A Methanolic Extract of Ocimum basilicum Exhibits Antioxidant Effects and Prevents Selenite-induced Cataract Formation in Cultured Lenses of Wistar Rats

Objective: An extract (Methanolic) of the Ocimum basilicum leaf was analysed for potential to abrogate experimental formation of cataract in-vitro. Methods: Phytoconstituents were first detected in O. basilicum extracts (Aqueous or methanolic) by gas chromatographic-mass spectrometric analysis. The putative antioxidant activity of these extracts was then assessed by measuring in-vitro radical-scavenging activity, ion-chelating potential and reducing potency. Potential cytotoxicity of the extract on Human lenticular epithelial B3 (HLE-B3) cells was also sought. Finally, possible prevention of cataract formation by the methanolic extract was gauged in selenite-exposed lenses obtained from Wistar rats. There were 3 groups (8 Lenses in each): Group I (Lenses incubated in Dulbecco’s modified Eagle’s medium [DMEM] alone); Group II (Lenses incubated in DMEM with sodium selenite [100 μM/ml]); Group III (Lenses incubated in DMEM with selenite [100 μM/ml] and the O. basilicum methanolic extract (200 μg/ml DMEM). Gross lenticular morphology was assessed. Levels of lenticular malondialdehyde (MDA) and reduced glutathione (GSH) were also measured. Results: A higher intensity of antioxidative activity was noted in the methanolic extract than in the aqueous extract. The methanolic extract exhibited negligible cytotoxicity. On morphological examination, marked opacification was seen in all 8 Group II lenses whereas there was no opacification in 7 of 8 Group III lenses. Near normal mean levels of reduced glutathione and malondialdehyde, were noted within Group III lenses. Conclusion: The methanolic extract of the O. basilicum leaf appears to prevent selenite-induced cataract formation in-vitro.