Therapeutic potential and physicochemical standardisation of Lesotho propolis based on geographical location and botanical sources: a pilot study in Mohale’s Hoek district

Abstract

We evaluated the therapeutic potential and physicochemical characteristics of propolis samples collected from three councils, namely Khoelenya (F03), Lithipeng (F04) and Thaba-mokhele (F05), in the Mohale's Hoek district, Lesotho. The aim of this study was to investigate the relationship of the therapeutic potential, physicochemical characteristics and colour variation to the geographical location and botanical sources of the collected propolis samples. The collected samples presented remarkable colour variation, ranging from green (25%) to brown (58%) to grey (17%). The highest antioxidant activity was observed in green-coloured propolis samples collected from Lithipeng F04P01 and Khoelenya F03P01, with 2,2–diphenyl–1–picryl–hydrazyl–hydrate (DPPH) half maximal inhibitory concentration (IC₅₀) values of 0.21 and 0.23 mg/mL, respectively. The antioxidant activity (DPPH IC₅₀) did not correlate completely with the total polyphenolic content (R² = 0.1733) and total flavonoid content (R² = 0.4836). Moreover, the highest antimicrobial activity was observed on grey propolis collected from Thaba-mokhele, F05P04 and F05P03, with minimum inhibitory concentration of 3.13 mg/mL for both samples, especially against Staphylococcus aureus. The qualitative phytochemical analysis detected the presence of polyphenols, alkaloids and flavonoids in all collected samples. Thus, our findings could lead to the formulation of a “local” Lesotho type of propolis that could be used as an official medicine. This could be a big marketing advantage for the Lesotho pharmaceutical and beekeeping industries.

Keywords:

• green propolis
• grey propolis
• antioxidant activity
• antibacterial activity
• phytochemicals

Acknowledgements

Special thanks are extended to all beekeepers who participated in the early stages of this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data Figures S1 and S2, and Tables S1 and S2 for this article can be accessed at http://dx.doi.org/10.1080/0035919X.2022.2163000.

Additional information

Funding

This work was supported by the 2015–2022 United Nations Development Programme supported Global Environment Facility-funded project in Lesotho.