Phytochemical Analysis, α-glucosidase Inhibition Activity <i>in-vitro</i> and Enzyme Kinetics of Ethyl Acetate and Hexane Extracts of <i>Graptophylum pictum</i> (L.) Griff

Abstract

The species Graptophylum pictum (L.) Griff, also known as “daun ungu” in Indonesia, is a traditional herbaceous plant believed to have antidiabetic potential. The number of people in the world with diabetes has increased dramatically over the recent years. The treatment of type II diabetes is complicated by several factors inherent to the disease. Elevated postprandial hyperglycemia is one of the risk factors and the intestinal digestive enzyme α-glucosidase plays a vital role in carbohydrate metabolism. One of the antidiabetic therapeutic approaches which reduces the postprandial glucose level in blood is by the inhibition of α-glucosidase. In this study, phytochemical analysis, α- glucosidase inhibitory activity and enzyme kinetics of ethyl acetate- and hexane extracts of G. pictum were evaluated with the aim to analyze its antidiabetic potential. Phytochemical analysis revealed the presence of tannins, steroids, and alkaloids. Steroids were present in ethyl acetate extract but absent in hexane extract, while alkaloids were present in hexane extract but absent in ethyl acetate extract. The ethyl acetate and hexane extracts had 30.68 and 49.82 % inhibitory effect on α-glucosidase activity respectively. The kinetics of glucosidase enzyme of ethyl acetate and hexane extracts were determined by Lineweaver Burk plots. These exhibited uncompetitive and noncompetitive inhibition to alpha-glucosidase activity respectively. From the enzyme assay, we infer that ethyl acetate and hexane extracts of G. pictum contain potential α-glucosidase inhibitors that have the potential to be exploited for use in the treatment of diabetes

Isolation of a Potential Probiotic Levilactobacillus brevis and Evaluation of Its Exopolysaccharide for Antioxidant and α-Glucosidase Inhibitory Activities

“…After incubation at 37°C for 5 min, 50 μl of p -NPG was added as substrate, and the reaction proceeded at 37°C for 30 min. Kinetic parameters were determined using Michaelis–Menten kinetics [ 31 , 32 ].…”

Optimization of Graptophyllum pictum leaves extraction using a simplex centroid design focused on extracting flavonoids with antioxidant activity

“…Graptophyllum pictum is endemic to Papua New Guinea, although it has now spread to several other countries, including Asia (such as Indonesia), Ghana, India, Mexico, and Bolivia (Makkiyah et al, 2021). Several studies reported that this plant leaves contained phytochemicals including glycosides, flavonoids, alkaloids, steroids, phenolic, carbohydrates, phenolics, anthraquinones, coumarins, and tannins (Jiangseubchatveera et al, 2017;Poh-Yen et al, 2018). The plant's leaves are beneficial in traditional medicine for treating rheumatism, hemorrhoid, scabies, swelling, hepatomegaly, constipation, ulcers, urinary infection, maturing boil process, and ear disease and smoothing skin, increasing fertility, and wound healing (Ibrahim et al, 2022).…”

“…The plant's leaves are beneficial in traditional medicine for treating rheumatism, hemorrhoid, scabies, swelling, hepatomegaly, constipation, ulcers, urinary infection, maturing boil process, and ear disease and smoothing skin, increasing fertility, and wound healing (Ibrahim et al, 2022). Furthermore, the plant leaves exhibit multiple pharmacological properties, including anticancer, antibacterial, antioxidant (Jiangseubchatveera et al, 2015), antihemorrhoid (Kusumawati et al, 2022), nephroprotective (Srinivasan et al, 2015), inhibitory a-glucosidase (Nurcholis et al, 2014), and photoprotective activities (Poh-Yen et al, 2018). However, standardization of the G. pictum extract is still necessary to demonstrate the phytochemical content and pharmacological activity.…”

“…Antioxidants are molecules that can protect cells from O n l i n e F i r s t free radicals, which have been linked to stroke, heart disease, and cancer (Sharifi-Rad et al, 2020). Research related to polyphenolic compounds is growing, especially its application in the therapeutic field, including in the treatment of ischemic stroke (Liu et al, 2022), coronavirus (Park et al, 2021), fatty liver (Abenavoli et al, 2021), and heart diseases (Qi et al, 2021). The important polyphenol compound class in human health is flavonoids (Carey et al, 2021).…”

“…Time, solvent, and raw material consumption may all be minimized with the help of the mixture design (Alara et al, 2018;Icyer et al, 2016;Lonni et al, 2012). Evaluation of optimal conditions for extracting flavonoid compounds from a plant matrix has been performed using the simplex centroid design (Dos Santos et al, 2020;Fadil et al, 2022;Nurcholis et al, 2021;Wibisono et al, 2019).…”