Antioxidant and Antidiabetic Activities of Ethanolic Extract from the Inflorescence of Musa ABB cv. ‘Kluai Namwa’

Abstract

Banana inflorescence is known as banana flower, banana blossom, or banana heart that belongs to the Musaceae family. It is widely known to have a great potential for control of diabetes. However, the ability of an ethanolic extract from banana inflorescence to stimulate glucose uptake in skeletal muscle cell line has not been illustrated. Therefore, extraction and characterization of ethanolic extract from banana inflorescence was performed. Additionally, the antioxidant and antidiabetic activities of the extract were investigated. The inflorescence from ‘Kluai Namwa Mali-Ong’ was used in this study. These results showed that the banana inflorescence extracts contained carbohydrate, protein, phenolic, flavonoid, and fatty acids. The extract also exhibited antioxidant activities in 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging (DPPH), ferric ion reducing antioxidant power (FRAP), and 2,2’-azinobis (3- ethylbenzothiazoline- 6- sulphonic acid) free radical scavenging activity (ABTS) assays. The inhibitory concentration of the extract to scavenge 50% (IC50) values in the DPPH and ABTS assays were 27.89 ± 0.54 and 21.33 ± 0.87 mg/mL, respectively. In addition, the antioxidant activity in the FRAP assay was 752.21 ± 17.09 mM TE/g extract. The biochemical profiling of the extract was characterized using the ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHLC-ESI-QTOF/MS) technique in both positive and negative electrospray ionization modes. A total of ten and eleven major compounds in the positive and negative-ion modes were identified. Moreover, the extract showed a dose-dependent effect in a concentration range from 0.125 – 0.5 mg/mL and time-dependent effect on a stimulation of glucose uptake in C2C12 myotubes without cytotoxicity to the cells. These results suggest the biological activities of the crude ethanolic extract from ‘Kluai Namwa Mali-Ong’. Future experimentations will be required to develop the extract into an antidiabetic drug.