Effect of Heavy Metals Stress on Polyphenolic Compounds in Hydroalcoholic Extract of Basil (Ocimum basilicum L.)

Abstract

Heavy metals are important environmental pollutants and can affect the lives of plants and subsequently the lives of humans and other organisms. On the other hand, medicinal plants and their polyphenolic constituents have received much attention due to their confirmed positive effects on human health. Therefore, in this study, the effect of heavy metal lead, one of the most important toxic metals in the environment, on the polyphenolic compounds of the basil medicinal plant (Ocimum basilicum L.) was investigated. The purpose of this study was to evaluate the resistance of this medicinal plant to stress induced by lead toxic metal and also the content of polyphenolic compounds. The method was planted in basil greenhouse and factorial experiment in a completely randomized design with three replications. Lead metal treatment with 0, 25, 50 and 75 ppm levels, EDTA treatment with 0 and 1 mmol L-1 and humic acid treatment with 0 and 2 kg ha-1 were applied. After harvesting at flowering stage, the hydroalcoholic extract of dry shoots was prepared and the amount of polyphenolic compounds in the extracts was measured. The results showed that lead in soil significantly changed the content of polyphenolic compounds of basil. Increasing the amount of lead metal generally decreased the polyphenolic compounds of the plant. The presence of EDTA also increased polyphenolic compounds and reduced the content of polyphenolic compounds using humic acid.

Keywords: Antioxidant, EDTA, Humic acid, Lead

DOI: 10.7176/JSTR/5-12-06