Abstract

PHYTOCHEMICAL STUDIES AND ACTIVITIES OF LEAF EXTRACTS OF JUSTICIA SECUNDA AND PERSEA AMERICANA AGAINST SELECTED CLINICAL MICROBIAL ISOLATES

Nnadozie C.*, Onwusonye J.C., Odu D. A., Ononogbo C. N. and Ogbonna J. O.

Abstract

The phytochemical compositions and antimicrobial activities of methanol leaf extracts of Justicia secunda and Persea americana on selected clinical isolates were investigated using standard agar well diffusion method at concentrations of 50,150, 200, 250 and 300mg/ml. Qualitative and quantitative phytochemical revealed the presence of saponins (0.58±0.008) %, flavonoid (0.07± 0.0 12) %, tannins (0.96± 0.0 13) %, steroids (2.66± 0.006) %, cardiac glycoside (0.24±0.008) %, alkaloid (12.25±0.013)%, for Justicia secunda. That of Persea americana were; saponin (0.18±0.012)%, flavonoid (O.73±O.012)%, tannins (2.74±0.006)%, steroids (O.89±O.013)%, cardiac glycoside(O.75.±O.OlO)%, Alkaloid (10.24±0.008)%. The highest zone of inhibition for Justicia secunda leaves against E. coli. Staphylococcus aureus, pseudomonas aeruginosa and Bacillus spp were 19.0mm, 17.2mm, and 9.3mm, whereas the highest zone of inhibition for Persea americana leave against the microorganisms were 14.2mm, 13.3mm and 9.6mm respectively. There were resistances of Bacillus spp and pseudomonas aeruginosa against Persea americana methanol extract. However, the tube dilution method was employed for determining the minimum inhibitory concentration (MIC) of the extracts. The MIC values on E.coli, staphylococcus aereus, pseudomonas aeruginosa and Bacillus spp for methanol extract of Justicia secunda were 3.06mg/lml, 12.50mg/ml, 6.13mg/ml and 12.5mg/mI. MIC for Persea americana extract were 1.53mg/mI, 6.13mg/mI and 0.76mg/mI respectively. The presence of phytochemical constituents in the leaves supports their use against some pathogenic microorganisms.

Keywords: Antimicrobial, phytochemical, Justicia secunda, Persea americana.