In vitro investigation of potential anti-diabetic activity of the corm extract of Hypoxis argentea Harv. Ex Baker

The corms of Hypoxis argentea are widely used as a traditional remedy for diabetes mellitus in South Africa. In this study, we investigated the effects of non-toxic concentrations (12.5–100 µg mL–1) of the aqueous extract of H. argentea (HAA) corms on glucose uptake, pancreatic beta cell proliferation, and adipocyte differentiation. HAA stimulated glucose uptake in HepG2 cells up to 19.6 % and 17.0 % in L6 myotubes. Live-cell imaging microscopy revealed significant increases (p < 0.001) in total INS-1 cell numbers exposed to HAA, although no effect was observed on adipogenesis in 3T3-L1 pre-adipocytes. HAA produced weak to moderate inhibition of porcine pancreatic α-amylase, α-glucosidase, porcine pancreatic lipase, dipeptidyl peptidase IV (DPP IV) activities, as well as protein glycation. Our results suggest that the acclaimed anti-diabetic effects of H. argentea could be mediated by its promotion of glucose utilization and preservation of pancreatic beta cell populations while preventing fat accumulation in adipocytes

ANTI-PROLIFERATIVE ACTIVITIES OF THE AQUEOUS ROOT EXTRACT OF DIANTHUS THUNBERGII SS HOOPER (CARYOPHYLLACEAE)

Background: The roots of Dianthus thunbergii SS Hooper are used traditionally in South Africa for the treatment of diabetes, wounds, colic, chest complaints and cancer. This study was aimed at investigating the potential anti-proliferative activities of the D. thunbergii in mammalian cancer cell lines. Materials and Methods: Aqueous and ethanol extracts of D. thunbergii were tested in vitro on two cancer cell lines: human hepato-cellular carcinoma (HepG2) cells and murine insulinoma (INS-1) cells using the 3-(4,5-Dimethylthiazol-2- yl) 2,5-diphenyltetrazolium bromide (MTT) and crystal violet cell viability assays, as well as live-cell fluorescence imaging microscopy. A tentative profiling of the aqueous extract was also carried out using liquid chromatography-mass spectrometry (LC-MS). Results: The aqueous extract (50-200μg/ml) exhibited significant (

Evaluation of the wound healing properties of South African medicinal plants using zebrafish and in vitro bioassays

Ethnopharmacological relevance In South Africa, medicinal plants have a history of traditional use, with many species used for treating wounds. The scientific basis of such uses remains largely unexplored. Aim of the study To screen South African plants used ethnomedicinally for wound healing based on their pro-angiogenic and wound healing activity, using transgenic zebrafish larvae and cell culture assays

In Vitro Investigation of Potential Anti-Diabetic Activity of the Corm Extract of Hypoxis Argentea Harv. Ex Baker

The corms of Hypoxis argentea are widely used as a traditional remedy for diabetes mellitus in South Africa. In this study, we investigated the effects of non-toxic concentrations (12.5-100 μg mL-1) of the aqueous extract of H. argentea (HAA) corms on glucose uptake, pancreatic beta cell proliferation, and adipocyte differentiation. HAA stimulated glucose uptake in HepG2 cells up to 19.6 % and 17.0 % in L6 myotubes. Live-cell imaging microscopy revealed significant increases (p < 0.001) in total INS-1 cell numbers exposed to HAA, although no effect was observed on adipogenesis in 3T3-L1 pre-adipocytes. HAA produced weak to moderate inhibition of porcine pancreatic α-amylase, α-glucosidase, porcine pancreatic lipase, dipeptidyl peptidase IV (DPP IV) activities, as well as protein glycation. Our results suggest that the acclaimed anti-diabetic effects of H. argentea could be mediated by its promotion of glucose utilization and preservation of pancreatic beta cell populations while preventing fat accumulation in adipocytes

In Vitro Antidiabetic Activity and Mechanism of Action of Brachylaena elliptica (Thunb.) DC

In South Africa, the number of people suffering from diabetes is believed to be rising steadily and the current antidiabetic therapies are frequently reported to have adverse side effects. Ethnomedicinal plant use has shown promise for the development of cheaper, cost-effective antidiabetic agents with fewer side effects. The aim of this study was to investigate the antidiabetic activity and mechanism of action of aqueous leaf extract prepared from Brachylaena elliptica. The potential of the extract for cytotoxicity was evaluated using MTT assay in HepG2 cells. The effects of the plant extract on glucose utilization in HepG2 cells and L6 myotubes, triglyceride accumulation in 3T3-L1, INS-1 proliferation, glucose metabolism in INS-1 cells, and NO production in RAW macrophages were also investigated using cell culture procedures. The inhibitory effects of the extract on the activities of different enzymes including alpha-amylase, alpha-glucosidase, pancreatic lipase, dipeptidyl peptidase IV (DPP-IV), collagenase, and CYP3A4 enzymes were evaluated. The extract also tested against protein glycation using standard published procedure. The plant extract displayed low level of toxicity, where both concentrations tested did not induce 50% cell death. The extract caused a significant increase in glucose uptake in HepG2 liver cells, with efficacy significantly higher than the positive control, berberine. The crude extract also displayed no significant effect on muscle glucose uptake, triglyceride accumulation in 3T3-L1, glucose metabolism in INS-1 cells, alpha-amylase, alpha-glucosidase, DPP-IV, lipase, protein glycation, and collagenase compared to the respective positive controls. The extract displayed a proliferative effect on INS-1 cells at 25 μg/ml when compared to the negative control. The plant also produced a concentration-dependent reduction in NO production in RAW macrophages and also demonstrated weak significant inhibition on CYP3A4 activity. The findings provide evidence that B. elliptica possess antidiabetic activity and appear to exact its hypoglycemic effect independent of insulin

In Vitro Evaluation of the Phytopharmacological Potential of <i>Sargassum incisifolium</i> for the Treatment of Inflammatory Bowel Diseases

Background: Comprised of Crohn&#8217;s disease and ulcerative colitis, inflammatory bowel diseases (IBD) are characterized by chronic inflammation of the gastro-intestinal tract, which often results in severe damage to the intestinal mucosa. This study investigated metabolites from the South African endemic alga, Sargassum incisifolium, as potential treatments for IBD. Phytochemical evaluation of S. incisifolium yielded prenylated toluhydroquinones and toluquinones, from which semi-synthetic analogs were derived, and a carotenoid metabolite. The bioactivities of S. incisifolium fractions, natural products, and semi-synthetic derivatives were evaluated using various in vitro assays. Methods: Sargahydroquinoic acid isolated from S. incisifolium was converted to several structural derivatives by semi-synthetic modification. Potential modulation of IBD by S. incisifolium crude fractions, natural compounds, and sargahydroquinoic acid analogs was evaluated through in vitro anti-inflammatory activity, anti-oxidant activity, cytotoxicity against HT-29 and Caco-2 colorectal cancer cells, and PPAR-&#947; activation. Results: Sargahydroquinoic acid acts on various therapeutic targets relevant to IBD treatment. Conclusions: Conversion of sargahydroquinoic acid to sarganaphthoquinoic acid increases peroxisome proliferator activated receptor gamma (PPAR-&#947;) activity, compromises anti-oxidant activity, and has no effect on cytotoxicity against the tested cell lines

Wild-Type Zebrafish (Danio rerio) Larvae as a Vertebrate Model for Diabetes and Comorbidities: A Review

Zebrafish have become a popular alternative to higher animals in biomedical and pharmaceutical research. The development of stable mutant lines to model target specific aspects of many diseases, including diabetes, is well reported. However, these mutant lines are much more costly and challenging to maintain than wild-type zebrafish and are simply not an option for many research facilities. As an alternative to address the disadvantages of advanced mutant lines, wild-type larvae may represent a suitable option. In this review, we evaluate organ development in zebrafish larvae and discuss established methods that use wild-type zebrafish larvae up to seven days post fertilization to test for potential drug candidates for diabetes and its commonly associated conditions of oxidative stress and inflammation. This provides an up to date overview of the relevance of wild-type zebrafish larvae as a vertebrate antidiabetic model and confidence as an alternative tool for preclinical studies. We highlight the advantages and disadvantages of established methods and suggest recommendations for future developments to promote the use of zebrafish, specifically larvae, rather than higher animals in the early phase of antidiabetic drug discovery