Pharmacological evaluation of the hypoglycemic and anti-Alzheimer's activities of aerial parts of Breynia distachia (Phyllanthaceae)

Purpose: To determine the cytotoxic, bronchorelaxant, spasmolytic, antidiabetic, alpha-glucosidase, acetylcholinesterase, butyrylcholinesterase, alpha-chymotrypsin and lipoxygenase inhibitory attributes of methanol and dichloromethane extracts of the aerial parts of Breynia distachia. Methods: The dichloromethane and methanol extracts of the aerial parts of the plant were prepared by maceration. Various ex vivo assays were employed, such as the brine shrimp lethality assay, lipoxygenase inhibitory activity assay, alpha-glucosidase inhibitory assay and alpha-chymotrypsin assay, as well as assays to assess the spasmolytic and bronchorelaxant activity. Meanwhile, the hypoglycaemic effect were analysed using an alloxan-induced diabetic model in Wistar albino rats. Results: The methanol extract (aerial) showed significant (p <= 0.05) cytotoxicity towards brine shrimp larvae at concentrations of 10, 100 and 1,000 mu g/mL, respectively, whereas the dichloromethane extract (aerial) of the plant showed non-significant (p >= 0.05) results. The methanol extract (aerial parts) also demonstrated significant (p <= 0.05) alpha-glucosidase inhibitory activity and lipoxygenase inhibitory activity, with IC50 (half-maximal inhibitory concentration) values of 40.37 +/- 5.29 mu g/mL and 132.9 +/- 0.33 mu g/mL, respectively, while the dichloromethane extract exhibited significant (p <= 0.05) alpha-glucosidase inhibitory activity, with an IC50 value of 135.43 +/- 8.29 mu g/mL. An in vivo antidiabetic model showed that the administration of 150 and 300 mg/kg methanol extract of the aerial parts significantly (p <= 0.05) lowered the blood glucose level in alloxan-induced diabetic rats compared to control (treated with water). Conclusion: Data from different in vitro and in vivo models suggest that the methanol extract (aerial parts) of B. distachia shows significant cytotoxic, bronchorelaxant, spasmolytic, antidiabetic and anti-Alzheimer's activity Hence, these findings validate the folkloric use of B. distachia and highlight the need to further explore its medicinal potential and the phytoconstituents responsible for its pharmacological actions.