Abstract: OBJECTIVE: To investigate the phytochemicals and in vitro antioxidant, antimicrobial and cytotoxic potential of Rumex dentatus(R. dentatus) leaf extracts.METHODS: The total phenolics and flavonoids content of R. dentatus extracts were evaluated by the Folin-Ciocalteu and aluminum chloride colorimetric methods respectively. Antioxidant potential of studied plant extracts was assessed through 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, total reducing power and total antioxidant methods. Moreover, antibacterial and antifungal capacity was also evaluated by disc diffusion method against six clinically isolated multi-drug resistant bacterial strains as well as six fungal isolates. Further, cell cytotoxicity was also evaluated through3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay.RESULTS: Ethanol extract showed highest total phenolic [(38.9 ± 1.5) μg gallic acid equivalent/mg]and total flavonoids [(17.2 ± 1.9) μg quercetin equivalent/mg] contents. Antioxidant assays indicated that ethanol and methanol extracts possess potent antioxidant potential. Moreover, it was observed that ethanol and hexane extracts have the potential to inhibit most of the tested multi-drug resistant bacterial strains while methanol, chloroform and hexane extracts could inhibit the growth of pathogenic fungal strains successfully. Among all the studied extracts, ethanolic extract showed highest cytotoxicity against MCF-7 cell line then Hep-2 and DU-145 cell lines by MTT assay with lowest IC50 of 47.3 μg/m L.CONCLUSION: These results suggest that R. dentatus could be a potent alternative candidate for treatment of microbial infections and for breast cancer treatment.

Key words: Rumex, Atioxidants, Anti-infective agents, Drug resistant,multiple, Cytotoxins