Abstract
Purpose::
To determine the effects of two grape proanthocyandin compounds, GSE (grape seed extract) and IH636 (GSE + resveratrol, RES) on canine lens epithelial cells (LEC). Both GSE and RES have been shown to have anti-oxidant and free radical scavenging as well as variable anti-inflammatory, antihistaminic, and other properties. Numerous rodent models have shown that IH636 can prevent the development of inherited, galactosemia, and selenite-induced cataracts. We hypothesized that GSE alone or in combination with RES would attenuate free radical formation and decrease stress-induced cell signaling following exposure to oxidative stress.
Methods::
The DCF assay was used to evaluate the free radical scavenging ability of GSE, IH636, and controls (trolox and vehicle only) following exposure to oxidative stress (tertiary butyl-hydroperoxide, TBHP). Following the same treatments, markers of oxidative stress were evaluated by Western blot analysis (ERK, SAPK/JNK, p38, and Akt).
Results::
GSE and IH636 significantly reduced ROS production following 30 minutes exposure to TBHP. Only GSE significantly reduced ROS production following 120 minutes exposure to TBHP. GSE reduced TBHP-induced expression of p-ERK 1/2, p-p38, p-SAPK/JNK, and p-Akt 1/2.
Conclusions::
These results confirm the free radical scavenging ability of GSE and IH636 in canine LEC. GSE inhibits key components associated with cataract formation i.e. oxidative stress and stress-induced cell signaling. We are optimistic about our findings and propose that these may be the mechanisms by which GSE and RES have prevented cataracts in rats with various types of cataract. Based on our data, there is strong evidence that GSE could be used as a dietary supplement to delay or possibly prevent cataract progression in other species including humans.
Keywords: antioxidants • cataract • protein modifications-post translational