Anti-diabetic potential of Corn silk (Stigma maydis): An in-silico approach

Corn silk is known to possess anti-diabetic activity, the current study is aimed to predict the binding affinity of bio-actives from corn silk against targets involved in diabetes mellitus i.e. Protein Tyrosine Phosphatase 1-B (PTP1B), Glucose Transporter-1 (GLUT1), Dipeptidyl Peptidase-4 (DPP4), α-glucosidase, and α-amylase. The 3D molecular structure of bio-actives was retrieved from the PubChem database and the structure of targets was retrieved from protein data bank. Later, hetero atoms were removed using Discovery studio visualizer 2019. Molecular docking was performed using Autodock4.0. Ten different poses were obtained from which the pose possessing the highest binding affinity was visualized for protein-ligand interaction in Discovery studio visualizer 2019. Twenty-six bio-actives were docked against five different targets i.e. PTPN1B, GLUT1, DPP4, α-glucosidase, and α-amylase from which flavones were found to possess the highest binding affinity towards PTPN1B with a binding energy of -8.5 kcal/mol. Similarly, β-carotene, gallotannins, 3-O-caffeoylquinic acid, and stigmasterol were predicted to possess the highest binding affinity towards GLUT1, DPP4, α-glucosidase, and α-amylase with binding energy -11.1 kcal/mol, -10.7 kcal/mol, -8.9 kcal/mol, and -9.8 kcal/mol respectively. Our study screened the anti-diabetic potential of 26 bio-actives towards five different diabetic proteins indicating a possibility of bio-actives from corn silk to possess anti-diabetic potential which needs to be further validated via experimental protocols; this serves as a future scope as well as lacuna for the present study. Thus, bio-actives from corn silk have anti-diabetic potential and can be used in the future to investigate and develop novel anti-diabetic molecule.

Phytochemical characterization of Tabernanthe iboga root bark and its effects on dysfunctional metabolism and cognitive performance in high-fat-fed C57BL/6J mice

Preparations of the root bark of Tabernanthe iboga have long been used in Central and West African traditional medicine to combat fatigue, as a neuro-stimulant in rituals, and for treatment of diabetes. The principal alkaloid of T. iboga, ibogaine, has attracted attention in many countries around the world for providing relief for opioid craving in drug addicts. Using a plant metabolomics approach, we detected five phenolic compounds, including 3-O-caffeoylquinic acid, and 30 alkaloids, seven of which were previously reported from T. iboga root bark. Following a report that iboga extracts contain insulinotropic agents, we aimed to determine the potential alleviating effects of the water extract of iboga root bark on high-fat diet (HFD)-induced hyperglycemia as well as its effects on cognitive function in male C57BL/6J mice. Feeding a HFD to mice for 10 weeks produced manifestations of metabolic syndrome such as increased body weight and increased plasma levels of glucose, triacylglycerols, total cholesterol, LDL-cholesterol, insulin, leptin, and pro-inflammatory mediators (IL-6, MCP-1, ICAM-1), as compared to mice fed a low-fat diet (LFD). Supplementation of HFD with iboga extract at ibogaine doses of 0.83 (low) and 2.07 (high) mg/kg/day did not improve these HFD-induced metabolic effects except for a reduction of plasma MCP-1 in the low dose group, indicative of an anti-inflammatory effect. When the HFD mice were tested in the water maze, the high-dose iboga extract caused hippocampus-dependent impairments in spatial learning and memory, as compared to mice receiving only a HFD.

Identification and quantification of free, conjugate and total phenolic compounds in leaves of 20 sweetpotato cultivars by HPLC-DAD and HPLC-ESI-MS/MS

The study systematically investigated free, conjugate and total phenolics (phenolic acids and flavonoids) in leaves of 19 Chinese and one American sweetpotato cultivars grown in China. Three extraction/hydrolytic methods (direct extraction and acidic and basic hydrolysis) for sample preparation were employed to obtain different forms of phenolics. Twenty-nine phenolics were separated and identified using HPLC-DAD and HPLC-ESI-MS/MS. Three quercetin glycosides were characterised for the first time from this plant. Contents of the principal phenolics identified were determined by the HPLC-DAD procedure, which was validated in terms of linearity, precision, accuracy and limit of detection and quantification. Moreover, to the best of our knowledge, it is the first to reveal and demonstrate artifacts of esterification during acidic methanolic and ethanolic hydrolysis, and chromatographic behaviours, UV spectra and MS data of 20 hydroxycinnamic acid methyl and ethyl esters were obtained using acidic methanolic and ethanolic hydrolysis.