Cytotoxic Flavokawain B Inhibits the Growth and Metastasis of Hepatocellular Carcinoma through UCK2 Modulation of the STAT3/Hif-1α/VEGF Signalling Pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is associated with a high mortality rate due to early recurrence and its metastasis features. To this day, effective treatment options for metastatic HCC remain a major challenge to patient treatment. Flavokawain B (FKB) is a naturally occurring chalcone molecule capable of providing effective therapy against this life-threatening disease. OBJECTIVE: This study investigated the anti-metastatic effects of FKB on the growth and development of metastatic HCC. METHODS: HepG2 cells were used in this study and a neutral red assay was performed to determine the IC50 value of FKB. Cell scratch and exclusion zone assays were performed to assess the rate of cell migration and invasion. Relative mRNA levels of UCK2, STAT3, VEGF and HIF-1α genes were quantified using RT-qPCR. RESULTS: FKB inhibited the proliferation of HepG2 cells at an IC50 value of 28 µM after 72 h of incubation. Its cytotoxic effect was confirmed to induce apoptosis through the phase-contrast inverted microscope. Cell migration and invasion were significantly inhibited at 7, 14, and 28 µM of FKB as compared to untreated cells. The inhibition in the cell migration significantly increased with the increasing concentrations of the bioactive compound. The relative expression levels of the UCK2 gene and its downstream genes, STAT3, VEGF and HIF-1α, were significantly downregulated after 72 h exposure to FKB treatment. CONCLUSION: Our data suggest that FKB inhibited HepG2 proliferation and further suppressed its metastasis partly by regulating the STAT3/Hif-1α/VEGF signalling pathway. FKB could be a potential alternative and viable strategy against HCC.

Evaluation of acute and sub-acute toxicity profile of 5-methylcoumarin-4ß-glucoside in mice.

Vernonia glaberrima leaves are traditionally used to alleviate bodily pain, skin cancer, and other skin-related disorders. The purpose of the study was to investigate the acute and sub-acute toxicity of 5-methylcoumarin-4ß-glucoside, a promising chemotherapeutic agent against colon cancer isolated from the leaves of Vernonia glaberrima. 5-methylcoumarin-4ß-glucoside was isolated from the methanol leaf extract of Vernonia glaberrima following a previously described method. The acute toxicity study involved a two-phase 24 h observation for signs of mortality and toxicity following single oral dose administration of the isolated compound. For the sub-acute study, four groups of mice, averagely aged eight weeks, were administered graded doses of the compound (250, 500 and 1000 mg/kg) or vehicle for 28 days. On the 29th day, the mice were fasted, anesthetized, euthanized, then their blood and tissues were harvested for hematological, biochemical and histopathological evaluations. There were no signs of mortality or moribund status with an increasing dose of up to 5000 mg/kg over a 24 h period in the acute study. Also, there was no evidence of toxicity on the biochemical or hematopoietic systems in the sub-acute study (p < 0.05). At the dose of 1000 mg/kg, the mice showed some distorted histology with no corresponding alterations in serum biochemicals. Overall, the results showed that 5-methylcoumarin-4ß-glucoside at dosages up to 500 mg/kg is tolerable in mice.

Dihydroartemisinin as a potential drug candidate for cancer therapy: a structural-based virtual screening for multitarget profiling.

Cancer is a rapidly growing non-communicable disease worldwide that is responsible for high mortality rates, which account for 9.6 million death in 2018. Dihydroartemisinin (DHA) is an active metabolite of artemisinin, an active principle present in the Chinese medicinal plant Artemisia annua used for malaria treatment. Dihydroartemisinin possesses remarkable and selective anticancer properties however the underlying mechanism of the antitumor effects of DHA from the structural point of view is still not yet elucidated. In the present study, we employed molecular docking simulation techniques using Autodock suits to access the binding properties of dihydroartemisinin to multiple protein targets implicated in cancer pathogenesis. Its potential targets with comprehensive pharmacophore were predicted using a PharmMapper database. The co-crystallised structures of the protein were obtained from a Protein Data Bank and prepared for molecular docking simulation. Out of the 24 selected protein targets, DHA has shown about 29% excellent binding to the targets compared to their co-crystallised ligand. Additionally, 75% of the targets identified for dihydroartemisinin binding are protein kinases, and 25% are non-protein kinases. Hydroxyl functional group of dihydroartemisinin contributed to 58.5% of the total hydrogen interactions, while pyran (12.2%), endoperoxide (9.8%), and oxepane (19.5%) contributed to the remaining hydrogen bonding. The present findings have elucidated the possible antitumor properties of dihydroartemisinin through the structural-based virtual studies, which provides a lead to a safe and effective anticancer agent useful for cancer therapy.Communicated by Ramaswamy H. Sarma.

Medicinal Potential of Isoflavonoids: Polyphenols That May Cure Diabetes.

In recent years, there is emerging evidence that isoflavonoids, either dietary or obtained from traditional medicinal plants, could play an important role as a supplementary drug in the management of type 2 diabetes mellitus (T2DM) due to their reported pronounced biological effects in relation to multiple metabolic factors associated with diabetes. Hence, in this regard, we have comprehensively reviewed the potential biological effects of isoflavonoids, particularly biochanin A, genistein, daidzein, glycitein, and formononetin on metabolic disorders and long-term complications induced by T2DM in order to understand whether they can be future candidates as a safe antidiabetic agent. Based on in-depth in vitro and in vivo studies evaluations, isoflavonoids have been found to activate gene expression through the stimulation of peroxisome proliferator-activated receptors (PPARs) (α, γ), modulate carbohydrate metabolism, regulate hyperglycemia, induce dyslipidemia, lessen insulin resistance, and modify adipocyte differentiation and tissue metabolism. Moreover, these natural compounds have also been found to attenuate oxidative stress through the oxidative signaling process and inflammatory mechanism. Hence, isoflavonoids have been envisioned to be able to prevent and slow down the progression of long-term diabetes complications including cardiovascular disease, nephropathy, neuropathy, and retinopathy. Further thoroughgoing investigations in human clinical studies are strongly recommended to obtain the optimum and specific dose and regimen required for supplementation with isoflavonoids and derivatives in diabetic patients.

Integration of medicinal plants into the traditional system of medicine for the treatment of cancer in Sokoto State, Nigeria.

This study was designed to explore and record various medicinal plants integrated into the traditional system of medicine for the treatment of cancer. The traditional system of medicine is a routine practiced among the indigenous ethnic groups of Sokoto state. A semi-structured questionnaire was designed and used for data collection around the selected Local Government Areas. A substantial number of plant species were identified, recorded, and collected for preservation. Data collected for each specie was analysed to assess its frequent use among the medicinal plants. A total of 67 species belonging to 31 families have been identified and recorded. Out of the 473 frequency of citation (FC), Acacia nilotica was the most frequently cited specie (32 FC, 64% FC, 0.6 RFC), followed by Guiera senegalensis (27 FC, 54% FC, 0.5 RFC), Erythrina sigmoidea (17 FC, 34% FC, 0.3 RFC), and subsequently Combretum camporum (15 FC, 30% FC, 0.3 RFC). The most common parts of the plants used include the barks (55.2%), the roots (53.2%), and the leaves (41.8%). Additionally, decoction (74.6%), powdered form (49.3%), and maceration (46.3%) are the most frequently used mode of preparation. The historical knowledge of a traditional system of medicine practiced by the native traditional healers of Sokoto for the treatment of cancer has been documented. The present study further provides a baseline for future pharmacological investigations into the beneficial effects of such medicinal plants for the treatment of cancer.

A new sulphated flavone and other phytoconstituents from the leaves of Tetracera indica Merr. and their alpha-glucosidase inhibitory activity.

The bioactivity guided fractionation of Tetracera indica leaves crude ethanolic extract has afforded the isolation and characterization of six compounds including a new natural product viz., 5,7-dihydroxyflavone-O-8-sulphate (1) and five known flavonoids (2-6). The structures of the compounds were elucidated using 1D and 2D NMR and HRESIMS spectroscopic analyses. All the isolated compounds were evaluated for their in vitro inhibitory activity against alpha-glucosidase. Compound 1, 5 and 6 showed strong alpha-glucosidase inhibitory activity, 3 and 4 displayed weak activity while compound 2 was inactive. The interactions of the active compounds with alpha-glucosidase were further investigated using molecular docking to confirm their antidiabetic potential.

Methylation and Acetylation Enhanced the Antidiabetic Activity of Some Selected Flavonoids: In Vitro, Molecular Modelling and Structure Activity Relationship-Based Study.

Flavonoids have been reported to exert antihyperglycemic effects and have potential to enhance the current therapy options against type 2 diabetes mellitus. However, the structure activity relationships (SAR) studies of flavonoids against this disease have not been thoroughly comprehended. Hence, in the present study, 14 structurally related flavonoids viz. wogonin, techtochrysin, norwogonin, isoscutellarein, hypolaetin, kaempferol, quercetin, methyl ether of wogonin, acetate of wogonin, acetate of norwogonin, 8-hydroxy-7-methoxyflavone, chrysin, (+)-catechin and (-)-epicatechin were taken into account for in vitro antidiabetic evaluation. Cell viability of RIN-5F pancreatic cells and 3T3-L1 pre-adipocyte cells was initially tested, then an insulin secretion assay of RIN-5F as well as adipogenesis and glucose uptake measurements of adipocyte were investigated. Subsequently, protein expressions study through adipokines measurement (leptin, adiponectin, TNF-α, RBP-4) via enzyme-linked immunosorbent assay (ELISA) kit, Western blotting analysis against GLUT4 and C/EBP-α as well as molecular docking against GLUT1 were analyzed. The results from cell culture antidiabetic assays (insulin secretion, adipogenesis, and glucose uptake), protein expressions and molecular docking pointed that the methoxy group at position C-8 is responsible for antidiabetic property of selected flavonoids via glucose uptake mechanism indicated by up regulation of GLUT4 and C/EBP-α expressions. The mechanism could be enhanced by the addition of an acetate group at C-5 and C-7 of the flavone skeleton.

Antiradical and Xanthine Oxidase Inhibitory Activity Evaluations of Averrhoa bilimbi L. Leaves and Tentative Identification of Bioactive Constituents through LC-QTOF-MS/MS and Molecular Docking Approach.

The objective of the present study was to investigate the antiradical and xanthine oxidase inhibitory effects of Averrhoa bilimbi leaves. Hence, crude methanolic leaves extract and its resultant fractions, namely hexane, chloroform, and n-butanol were evaluated for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect and xanthine oxidase inhibitory activity. The active constituents were tentatively identified through LC-QTOF-MS/MS and molecular docking approaches. The n-butanol fraction of A. bilimbi crude methanolic leaves extract displayed significant DPPH radical scavenging effect with IC50 (4.14 ± 0.21 µg/mL) (p < 0.05), as well as xanthine oxidase inhibitory activity with IC50 (64.84 ± 3.93 µg/mL) (p < 0.05). Afzelechin 3-O-alpha-l-rhamnopyranoside and cucumerin A were tentatively identified as possible metabolites that contribute to the antioxidant activity of the n-butanol fraction.

Flavonoids from Tetracera indica Merr. induce adipogenesis and exert glucose uptake activities in 3T3-L1 adipocyte cells.

BACKGROUND: Tetracera indica Merr. (Family: Dilleniaceae), known to the Malay as 'Mempelas paya', is one of the medicinal plants used in the treatment of diabetes in Malaysia. However, no proper scientific study has been carried out to verify the traditional claim of T. indica as an antidiabetic agent. Hence, the aims of the present study were to determine the in vitro antidiabetic potential of the T. indica stems ethanol extract, subfractions and isolated compounds. METHODS: The ethanol extract and its subfractions, and isolated compounds from T. indica stems were subjected to cytotoxicity test using MTT viability assay on 3T3-L1 pre-adipocytes. Then, the test groups were subjected to the in vitro antidiabetic investigation using 3T3-L1 pre-adipocytes and differentiated adipocytes to determine the insulin-like and insulin sensitizing activities. Rosiglitazone was used as a standard antidiabetic agent. All compounds were also subjected to fluorescence glucose (2-NBDG) uptake test on differentiated adipocytes. Test solutions were introduced to the cells in different safe concentrations as well as in different adipogenic cocktails, which were modified by the addition of compounds to be investigated and in the presence or absence of insulin. Isolation of bioactive compounds from the most effective subfraction (ethyl acetate) was performed through repeated silica gel and sephadex LH-20 column chromatographies and their structures were elucidated through 1H-and 13C-NMR spectroscopy. RESULTS: Four monoflavonoids, namely, wogonin, norwogonin, quercetin and techtochrysin were isolated from the T. indica stems ethanol extract. Wogonin, norwogonin and techtochrysin induced significant (P < 0.05) adipogenesis like insulin and enhanced adipogenesis like rosiglitazone. Wogonin and norwogonin also exhibited significant (P < 0.05) glucose uptake activity. CONCLUSION: The present study demonstrated that the flavonoids isolated from the T. indica stems possess antidiabetic potential revealing insulin-like and insulin-sensitizing effects which were significant among the compounds. This also rationalizes the traditional use of T. indica in the management of diabetes in Malaysia.

Antioxidant and Antidiabetic Effects of Flavonoids: A Structure-Activity Relationship Based Study.

The best described pharmacological property of flavonoids is their capacity to act as potent antioxidant that has been reported to play an important role in the alleviation of diabetes mellitus. Flavonoids biochemical properties are structure dependent; however, they are yet to be thoroughly understood. Hence, the main aim of this work was to investigate the antioxidant and antidiabetic properties of some structurally related flavonoids to identify key positions responsible, their correlation, and the effect of methylation and acetylation on the same properties. Antioxidant potential was evaluated through dot blot, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS+ radical scavenging, ferric reducing antioxidant power (FRAP), and xanthine oxidase inhibitory (XOI) assays. Antidiabetic effect was investigated through α-glucosidase and dipeptidyl peptidase-4 (DPP-4) assays. Results showed that the total number and the configuration of hydroxyl groups played an important role in regulating antioxidant and antidiabetic properties in scavenging DPPH radical, ABTS+ radical, and FRAP assays and improved both α-glucosidase and DPP-4 activities. Presence of C-2-C-3 double bond and C-4 ketonic group are two essential structural features in the bioactivity of flavonoids especially for antidiabetic property. Methylation and acetylation of hydroxyl groups were found to diminish the in vitro antioxidant and antidiabetic properties of the flavonoids.

Averrhoa bilimbi Linn.: A review of its ethnomedicinal uses, phytochemistry, and pharmacology.

Averrhoa bilimbi Linn. is principally cultivated for medicinal purposes in many tropical and subtropical countries of the world. Literature survey about this plant shows that A. bilimbi is mainly used as a folk medicine in the treatment of diabetes mellitus, hypertension, and as an antimicrobial agent. The prime objective of this review is to accumulate and organize literature based on traditional claims and correlate those with current findings on the use of A. bilimbi in the management of different ailments. Through interpreting already published scientific manuscripts (1995 through 2015) retrieved from the different scientific search engines, namely Medline, PubMed, EMBASE, and Science Direct databases, published articles and reports covering traditional and scientific literature related to A. bilimbi's potential role against various ailments have been thoroughly evaluated, interpreted, and discussed. Several pharmacological studies have demonstrated the ability of this plant to act as antidiabetic, antihypertensive, thrombolytic, antimicrobial, antioxidant, hepatoprotective, and hypolipidemic agent. A. bilimbi holds great value in the complementary and alternative medicine as evidenced by the substantial amount of research on it. Therefore, we aimed to compile an up-to-date and comprehensive review of A. bilimbi that covers its traditional and folk medicine uses, phytochemistry, and pharmacology. Hence, this paper presents an up-to-date and comprehensive review of the ethnomedicinal uses, different chemical constituents, and pharmacological activities of A. bilimbi. So far, the biologically active agents have not been isolated from this plant and this can be a good scientific study for the future antidiabetic, antihypertensive, and antimicrobial implications. Hence, this review targets at emphasizing the diverse traditional claims and pharmacological activities of A. bilimbi with respect to carrying out more scientific studies to isolate active principles through advanced technology.

Report: Anxiolytic, sedative and toxicological effect of hydromethanolic stem bark extract of Maerua angolensis DC. in Wister rats.

Maerua angolensis DC is traditionally used for the treatment of epilepsy and insomnia. The present study was designed to investigate the anxiolytic, sedative and toxicological effect of hydromethanolic stem bark extract of M. angolensis using animal model. Sub-chronic doses of the plant extract on liver and kidney function test were investigated. Elevated plus maze (EPM) and diazepam-induced sleeping time test was used in this investigation. The possible involvement of M. angolensis with GABAA receptor was also investigated using flumazenil. The results of acute toxicity studies showed LD50 to be greater than 5000mg/kg body weight. The test extract (40 and 80mg/kg) significantly (p<0.05) increased the number of open arm entries and time spent in the open arm entries. However, flumazenil with 80mg/kg plant extract showed no significant (p >0.01) difference in the number of entries into open arm when compared to control. The stem bark extract of M. angolensis significantly (p<0.01) increased the duration of sleep induced by diazepam in a dose-dependent manner. However, flumazenil with 80mg/kg extract showed no significant (p>0.01) sedative effect when compared to normal control. In conclusion, the result of our present findings revealed that M. angolensis may apparently be safe and non toxic at therapeutic dose. However, the plant may possess anxiolytic and sedative properties, which exert their effect on GABAA receptors.