Phytochemical screening, cytotoxic and antimicrobial activities of Limonium socotranum and Peperomia blanda extracts

摘要

Limonium socotranum and Peperomia blanda are used in ethnomedicine to treatseveral diseases, such as infection, cancer, and inflammation. P. blanda (family: Piperaceae)is from the genus Peperomia, and mostly found in Madagascar, Yemen, USA to South America,while L. socotranum (family: Plumbaginaceae) from the genus Limonium and this speciesis found only on Socotra Island, Yemen. These plants have attracted great interest in recentyears because of their phytochemical contents. Consequently, the current study is aimed toinvestigate the phytochemical constituents, the cytotoxic and antimicrobial activities of L.socotranum (leaves and stem) and P. blanda extracts. Successive extraction had beenperformed which resulted in nine crude extracts. Phytochemical screening of the extractswas then conducted using qualitative chemical analysis. The antimicrobial activity of theplant extracts was determined using the well diffusion method against eleven selectedpathogenic microbes and the minimum inhibitory concentrations (MIC) were measured. Thecytotoxic activities of the plant extracts against MCF-7 and HepG2 cell lines were investigatedusing sulforhodamine B assay. It was noted that methanol leaves extract from L. socotranumexhibited higher antibacterial activity against Micrococcus luteus (MIC 15.6 μg/mL),Staphylococcus aureus (MIC 125 μg/mL) and Pseudomonas aeruginosa (MIC 125 μg/mL),than stem parts, while petroleum ether extract displayed stronger antifungal activity, withMIC of 125 μg/mL. On the other hand, petroleum ether extract of P. blanda was effectiveagainst Gram-positive bacteria and exhibited moderate antifungal activity. Petroleum etherextract of P. blanda displayed cytotoxic activity against MCF-7 cells, with an IC50 of 4.60 ±0.02 μg/mL, while the methanol extracts showed higher activity against the HepG2 cell line,with an IC50 of 13.90 ± 0.14 μg/mL. Phytochemical findings confirmed the presence offlavonoids, alkaloids and terpenoids. The promising obtained results suggest the potentialuse of these plants in cancer and antimicrobial therapies.