Phytochemicals and in silico investigations of Sudanese roselle

Abstract

We analysed four different Sudanese roselle samples for their potential as novel xanthine oxidase (XO) inhibitors. Phytochemical screening showed the presence of polyphenols, flavonoids, organic acids, saponins and sterols in all samples. Liquid chromatography with tandem mass spectrometry (LC-MS/ MS) was used to identify and characterise five anthocyanins in all samples: cyanidin-3-glucoside (cy-3-glu), delphinidin-3-sambubioside (dp-3-sam), cyanidin-3-rhamnoside (cy-3-rhm), delphinidin-3‑rhamnoside (dp-3-rhm) and pelargonidin-3-glucoside (pg-3-glu). Identification of cy-3-rhm, dp-3-rhm and pg-3-glu confirmed the selectivity and sensitivity of LC-MS as a powerful technique for identifying anthocyanins. In silico studies of the identified anthocyanins were performed to explore their promising inhibitory activity toward XO. Interactions between the ligand and the enzyme were via the H-bond, and hydrophobic (π-alkyl, π-sigma and alkyl) and/or electrostatic (π-cation) bonds. Inhibition of the anthocyanins was compared with that of topiroxostat, a commercial drug for hyperuricaemia. Dp-3-rhm was the most active inhibitor with a binding energy of ca. -10.90 kcal/mol compared to topiroxostat’s binding energy of ca. -8.60 kcal/mol. The good inhibition results obtained from anthocyanins toward XO suggest their application as a drug candidate to treat gout and other diseases related to the activity of XO.

Mechanism of flavonoids inhibiting xanthine oxidase and alleviating hyperuricemia from structure–activity relationship and animal experiments: A review

“…Black rice anthocyanins decreased the proportion of β‐turns and random coil in XO, limited the binding and catalysis of the substrate with XO, and thus, reduced the XO activity. The anthocyanins in S. roselle were mainly glycosylated cyanidin and delphinidin, which interact with XO through hydrogen bonds, hydrophobic interactions, and/or electrostatic repulsions (El‐Naeem et al., 2022). Among them, delphinidin‐3‐rhamnoside was the most active substance.…”

“…Among them, delphinidin‐3‐rhamnoside was the most active substance. Its main binding sites to XO were Thr354 and Arg394 (via hydrogen bonds), and the binding energy of delphinidin‐3‐rhamnoside was −10.9 kcal/mol, which was lower than that of topiroxostat (a standard drug for the treatment of HUA) with −8.6 kcal/mol (El‐Naeem et al., 2022). The findings suggest that anthocyanins are potential drugs for the treatment of HUA.…”

“…Genistein, daidzin, daidzein, and puerarin isolated from Pueraria lobata roots showed strong inhibitory effects on XO, with half‐maximal inhibitory concentration (IC 50 ) values of 3.02, 5.31, 14.5, and 30.8 μg/mL, and exhibited protective effects on the oxidative stress model of human gastric epithelial cells, improving cell viability and reducing mortality (Tang et al., 2020). In addition, a large number of flavonoids with inhibitory effects on XO have been found in Sudanese roselle , sunflower, and shallot (El‐Naeem et al., 2022; Mehmood et al., 2018; Nguyen Thu et al., 2021). Hence, it is evident that flavonoids are potential drug candidates for the treatment of HUA.…”

Comparative Study on the Chemical Profile, Antioxidant Activity, and Enzyme Inhibition Capacity of Red and White Hibiscus sabdariffa Variety Calyces

“…Phenolic acids like neochlorogenic acid and chlorogenic acid, in addition to organic acids such as hydroxycitric acid, hibiscus acid, and hibiscus acid hydroxyethyl ester were also identified. Few phytochemical studies were conducted on the white calyx, and phytochemical screening showed that polyphenols, flavonoids, organic acids, sterols, and saponins were detected . Pharmacologically, H.…”

“…sabdariffa and it is frequently consumed as a hot or cold beverage and used in traditional medicine, there has been limited systematic study on the efficiency of different solvent extractions on bioactive molecules. Moreover, there are few studies on the chemical and biological activities of white roselle (WR) variety. , In this context, the present study was designed to investigate the chemical profiles, antioxidant activity, and enzyme inhibition property of extracts from red roselle (RR) and WR varieties obtained through maceration, infusion, and decoction by using water and methanol as extraction solvents.…”