Development and Evaluation of Alternanthera sessilis Extract-Loaded Nanoparticles for Ocular Delivery and Anti-Cataract Activity: Review

Abstract

Cataract remains a leading cause of visual impairment worldwide. Oxidative stress plays central role in cataractogenesis through depletion of antioxidant defences, lipid peroxidation, aggregation of lens proteins. Current management relies on surgical extraction with limitations. Alternanthera sessilis commonly known as Ponaganti Koora or sessile joyweed, is widely consumed leafy vegetable in South India with reported flavonoids, phenolics, carotenoids, quercetin derivatives.  Aim: This review aims to comprehensively compile the phytochemistry, anti-oxidant and anti- cataract potential of Alternanthera sesslis and provide rationale for development of  extract loaded  chitosan nanoparticles for ocular delivery.

Literature search was conducted using PubMed, Scopus and Web of science from 2009-2025 using keywords Alternanthera sesslis, cataract, quercetin, chitosan nanoparticles, Nrf2/HO-1. Previous work demonstrated cataract preventive activity in glucose-induced and UV-induced goat lens models and galactose-induced rat model. Recent 2022 comprehensive review (Hwong et al., J Ethnopharmacol) confirmed potent antioxidant activity due to polyphenols, terpenes, alkaloids, carotenoids plus vitamins C, E. However, conventional extracts exhibit poor ocular bioavailability (<5%) due to tear drainage, blinking, corneal barrier. Chitosan-based nanoparticles prepared by ionic gelation offer mucoadhesion, sustained release, improved corneal permeation. Latest 2025 study (ACS) developed chitosan-coated quercetin nanoemulsion eye drops showing protection against H2O2-induced oxidative stress in lens epithelial cells with viability >70% and Bcl-2 upregulation.

Keywords: Alternanthera sessilis, Cataract, Quercetin, Chitosan nanoparticles, Nrf2/HO-1, Ocular delivery, Nanoemulsion