In Vitro antioxidative and anti-inflammatory activities of the ethanol extract of eggplant (Solanum melongena) stalks in macrophage RAW 264.7 cells

Solanum melongena or eggplant is a species of the nightshade family. According to Korean folk medicine, S. melongena stalk possesses excellent therapeutic effects on warts, burns, and many inflammatory diseases, such as stomatitis, arthritis, and gastritis. In order to investigate the anti-inflammatory effects of S. melongena stalk, an ethanol extract of the stalk was prepared, and fractionated into hexane, dichloromethane, ethyl acetate, n-butanol, and water fractions. The results showed that the ethyl acetate and n-butanol fractions contained high levels of phenol and reduced artificial free radicals. In contrast, the hexane and dichloromethane fractions decreased the production of nitric oxide, pro-inflammatory cytokines, and prostaglandin E₂, despite the presence of low levels of phenols implying that other compounds than phenols are involved in anti-inflammatory reactions. The data suggest that S. melongena stalk possesses pharmacological activity and might be useful for development of antioxidant, anti-inflammatory agents, or dietary supplements.