Phytochemical screening and In-vitro evaluation of kiwi fruit

Abstract

The fruit of Actinidia deliciosa (A. Chev.) C.F. Liang & A.R. Ferguson, commonly known as kiwifruit, is often referred to as "China’s miracle fruit" and the "Horticultural wonder of New Zealand." It is widely recognized for its exceptional bioactive properties that contribute to various health benefits. Kiwifruit promotes healthy skin and improved sleep due to its rich antioxidant and serotonin content. Additionally, it supports cardiovascular health and regulates blood pressure, being a valuable source of potassium, fiber, and antioxidants. Its antioxidant properties aid in anti-aging and blood purification, while its antihyperglycemic compounds may have potential antidiabetic effects. This study aimed to analyze the biochemical composition of kiwifruit and assess its antioxidant and antihyperglycemic potential. Chemical profiling of kiwifruit extracts prepared in ethanol and methanol solvents confirmed the presence of steroids, cardiac glycosides, terpenoids, flavonoids, and carbohydrates. Antioxidant activity was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical inhibition assay, while the α-amylase inhibitory assay was conducted using α-amylase from Aspergillus oryzae. Among the two extracts, the methanolic extract (MKE) exhibited the highest inhibitory activity against both DPPH free radicals and α-amylase compared to the ethanolic extract (EKE). The IC50 values, representing the concentration required for 50% inhibition, were determined for both extracts. For the DPPH scavenging assay, the IC50 value was 4.2 ± 0.073 mg/mL for MKE and 3.14 ± 0.153 mg/mL for EKE. Meanwhile, in the α-amylase inhibition assay, the IC50 values were 1.53 ± 0.158 mg/mL for MKE and 2.05 ± 0.639 mg/mL for EKE. Kinetic analysis indicated that both MKE and EKE exhibited a competitive mode of inhibition toward α-amylase.