Functional relevance of Gedunin as a bona fide ligand of NADPH oxidase 5 and ROS scavenger: An in silico and in vitro assessment in a hyperglycemic RBC model

Hypoglycemic activities of flowers of Xanthoceras sorbifolia and identification of anti-oxidant components by off-line UPLC-QTOF-MS/MS-free radical scavenging detection

Objective

To identify phytochemical constituents present in the extract of flowers of Xanthoceras sorbifolia and evaluate their anti-oxidant and anti-hyperglycemic capacities.

Methods

The AlCl3 colorimetric method and Prussian Blue assay were used to determine the contents of total flavonoids and total phenolic acids in extraction layers, and the bioactive layers was screened through anti - oxidative activity in vitro. The Waters ACQUITY UPLC system and a Waters ACQUITY UPLC BEH C18 column (2.0 mm × 150 mm, 5 μm) were used to identify the ingredients. And anti-oxidative ingredients were screened by off-line UPLC-QTOF-MS/MS-free radical scavenging. The ameliorative role of it was further evaluated in a high-fat, streptozotocin-induced type 2 diabetic rat model and the study was carried out on NADPH oxidase (PDB ID: 2CDU) by molecular docking.

Results

Combined with the results of activity screening in vitro, the anti - oxidative part was identified as the ethyl acetate layer. A total of 24 chemical constituents were identified by liquid chromatography-mass spectrometry in the ethyl acetate layer and 13 main anti-oxidative active constituents were preliminarily screened out through off-line UPLC-QTOF-MS/MS-free radical scavenging. In vivo experiments showed that flowers of X. sorbifolia could significantly reduce the blood glucose level of diabetic mice and alleviate liver cell damage. Based on the results of docking analysis related to the identified phytocompounds and oxidase which involved in type 2 diabetes, quercetin 3-O-rutinoside, kaempferol-3-O-rhamnoside, isorhamnetin-3-O-glucoside, and isoquercitrin showed a better inhibitory profile.

Conclusion

The ethyl acetate layer was rich in flavonoids and phenolic acids and had significant anti-oxidant activity, which could prevent hyperglycemia. This observed activity profile suggested X. sorbifolia flowers as a promising new source of tea to develop alternative natural anti-diabetic products with a high safety margin.

Azadiradione, a Component of Neem Oil, Behaves as a Superoxide Dismutase Mimic When Scavenging the Superoxide Radical, as Shown Using DFT and Hydrodynamic Voltammetry

The neem tree, Azadirachta indica, belongs to the Meliaceae family, and its use in the treatment of medical disorders from ancient times to the present in the traditional medical practices of Asia, Africa and the Middle East is well-documented. Neem oil, extracted from the seeds of the fruit, is widely used, with promising medicinal benefits. Azadiradione, a principal antioxidant component of the seeds of A. indica, is known to reduce oxidative stress and has anti-inflammatory effects. To directly measure the antioxidant ability of neem oil, we used Rotating Ring Disk Electrode (RRDE) hydrodynamic voltammetry to quantify how it can scavenge superoxide radical anions. The results of these experiments show that neem oil is approximately 26 times stronger than other natural products, such as olive oil, propolis and black seed oil, which were previously measured using this method. Next, computational Density Functional Theory (DFT) methods were used to arrive at a mechanism for the scavenging of superoxide radical anions with azadiradione. Our work indicates that azadiradione is an effective antioxidant and, according to our DFT study, its scavenging of the superoxide radical anion occurs through a reaction mechanism in which azadiradione mimics the antioxidant action of superoxide dismutase (SOD). In this mechanism, analogous to the SOD enzymatic reaction, azadiradione is regenerated, along with the production of two products: hydrogen peroxide and molecular oxygen. This antioxidant process provides an explanation for azadiradione's more general and protective biochemical effects.

Use of haematological signatures in conjunction with conventional biomarkers to assess Reno-protective effects of Gedunin in diabetic nephropathy of Streptozotocin induced diabetic rats

Purpose

The present study was aimed at analysing the reno-protective potential of Gedunin (a limonoid from Neem leaves) through haematological and serological assays and renal histopathology studies in streptozotocin induced diabetic rats.

Method

Four weeks old Wister albino rats were chosen for the study. The rats were divided into four groups of 8 rats each. Group 1 (normal control rats); Group 2 (diabetic control rats); Group 3 (Drug control rats: normal rats treated with 1 mg/kg body weight of Gedunin thrice a week through oral gavage for 2 weeks); Group 4 (diabetic rats treated with Gedunin similar to Group 3). Diabetes was induced using a single intraperitoneal injection of streptozotocin (50 mg/kg) in the pre-determined groups. After completion of treatment, the rats were sacrificed and haematological and serological parameters including functional indices of blood cells and renal markers were evaluated through spectrophotometric methods. Renal histology studies were carried out and images were captured on Olympus SC 100, 10 Mega Pixel camera.

Results

Streptozotocin induced diabetes lead to marked reduction in the RBC count, haemoglobin, PCV, WBC count, lymphocyte, elevated levels of fasting blood glucose, kidney function markers such as urea, creatinine, uric acid in rats. Administration of Gedunin significantly (P < 0.05) ameliorated the elevated levels of fasting glucose, RDW%, MCHC%, NLR% and platelet count. A significant reversal of renal tissue damage was also observed.

Conclusion

The restoration of renal serological markers and reversal of renal tissue injuries are all indicative of promising reno-protective potential of Gedunin. Remarkable improvement of haematological parameters supports their use as reno-protection markers.

Oxidative Stress and Hypertension

A link between oxidative stress and hypertension has been firmly established in multiple animal models of hypertension but remains elusive in humans. While initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly. In this review, we summarize recent advances in delineating the primary and secondary sources of reactive oxygen species (nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, endoplasmic reticulum, and mitochondria), the posttranslational oxidative modifications they induce on protein targets important for redox signaling, their interplay with endogenous antioxidant systems, and the role of inflammasome activation and endoplasmic reticular stress in the development of hypertension. We highlight how oxidative stress in different organ systems contributes to hypertension, describe new animal models that have clarified the importance of specific proteins, and discuss clinical studies that shed light on how these processes and pathways are altered in human hypertension. Finally, we focus on the promise of redox proteomics and systems biology to help us fully understand the relationship between ROS and hypertension and their potential for designing and evaluating novel antihypertensive therapies.