Comparative study of different Ethiopian propolis: In vivo wound healing, antioxidant, antibacterial, physicochemical properties and mineral profiles

Abstract

Mitiku Diriba Jobir, Abera Belay

Introduction: Propolis is one of the natural beehive products and a sticky material pro-duced by honeybees to protect their hives from bacterial and fungal infections.Aim: The objective of this study is to investigate the wound healing, antioxidant, antibac-terial, physicochemical, and mineral profiles of propolis collected from three different regions in Ethiopia: Asela, Sheka, and Gambela.Methods: Physicochemical properties and mineral profiles were determined using stan-dard analytical methods; antibacterial examination was determined using the disk-diffusion method; antioxidant properties were examined using spectrophotometric method; and a rodent model was used to investigate the wound healing properties of propolis.Results: Ethiopian propolis has physicochemical properties, such as moisture (3.64%–6.69%), ash (2.05%–3.54%), soluble substances (45.28%–71.85%), insoluble substances (28.15%–54.74%), saponification value (82.27–127.89), conductivity (0.13–0.24), pH (4.82–5.49), waxes (7.80%–8.89%), acid value (10.07–35.14), ester value (63.84–107.03), and melting point (63.03–83.95). Minerals found in propolis were Na, Ca, Mg, K, Fe, Zn, Cu, and Co. The inhibition zone (mm) for the antibacterial properties range from 6.55 ± 0.20 to 10.21 ± 0.16 (water extract) and 7.09 ± 0.06 to 12.06 ± 0.03 (ethanol extracts). The phenolic contents of propolis in Asela, Sheka, and Gambela were 63.09 ± 3.55, 72.26 ± 7.65, and 82.07 ± 3.72 mg GAE/g, respectively. The flavonoid contents of propolis in Asela, Sheka, and Gambela were 24.42 ± 0.53, 17.26 ± 0.35 and 22.68 ± 0.94 mg QE/g, respec-tively, which also have good antioxidant activities. The inhibition concentration values of 1, 1-Diphenyl-2-picrylhydrazyl radical scavenging and ascorbic acid in propolis in Asela, Sheka, and Gambela were 18.13 ± 0.002, 12.17 ± 0.002, 22.07 ± 0.001 and 15.20 ± 0.002 (μgml−1), respectively. There was a significant difference between the four treatments. The wound area in propolis in Asela, Sheka, and Gambela (mm2) on day 14 was 0.51 ± 0.01, 0.60 ± 0.01, 0.49 ± 0.01, respectively. The highest wound improvement (%) was 84.49 ± 0.20 (propolis in Gambela), followed by propolis in Asela (83.75 ± 0.33) and Sheka (80.88 ± 0.32).Conclusion: Propolis collected from Ethiopia has various wound healing, antioxidant, antibacterial, physicochemical properties and mineral profiles. These properties and profiles make it a good candidate in the food industry, pharmaceutical industry, and in traditional healing practices.