Phytochemical Profile, Antibacterial, and Antioxidant Activities of Apis Mellifera Propolis from Selected Regions in Kenya

Abstract

Currently, there is an increase in demand for natural products like propolis, yet little information is currently available on the chemical composition of African propolis and their biofunctional properties. Therefore, this study was aimed at quantifying the phytochemicals, determining the antioxidant, and anti-microbial properties of Apis mellifera propolis sourced from various selected regions in Kenya. The samples were analysed by colourimetric assays and Gas Chromatography-Mass Spectrometry (GCMS) for phytochemicals profiles and antioxidant activities. While disc diffusion assays were used to determine the antibacterial properties. The phytochemical analysis of propolis samples from different regions in Kenya revealed significant variations in the levels of flavonoids, phenolics, terpenoids, and alkaloids (p < 0.05). Flavonoid content was highest in samples from Marigat (2,131.4 mg QE) and lowest in Taita Hills (102.2 mg QE). Phenolic compounds were most abundant in samples from icipe, Nairobi (3,711.8 mg GAE), while the lowest levels were observed in Taita Hills (522.6 mg GAE). Terpenoid levels were generally higher in Marigat and South Kitui, with the lowest recorded in icipe. Alkaloid content showed the greatest variability, with the highest concentrations found in Lower Taita (8,767.5 mg CE) and the lowest in Taita Hills (3,014 mg CE). Propolis samples also demonstrated stronger activity against B. thuringiensis than E. coli. Likewise, the antioxidant activity varied significantly across the different locations. The highest antioxidant activity was observed in samples from Marigat and the least from Taita Hills. The propolis samples collected from hotter climatic conditions not only contained relatively higher composition of total phytochemicals, but they also displayed higher antioxidant and anti-microbial activities than those obtained from cooler climatic conditions. Some of the compounds identified included triterpenoids alpha- and beta-amyrin, oleanen-3-yl-acetate, urs-12-en-24-oic acid, lanosta-8,24-dien-3-one, and hydrocarbons tricosane and nondecane, which have been reported to have either anti- microbial or antioxidant activities. Key findings of this study demonstrate the occurence of relatively higher phytochemical content in Kenya’s propolis, which has both antioxidant and anti-microbial properties; hence this property of propolis could be harnessed for disease control. The limitations of the study were that the samples may not have represented all possible climatic regions of the country and lack of resources to do other analysis for better chemical profile results.