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

Abstract

Context: 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.

Materials and 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.

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

• Cancer
• DPPH assay
• medicinal plants
• MTT assay
• traditional medicine

Acknowledgements

This study was supported by Shiraz University of Medical Sciences, Vice-chancellor for Research, Iran (Grants 4678, 89-5496) and Iranian National Science Foundation, Iran (Grant 87041859).