Overproduction Of Free Radicals Research Articles

GCMS and HPLC profiling, antioxidant and anti-inflammatory activities of Crotalaria medicaginea Lamk

Inflammation is the underlying process to many degenerative diseases such as emphysema, cancer, Alzheimer's, arthritis, diabetes, and more recently COVID-19. The overproduction of free radicals in the cells is the major factor that leads to inflammation due to oxidative stress. These free radicals damage macromolecules in cells, including nucleic acids, proteins, lipids, and polyunsaturated fatty acids, through oxidation, thus affecting cell metabolism. Antioxidants can delay the oxidation of these molecules through inhibition of oxidizing chain reactions and can be helpful in treating inflammatory diseases. Crotalaria medicaginea Lamk (Fabaceae) is an important medicinal plant that is not extensively explored for its biological and pharmacological potential on scientific grounds. In this study, in vitro antioxidant and anti-inflammatory activities of the crude methanolic extract and different solvent fractions of the plant were determined. Phenolics, flavonoids, tannins, and saponins were quantified in each plant sample. The crude extract was characterized for its phytochemical constituents through GC–MS and HPLC analysis. Strong antioxidant and anti-inflammatory activities of plant extracts were recorded which can be attributed to the presence of phenolics, flavonoids, saponins, terpenes, and tannins in these extracts. GC–MS analysis confirmed the presence of Hexadecanoic acid, methyl ester, 9,12-Octadecadienoic acid (Z,Z)-, methyl ester, and 9-Octadecenoic acid, methyl ester, (E)- as major compounds while HPLC analysis confirmed the presence of gallic acid, taxifolin, quercetin and kaempferol in the plant.

Redox mechanisms of environmental toxicants on male reproductive function.

Humans and wildlife, including domesticated animals, are exposed to a myriad of environmental contaminants that are derived from various human activities, including agricultural, household, cosmetic, pharmaceutical, and industrial products. Excessive exposure to pesticides, heavy metals, and phthalates consequently causes the overproduction of reactive oxygen species. The equilibrium between reactive oxygen species and the antioxidant system is preserved to maintain cellular redox homeostasis. Mitochondria play a key role in cellular function and cell survival. Mitochondria are vulnerable to damage that can be provoked by environmental exposures. Once the mitochondrial metabolism is damaged, it interferes with energy metabolism and eventually causes the overproduction of free radicals. Furthermore, it also perceives inflammation signals to generate an inflammatory response, which is involved in pathophysiological mechanisms. A depleted antioxidant system provokes oxidative stress that triggers inflammation and regulates epigenetic function and apoptotic events. Apart from that, these chemicals influence steroidogenesis, deteriorate sperm quality, and damage male reproductive organs. It is strongly believed that redox signaling molecules are the key regulators that mediate reproductive toxicity. This review article aims to spotlight the redox toxicology of environmental chemicals on male reproduction function and its fertility prognosis. Furthermore, we shed light on the influence of redox signaling and metabolism in modulating the response of environmental toxins to reproductive function. Additionally, we emphasize the supporting evidence from diverse cellular and animal studies.

Effect of the Novel Free Radical Scavenger 4′-Hydroxyl-2-Substituted Phenylnitronyl Nitroxide on Oxidative Stress, Mitochondrial Dysfunction and Apoptosis Induced by Cerebral Ischemia–Reperfusion in Rats

Mitochondrial dysfunction, which results in the overproduction of oxygen free radicals, is a crucial mechanism underlying cerebral ischemia–reperfusion injury. 4′-Hydroxyl-2-substituted phenylnitronyl nitroxide (HPN), which is an antioxidant and free radical scavenger, can effectively scavenge oxygen free radicals, suggesting its potential as a protective agent against cerebral ischemia–reperfusion injury. In this study, we investigated the effects of HPN on mitochondrial function and apoptosis following cerebral ischemia/reperfusion injury in rats. Healthy adult SD rats were chosen as the experimental subjects, and the rat ischemia/reperfusion injury model was generated using the modified Zea Longa method. The administration of HPN significantly enhanced the activity of endogenous antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). Additionally, HPN effectively preserved the morphology and function of mitochondria, reduced the protein and gene expression of Caspase-3 and Bax, increased the protein and gene expression of Bcl-2, mitigated neuronal apoptosis, improved neurological deficits, and decreased the volume of cerebral infarction. Of interest, the protective effect on brain tissue was more evident with increasing doses of HPN. These findings indicate that HPN can serve as an effective protective agent against cerebral ischemia–reperfusion injury.

Synthesis and biological evaluation of gallic acid esters as phagocyte oxidative burst inhibitors

Several degenerative diseases, including cancer, are caused by oxidative stress, which is caused by the overproduction and accumulation of free radicals. The purpose of the study was to synthesize gallic acid (GA or 3,4,5-trihydroxybenzoic acid) esters and evaluate their anti-inflammatory potential through the inhibition of reactive oxygen species (ROS). The compounds methyl gallate (2), sec-butyl gallate (3), ethyl gallate (4), isopropyl gallate (5), 2-methoxyethyl gallate (6), 4-methoxybutyl gallate (7), 2-methylbutyl gallate (8) and pentan-3-yl gallate (9) were synthesized. 1H NMR, MS and IR data are reported for compounds 2-9, and 13C NMR data for compounds 2, 3, 5, and 6. The molecular formulae of compounds 3 and 7-9 were established by HREI-MS spectroscopic data. All the synthesized compounds were tested for their anti-inflammatory and cytotoxic activities by chemiluminescence and MTT cytotoxicity assay respectively. The results revealed the anti-inflammatory potential of compounds 2-8 with an IC50 range between (13.3 – 54.3 µM) as compared to the standard anti-inflammatory drug, Ibuprofen (IC50 = 54.3 ± 9.2 μM). The most potent inhibitors were found to be compound 3 (ROS IC50 = 15.0 ± 6.6 µM) and compound 7 (ROS IC50 = 13.3 ± 0.8 µM). All compounds were found to be non-cytotoxic in the NIH-3T3 fibroblast cell line. Compounds 3, 7- 9 were identified as new compounds.

Effects of tetrahydroxy stilbene glycoside derivatives on free radical damage and apoptosis in APP695V717I transgenic mice

ABSTRACTMitochondrial dysfunction leading to overproduction of oxygen free radicals is an important event in the development of Alzheimer's disease. Tetrahydroxy stilbene glycoside (TSG) is one of the main effective components of Polygonum multiflorum and has a certain free radical scavenging effect. We synthesized tetrahydroxy stilbene glycoside derivatives (Mito-TSGs) that can cross the mitochondrial membrane and may provide effective protection against Alzheimer's disease. This experiment investigates the protective mechanism of tetrahydroxy stilbene glycoside derivatives against mitochondrial free radical damage and apoptosis in APP695V717I transgenic model mice. The experimental subjects were healthy 3-month-old APP695V717I transgenic model mice, while C57BL/6J mice of the same age and genetic background served as controls. The results demonstrated that the tetrahydroxy stilbene glycoside derivatives significantly improved mouse behavioral performance. It also led to a decrease in the levels of H2O2, NO, MDA, and LD, along with an increase in LDH activity and in the antioxidant enzyme activity of SOD, CAT, and GSH-Px. Moreover, it elevated the mitochondrial membrane potential, decreased the gene and protein expression of Caspase-3 and Bax, and increased the gene and protein expression of Bcl-2. Notably, the effectiveness of tetrahydroxy stilbene glycoside derivatives was superior to that of traditional tetrahydroxy stilbene glycoside.

Quantum Sensing for Detection of Zinc‐Triggered Free Radicals in Endothelial Cells

AbstractOxidative stress originating from the overproduction of free radicals poses a major threat to cell fate, therefore it is of great importance to address the formation of free radicals in cells subjected to various pathological stimuli. Here we investigate the free radical response of endothelial cells to biodegradable zinc. In addition to the standard free radical assays, relaxometry was used for determining the production of free radicals in cells exposed to non‐physiological concentrations of zinc ions. The cellular morphology, intracellular zinc accumulation, as well as the levels of reactive oxygen/nitrogen species, are determined using standard fluorescent methods. For endothelial cells subjected to 50% zinc extracts, deviations from the normal cell shape and cell agglomeration tendency are observed. The culture medium containing the highest amount of zinc ions caused nuclei fragmentation, blebbing, and cell shrinkage, indicating cell death. A potential explanation for the observed phenomena is an overproduction of free radicals. In the case of 1% and 10% zinc extracts, the formation of free radicals is clearly confirmed by relaxometry, while the results obtained by using fluorescent techniques are unambiguous. It is revealed that high concentrations of zinc ions released from biodegradable samples induce a deleterious effect on endothelial cells.

Unraveling the harmful effect of oxidative stress on male fertility: A mechanistic insight.

Male infertility is a widely debated issue that affects males globally. There are several mechanisms involved. Oxidative stress is accepted to be the main contributing factor, with sperm quality and quantity affected by the overproduction of free radicals. Excess reactive oxygen species (ROS) cannot be controlled by the antioxidant system and, thus, potentially impact male fertility and hamper sperm quality parameters. Mitochondria are the driving force of sperm motility; irregularities in their function may lead to apoptosis, alterations to signaling pathway function, and, ultimately, compromised fertility. Moreover, it has been observed that the prevalence of inflammation may arrest sperm function and the production of cytokines triggered by the overproduction of ROS. Further, oxidative stress interacts with seminal plasma proteomes that influence male fertility. Enhanced ROS production disturbs the cellular constituents, particularly DNA, and sperms are unable to impregnate the ovum. Here, we review the latest information to better understand the relationship between oxidative stress and male infertility, the role of mitochondria, the cellular response, inflammation and fertility, and the interaction of seminal plasma proteomes with oxidative stress, as well as highlight the influence of oxidative stress on hormones; collectively, all of these factors are assumed to be important for the regulation of male infertility. This article may help improve our understanding of male infertility and the strategies to prevent it.

Converging Role for REEP1/SPG31 in Oxidative Stress.

Mutations in the receptor expression-enhancing protein 1 gene (REEP1) are associated with hereditary spastic paraplegia type 31 (SPG31), a neurological disorder characterized by length-dependent degeneration of upper motor neuron axons. Mitochondrial dysfunctions have been observed in patients harboring pathogenic variants in REEP1, suggesting a key role of bioenergetics in disease-related manifestations. Nevertheless, the regulation of mitochondrial function in SPG31 remains unclear. To elucidate the pathophysiology underlying REEP1 deficiency, we analyzed in vitro the impact of two different mutations on mitochondrial metabolism. Together with mitochondrial morphology abnormalities, loss-of-REEP1 expression highlighted a reduced ATP production with increased susceptibility to oxidative stress. Furthermore, to translate these findings from in vitro to preclinical models, we knocked down REEP1 in zebrafish. Zebrafish larvae showed a significant defect in motor axon outgrowth leading to motor impairment, mitochondrial dysfunction, and reactive oxygen species accumulation. Protective antioxidant agents such as resveratrol rescued free radical overproduction and ameliorated the SPG31 phenotype both in vitro and in vivo. Together, our findings offer new opportunities to counteract neurodegeneration in SPG31.

Moderate-Intensity Exercise Maintains Redox Homeostasis for Cardiovascular Health.

It is well known that exercise is beneficial for cardiovascular health. Oxidative stress is the common pathological basis of many cardiovascular diseases. The overproduction of free radicals, both reactive oxygen species and reactive nitrogen species, can lead to redox imbalance and exacerbate oxidative damage to the cardiovascular system. Maintaining redox homeostasis and enhancing anti-oxidative capacity are critical mechanisms by which exercise protects against cardiovascular diseases. Moderate-intensity exercise is an effective means to maintain cardiovascular redox homeostasis. Moderate-intensity exercise reduces the risk of cardiovascular disease by improving mitochondrial function and anti-oxidative capacity. It also attenuates adverse cardiac remodeling and enhances cardiac function. This paper reviews the primary mechanisms of moderate-intensity exercise-mediated redox homeostasis in the cardiovascular system. Exploring the role of exercise-mediated redox homeostasis in the cardiovascular system is of great significance to the prevention and treatment of cardiovascular diseases.

Quantitative Phytochemical Profile and In Vitro Antioxidant Properties of Ethyl Acetate Extracts of Xerophyta spekei (Baker) and Grewia tembensis (Fresen).

Overproduction of free radicals in excess of antioxidants leads to oxidative stress which can cause harm to the body. Conventional antioxidants have drawbacks and are believed to be carcinogenic. The present study seeked to confirm folklore use and validate the antioxidant potentials of Grewia tembensis and Xerophyta spekei which have been widely used in the Mbeere community as medicinal plants. Antioxidant properties were determined through scavenging effects of diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide radicals as well as iron chelating effects. The data obtained was assayed in comparison to the standards (Ascorbic acid and EDTA). Ascorbic acid had a significantly greater DPPH radical scavenging property with an inhibitory concentration (IC50) value of 20.54 ± 2.24 µg/mL in comparison to the plant extracts, which had IC50 values of 33.00 ± 1.47 µg/mL, 69.66 ± 1.01 µg/mL and 86.88 ± 2.64 µg/mL for X. spekei, G. tembensis leaf and G. tembensis stem bark extracts, respectively. EDTA demonstrated a significantly greater iron chelating effect having a significantly lesser IC50 value of 25.05 ± 0.79 µg/mL as opposed to 43.56 ± 0.46 µg/mL, 89.78 ± 0.55 µg/mL, and 120.70 ± 0.71 µg/mL for X. spekei, G. tembensis leaf, and G. tembensis stem bark extracts respectively. Additionally, ascorbic acid also exhibited stronger hydrogen peroxide radical scavenging effect than the studied extracts. Generally, X. spekei extract had higher antioxidant activities as compared to both the leaf and stem bark extracts of G. tembensis. The phytochemical screening demonstrated the presence of secondary metabolites associated with antioxidant properties. The present study therefore, recommends ethno medicinal and therapeutic use of G. tembensis and X. spekei in the treatment and management of oxidative stress related infections.

Kadmiyuma Maruz Bırakılan Farelerin Oksidatif Stres Parametreleri ve Kan Lipid Profili üzerinde Resveratrolun Dokuya Özgü İyileştirici Etkisi

Cadmium can cause oxidative damage in organisms through overproduction of free radicals and suppression of the antioxidant defense system. Resveratrol is known as a nutraceutical with antioxidant properties accepted to have protective effects to the toxicity of heavy metals. In this study, we investigated if resveratrol could overwhelm the toxic effect of sub-acute cadmium exposure. Animals were divided to the following groups: 1) Control, 2) Vehicle control, 3) Cadmium (Cd), 4) Resveratrol (Res), 5) Exposure to both Cd and Res (Cd+Res). Increased lipid peroxidation and total sialic acids were determined in testis and lung tissues of mice exposed to Cd with the decreased in paraoxonase (PON1) level and GSH amount. Interestingly, we also found an increased lipid peroxidation and NO levels in lung tissue of mice exposed to Res and Cd + Res, but not in testis tissue. Moreover, increased triglycerides, total cholesterol, very low-density lipoproteins, and low-density lipoproteins as well as reduced high-density lipoproteins were found in mice exposed to Cd and Cd + Res compared to controls. Our results revealed that cadmium induces oxidative damage in tissues, via increased lipid peroxidation, total sialic acids and decreased antioxidant levels as well as disturbs lipid profile. Moreover, our findings indicate that resveratrol may act as “ameliorative” factor against the cadmium exposure in only testis tissue. Thus, we may suggest that ameliorative effect of resveratrol may vary depending on the exposure dose, exposure duration and exposed tissues of animals to the heavy metals.

Comparative analysis of the antihepatotoxic effects of Ginkgo biloba leaf extract and Legalon using histological and biochemical techniques

Drugs, alcohol, and poor nutrition all contribute to the overproduction of free radicals, which linked to numerous diseases and resulted in a high number of cases of liver injury. Antioxidants have shown to play a significant role in reducing the harm caused by these compounds in recent studies. Treatment of liver disease with plants from the natural world has received considerable attention for quite some time. This study compared Ginkgo biloba leaf extract (GbE) with a commonly used drug in Egypt called Legalon for treating liver disorders, in order to assess GbE's hepato-protective effect against hepatotoxicity induced experimentally by CCl4. Before the first dose of CCl4, animals given GbE (100 ml/kg) and Legalon drug (100 ml/kg) orally, once a day, for a week. After that, CCl4 given orally at a dose of (2.5 ml/kg) in olive oil daily for 8 weeks to induce liver fibrosis, and the administration of GbE and Legalon maintained at the same dose and duration. The protective effect of GbE was determined by observing the result of the experiment, which included a shift in biochemical indictors and the outcomes of histopathological studies. In comparison to the control group, CCl4 significantly (P<0.5) increased the levels of ALT, AST, ALP, MDA, and lipid profile. In contrast, markers of oxidative stress, including TP, ALB, HDL, TAC, GSH, GPx, CAT, and SOD, were significantly lower in the study's experimental group than in the control group. Nevertheless, GbE treatment led to differences across the board when compared to the CCl4-intoxicated and Legalon groups. With the help of the histopathological investigations, all of these findings verified. Conclusion: Liver damage caused experimentally by CCl4 mitigated when the animals pretreated with GbE. Both biochemical and histopathological studies found that GbE acts as a powerful antioxidant, suppressing oxidative stress to reduce hepatotoxicity and slow the development of liver fibrosis.

The Effects of Urolithin B and Auraptene on Quinolinic Acid-induced Toxicity in the SH-SY5Y Neuroblastoma Cell Line

The pathological accumulation of quinolinic acid (QA) is often associated with neuritis and neuronal cell death in several neurodegenerative diseases, through the overproduction of free radicals. Urolithin B and auraptene have been reported to exert potent antioxidant effects - however, little is known about the protective effects of these compounds against QA-induced neurotoxicity. Therefore, this study aimed to explore the in vitro protective effects of urolithin B and auraptene against QA-induced neurotoxicity in the SH-SY5Y neuroblastoma cell line. The MTT assay was used to evaluate cell viability, and flow cytometry was carried out to evaluate effects on the cell cycle and apoptosis. The intracellular levels of reactive oxygen species (ROS) were also determined. Our findings showed that auraptene at non-toxic concentrations had no protective effect on QA-induced toxicity. However, urolithin B at concentrations of 0.6 μM and 2.5 μM enhanced the viability of cells treated with QA. Moreover, while the percentage of apoptotic cells (i.e. in the sub-G1 phase) was shown to significantly increase after QA treatment, pre-treatment with urolithin B reduced the number of these apoptotic cells. Furthermore, urolithin B, as an antioxidant, also significantly reduced QA-induced ROS production. Our findings suggest that urolithin B may possess potent antioxidant and neuroprotective effects against QA-induced neurotoxicity that merit further investigation.

Protocatechuic acid-mediated injectable antioxidant hydrogels facilitate wound healing

Overproduction of free radicals in vivo leads to oxidative stress, which substantially slows the healing of wound. Here, a series of injectable antioxidant hydrogels were designed by protocatechuic acid (PA)-mediated carboxylated chitosan (CCS) composed by conjugating oxidized hyaluronic acid (OHA). These biocompatible OHA/CCS-PA composite hydrogels presented stable chemical structure, physical properties, and effective antibacterial properties against common pathogens exceeding 99%. In addition, OHA/CCS-PA hydrogels demonstrated satisfactory antioxidant capacity to scavenge over 85% of overproduced free radicals, which could reduce the damage of oxidative stress to cellular activity and diminish the expression of reactive oxygen species in vitro by the long-lasting release of phenolic hydroxyl element. More importantly, the results of in vivo animal tests confirmed that OHA/CCS-PA hydrogels could significantly promote wound healing with higher collagen disposition (86.29%) in comparison with commercial Tegaderm™ film and the control hydrogel with physical mixing of PA. These findings indicated that OHA/CCS-PA hydrogel had great potential for wound healing.

The Influence of Circadian Rhythm on the Activity of Oxidative Stress Enzymes.

The circadian system synchronizes daily with the day-night cycle of our environment. Disruption of this rhythm impacts the emergence and development of many diseases caused, for example, by the overproduction of free radicals, leading to oxidative damage of cellular components. The goal of this study was to determine the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione transferase (GST), glutathione reductase (R-GSSG), and the concentration of glutathione (GSH) in the circadian rhythm. The study group comprised 66 healthy volunteers (20-50 years; 33 women; 33 men). The blood was collected at 2, 8 a.m., and 2, 8 p.m. All samples marked the serum melatonin concentration to confirm the correct sleeping rhythm and wakefulness throughout the day. The activity of study enzymes and the concentration of GSH were measured by the spectrophotometric method. Confirmed the existence of circadian regulation of oxidative stress enzymes except for GST activity. The peak of activity of study enzymes and GSH concentration was observed at 2 a.m. The increased activity of enzymes and the increase in GSH concentration observed at night indicate that during sleep, processes allowing to maintain of the redox balance are intensified, thus limiting the formation of oxidative stress.

Protective effect of cerium oxide on testicular function and oxidative stress after torsion/detorsion in adult male rats.

Testicular torsion (T)/detorsion (D) can cause testicular injury due to the rotation of the spermatic cord and its vessels, therefore it represents an urological emergency that is surgically treated. Oxidative damage occurs in the testis and distant organs because of the overproduction of free radicals and overexpression of proinflammatory cytokines by reperfusion after surgery. Cerium oxide (CeO2) nanoparticles, a material also known as nanoceria, have regenerative antioxidant properties on oxidative stress. The present study aimed to investigate the effects of nanoceria on testis tissues in testicular T/D in rats. A total of 24 rats were equally and randomly divided into four groups: Control, CeO2, T/D and CeO2-T/D groups. Left inguinoscrotal incision was performed in the control group. In the CeO2 group, 0.5 mg/kg CeO2 was given intraperitoneally 30 min before inguinoscrotal incision. In the T/D group, unilateral testicular T/D was performed through an inguinoscrotal incision and rotating the left testis 720˚ clockwise, which was then left ischemic for 120 min, followed by 120 min of reperfusion. In the CeO2-T/D group, 0.5 mg/kg CeO2 was given intraperitoneally 30 min before testicular T/D. At the end of the experiment, testis tissues were removed for histopathological and biochemical examinations. The samples were histologically examined, Glutathione-s transferase (GST), catalase (CAT), paraoxonase (PON) activities and malondialdehyde (MDA) levels were measured via biochemical analysis methods, while the expression levels of p53, Bax and Bcl-2 were detected using immunohistochemistry. The present results revealed statistically significant inter-group differences in PON, CAT and GST activities and MDA levels. GST, CAT and PON activities were significantly higher, whereas MDA levels in the CeO2-T/D group were significantly lower compared with those in the T/D group. The T/D group had increased Bax and decreased Bcl-2 expression levels in their seminiferous tubules compared with the control and CeO2 groups. CeO2 treatment led to downregulation of Bax and upregulation of Bcl-2. The expression of p53 was high in the T/D group compared with that in the control and CeO2 groups, and was upregulated in all germinal cells. However, compared with that in the T/D group, p53 expression was significantly decreased in the CeO2-T/D group. The testicular injury score significantly increased in the CeO2-T/D group compared with the control and CeO2 groups. Rats in the CeO2-T/D group demonstrated significantly milder tissue lesions compared with those in T/D group. The present findings indicated that nanoceria may protect testis in rats against the harmful effects of T/D. Further studies are required to evaluate how CeO2 reduces oxidative stress and cell death in testis tissue that underwent T/D-related injury.

Green Synthesis of Titanium Dioxide Nanoparticles Using Ocimum sanctum Leaf Extract: In Vitro Characterization and Its Healing Efficacy in Diabetic Wounds.

Diabetes mellitus is one of the most prevalent metabolic disorders characterized by hyperglycemia due to impaired glucose metabolism. Overproduction of free radicals due to chronic hyperglycemia may cause oxidative stress, which delays wound healing in diabetic conditions. For people with diabetes, this impeded wound healing is one of the predominant reasons for mortality and morbidity. The study aimed to develop an Ocimum sanctum leaf extract-mediated green synthesis of titanium dioxide (TiO2) nanoparticles (NPs) and further incorporate them into 2% chitosan (CS) gel for diabetic wound healing. UV-visible spectrum analysis recorded the sharp peak at 235 and 320 nm, and this was the preliminary sign for the biosynthesis of TiO2 NPs. The FTIR analysis was used to perform a qualitative validation of the biosynthesized TiO2 nanoparticles. XRD analysis indicated the crystallinity of TiO2 NPs in anatase form. Microscopic investigation revealed that TiO2 NPs were spherical and polygonal in shape, with sizes ranging from 75 to 123 nm. The EDX analysis of green synthesized NPs showed the presence of TiO2 NPs, demonstrating the peak of titanium ion and oxygen. The hydrodynamic diameter and polydispersity index (PDI) of the TiO2 NPs were found to be 130.3 nm and 0.237, respectively. The developed TiO2 NPs containing CS gel exhibited the desired thixotropic properties with pseudoplastic behavior. In vivo wound healing studies and histopathological investigations of healed wounds demonstrated the excellent wound-healing efficacy of TiO2 NPs containing CS gel in diabetic rats.

Assessment of antioxidant and cytotoxic potential of silver nanoparticles synthesized from root extract of Reynoutria japonica Houtt

Free radicals, mostly consist of reactive oxygen species, are generated in human body by several exogenous and endogenous systems. Overproduction of free radicals is known to cause several degenerative disorders including cancer. The aim of this study is to synthesize silver nanoparticles (AgNPs) using root extract of Reynoutria japonica and to investigate its antioxidant and cytotoxic potential. AgNPs were synthesized by green approach and subsequently characterized using UV–vis spectroscopy, SEM, TEM, FTIR, XRD, EDS and DLS. The antioxidant activity was investigated using DPPH, FRAP, H2O2, and ABTṠ+ radical scavenging assays while the cytotoxic effect was assessed using different human cancer cell lines including lung (A549), liver (Hep-G2) and breast (MDA-MB-231) by MTS assay. Moreover, the specificity of NPs was assessed against two normal human cell lines e.g. alveolar and renal primary epithelial cells (HPAEpiC and HRPTEpiC). The UV–vis spectra confirmed the synthesis of AgNPs by producing a characteristic peak at 410 nm. Further analysis confirmed that AgNPs were crystalline in nature, predominantly spherical in shape, with an average width and area of 17.34 nm and 164.46 nm2, respectively. DLS analysis revealed that NPs possess a high negative zeta potential value (−28.5 mV), thus facilitating its electrostatic stabilization. AgNPs showed dose dependent antioxidant activity against DPPH, FRAP, H2O2 and ABTS with IC50 values 19.25, 22.45, 24.20 and 18.88 µg/ml, respectively. The AgNPs depicted significant cytotoxic effects against A549, Hep-G2 and MDA-MB-231 cell lines with IC50 values of 4.5, 5.1 and 3.46 µg/ml, respectively. Moreover, the NPs exhibited highest selectivity index (>2.0) for A549, Hep-G2 and MDA-MB-231, confirming its specificity towards cancer cell lines. In conclusion, AgNPs prepared from root extract of R. japonica possess strong antioxidant and cytotoxic potential which suggests that they should be investigated further in order to develop safe and effective antioxidant and/or cytotoxic formulations.

Diabetes Mellitusta Metabolik Hafızanın Rolü

Diabetes Mellitus, morbidite ve mortalitenin artmasına neden olan, önemli bir halk sağlığı problemidir. Diyabete spesifik hiperglisemi, çeşitli ilaçlar veya ekzojen insülin uygulaması yolu ile klinik olarak kontrol edilmeye çalışılmaktadır fakat gerek tedavi gerekse takipteki gelişmelere rağmen diyabetli birçok hastada vasküler komplikasyon gelişme durumunun önüne hâlen tam anlamı ile geçilememiştir. Çeşitli epidemiyolojik ve geniş kapsamlı çalışmalar, erken ve yoğun hiperglisemi kontrolünün diyabet ile ilişkili komplikasyon riskini azalttığını göstermiştir ve ilgili çalışmaların tamamı, erken glisemik kontrolün gerekliliğini vurgulamaktadır. Erken dönemdeki hiperglisemi kontrolü yakın zamanda “metabolik hafıza” olarak tanımlanmıştır. Mitokondri ve endotel hücrelerinde serbest oksijen radikallerinin aşırı üretimi, mitokondriyal deoksiribonükleik asit (DNA) hasarı, protein kinaz C aktivasyonu, poliol ve hekzoamin yolağı aktivasyonu, ileri glikozilasyon son ürünlerinin ve reseptörlerinin artışı gibi birçok mekanizma metabolik hafıza patogenezinde önemli rol oynamaktadır. Bu mekanizmalar, gen ekspresyonunu kalıcı olarak indükleyerek epigenetik değişikliklere neden olmaktadır. Metabolik hafıza; histon modifikasyonu, DNA metilasyonu ve mikro-ribonükleik asit (RNA) ile ilişkili mekanizmalar gibi epigenetik değişiklikler ile gerçekleşir. Klinik açıdan değerlendirildiğinde ise metabolik hafıza teorisi, metabolik kontrolü en kısa sürede sağlamak için erken ve yoğun tedavi rejiminin gerekliliğini vurgulamaktadır. Uzun süreli diyabetik komplikasyonları en aza indirgemek amacıyla erken ve yoğun hiperglisemi kontrolünün yanı sıra, reaktif oksijen türleri ve glikozilasyonu azaltabilen terapötik ajanlardan ve/veya epigenetik tedaviden de yararlanılabilir. Bu derlemede; metabolik hafıza teorisine, metabolik hafızanın tanımı ve patogenezine, epigenetik mekanizmalara ve terapötik yaklaşımlara yer verilmiştir.

GC-MS Analysis, Antibacterial and Antioxidant Potential of Ethyl Acetate Leaf Extract of Senna singueana (Delile) Grown in Kenya.

Bacterial diseases are a leading cause of mortality and morbidity globally. During bacterial diseases, an elevation of host immune response occurs, which involves the production of free radicals in response to the bacterial infection. The overproduction of free radicals in excess of the antioxidants leads to oxidative stress. Conventional antibiotics are linked to side effects such as hypersensitivity reactions in addition to bacterial pathogens developing resistance against them. Artificial antioxidants are said to be carcinogenic. This study sought to confirm folklore use and validate the antibacterial and antioxidant potential of Senna singueana which has been widely used in the Mbeere community. The in vitro antibacterial potentials of the plant extract were investigated on Bacillus subtilis ATCC 21332, Escherichia coli ATCC 25922, Salmonella typhi ATCC 1408, and Staphylococcus aureus ATCC 25923. Ciprofloxacin (100 µg/ml) drug was used as a standard reference, whereas 5% DMSO was used as a negative reference. The antibacterial tests included disc diffusion and minimum inhibitory and bactericidal concentrations. S. singueana ethyl acetate extract showed broad-spectrum potential against tested bacterial microbes producing mean zones of inhibition (MZI) from 07.67 ± 0.33 to 17.67 ± 0.33 mm. The extract demonstrated a greater effect on Gram-positive than Gram-negative bacterial pathogens. Antibacterial properties of ciprofloxacin were significantly greater in comparison to plant extract in all the dilutions (p < 0.05), while 5% DMSO was inactive against all the tested bacteria. MBC values were greater than MIC values. Antioxidant properties of the extract were determined through scavenging effects of DPPH and hydroxyl radicals (•OH) as well as ferric reducing antioxidant potential (FRAP) assay. S. singueana demonstrated effects against all radicals formed. Additionally, the extract exhibited ferric reducing abilities. The extract also contained various phytocompounds with known antibacterial and antioxidant properties. This study recommends the therapeutic use of S. singueana as an antibacterial as well as an antioxidant agent.