Spectroscopic studies on free radical coalescing antioxidants and brain protein cystatin

Advances on nanoformulation approaches for delivering plant-derived antioxidants: A case of quercetin

Oxidative stress has been implicated in tumorigenic, cardiovascular, neuro-, and age-related degenerative changes. Antioxidants minimize the oxidative damage through neutralization of reactive oxygen species (ROS) and other causative agents. Ever since the emergence of COVID-19, plant-derived antioxidants have received enormous attention, particularly in the Indian subcontinent. Quercetin (QCT), a bio-flavonoid, exists in the glycosylated form in fruits, berries and vegetables. The antioxidant potential of QCT analogs relates to the number of free hydroxyl groups in their structure. Despite presence of these groups, QCT exhibits substantial hydrophobicity. Formulation scientists have tested nanotechnology-based approaches for its improved solubilization and delivery to the intended site of action. By the virtue of its hydrophobicity, QCT gets encapsulated in nanocarriers carrying hydrophobic domains. Apart from passive accumulation, active uptake of such formulations into the target cells can be facilitated through well-studied functionalization strategies. In this review, we have discussed the approaches of improving solubilization and bioavailability of QCT with the use of nanoformulations.

Antifibrotic preventive effect of polyethylene glycol (PEG) 3350 in methotrexateinduced hepatoxicity model

PURPOSE

Liver damage caused by drugs and other chemicals accounts for about 5% of all cases. Methotrexate (MTX), a folic acid analogue, is a first-line synthetic antimetabolite agent routinely used in the treatment of rheumatoid arthritis and other autoimmune and chronic inflammatory diseases. Polyethylene glycol (PEG) has antioxidant activity. In this study, we evaluated biochemically and histopathologically the antifibrotic effect of PEG 3350 administered intraperitoneally to prevent methotrexate-induced liver damage in rats.

METHODS

A total of 30 male rats including 10 rats was given no drugs (normal group), and 20 rats received single-dose 20 mg/kg MTXfor induced liver injury in this study. MTX was given to 20 rats, which were divided in two groups. Group 1 rats was given PEG30 mg/kg/day (Merck) intraperitoneally, and Group 2 rats % 0.9 NaCl saline 1 mL/kg/day intraperitoneally daily for two weeks.

RESULTS

Transforming growth factor beta (TGF-β), plasma malondialdehyde (MDA), liver MDA, serum tumour necrosis factor alpha (TNF-α), alanine aminotransferase and plasma pentraxin-3 levels and, according to tissue histopathology, hepatocyte necrosis, fibrosis and cellular infiltration were significantly better in MTX+PEG group than in MTX+saline group.

CONCLUSIONS

PEG 3350 is a hope for toxic hepatitis due to other causes, since liver damage occurs through oxidative stress and cell damage, similar to all toxic drugs.

Protective Effects of Grape Seed Proanthocyanidin Extract in Preventing DSS Induced Ulcerative Colitis Based on Pharmacodynamic, Pharmacokinetic and Tissue Distribution

BACKGROUND

Based on pharmacodynamic, pharmacokinetic and tissue distribution studies, we explored the potential effect of grape seed proanthocyanidin extract (GSPE) on dextran sodium sulfate (DSS) -induced ulcerative colitis in mice and its underlying mechanism.

METHODS

A liquid chromatography-mass spectrometry method was developed to measure the content of five components of GSPE in rat plasma and tissue. After oral administration of GSPE, correlative index levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), factor-α (TNF-α), Nitric Oxide (NO), malonaldehyde (MDA), and superoxide dismutase (SOD) were detected in the serum and colon tissues. The protein expression levels of HO-1, Nrf2 and NF-κB in the mouse colonic mucosa were analysed using immunohistochemistry.

RESULTS

Pharmacodynamic tests showed substantially reduced mice body weight, diarrhea, and bloody stool in the model group. The pathological damage to the colonic mucosa of mice in the GSPE groups was remarkably reduced in a dose-dependent manner. The histopathological score of the colon in the model group was significantly higher than that of the control group (P <0.05), suggesting that DSS caused severe damage to the colon. After oral administration of GSPE, the serum and colonic tissue levels of IL-1β, IL-6, TNF-α, NO, and MDA decreased, whereas SOD content increased, Moreover, the protein levels of NF-κB and Keap-1 were significantly decreased, whereas the expression levels of Nrf2 and HO-1 proteins increased (P＜0.01) based on the results of the microwave-immunohistochemical assay. The pharmacokinetic results showed that catechin, epicatechin, and procyanidins B1, B2, and B4 are widely distributed in the tissues and blood of rats and may accumulate in some tissues. Catechin and epicatechin peaked at 0.25 and 1.5 h for the first and second time, respectively. Procyanidin B1, B2, and B4 peaked at 0.5 and 1.5 h for the first and second time, respectively, owing to the effect of the hepato-enteric circulation. The active components of GSPE can reach the colon of the lesion site, and hepatoenteric circulation can increase the residence time of the active components in the body, which further increases the anti-ulcer activity.

CONCLUSION

Our findings suggest that GSPE has a potential protective effect against DSS-induced ulcerative colitis in mice.

Direct effects of low-energy electrons on including sulfur bonds in proteins: a second-order Møller-Plesset perturbation (MP2) theory approach

In an attempt to describe how low-energy electrons (LEEs) damage the polypeptide chain at disulfide bridges, ab initio electronic structure estimates on LEE interactions with cysteine-cysteine (Cys-Cys) disulfide bond model have been performed. Here, the fundamental mechanisms in LEE impression on S-S and C-S bond ruptures in the Cys-Cys model have been discussed. The electronic energy was calculated using the MP2 method with a Hartree-Fock exchange during the SCF and the Møller-Plesset correlation energy correction on the converged HF orbitals with 6-311++G(d,p) atomic orbital basis set. Further, six more sets of diffuse s and p functions with extra basis on the sulfur and relevant carbon atoms were used to describe the added electron to located away as much as possible from the nuclei in anions. The bonds rupture mechanisms involve the primary placement of LEEs to the π* orbital of the model to construct the shape-resonance state following by an adiabatic or nonadiabatic electron migration to either S-S or C-S bond σ* orbital. The formed radical anion undergoes S-S or C-S bonds cleavage by energy barriers of ca. 5.68 and 9.19 kcal/mol, respectively, to produce either (2-amino-2-carboxyethyl) sulfanyl (cysteine radical), aziridine-2-carboxylic acid or mercapto-L-cysteine lesions. In SMD solvent, calculations suggest electronically stable of the formed π* and σ* states by solvation, something that induces either S-S or C-S bond break even when the electron energy is near zero. The required barrier energy of only 0 to < 0.4 eV indicates a high kinetic favorable fragmentation for involved sulfur polypeptides with LEEs.Communicated by Ramaswamy H. Sarma.

In vitro antioxidant assessment, screening of enzyme inhibitory activities of methanol and water extracts and gene expression in Hypericum lydium

Hypericum lydium Boiss. is a perennial plant of the Hypericaceae family, which has been used in particular to treat depression. The aim of this study was to determine in vitro antioxidant, antimicrobial activities, anticholinesterase (acetylcholinesterase (AChE)/butyrylcholinesterase (BChE)), antidiabetic activities (α-glucosidase/α-amylase) and Tyrosinase inhibitor activity of methanol and water extracts of H. lydium. Also, gene expression has been evaluated in the shoot and root by microarray technology. So, in general, the purpose of this study is to study the active molecules such as antioxidant, antimicrobial, antidiabetic, enzymes and genes in the plant, which is the first to be reported. The experiments were conducted in a completely randomized design with three replications. In addition, gene expression was compared in the shoot and root parts. Expression profiling was carried out by microarrays. According to the results, the highest chemical components were determined in methanol extract rather than water extract. There was a difference between the obtained components. While the highest antioxidant activity was determined from the methanol extract of plant herbs for DPPH Free Radical Scavenging Activity, antioxidant activity was the same in both methanol and water extracts using the ABTS method. The methanol extract demonstrated stronger anticholinesterase (AChE and BChE) and α-amylase inhibition activity. This study was complemented by the detection of antioxidant activity and some enzyme inhibition activity in the methanol extract. Microarray showed 10,784 genes had significantly different expression in root and shoot. There was a positive effect of methanol extract in respect of different activities compared to the water extract. Gene expression showed that the number of expressed genes in the root was greater than the shoot.