Abstract

This study investigated the in vitro chelating ability, antioxidant activity, total phenolic and flavonoid contents of 70% ethanolic extract of thorn apple (Datura stramonium). The ethanolic root extract of the plant displayed potent chelating ability (70%) at the lowest concentration (2%) investigated. The chelating ability of the extract showed concentration dependency. There were significant decreases in vitro chelating ability of the root extract from 2 to 10% concentrations (P<0.05). The root extract also demonstrated exhibited concentration dependent increases in antioxidant activity, which were non-significant from 2 to 6% concentrations (P>0.05) and significant from 8 to 10% (P<0.05). The ethanolic root extract displayed maximum activity [106.20±0.84% standard deviation (SD)] at the highest concentration (10%). The preliminary phytochemical screening of the aqueous extract of D. stramonium revealed the presence of flavonoids, tannin and alkaloid, but saponin was absent. The aqueous root extract of the plant also exhibited potent antioxidant potential (71.00%) at 2% concentration. The antioxidant activity of the aqueous root extract of the plant closely approximated the antioxidant activity of the ethanolic root extract of the plant (71.00 and 71.40%, at different concentrations, 2 and 5%, respectively). The aqueous root extract of the plant showed good in vitro nitric oxide radical scavenging activity (67.80%). The absolute and 70% acetone root extracts of the plant were dull nitric oxide scavengers (33.38 and 26.00%, respectively). The total flavonoid and phenolic contents of ethanolic root extract of D. stramonium showed non-significant increases as the concentration increased (P>0.05). The ethanolic root extract failed chelate ion at the highest concentration (10%) (-20.0% activity).

Key words: Phytotoxicology, clinical toxicology, iron-overload, clinical medicine, natural product.