Cytotoxic and antimicrobial activities of Rydingia michauxii methanolic extracts during various growth stages

Abstract Over recent years, more attention has been paid to replace synthetic chemicals with green natural compounds. The present study was undertaken for the first time to evaluate the cytotoxic and antimicrobial activities of Rydingia michauxii extract as an environmentally friendly agent during the dormant, vegetative and flowering stages. The results showed that vegetative and flowering stages contained the maximum cytotoxic activity on MCF-7 tumor cells with the IC50 values equal to 1.24 and 1.23 mg/ml, respectively. On the other hand, the plant extract at the dormant stage exhibited the highest inhibitory activity against bacteria and viruses. Bacillus subtilis showed the lowest average MIC (13.33 mg/ml) as the most sensitive bacteria, while Staphylococcus aureus and Escherichia coli were the most resistant tested bacteria with the highest average MIC (53.33 mg/ml). In addition, the methanolic extract of R. michauxii at the dormant stage inhibited Tobacco mosaic virus (TMV) and Cucumber mosaic virus (CMV) infections with 51.88 and 44.84%, respectively. Taken together, these results suggest that R. michauxii as a green alternative shows various degrees of cytotoxic and antimicrobial activities depending on the plant growth stage.