Preliminary antibacterial and phytochemical screening of three medicinal plants used in the folkloric treatment of skin infection

Abstract

The in vitro effects of Schwenkia americana, Mormodica charantia and Lippia multiflora extract in water, ethanol and ethyl acetate were evaluated on some pathogenic bacteria namely Staphylococcus aureus, Pseudomonas aeruginosa and β-heamolytic Streptococcus pyogenes. The work was carried out using the agar well diffusion method at concentrations ranging from 25mg/ml to 100mg/ml of extracts. The ethanol extract of Schwenkia americana and Lippia multiflora showed zones of inhibition of 24+1.19cfu against Staphylococcus aureus, at 100mg/ml stock concentration. The aqueous extract of Lippia multiflora showed a zone of inhibition of 22+0.60cfu at 100mg/ml against Staphylococcus aureus while the ethyl acetate extract of Schwenkia americana showed highest zone of inhibition of 24+1.19cfu at 100mg/ml of extract against Staphylococcus aureus, Streptococcus pyogenes was the least active of all the organisms to the test plants with Lippia multiflora showing a zone of inhibition of 10cm at 100mg/ml. Generally all the test plants are active against the organisms. Phytochemical screening revealed that the plants contain flavonoids, tannins, alkaloid, saponin, and steroids. In all the test plants, Positive antibiotic disk control and antiseptic test showed the microorganisms to be resistant to most of the antibiotic disk as well as the antiseptics used at concentrations ranging between 5%-20% of dettol, izal, ethanol and Lysol. The plants showing antimicrobial activities can be inculcated into the treatment of bacterial infections involving the test organisms to help fight the ever increasing antibiotic resistance.