Antibacterial and Antifungal Efficacy of Partially Partitioned Fractions of Spondias mombin (Linn) Extracts (Root, Leaf and Stem Bark) against Clinical and Environmental Isolates

Abstract

The purpose this research work is to determine the antibacterial and antifungal assay of partitioned fractions of S. mombin (Linn) extracts against clinical and environmental isolates. The root, leaf and stem-bark of S. mombin were harvested and air-dried. The dried S. mombin was milled into powdered form using manual grinder. Powdered S. mombin (1 kg) each of the different S. mombin parts was extracted with 3 L of 70% (v/v) ethanol, ethyl acetate and distilled water for 72 h at room temperature. The SMRE and SMREA were used to code for root part; SMLE and SMLEA for the leaf part; and SMSBE and SMSBEA for the stem-bark part, each was fractionated on column chromatography with silica as the stationary phase using n-hexane, ethyl acetate and ethanol as the eluting solvent to obtain n-hexane, ethyl acetate and ethanol fractions. Antimicrobial and antifungal screened was observed using agar well diffusion test. The result obtained showed that in partially purified ethyl acetate leaf extracts, Fraction (F1 SMLEAH) showed significant inhibitory effect (p ≤ 0.05) on all the test bacteria, except Klebsiella pneumoniae and Salmonella typhi at concentrations of 20.0-2.5 mg/ml, Fraction (F2 SMLEAEA) was not effective against Salmonella cholleraesuis, B. substilis, Citrobacter koseri and Salmonella typhi. Fraction (F3 SMLEAE) showed little or no inhibitory effect on most of the bacteria at all the concentration used. It can be deduced that in partially purified ethanolic leaf extracts, Fraction (F1 SMLEH) showed inhibitory effect on Burkholderia cepacia. All the organisms were not susceptible to all the fractions except F1 which had diameter of zones of growth inhibition ranging between 4.0-1.0 mm at 5 mg/ml-0.625 mg/ml on Mycobacterium abscessus. Partially purified ethanolic stem bark extracts, antifungal activity of the partially purified ethanolic extracts of S. mombin, Fractions (F1 SMLEH, F2 SMLEEA) and F3 SMLEE), significant antifungal activity (p ≤ 0.05) was observed at 20.0 mg/ml with most test fungi. Trichoderma horizionum was not susceptible to all the three fractions, while Aspergillus niger and Syncephala strumracemosum were susceptible to only fraction (F2 SMLEEA). Fractions (F1 SMSBEH, F2 SMSBEEA), F3 SMSBEE) on the test as the eluting solvent. Significant inhibitory effect (p ≤ 0.05) was observed in all the fractions at 20 mg/ml against most of the test bacteria. While, zones of growth inhibition of the various fractions varied with the test bacteria with the highest diameter zone of 8.0 mm recorded in fraction F1 against Salmonella typhi. Fractions (F2 SMSBEEA and F3 SMSBEE) possessed significant inhibitory effect (p ≤ 0.05) at 20.0-5.0 mg/ml on the test fungi, except Candida kruise and Rhizopus stonifer. The plant part by solvent interactive effect was significant (p<0.05), suggesting that the MICs and MBCs of test bacteria were observed at 0.3125 and 0.1562 mg/ml and MICs and MFCs test fungal were observed at 0.3125 and 0.1562 mg/ml respectively, The various plants differ significantly according to extraction solvent, These findings demonstrate the possible effectiveness of the S. mombin plant, especially its stem bark extracts, in treating microbial infections.