Abstract:
Antidesma madagascariense Lam. (AM) is used in the treatment and management of a panoply of human diseases.
Leaf decoction, acetone extracts and fractions of AM were evaluated for antimicrobial, antioxidant,
anti-inflammatory, cytotoxicity and acetylcholinesterase (AChE) inhibitory activity. The antibiotic potentiating
activity of crude acetone extract (AE) was assessed against ATCC bacterial strains of Escherichia coli ATCC
25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 using standard antibiotics.
Decoction extract showed significant inhibitory activity against Acinetobacter spp. (MIC: 0.25 mg/mL) which
had higher inhibitory effect compared to the positive control Streptomycin (MIC: 1.00 mg/mL). Acetone and decoction
extracts inhibited the growth of Candida albicans (MIC: 4.00 mg/mL). All fractions of AE showed broad
spectrum activity against ATCC and clinical strains (MIC 0.03–4.00 mg/mL). The results of the combination pro-
files of the AE with Ciprofloxacin, Chloramphenicol and Streptomycin revealed synergistic interactions (FICI ≤
0.50) against P. aeruginosa. Crude decoction, acetone extract and fractions were found to be potent reducing
agent as well DPPH radical scavenger and ABTS cation scavenger. A significant correlation between DPPH,
ABTS and total phenolic content (p b 0.05, r=−0.75 and −0.82 respectively) was recorded. Three fractions namely
DCM:MeOH (85:15) (F5), DCM:MeOH (95:05) (F3) and DCM (F2) [IC50 0.02–0.09 mg/mL] demonstrated significant
anti-inflammatory activity as compared to the positive control, diclofenac sodium [IC50 0.18 (0.10–0.31) mg/mL]. AE
and its fractions showed AChE inhibitory activities at an IC50 of 35.92–492.6 μg/mL. Cytotoxicity study against Vero
cells revealed that AE and hexane fraction were non-cytotoxic while decoction showed cytotoxic effect. Further
studies are required to explore the potential of AM crude extracts and fractions as natural source of antimicrobial,
antioxidant, anti-inflammatory agents as well as AChE inhibitors.
