Water-soluble compounds in the herbal preparation Abana inhibit lipid biosynthesis and enhance cholesterol efflux in HepG2 cells

Anti-platelet and Anti-thrombotic Effects of a Poly-ingredient formulation: In vitro and in vivo experimental evidences

OBJECTIVE

The present study was conducted to evaluate the efficacy of Abana^® (a poly-ingredient formulation with natural constituents) on in vitro platelet aggregation and occlusion-induced deep venous thrombosis in rats.

METHODS

Anti-platelet property of Abana^® was evaluated using ADP (Adenosin 5-diphosphate) and adrenaline-induced platelet aggregation models, and anti-thrombotic activity was evaluated against occlusion-induced deep venous thrombosis model in wistar rats.

RESULTS

Under the in vitro conditions, Abana® (250, 500 and 1000 µg/ml) alleviated ADP and adrenaline-induced platelet aggregation in a dose-dependent manner. Abana® (1000 µg/ml) inhibited ADP and adrenaline-induced platelet aggregation by as much as 50.69% and 64.83% respectively. Furthermore, 6 days pre-treatment with Abana® (250 and 500 mg/kg, p.o.) in an in vivo study showed significant and dose-dependent protection against occlusion-induced deep venous thrombosis in rats.

CONCLUSION

These findings suggest that Abana^®, a polyherbal formulation possesses anti-platelet and anti-thrombotic activities in the experimental models of in vitro platelet aggregation and in vivo deep venous thrombosis in rats.

Alcohol depletes coenzyme-Q(10) associated with increased TNF-alpha secretion to induce cytotoxicity in HepG2 cells

Alcohol consumption has been implicated to cause severe hepatic steatosis which is mediated by alcohol dehydrogenase (ADH) activity and CYP(450) 2E1 expression. In this context, the effect of ethanol was studied for its influence on lipogenesis in HepG2 cell which is deficient of ADH and does not express CYP(450) 2E1. The results showed that ethanol at 100mM concentration caused 40% cytotoxicity at 72h as determined by MTT assay. The incorporation of labeled [2-(14)C] acetate into triacylglycerol and phospholipid was increased by 40% and 26% respectively upon 24h incubation, whereas incorporation of labeled [2-(14)C] acetate into cholesterol was not significantly increased. Further, ethanol inhibited HMG-CoA reductase which is a rate-limiting enzyme in the cholesterol biosynthesis. It was observed that, HMG-CoA reductase inhibition was brought about by ethanol as a consequence of decreased cell viability, since incubation of HepG2 cells with mevalonate could not increase the cholesterol content and increase the cell viability. Addition of ethanol significantly increased TNF-alpha secretion and depleted mitochondrial coenzyme-Q(10) which is detrimental for cell viability. But vitamin E (10mM) could partially restore coenzyme-Q(10) and glutathione content with decreased TNF-alpha secretion in ethanol treated cells. Further, lipid peroxidation, glutathione peroxidase and superoxide dismutase enzyme activities remained unaffected. Ethanol decreased glutathione content while, GSH/GSSG ratio was significantly higher compared to other groups showing cellular pro-oxidant and antioxidant balance remained intact. Alanine amino transferase activity was increased by 4.85 folds in cells treated with ethanol confirming hepatocyte damage. Hence, it is inferred that ethanol induced cytotoxicity in HepG2 cells due to coenzyme-Q(10) depletion and increased TNF-alpha secretion.