UPLC-ESI-QTOF-MS phenolic compounds identification and quantification from ethanolic extract of Myrtus communis 'Variegatha': In vitro antioxidant and antidiabetic potentials

Global public health is seriously threatened by diabetes and its complications. Although several synthetic drugs are currently employed for managing diabetes, however, the adverse effects associated with their use cannot be underestimated. Thus, the quest for a safe and cost-effective alternative is highly imperative. In the present study, the phenolic contents, antioxidant, antidia-betic, and cytotoxic potentials of 70% ethanolic crude extract of Myrtus communis 'Variegatha' were investigated using in vitro biochemical protocols. The total polyphenols content was 116.44 mg GAE/g, flavonols (6.74 mg QE/g), flavanols (2.46 mg CE/g) and the ferric reducing antioxidant power (FRAP) value was 1267.28 mmol AAE/g, 2,2-diphenyl-1-picrylhydrazyl (DPPH) (1165.37 mmol TE/g), and Trolox equivalent antioxidant capacity (TEAC) (775.52 mmol TE/g). High-resolution ultra-performance liquid chromatography coupled with electrospray ionisation/q uadrupole-time-of-flight-mass spectrometry (UPLC-ESI-QTOF-MS) was explored to identify the phenolic compounds, most of which were flavonoids. The extract demonstrated a strong a-glucosidase inhibition potential in a concentration-dependent manner with IC50 (3.159 mu g/mL), which was higher than epigallocatechin gallate (EGCG) (6.208 mu g/mL), a positive control antidia-betic drug. A slight increase in glucose utilization was observed after 24 h of treatment in C3A hep-atocytes at 25 lg/mL whereas an increase in glucose uptake was recorded at 25 and 50 lg/mL. The extract exhibited a cytotoxic effect (IC50 76.85 mu g/mL) against C3A hepatocytes at 100 mu g/mL, which correlates to the glucose utilization and uptake recorded. The findings from the study show the prospect of M. communis 'Variegatha' as a promising source of bioactive compounds that could be used in the development of new anti-diabetic agents, thus, further research into the plant is rec-ommended.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).