The Claim of Anti-Cataract Potential of Heliotropium indicum: A Myth or Reality?

Introduction: Heliotropium indicum has several uses in traditional medicine attributable to its numerous bioactive compounds. It is used as a traditional remedy for cataracts in Ghana without any scientific verification. This study aimed at verifying the anti-cataract properties of an aqueous whole plant extract of H. indicum. Methods: The effect (cataract score) of 30, 100, and 300 mg kg(-1) extract (bid for 21 days, per os) on the development of 30 lmol kg(-1) sodium selenite-induced cataract in 10-day-old rat pups was investigated. Soluble lens proteins alpha A and alpha B crystallins, total lens protein, total lens glutathione, and aquaporin 0 in enucleated lens homogenates were determined spectrophotometrically using commercially available kits. Histopathological studies on the lenses were also performed. The 2,2-diphenyl-1-picrylhydrazyl scavenging effect and linoleic acid autoxidation (antioxidant properties) of the extract (0.1-3.0 mg ml(-1)), compared to n-propyl gallate, were ascertained using standard procedures. Results: Cataract scores showed that the extract, at all dose levels, significantly alleviated selenite-induced cataracts (P <= 0.001). Markers of lens transparency (aquaporin 0, alpha A and B crystallins), as well as total lens proteins and lens glutathione levels, were significantly preserved (P <= 0.01-0.001). The extract exhibited activity relevant for scavenging free radicals and inhibition of lipid peroxidation. Epithelial and lens fiber integrity in the histopathological assessment were maintained with HIE treatment. Conclusion: The aqueous whole plant extract of H. indicum significantly inhibited the development of cataracts in rats via multiple mechanisms.