Abstract
Purpose:
Cataract the opacification in the lens is the leading cause of vision impairment. Biochemical evidences suggest that oxidative damage of the lens proteins is involved in the genesis of cataract. Usually this eye disorder is treated surgically. Besides possible complications and charge of costs, an artificial lens does not have the optical properties of the normal lens. Delaying the onset of cataract by pharmacological means may bridge the gap between the high incidence of cataract blindness and the provision of surgical treatment. Broccoli (Brassica oleracea var italica) offers many health-promoting properties owing to its content of antioxidants. We conducted the study to illustrate the efficacy of broccoli flavonoid fraction (FFB) on rat-lens crystallins in selenite-induced cataract in vivo.
Methods:
Rat pups, eight-day-old Sprague-Dawley were grouped as control (G I), experimental (G II) and FFB treated (G III). The rat pups in G II, and G III received a single subcutaneous injection of sodium selenite (4 μg/g bodyweight). The treatment groups (G III) were administered with FFB (2.5 mg /kg body weight) respectively from the 8th to 15th day. Cataract was visualized from the 16th day. Size exclusion chromatography was done for isolation of lens crystallins (α, β, and γ). The chaperone activity of α crystallins was measured by heat, DTT, and oxidation-induced aggregation and refolding assays. Concentration of total proteins (soluble and insoluble) and SDS-PAGE analysis of soluble proteins were also done.
Results:
Alterations in protein profile and insolubilization of soluble proteins have been considered to be the ultimate factor in lens opacification. This study shows that treatment with FFB prevented the loss of α crystallin chaperone activity, and prevent subsequent protein insolubilization prevailed during selenite-induced cataract.
Conclusions:
These results suggest the protective effects of FFB-rich in antioxidants- in modulating the chaperone activity of lens crystallins in experimental cataract. Synergism between bioactive components of a plant may result in unexpected metabolic outcomes within the plant and within the animal that consumes it.
Keywords: 445 cataract •
488 crystallins •
424 antioxidants