Antimicrobial activity and cytotoxic effects of stachytarpheta jamaicensis (L.) vahl crude plant extracts

Abstract

Medicinal plants are known for their ability to treat diseases due to the presence of bioactive constituents such as alkaloids, phenolic compounds, saponin, tannins and terpenoids. They can be used as anti-inflammation, antioxidants, antibiotics and anti infection drugs. Stachytarpheta jamaicensis (L.) Vahl is one of the medicinal plants found to be useful for treatment of diseases based on its traditional usage. This plant belongs to the family of Verbenacea and can grow up to 90 to 120 cm tall. Unfortunately, less research has been done on this plant. In this research, the objectives are to screen for the presences of phytochemicals in the crude plant extract and its antimicrobial activity. Antimicrobial activity was performed using disk diffusion method. The crude extracts were tested for saponin, tannin, flavonoid, phlobatannin, coumarin, phenolic compound and terpenoids using phytochemicals screening test. It was found that the extracts contained phytochemicals such as phenolic compound, tannin, saponin, terpenoids and flavonoid but absences of phlobatannin and coumarin. From the antimicrobial test, it showed highest inhibition zone on Pseudomonas aeruginosa with diameter of 10.5 mm by root extracts and slight or less inhibition on the growth of Streptococcus sp on all three extracts compared to other types of bacteria. The root extracts are found to inhibit most of the bacteria growth other than leaves and stem extracts maybe because of the presence of most of the phytochemicals in it. Root extract can be concluded to be the best parts to be used as antimicrobial drugs. In the study for cytotoxic effect, leaves extract shows the highest inhibition on the growth of Hela cancer cells compare to root and stem extract. During incubation of 24 and 72 hours, all of the extracts showed positive results, however, during 48 hours incubation, the cell activities or growth became unstable. Hence, the extracts can only be exposed to the cancer cell line at shorter time to avoid the lost of its phytochemicals from time to time.