en-3,29,30-triol along with one seco-triterpenoid, dihydrocanaric acid(2) and one known pentacyclic triterpenoid, betulin(3) have been isolated from Holarrhena antidysenterica (L.)Wall. (Family: Apocynaceae). The structures of the compounds were elucidated by extensive IR, 1D, 2D NMR and mass spectrometric analysis. The optimised geometry of (1) was calculated by density-functional theory (DFT) using M06-2X hybrid functional and 6-31 G(D) basis set. The compounds showed differential cytotoxic activities in the cell lines-HeLa, EAC, Raji and T24. Seco-triterpenoid (2) showed highest sensitivity (IC50: 1.710 µg/mL) against the bladder cancer cell line T24 followed by (1) (IC50 9.698 µg/mL) and (3) (IC50 11.769 µg/mL). Compound (1) showed highest reactive oxygen species (ROS) generation in T24 cell line followed by (3) and (2) resulting in induction of apoptosis through activation of caspase, cleavage of PARP and reduction of Bcl-2/Bax ratio. Thus compounds (1), (2) along with (3) could be potent anticancer agents.

An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells.

Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentageTM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.

Cytotoxic and cell cycle arrest properties of two steroidal alkaloids isolated from Holarrhena floribunda (G. Don) T. Durand & Schinz leaves.

BACKGROUND: The plant Holarrhena floribunda (H. floribunda; G. Don) is indigenous to sub-Saharan Africa and is traditionally used to treat several ailments. The present study was carried out to isolate and characterize bioactive compounds with anti-proliferative activity present in H. floribunda extracts. METHODS: Compounds were isolated from H. floribunda using the bioassay-guided fractionation technique of repeated column chromatography and the step-wise application of the MTT reduction assay to assess antiproliferative bioactivity. The structures of the compounds were identified mainly using NMR. The effects of the isolated compounds on the viability, cell cycle and proliferation of human cancer cell lines (MCF-7, HeLa and HT-29) as well as the non-cancerous human fibroblast cell line (KMST-6) were investigated. RESULTS: Bioassay-guided fractionation yielded two steroidal alkaloids: holamine (1) and funtumine (2). The MTT reduction assay shows that both compounds exhibited selective dose-dependent cytotoxicity against the cancer cell lines studied. The isolated compounds induced cell cycle arrest at the G0/G1 and G2/M phases in the cancer cell lines with significant reduction in DNA synthesis. The results obtained show that the cancer cells (MCF-7, HeLa and HT-29) used in this study were more sensitive to the isolated compounds compared to the noncancerous fibroblast cells (KMST-6). CONCLUSION: The ability of the isolated compounds to cause cell cycle arrest and reduce DNA synthesis raises hopes for their possible development and use as potent anticancer drugs. However, more mechanistic studies need to be done for complete validation of the efficacy of the two compounds.

Antimalarial and cytotoxic activities of pregnene-type steroidal alkaloids from Holarrhena pubescens roots.

The phytochemical investigation of an alkaloidal extract of Holarrhena pubescens roots led to the isolation and identification of a new pregnene-type alkaloid, mokluangin D (1), together with nine known steroidal alkaloids (2-10). The structure of the new metabolite was determined on the basis of spectroscopic analyses including 1D- and 2D-NMR spectroscopy and mass spectrometry. Compounds 3 and 4 showed potent antimalarial activity against Plasmodium falciparum K1 stain with IC50 values of 1.2 and 2.0 µM, respectively, and showed weak cytotoxic activity against the NCI-H187 cell line with IC50 values of 27.7 and 30.6 µM, respectively. The substituent groups at C-3 and the carbonyl group at C-18 are important for the activity against the P. falciparum K1 stain.

Green synthesis of silver nanoparticles using Holarrhena antidysenterica (L.) Wall.bark extract and their larvicidal activity against dengue and filariasis vectors.

The present study was carried out to evaluate the larvicidal potential of methanol, hexane, acetone, chloroform, and aqueous bark extracts of Holarrhena antidysenterica (L.) Wall. and silver nanoparticles (AgNPs) synthesized using aqueous bark extract against the third instar larvae of Aedes aegypti L. and Culex quinquefasciatus Say. AgNPs were prepared by adding 10 ml of aqueous bark extract in 90 ml of 1 mM silver nitrate (AgNO3) solution. After 5 min of mixing, a change in color from yellow to dark brown occurred indicating the synthesis of AgNPs. Their further characterization was done through ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction analysis (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). UV-Vis spectrum of synthesized AgNPs showed a maximum absorption peak at 420 nm wavelength. Crystalline nature of AgNPs was confirmed by the presence of characteristic Bragg reflection peaks in XRD pattern. TEM images have shown that most of the AgNPs were spherical in shape with an average size of 32 nm. FT-IR spectrum of AgNPs showed prominent absorbance peaks at 1012.2 (C-O) and 3439.44 cm-1 (O-H) which represent the major constituents of phenolics, terpenoids, and flavonoids compounds. LC-MS analysis of the bark extract confirmed the presence of carbonyl and hydroxyl functional groups which were directly correlated with FT-IR results. These AgNPs were assayed against different mosquito vectors, and the maximum mortality was recorded against the larvae of A. aegypti with LC50 and LC90 values being 5.53 and 12.01 ppm, respectively. For C. quinquefasciatus, LC50 and LC90 values were 9.3 and 19.24 ppm, respectively, after 72 h of exposure. Bark extracts prepared in different solvents such as methanol, chloroform, hexane, acetone, and water showed moderate larvicidal activity against A. aegypti their respective LC50 values being 71.74, 94.25, 102.25, 618.82, and 353.65 ppm and LC90 values being 217.36, 222.24, 277.82, 1056.36, and 609.37 ppm. For C. quinquefasciatus, their LC50 values were 69.43, 112.39, 73.73, 597.74, and 334.75 ppm and LC90 values of 170.58, 299.76, 227.48, 1576.98, and 861.45 ppm, respectively, after 72 h of treatment. AgNPs proved to be nontoxic against the non-target aquatic organism, Mesocyclops thermocyclopoides Harada when exposed for 24, 48, and 72 h. The results showed that bark extract-derived AgNPs have extremely high larvicidal potential compared to other organic solvents as well as aqueous bark extract alone. These AgNPs, therefore, can be used safely for the control of dengue and filarial vectors that cause severe human health hazards.

Isolation and antioxidant activity of flavonoids from Holarrhena floribunda (G.don) leaves.

Bioactive polyphenolics are ubiquitously present in plants and may play an important role in the prevention and management of certain human diseases. Three known flavonoids viz Kaemperol-3-O-rutinoside (1), quercetin-3-O-glucoside (2) and kaemperol-3-O-glucoside (3) and inseparable mixture (1:1) of quercetin-3-O-glucose/galactose (4) were isolated, and identified for the first time from Holarrhena floribunda. The antioxidant capacity using the ORAC, FRAP and TEAC assays and inhibition of lipid peroxidation were measured for isolated flavonoids. The result showed that compounds 2 and 4 showed significantly increased ORAC, TEAC, and FRAP activities with low pro-oxidant potential as well as improved lipid peroxidation inhibition levels when compared to compounds 1 and 3. The most active compounds were found to be flavonoids with a quercetin basic structure. These results imply that the isolated flavonoid glycosides are responsible for the antioxidant activity of the plant leaves and it forms the scientific basis for its traditional usage.

In vitro cytotoxic activity of leaves extracts of Holarrhena antidysenterica against some human cancer cell lines.

In vitro cytotoxic potential of extracts (95% and 50% ethanolic extract and hot water extract at concentration of 100 microg/ml) from leaves of Holarrhena antidysenterica was evaluated against fourteen human cancer cell lines--A-549, COLO-205, DU-145, HeLa, HEP-2, IMR-32, KB, MCF-7, NCI-H23, OVCAR-5, SiHa, SK-N-MC, SW-620 and ZR-75-1 from nine different tissues (breast, colon, cervix, CNS, lung, liver, oral, ovary and prostate) using SRB assay. The 95% ethanolic extract displayed maximum anti-proliferative effect in the range of 73-92% against eight human cancer cell lines, while 50% ethanolic extract showed cytotoxic activity in the range of 70-94% against seven human cancer cell lines. However, the hot water extract did not show any activity. Among the fractions of 95% and 50% ethanolic extract, significant cytotoxic activity was found in the chloroform soluble fraction of 95% ethanolic extract at 100 microg/ml; it inhibited the growth in the range of 71-99% of seven human cancer cell lines from five different tissues viz., OVCAR-5 (ovary), HT-29 (colon), SK-N-MC (neuroblastoma), HEP-2 (liver), COLO-205 (colon), NIH-OVCAR-3 (ovary) and A-549 (lung). The cytotoxic activity of chloroform soluble fraction was found to be higher than 5-flurouracil, adriamycin, mitomycin-c and paclitaxel (anticancer drugs used as positive controls). Further in vivo studies and identification of active components from the chloroform fraction and their exact mechanism of action could be useful in designing new anticancer therapeutic agents.

Evaluation of antioxidant, antimutagenic, and lipid peroxidation inhibitory activities of selected fractions of Holarrhena floribunda (G. Don) leaves.

Exposure to environmental pollutants often leads to an upsurge in the production of reactive oxygen species (ROS). ROS oxidize cellular fatty acids to produce lipid peroxyl radicals, subsequently transformed into lipid peroxides, which decrease membrane fluidity and increase the activity of various enzymes implicated in degenerative diseases and cancer formation. Edible plants that contain exogenous compounds like curcumeroid, ß-carotene, turmeric, and so on, protect the aerobic cells from oxidation of free radicals. This study thus evaluates antioxidant and antimutagenic activities of ethyl acetate, aqueous and methanolic fractions of Holarrhena floribunda leaves. Inhibitory activities of the ethyl acetate fraction on Fe(2+)-induced lipid peroxidation in hen egg yolk; rat liver and brain tissues were also evaluated. The Allium cepa root assay was used to evaluate antimutagenic activity. Results showed that the ethyl acetate scavenged DPPH, OH•, and •O2(-) much stronger than other fractions, as evidenced by its lowest respective IC50 values. All the fractions displayed antimutagenic activities against cyclophosphamide-induced chromosomal aberrations. Likewise, all the fractions induced a reduction in mitotic index, a hallmark of cytotoxicity in the root meristem of Allium cepa. The decrease in mitotic index was most profound for the ethyl acetate fraction, which also demonstrated a significant lipid peroxidation inhibitory activity in the liver and brain homogenates, but not in egg yolk, compared with the ascorbic acid standard. In general, the results suggest that the ethyl acetate fraction might contain beneficial phytochemicals that should be explored as novel candidates for preclinical drug development.

Inhibitory effect of hydro-methanolic extract of seed of Holarrhena antidysenterica on alpha-glucosidase activity and postprandial blood glucose level in normoglycemic rat.

ETHNOPHARMACOLOGICAL RELEVANCE: The present experiment was conducted to search out the effect of hydro-methanolic extract of seed of Holarrhena antidysenterica on intestinal α-glucosidase activity in dose dependent manner and on the management of postprandial hyperglycemia in starch loaded rats. MATERIALS AND METHODS: Activity of intestinal α-glucosidase was measured by in vitro method. Fasting blood glucose level was determined by single touch glucometer. Total phenol and flavonoids of seed extract of Holarrhena antidysenterica were estimated using gallic acid and quercetin standard curves, respectively. RESULTS: The degree of elevation in blood glucose level after starch administration was significantly (p<0.05) less by the extract in respect to the control. The said extract also inhibited α-glucosidase activity having an IC(50) of 0.52mg/ml. Phytochemical study revealed that the extract is rich in phenolic compounds (60.23mg of gallic acid equivalent/g of extract) and flavonoids (360.23mg of quercetin equivalent/g of the extract). CONCLUSION: The extract exerts its antihyperglycemic effect by retarding the carbohydrate absorption from intestine through the inhibition in α-glucosidase activity and therefore resists postprandial hyperglycemia.

Effect of defatted methanolic extract of Holarrhena floribunda leaves in sodium arsenite-induced clastogenecity in Wistar albino rats.

This study examined the effect of defatted methanolic extract of Holarrhena floribunda leaves on sodium arsenite-induced clastogenecity and toxicity in male wistar rats. Animals were randomly allotted into six groups of five rats each and treated as follows; Group A (sodium arsenite (NaAsO3)), Group B (100 mg/kg extract), Group C (100 mg/kg extract plus NaAsO3), Group D (200 mg/kg extract), Group E (200 mg/kg extract plus NaAsO3) and Group F had distilled water. Sodium arsenite (2.5 mg/kg) was given intraperitoneally once per week. The extract was administered through oral gavage for 28 consecutive days. Clastogenecity was evaluated by studying micronuclei formation in polychromatic erythrocytes cells (PCEs) in the bone marrow. Plasma levels of Gamma Glutamyl Transferase (ãGT), Aspartate Amino Transferase (AST), Alanine Amino Transferase (ALT) were determined. Hepatic Reduced Glutathione (GSH), Superoxide Dismutase (SOD), Catalase (CAT), protein and lipid peroxidation were determined. Liver histopathological evaluation was also carried out.The results obtained show that NaAsO3-induced micronuclei formation in PCEs was reduced at 100 and 200 mg/kg of the extract by 7.7% and 38.5% respectively while elevated plasma ãGT and ALT levels were significantly ameliorated (P<0.001). There was no significant difference in plasma AST levels and hepatic SOD activities in all the treated groups as compared with the control. Sodium arsenite-induced reduction of GSH concentration was elevated by the extract at 100 and 200 mg/kg by 18.5% and 11.9% respectively. The reduction of CAT activity by NaAsO3 was also ameliorated at 200 mg/kg extract by 23.3%. The extract at 100 mg/kg significantly reduced NaAsO3-induced lipid peroxidation by 16.4% (P < 0.05). Histological examinations showed that the extract at 100 mg/kg protected NaAsO3-induced liver damage. This study revealed that the leaf extract has potential to ameliorate clastogenecity and toxicity induced by sodium arsenite in rats.

Inhibition of enteropathogenic Escherichia coli adhesion on host epithelial cells by Holarrhena antidysenterica (L.) WALL.

Bacterial adhesion is the first step in the sequence of events leading to infection. Previous data are available on the effect of Holarrhena antidysenterica on antidiarrhoeal and antibacterial action, but there is little information on the mechanism of action of the various aspects of EPEC-induced diarrhoea, namely adherence and translocation of the effector molecule to intestinal epithelial cells. The aim of the present study was to investigate the effects of alkaloids of Holarrhena antidysenterica (AHA) on interference in the mechanism of enteropathogenic Escherichia coli (EPEC) adhesion on host epithelial cells (INT 407 and HEp2). To determine the impact of AHA on epithelial cells, cytotoxicity (LDH), adherence, apoptotic and ultrastructural studies were performed. To analyse the effect of AHA on EPEC secreted proteins, especially EspD, INT 407 monolayers were infected with EPEC and AHA-treated EPEC, followed by immunoblotting, probed with anti EspD antisera. The maximum percentage of LDH leakage was reduced in AHA-treated EPEC (400 microg/mL) in both cell lines. Reduced bacterial adherence was observed under light microscopy and altered apoptotic changes were visualized using propidium iodide staining in conjunction with fluorescence microscopy, in both cell lines infected with AHA-treated EPEC and these results were confirmed with transmission electron microscope images. The suppression of type III secretory proteins (TTSPs), EspD ( approximately 40 kDa), was detected in INT 407 cells infected with AHA-treated EPEC. In conclusion, AHA reduces initial bacterial adhesion to intact epithelial cells and it may exert an antiadherence effect against the pathogenesis of EPEC in host epithelial cells. Thus, the investigations provide a rational basis for the treatment of EPEC-mediated diarrhoea with AHA.