Phytochemical investigation, physicochemical characterization, and antimicrobial activities of Ethiopian propolis

Propolis is a natural resin substance produced by honeybees by collecting from parts of plants, buds, and exudates that are used for several biological activities such as antimicrobial, and fungicide functions. This study aimed to analyze the phytochemical, physicochemical, and antimicrobial activity of propolis collected from Boji Dirmaji and Fincha’a districts of western Ethiopia. The physicochemical characteristics, phytochemical screening, and antimicrobial activity of Ethiopian propolis against Aspergillus niger, Escherichia coli, and Staphylococcus aureus were evaluated using the disk diffusion method from its essential oils and crude ethanol extract were evaluated based on standard procedures. The results indicated that propolis was rich in saponins, tannins, flavonoids, steroids, triterpenes, and glycosides. Physicochemically, n-hexane extractable substances ranged between 8.6 and 33.9%, resins soluble 14.8–16.8%, insoluble residues 70.8–85.5%, moisture 1.7–4.6%, and ash content 2.8–9.7%, and 4.8 pH. The antimicrobial activities of essential oils propolis were active against Escherichia coli with an average inhibition zone of 18.3 ± 0.52 mm and 18.9 ± 0.06 mm at concentrations of 10 and 20 μl in Dirmaji districts. Moreover, the crude ethanol extracted propolis had nearly the same effect of inhibition to Escherichia coli. However, both crude extract and its essential oils didn’t show any activity on Staphylococcus aureus and Aspergillus niger. The analyzed propolis is promising antimicrobial activity from Gram-negative which is very notorious for people of the world.