Antioxidant activity and inhibition activity against α-amylase and α-glucosidase of Juniperus rigida Sieb extracts

Abstract

In this study, the antioxidant effect of water and ethanol extracts from Juniperus rigida Sieb were investigated. The activities of each of the extracts were measured based on their total phenolic and flavonoid contents and using antioxidant test such as of 2,2-azinobis (3-ethyl benzothiazoline-6-sulfonic acid (ABTs) radical scavenging activities, ferric reducing antioxidant power (FRAP), angiotensin I converting enzyme (ACE) inhibition activity, antioxidant protection fator (PF), thiobarbituric acid reactive substances (TBARs) content, and α-glucosidase and α-amylase inhibition activity assay. The result of the examination to measure the polyphenol content by investigating the antioxidativity of the J. rigida Sieb. extract showed 71.3 mg/g polyphenol content in the water extract, and 116.0 mg/g in the ethanol extract and a 17.7 mg/g flavonoid content in the water extract and in 76.4 mg/g in the ethanol extract. The ABTS radical cation decolorization showed 76.4% and 79.3% scavenging activities of the 500 µg/mL water extract and ethanol extract, respectively. The FRAP showed 1.83 mM efficacy in the water extract and a lower 1.77 mM in ethanol extract. Both the water extract and the ethanol extract showed reduced ACE activities of 75.39% and 71.25% at 500 µg/mL, respectively. The antioxidant protection factor of the water and 70% ethanol extracts of J. rigida Sieb were 1.5 PF and 2.1 PF, respectively. In the TBARS inhibitory activity, the extracts showed 55.78% and 71.48% antioxidant activities at the 500 µg/mL concentration. The results of the measurrement of the α-amylase inhibitory activity indicated more than 90% of activity inhibition in the 500 µg/mL concentration of the ethanol extract. For the α-glucosidase inhibitory activity, the ethanol extract showed 70% activity inhibition at the 500 µg/mL concentration.

Effects of age and tissue of Juniperus sabina L. on its phytochemical characteristics, anti-cholinesterase, antidiabetes, and anti-drug resistant bacteria activities

“…And the inhibitory activity of J. sabina leaves on AChE and BChE may come from their lignans and phenolic compounds alone or in combination. Additionally, the results of α-glucosidase inhibitory activity in J. sabina extracts are higher than those of other Juniperus extracts ( Kim et al., 2014 ; Orhan et al., 2017 ). At present, α-glucosidase inhibitors have become an important strategy for the treatment of diabetes (type II) ( Cardullo et al., 2020 ).…”

Biological activities of extracts from Tongue fern (Pyrrosia lingua)

“…Measurement of α-amylase inhibitory activity is the agar diffusion method by Kim et al [21], α-amylase inhibition a starch agar plate was prepared by autoclaving 1 L solution containing 5 g agar and 5 g soluble starch for 15 min at 121 o C. 15 mL of the autoclaved solution was dispensed to a petri dish. Disc paper (10 mm in diameter) was placed in the middle of the plate, and the solution containing 800 μL sample and 200 μL α-amylase (1,000 U/mL) was dispensed into the disc paper.…”