Effects of Ethanolic Stem Bark Extract of Parkia biglobosa (Locus Bean) on Aspergillus niger and Aspergillus fumigatus

Parkia biglobosa is used in folk medicine for the treatment of ailments such as cough, pneumonia, diarrhea, otitis, conjunctivitis, leprosy, violent colic, hemorrhoids, wounds, and hookworms. This study aims to investigate the antimicrobial attributes of the stem bark extract of Parkia biglobosa. Pure cultures of fungal isolates used for the in vitro antimicrobial assay were obtained from the Laboratory of the Department of Plant Science, Modibbo Adama University, Yola. Standard methods were adapted to obtain the plant extract, phytochemical screening, and antimicrobial assay. The diameter of clearance was measured and regarded as being directly proportional to the efficacy of the extract. Experimental studies were carried out in three replicates. Data obtained were subjected to one-way analysis of variance (ANOVA) using Statistical Package for Social Sciences (SPSS) version 20, USA. Results were presented as mean ± standard deviation (SD). Phytochemical screening of the ethanolic stem bark extracts of P. biglobosa revealed the presence of alkaloids, saponins, terpenoids, steroids, flavonoids, and tannins but without polysaccharides. The mean zone of inhibition obtained for the ethanolic stem bark extract of P. biglobosa against Aspergillus niger was higher at 60% concentration with a value of 70.61 mm and lowest at 20% concentration with a value of 33.11 mm for Aspergillus fumigatus, the highest zone observed at 60% concentration was 66.89 mm and least at 20% concentration was 29.39 mm. The higher the concentration of plant extracts the higher the antimicrobial action. However, only the least concentration, as well as the highest concentration, were statistically significant for both isolates.