Antimicrobial, Antioxidant and Cytotoxic Activities and Phytochemical Screening of Some Yemeni Medicinal Plants

The traditional medicine still plays an important role in the primary health care in Yemen. The current study represents the investigation of 16 selected plants, which were collected from different localities of Yemen. The plants were dried and extracted with two different solvents (methanol and hot water) to yield 34 crude extracts. The obtained extracts were tested for their antimicrobial activity against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistantStaphylococcusstrains using agar diffusion method, for their antioxidant activity using scavenging activity of DPPH radical method and for their cytotoxic activity using the neutral red uptake assay. In addition, a phytochemical screening of the methanolic extracts was done. Antibacterial activity was shown only against Gram-positive bacteria, among them multiresistant bacteria. The highest antimicrobial activity was exhibited by the methanolic extracts ofAcalypha fruticosa,Centaurea pseudosinaica,Dodonaea viscosa,Jatropha variegata,Lippia citriodora,Plectranthus hadiensis,Tragia pungensandVerbascum bottae.Six methanolic extracts especially those ofA. fruticosa,Actiniopteris semiflabellata,D. viscosa,P. hadiensis,T. pungensandV. bottaeshowed high free radical scavenging activity. Moreover, remarkable cytotoxic activity against FL-cells was found for the methanolic extracts ofA. fruticosa,Iris albicans,L. citriodoraandT. pungens. The phytochemical screening demonstrated the presence of different types of compounds like flavonoids, terpenoids and others, which could be responsible for the obtained activities.