Antioxidant, Antidiabetic and Structural Analysis of Spinacia Oleracea Leaf

Abstract

Medicinal plants have been conventionally used to sustain health and treat many diseases such as diabetes for years. Spinacia oleracea L., common name palak, belong to the class Amaranths and family Amaranthaceous. It is used as an anti-bacterial, antidiabetic, anticancer, anti-inflammatory, antioxidant, and hepatoprotective agent. In this study, methanol, ethanol, n-hexane and aqueous extracts of the Spinacia oleracea leaf were used to evaluate antioxidant contents, antioxidant activity, antidiabetic activity (inhibition of glycation, alpha amylase, alpha glucosidase, acetylchlinesterase). Additionally, identification of bioactive compounds and functional groups was done by Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC). Among all the extracts, total phenol and flavonoid contents were 32.09 ± 0.99 g GAE/100 g to 78.38 ± 1.15 g GAE/100 g and 22.77 ± 0.16 g CE/100 g to 54.56 ± 0.87 g CE/100 g. While DPPH reducing activity range was 45.14% -75.77%. Methanol extract was most potent as it extracted maximum antioxidant contents. Glycation and alpha amylase inhibition percentages were 15.31 to 34.28 and 19.83-36.32 among all tested samples of spinach. Whereas, 12.67-43.77% and 17.3% to 28.04% blocking of alpha glucosidase and acetylcholinesterase activities were observed. HPLC analysis identified various flavonoids and phenolics acids such as quercetin, gallic acid, caffeic acid, sinopic acid, cinnamic acid. FTIR showed that S. oleracea contains several phenols, amines, alkaloids, alcohols and fluoro compounds in the methanolic leaves extract. This research indicated that S. oleracea has wide potential to be further investigated in the future and it can prove as a wonderful natural drug for healthcare systems in the upcoming years.