Cytotoxic, antioxidant and antimicrobial effects of nine species of woundwort (Stachys) plants.

BACKGROUND

Woundwort (Stachys) plants from the Lamiaceae family have been used in folk medicine for various purposes.

OBJECTIVE

This study was designed to analyze cytotoxic, antioxidant and antimicrobial activities of Stachys plants, because these fields have extensively benefited of drug discovery from natural sources.

METHODS

Nine Stachys plants were collected from different regions of Iran. Cytotoxic activities of methanol, 80% methanol and dichloromethane (DCM) extracts of these plants were assessed on three human cancer cell lines (HL-60, K562 and MCF-7 cells) with the MTT assay, while antioxidant and antimicrobial activities were determined on methanol extracts by DPPH and nutrient broth micro-dilution assays, respectively.

RESULTS

DCM extract of St. pilifera Benth. had the lowest IC₅₀ in three cancer cell lines ranging from 33.1 to 48.2 µg/ml, followed by the 80% methanol extract of St. persica S.G.Gmel. ex C.A.Mey. (IC₅₀ range: 62.1-104.1 µg/ml) and DCM extract of St. byzantina C. Koch (IC50 range: 62.7-131.0 µg/ml). St. byzantina. St. lavandulifolia Vahl., St. acerosa Boiss., St. obtusicrena Boiss. and St. persica showed lowest IC₅₀ values in the DPPH scavenging assay (135.1, 162.6, 164.7, 169.4 and 172.4 µg/ml, respectively), while their total phenolic contents were 23.9, 18.2, 18.6, 20.4, 27.8 mg equivalent of gallic acid in 1 g dry plant, respectively. The methanol extracts of St. byzantina and St. persica inhibited all six tested Gram-negative and Gram-positive bacterial strains.

CONCLUSIONS

Various Stachys species (especially St. byzantina and St. persica) are valuable sources of natural compounds with important biological properties.