Antioxidant and anti-diabetic activities of crude ethanolic extract from the banana inflorescence of musa (ABB group) namwa maliong

Background: Banana inflorescence is one of the edible parts of banana. It is well-known to have antioxidants and anti-diabetic potential health benefits. Methods: In this study, the banana inflorescence from Musa (ABB group) Namwa Mali-Ong was prepared using ethanol extraction and investigated for its biochemical compositions and biological activities. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric reducing antioxidant power (FRAP), and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging activity assays were performed. The phytochemical composition of the extract was analyzed using the ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHLC-ESI-QTOF/MS) technique. Additionally, the ability of the extract to stimulate glucose in C2C12 myotube was investigated. Results: The ethanolic extract of banana inflorescence contained carbohydrate, protein, phenolic, and flavonoid compounds. The results show that the extract exhibited low-level antioxidant activities.  For example, the half-maximal inhibitory concentration (IC50) in the DPPH and ABTS assays was at 27.89 ± 0.054 and 21.33 ± 0.87 mg/mL, respectively. Although the extract possesses low-level antioxidant activities, it stimulated glucose uptake in C2C12 myotubes in a dose- and time-dependent fashion. Consistently, the UHLC-ESI-QTOF/MS analysis in both positive and negative electrospray ionization modes reveals several components in the extract such as phytosphingosine and α-linolenic acid that have previously been shown to exhibit an anti-diabetic activity.Conclusion: The results show that the inflorescence ethanolic extract possesses antioxidant and anti-diabetic activities and may potentially be developed into a health-promoting product such as an anti-diabetic drug. Keywords: antioxidant activity; banana inflorescence; glucose uptake; anti-diabetic; C2C12 myotubes