The In Vitro Assessment of Antidiabetic Activity of the Plant Extracts Obtained from Portulacaria afra Jack. Grown under Concurrent Extreme Temperatures and Water-deficit Conditions

Abstract

The escalating global prevalence of diabetes mellitus presents a significant health concern, prompting exploration into alternative treatments. Recent research highlights the efficacy of newly developed bioactive medications sourced from plants in managing diabetes, surpassing currently used oral hypoglycemic drugs. Medicinal plants' therapeutic characteristics are from secondary metabolites and are greatly influenced by environmental factors. This study investigated the antidiabetic properties of Portulacaria afra, using various extraction solvents under different temperature settings with water deficit conditions, using an in vitro model. Aqueous, methanol, ethyl acetate, and n-hexane extracts from leaf, stem, and root were evaluated for antidiabetic potential under different treatments. Overall, extracts substantially increased in antidiabetic capacity compared to control samples. Aqueous leaf extracts at mid-range cold temperatures (10/15ºC) demonstrated the strongest antidiabetic activity, with an IC50 value of 2.33±0.832mg/ml after a 96-hour treatment. Under extreme cold temperatures (0/5ºC) with water deficit, ethyl acetate stem extracts showed the highest inhibitory action (IC50 2.85±0.111mg/ml). Aqueous stem extracts under hot temperatures showed the strongest inhibitory activity (IC50 1.70±0.666mg/ml) after a 48-hour treatment. Notably, the study provides the first data on the antidiabetic potential of P. afra's leaf, stem, and root extracts, particularly under temperature and water deficit conditions. This could be useful as leads worthy for further drug development against diabetes and related symptoms. The observed α-amylase inhibitory activity in aqueous and ethyl acetate stem extracts is most likely due to the polar compounds, establishing a foundation for future investigations.