Assessment of antioxidant potential in seed extracts of Nyctanthes arbor-tristis L. and phytochemical profiling by Gas Chromatography-Mass Spectrometry system

Abstract The present study has been carried out with the seed extracts of Nyctanthes arbor-tristis L. (Parijat) and evaluates its antioxidant potential and profiling the phytochemical constituents by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The antioxidant potential of the seed extracts was measured by four different in vitro assay like 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, superoxide anion free radical scavenging activity, ferric reducing antioxidant power (FRAP) and lipid peroxidation inhibition potential (LPIP) assay. The total phenol content (TPC) and total flavonoid content (TFC) were estimated. The ethyl acetate extract (EAE) of seeds showed potential DPPH free radical scavenging activity (EC50 129.49±3.55µg/ml), superoxide anion radical (EC50 969.94±8.03µg/ml) and LPIP (EC50 452.43±5.07 µg/ml) activities. The total phenol content was maximum in aqueous extract (AQE) which was 201.00±0.20 µg/mg gallic acid equivalent. The EAE was rich with total flavonoid and it was found to be 34.50±0.40 µg/mg rutin equivalent. The EAE was subjected for phytochemical-profiling using GC-MS system. The presence of different phytoconstituents supports the medicinal value of the seeds. The results suggest that EAE constitutes a promising new source of novel compounds. Further, it can be used for isolation and purification of specific compounds which have good antioxidant activities and possess useful biological activities.

Isolation and characterization of antihypertensive peptides from soy bean protein

Proteins and peptides are the most diverse biomolecules found in nature and make our interest due to their wide applications in food and pharmaceutical industry. Angiotensin Converting Enzyme (ACE) plays a major role in controlling blood pressure. The inhibition of ACE with peptides is a main target in the regulation of hypertension. The objective of the present study was to investigate the therapeutic potential of soy bean. This was accomplished by isolation of ACE inhibitory peptides using response surface methodology (RSM) and characterization of these bioactive peptides by mass spectrometry. 31 hydrolyzed fractions were isolated and evaluated for their ACE inhibition potential. Hydrolyzed fraction having highest ACE inhibitory activity was characterized by liquid chromatography-mass spectrometry (LC-MS) technique. RSM results showed maximum ACE inhibition potential (64%) by hydrolyzate was obtained at 45 ºC temperature, pH 8.0, E/S 0.2 in 2 hours hydrolysis time. Results of LC-MS analysis revealed Ser-Gly, Ser-Pro, Met-Ala, His-Ala, Lys-Pro, Phe-Thr, Met-Leu, Pro-Arg, Ala-Pro-Val, Pro-Ala-Leu, Val-Met-Gly, Pro-Leu-Val, Pro-Pro-Gln, His-Arg-Gly, Ser-Phe-Val-Leu, Ala-Val-His-Try, Arg-Thr-Val-Arg, His-His-Tyr-Leu-Val, Asp-Gly-Ala-Cys-Ser-Ala-Asn and MetVal-Thr-Gly-Pro-Gly-Cys-His bioactive peptides in hydrolyzed fraction of soy bean. Our data provide evidence that response surface methodology is a good approach for isolation of antihypertensive bioactive peptides with more potent activity as nutraceuticals or pharmaceuticals. Therefore soy bean can be use for industrial production of pharmaceutical grade natural medicines for handling high blood pressure.

Pancreatic lipase inhibitory constituents from Fructus Psoraleae / 中国天然药物

Pancreatic lipase (PL), a crucial enzyme in the digestive system of mammals, has been proven as a therapeutic target to prevent and treat obesity. The purpose of this study is to evaluate and characterize the PL inhibition activities of the major constituents from Fructus Psoraleae (FP), one of the most frequently used Chinese herbs with lipid-lowering activity. To this end, a total of eleven major constituents isolated from Fructus Psoraleae have been obtained and their inhibition potentials against PL have been assayed by a fluorescence-based assay. Among all tested compounds, isobavachalcone, bavachalcone and corylifol A displayed strong inhibition on PL (IC < 10 μmol·L). Inhibition kinetic analyses demonstrated that isobavachalcone, bavachalcone and corylifol A acted as mixed inhibitors against PL-mediated 4-methylumbelliferyl oleate (4-MUO) hydrolysis, with the K values of 1.61, 3.77 and 10.16 μmol·L, respectively. Furthermore, docking simulations indicated that two chalcones (isobavachalcone and bavachalcone) could interact with the key residues located in the catalytic cavity of PL via hydrogen binding and hydrophobic interactions. Collectively, these finding provided solid evidence to support that Fructus Psoraleae contained bioactive compounds with lipid-lowering effects via targeting PL, and also suggested that the chalcones in Fructus Psoraleae could be used as ideal leading compounds to develop novel PL inhibitors.