THE DEVELOPMENT OF AN IN VITRO SCREENING STRATEGY FOR TOPICALLY APPLIED PRODUCTS.

The objective of this study was the pharmaco-toxicological understanding of the constituents of an authenticated herbal mixture. The mixture was prepared by maceration in ethanol and subsequent dilution to produce a topically applied lotion, for which the intended target conditions are psoriasis and eczema. A three-tiered in vitro screening strategy was adopted for evaluating this product, comprising cytotoxicity assays; mutagenicity screening and therapeutic evaluation. Viability assays performed with dilutions of both the herbal concentrate and final product on organotypic cell lines indicated that neither preparation acted as an irritant. Genotoxicity screening using six strains of Salmonella typhimurium showed no mutagenic potential, and furthermore significant anti-microbial activity was evident. Therapeutic evaluation involved assessing the antioxidant potential of the extract, which can be correlated to an anti-inflammatory effect. Nitroblue-tetrazolium (NBT) assay results indicate that the extract can reduce superoxide anion generation by 45%. The extract also increased cell viability on exposure to hydrogen peroxide by 28%, illustrating its dismutation potential. A 3-D skin culture system, EpiDerm™, released 3000_g/ml upon exposure to the extract, implying that the components enhance arachidonic acid metabolism. Overall, it may be concluded that the herbal extract is sufficiently non-toxic for dermal application and possesses anti-inflammatory activity.

3-D skin model, Atopic eczema, Corrosion testing, Cytotoxicity assays, Dismutation, Eczema, Efficacy, EpiDerm, Genotoxicity, Genotoxicity screening, MTT, MTT ET 50 protocol, MTT assay, Metabolism, Mutagenicity screening, Nitroblue-tetrazolium assay, Pharmaco-toxicological, Phytochemicals, Prostaglandin E2 release assay, Prostaglandin E2,, Psoriasis, Screening strategy, Superoxide anion, Therapeutic evaluation, Toxicity, Viability assays