Evaluation of anti-infective potencies of formulated aloin A ointment and aloin A isolated from Aloe barbadensis Miller

Abstract

Abstract Introduction Isolated bioactive components of plants or their raw extract are utilized as complementary or alternate remedy in copious illnesses. The current research was aimed at assessing the activity of aloin A isolated from Aloe barbadensis Miller and its formulated ointment against six (6) selected clinical isolates. Methods The column chromatography was utilized in isolating aloin A from chloroform/methanol solvent polarity. The characterization of the isolated compound was performed by spectroscopy techniques corresponding to UV, IR, 1H- and 13C-NMR spectroscopy. It was formulated as ointment using polyethylene glycol (PEG) and both the ointment and the isolated compound were probed for in vitro antimicrobial activity. Results Aloin A has been isolated from chloroform/methanol solvent mixture. The structure has been explicated as (10S)-10-β-d-glucopyranosyl-1,8-dihydroxy-3-(hydroxymethyl)-9(10H)-anthracenone(1S)-1,5-anhydro-1-[(9S)-4,5-dihydroxy-2-(hydroxymethyl)-10-oxo-9,10-dihydro-9-anthracenyl]-d-glucitol. The minimum inhibitory concentration (MIC) of the isolated aloin A on the pathogens ranged from 2.5 to 5.0 mg/ml and 0.32 to 5.0 mg/ml for both aloin A and the formulated ointment respectively. It was further revealed that the activity of aloin A showed dose dependence against all the test microorganisms. There was no significant difference in the activity of the drug against K. pneumoniae, S. aureus, E. coli, C. albicans and T. flavus (P > 0.05) when the concentration was raised from 2.5 to 5 mg/ml, however, there was significant difference (P ˂ 0.05) in activity against P. aeruginosa. The formulated ointment exhibited dose dependent activity against all test microorganisms. At low concentrations, the ointment showed no significant difference in diameter zone of inhibition against all test microorganisms (P > 0.05) except P. aeruginosa which exhibited a highly significant difference (P < 0.05). Conclusion Both the isolated aloin A and its formulated ointment demonstrated substantial inhibition of growth of the pathogenic strains. These findings sturdily suggest that aloin A is a nascent drug that could be explored as skin and wound transmittable agent.