Ginkgo bilobaextract prevents against apoptosis induced by high glucose in human lens epithelial cells¹

Abstract

Aim: To investigate the protective effects of Ginkgo biloba extract (GBE) on high glucose-induced apoptosis of human lens epithelial cells (HLEC) and the possible molecular mechanisms. Methods: The cultured HLEC were allotted into 6 groups: normal group, high glucose group, low-, moderate-, and highdose GBE group, and the bendazac lysine group. Cell viability, cell apoptosis, the activities of cell antioxidases, aldose reductase, caspase-3, the levels of cell antioxidants, and the expressions of Bcl-2 and Bax were assessed by different methods. Results: After being incubated with high glucose for 24 h, HLEC underwent apoptosis and exhibited significant oxidative stress. In the presence of GBE at different doses, the rate of HLEC apoptosis was lower and the oxidative stress state was significantly ameliorated. The increased ratio of Bax to Bcl-2 was significantly reduced and the activation of caspase-3 was suppressed by GBE in a dose-dependent manner. Conclusion: GBE prevents HLEC from high glucose-induced apoptosis through inhibiting oxidative stress, reducing the ratio of Bax to Bcl-2, and decreasing the activity of caspase-3. Therefore, GBE has a potential protective effect against diabetic cataract formation.

Molecular mechanisms underlying the cholesterol-lowering effect of Ginkgo biloba extract in hepatocytes: a comparative study with lovastatin

“…When the cells were about 70% confluent, the medium was replaced with medium containing 2% FBS for drug treatment experiments. For dose-response experiments, a variety of concentrations of GBE (50, 100, and 200 µg/mL) were used, and the cells were treated for 24 h. For time course experiments, cells were treated for different times (6,12,24, and 48 h) with either 200 µg/mL of GBE or 0.5 μmol/L lovastatin. Control cells were treated with 0.1% DMSO (the vehicle) for the longest treatment time in the experiment.…”

“…The main active components of the standard GBE are flavonol glycosides (~24% total volume) and terpene lactones (~6%) [1] . The mixture of biologically active ingredients present in GBE has pleiotropic physiological effects, including the inhibition of amyloidformation [2,3] , antioxidant activity [4,5] , anti-apoptosis activity [6] , effects on vasodilation [7] and inhibition of platelet aggregation [8,9] . Recently, studies have shown that GBE modulates the metabolism of cholesterol.…”

Accumulation of argpyrimidine, a methylglyoxal-derived advanced glycation end product, increases apoptosis of lens epithelial cells bothin vitroandin vivo

“…High glucose has enhanced Bax expression and apoptosis in human LECs (Wu et al, 2008). In retinal pericytes, NF-κB activation by high glucose has increased Bax expression (Podesta et al, 2000; Romeo et al, 2002).…”

“…In LECs from patients with anterior polar cataracts, the mRNA and protein levels of Bcl-2 were decreased. Similarly, the ratio of Bax to Bcl-2 protein levels was increased in human LECs treated with high glucose (Wu et al, 2008). In this study, we also observed an increased ratio of Bax to Bcl-2 protein levels that favored apoptosis.…”

Lens epithelial cell apoptosis initiates diabetic cataractogenesis in the Zucker diabetic fatty rat

“…Apoptosis of LECs has been shown to be induced by a high concentration of glucose in vitro [47,48]. Diabetic cataracts have elevated Amadori products and AGEs when compared to normal lenses [49].…”