Chemical compositions, Antimicrobial activity and cytotoxicity of the essential oil from Mezonueron benthamianum (Baill)

Mezoneuron benthamianum (Baill) is a medicinal plant used traditionally in treatment of several ailments including microbial infection related diseases. The study investigate Chemical compositions, Antimicrobial activity and cytotoxicity of the essential oil from Mezonueron benthamianum . The essential oil from fresh leaves of M. benthamianum was obtained by hydro-distillation using Clevenger-type apparatus, Antimicrobial activity and cytotoxcicty of the essential oil obtained from M. benthamianum was evaluated using micro-dilution methods. A total of 57 compounds were identified, accounting for 84.61% of the total composition, following analysis by GC-MS. The essential oil was largely dominated by sesquiterpenes (41.08%), while a significant amount of monoterpenes were also identified. Monoterpene hydrocarbon, para-cymene (18.82%) is the most abundant constituent and the oxygenated diterpenoids were barely represented by phytone (1.03%) and phytol (1.52%). Other compounds of significant quantities are caryophyllene oxide (9.48%), beta-elemene (5.28%), carvacrol (4.81%), limonene (3.99%), pogostol (3.29%), iso-spathulenol (3.14%), trans-nerolidol (2.98%) and sesquiterpineol (2.88%). The essential oil demonstrated a remarkable activity against the Gram-positive bacteria with strongest bactericidal activity against Bacillus subtilis (MIC 7.81µg/mL and MBC 31.25µg/mL). Moderate inhibitory activity against Staphylococcus aureus with MIC and MBC values of 31.25µg/mL and 125µg/mL, respectively. M. benthamianum showed comparatively lower to moderate activities against Gram-negative bacteria. No inhibitory effect was observed against the fungus, Aspergillus fumigatus at the tested concentrations (MIC 0.00 µg/mL, MFC > 1000 µg/mL) and Penicillium notatum exhibited greater resistance towards M. benthamianum (MIC 125.00 µg/mL, MFC 500.00 µg/mL). M. benthamianum oil exhibited no hemolytic activity on the human red blood cells (hRBCs), in contrast to the positive control diclofenac (50 µg/mL) which showed complete hemolysis. M. benthamianum contain bioactive compounds with promising antibacterial and antifungi potentials which validate its traditional usage in combating microbial related infections.