Phytochemical screening and antifungal activity of sawdust and stem bark extracts from Erythrophleum suaveolens (Guill. & Perr) Brena

Abstract

This study was carried out to investigate the antifungal potentials of stem bark and sawdust of Erythrophleum suaveolens. Stem bark was collected from Federal University of Agriculture (FUAM) while sawdust sample was collected from Timber Shed Makurdi. Both samples were air dried while the stem bark was ground into powder for extraction. Extraction of samples was done sequentially by macerating 1000 g and 600 g of stem bark and sawdust, respectively using 1000 mL (w/v) of n-hexane for 24 hours and filtering off the hexane extract followed by ethyl acetate and methanol in that order for 24 hours each. Extracts were filtered and evaporated to obtain dried extracts and yields calculated. Phytochemical screening of samples was carried out according to AOAC standard methods. Diffusion method was used for antifungal screening of extracts. Sabouraud Dextrose agar was prepared as media in Petri dishes where Zones of Inhibition were observed for fungal growth. Minimum Inhibitory Concentration (MIC) of extracts was determined according to broth dilution technique at 40 g/mL, 20 g/mL, 10 g/mL, 5 g/mL and 2.5 g/mL. Minimum Fungicidal Concentration (MFC) determined by sub culturing MIC to determine the least concentration at which fungi were killed. Percentage yield of extract was highest (5.19 %) in stem bark and lowest (0.12 %) in sawdust. Methanol extracts had the highest yield (5.19 % and 3.42 %) for stem bark and sawdust followed by ethyl acetate (1.06 % and 0.36 %) and n’ hexane (0.16 % and 0.12 %), respectively. Flavonoids, glycosides, saponins, steroids, and tannins were in the stem bark while, anthraquinones, saponins and tannins were completely absent in the E. suaveolens sawdust. Zones of Inhibition (ZOIs) of antibiotics ranged between 27 mm – 35 mm while ZOIs for crude extracts ranged from 18 mm – 28 mm. At MIC of 5 mg/mL, E. Suaveolens stem bark methanol extract inhibited Coniophora puteana and Fomitopsis pinicoca growth. At MFC of 10 mg/mL the same microbes were killed. Erythrophleum suaveolens stem bark methanol can be used in the control of brown-rot decay and stem decay caused by Coniophora puteana and Fomitopsis pinicoca.

Keywords: Antifungal, brown-rot decay, stem decay, Erythrophleum suaveolens, Coniophora puteana, Fomitopsis pinicoca, Antimicrobial, Aspergillus fumigatus