Equisetum telmateia extracts: Chemical compositions, antioxidant activity and antimicrobial effect on the growth of some pathogenic strain causing poisoning and infection.

The aerial parts of Equisetum telmateia have been used as a source of biologically active compounds to treat inflammatory, diarrhea, stomach-ache, eczema and mouth infections in traditional medicine. The aim of this work is to evaluate the extraction yield, chemical compositions, antioxidant activity and antimicrobial activity of E. telmateia extracts on Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhi and Candida albicans. Chemical compositions E. telmateia was analyzed by high performance liquid chromatography (HPLC) using a C18 column. Analysis of E. telmateia extract by HPLC allowed the identification of Kaempferol 3-O-(6″-O-acetylglucoside) as major compound. The antioxidant activity of extracts was examined by measuring their ability to sequestrate 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The results showed that the DPPH (IC50  = 70.83 ± 0.2 μg/ml) were obtained in the case of supercritical fluid extraction (SFE) extract. MIC microdilution assay were used to determine the antimicrobial activities. Contrary to lower extraction yield (9.6 ± 0.5), the SFE extract exhibited the highest antimicrobial potency with MIC and MBC values of 32 mg/ml against S. aureus compared to the other extracts. The results suggest that SFE method is more appropriate for extraction of E. telmateia biologically active substances with antimicrobial and antioxidant activity than conventional solvent extraction methods.