Photochemical Screening and Inhibitory Effect of Bryophyllum Pinnatum on Dehydrogenase Activities of Staphylococcus Aerus and Pseudomonas Aeruginosa

The present study investigated the phytochemical screening and inhibitory effect of Bryophyllum pinnatum on dehydrogenase activities of Staphyloccocus aureus and Pseudomonas aeruginosa. The phytochemical composition of the extract was determined using gas chromatography fitted with a flame ionization detector (GC-FID). Gas chromatography mass spectrometry (GC-MS) was used to identify volatile chemical groups present in the extract. Inhibition of total dehydrogenase activity was measured using 2, 3, 5- triphenyltetrazolium chloride (TTC) as electron acceptor according to standard method. Result obtained from the study showed that B. pinnatum leaf extract is relatively rich in the phytochemicals catechin (20.54 µg/g), resveratrol (17.56 µg/g), steroids (13.61 µg/g), tannin (12.58 µg/g) and cyanogenic glycosides (10.52 µg/g). The major constituents in the ethanol extract were quantified as Benzofuran, 2,3-dihydro- (9.34%), 4-Fluorobenzoic acid, 4- pentadecyl ester (9.19%), 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- (8.63%), Phenol, 2,6-dimethoxy- (8.12%), 5-Hydroxymethylfurfural (7.25%), Linoleic acid ethyl ester (6.99%), Ethyl alpha-d-glucopyranoside (5.63%). Result of inhibition of total dehydrogenase activity show that B. pinnatum leaf ethanol extract stimulated total dehydrogenase activity of S. aureus at concentrations < 500 µg/ml; while at concentration of 1000 µg/ml the extract was inhibitory. The extract inhibited the total dehydrogenase activity of P. aeruginosa at all test doses. The threshold inhibitory concentration (IC50) of B. pinnatum leaf ethanol extract against S. aureus and P. aeruginosa was 2750.86 ± 14.38 µg/ml and 1602.80 ± 73.41 µg/ml respectively, while for ciprofloxacin, 50% of dehydrogenase activity was inhibited 11.20 ± 0.24 µg/ml for S. aureus and P. aeruginosa. The extract achieved 53.31% and 71.94 % inhibition of S. aureus and P. aeruginosa dehydrogenase activity respectively at the highest test dose of 3000 µg/ml. B. pinnatum leaf ethanol extract is rich in phytochemicals and inhibited the total dehydrogenase activity of S. aureus and P. aeruginosa, in a concentration dependent manner. The extract’s phytochemicals may be acting in synergy to inhibit the microorganisms.