Methanol Extract of <i>Camellia sinensis</i> L. Prevents <i>In Vitro</i> Glucose-induced Cataract on Isolated Goat Eye Lens

Background: The leading cause of blindness and visual impairment is cataracts. Diabetes causes cataracts owing to free radicals and oxidative stress. Most say antioxidants delay cataract development. Plant-based antioxidants are promising. Aldose reductase-mediated polyol accumulation causes intracellular fluid and lens oedema. Various metabolic pathways generate cataracts after swelling. Downregulation of AMPK is connected to cataracts. Tea plant leaves include antioxidant flavonoids catechin, epicatechin, gallocatechin, and epigallocatechin, which block aldose reductase enzymes and upregulate AMPK. Aim: Methanol extract of Camellia sinensis L. prevents in vitro glucose-induced cataract in isolated goat eye lens. Methods: The thirty-six lenses were evaluated in six groups (n=6). Group I had a 5.5 mM normal control, Group II a 55 mM disease, Group III a 12 ng/ml standard, Group IV 250 μg/ml Camellia sinensis leaves, Group V 500 μg/ml, and Group VI 1000 μg/ml. The evaluation parameter includes lens morphology and opacity photography. Biochemical parameters of total protein and catalase activity were measured. Results: Significant reduction in lens opacity was observed as a result of the antioxidant activity and inhibition of the aldose reductase-polyol pathway that was achieved by the use of the leaf extract of Camellia sinensis. A considerable increase in the level of total protein 250, 500, 1000 μg/ml (3.13 ± 0.39*), (4.19 ± 0.28*), (4.40 ± 0.37*) and catalase enzyme activity (1.83 ± 0.21*), (2.27 ± 0.19*), (2.65 ± 0.14*) was observed in comparison to the disease group. Conclusion: Antioxidant activity, suppression of the polyol pathway, and function in preventing diabetic cataract formation in patients were all demonstrated by the methanol leaf extract of Camellia sinensis. The experiment was conducted using an in vitro glucose-induced goat eye lens model.