Polyphenol fingerprinting and hypoglycemic attributes of optimizedCycas circinalisleaf extracts

BACKGROUND Cycas circinalisleaves are used to treat diabetes mellitus in local medicinal systems without any scientifically proved information on their medicinal potential and phytochemicals. In this study, the total phenolic contents, total flavonoid contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and inhibitory effects on alpha-glucosidase and alpha-amylase were determined for optimized hydroethanolic leaf extracts. Secondary metabolites were identified using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS).In vivostudies on diabetic albino mice were also carried out to evaluate the impact of the most active extract on their blood glucose levels. RESULTS The 60% ethanolic extract showed the highest extract yield (209.70 +/- 0.20 g kg(-1)) and total phenolic (154.24 +/- 3.28 mg gallic acid equivalent) and flavonoid (78.52 +/- 1.65 mg rutin equivalent per gram dried extract) contents and exhibited the maximum DPPH scavenging activity (IC50= 59.68 +/- 2.82 mu g mL(-1)). The IC(50)values for inhibition of alpha-glucosidase (58.42 +/- 2.22 mu g mL(-1)) and alpha-amylase (74.11 +/- 1.70 mu g mL(-1)) were also significant for the 60% ethanolic extract. The untargeted UHPLC-QTOF-MS/MS-based metabolite profiling confirmed the presence of iridoid glucoside, gibberellin A4,O-beta-d-glucosyl-4-hydroxy-cinnamate, 3-methoxy-2-phyenyl-4H-furo[2,3-h]chromen-4-one, kaempferol, withaferin A, amentoflavone, quercitin-3-O-(6 ''-malonyl glucoside), ellagic acid, and gallic acid. Plant extract at a dose of 500 mg kg(-1)body weight reduced the blood glucose level by a considerable extent and also improved the lipid profile of diabetic mice after a 28-day trial. CONCLUSION The findings revealed the medicinal potential ofC. circinalisleaves to treat diabetes mellitus and provided the nutraceutical leads for functional food development. (c) 2020 Society of Chemical Industry

Automated summary

This study identified the medicinal potential of 60% ethanolic Cycas circinalis leaf extract in treating diabetes mellitus, including inhibitory effects on enzymes related to diabetes and blood glucose regulation. In vivo studies confirmed the extract's ability to lower blood glucose levels and improve lipid profile in diabetic mice.