Free Radical Scavengers

The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin-Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test. All these assays are based on chemical reactions and assessing the kinetics or reaching the equilibrium state relies on spectrophotometry, presupposing the occurrence of characteristic colours or the discolouration of the solutions to be analysed, which are processes monitored by specific wavelength adsorption. These assays were successfully applied in antioxidant analysis or the determination of the antioxidant capacity of complex samples. As a complementary method in such studies, one may use methods based on electrochemical (bio)sensors, requiring stages of calibration and validation. The use of chemical methods together with electrochemical methods may result in clarification of the operating mechanisms and kinetics of the processes involving several antioxidants.

The use of F. religiosa might be beneficial in inflammatory illnesses and can be used for a variety of health conditions. In this article, we studied the identification of antioxidants using (DPPH) 2,2-Diphenyl-1-picrylhydrazylradical scavenging activity in Ficus religiosa, as F. religiosa is an important herbal plant, and every part of it has various medicinal properties such as antibacterial properties that can be used by the researchers in the development and design of various new drugs. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) is a popular, quick, easy, and affordable approach for the measurement of antioxidant properties that includes the use of the free radicals used for assessing the potential of substances to serve as hydrogen providers or free-radical scavengers (FRS). The technique of DPPH testing is associated with the elimination of DPPH, which would be a stabilized free radical. The free-radical DPPH interacts with an odd electron to yield a strong absorbance at 517 nm, i.e., a purple hue. An FRS antioxidant, for example, reacts to DPPH to form DPPHH, which has a lower absorbance than DPPH because of the lower amount of hydrogen. It is radical in comparison to the DPPH-H form, because it causes decolorization, or a yellow hue, as the number of electrons absorbed increases. Decolorization affects the lowering capacity significantly. As soon as the DPPH solutions are combined with the hydrogen atom source, the lower state of diphenylpicrylhydrazine is formed, shedding its violet color. To explain the processes behind the DPPH tests, as well as their applicability to Ficus religiosa (F. religiosa) in the manufacture of metal oxide nanoparticles, in particular MgO, and their influence on antioxidants, a specimen from the test was chosen for further study. According to our findings, F. religiosa has antioxidant qualities and may be useful in the treatment of disorders caused by free radicals.

Oxidative stress is important in the pathophysiology of obesity, altering regulatory factors of mitochondrial activity, modifying the concentration of inflammation mediators associated with a large number and size of adipocytes, promoting lipogenesis, stimulating differentiation of preadipocytes to mature adipocytes, and regulating the energy balance in hypothalamic neurons that control appetite. This review discusses the participation of oxidative stress in obesity and the important groups of compounds found in plants with antioxidant properties, which include (a) polyphenols such as phenolic acids, stilbenes, flavonoids (flavonols, flavanols, anthocyanins, flavanones, flavones, flavanonols, and isoflavones), and curcuminoids (b) carotenoids, (c) capsaicinoids and casinoids, (d) isothiocyanates, (e) catechins, and (f) vitamins. Examples are analyzed, such as resveratrol, quercetin, curcumin, ferulic acid, phloretin, green tea, Hibiscus Sabdariffa, and garlic. The antioxidant activities of these compounds depend on their activities as reactive oxygen species (ROS) scavengers and on their capacity to prevent the activation of NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells), and reduce the expression of target genes, including those participating in inflammation. We conclude that natural compounds have therapeutic potential for diseases mediated by oxidative stress, particularly obesity. Controlled and well-designed clinical trials are still necessary to better know the effects of these compounds.

ObjectiveTo evaluate the safety and efficacy of Edaravone Dexborneol in the treatment of acute ischemic stroke (AIS).MethodsRandomized clinical trials (RCTs) and Prospective cohort study on Edaravone Dexborneol for AIS were retrieved from PubMed, Embase, Cochrane Library, Web of Science, and CNKI. The quality of included studies was assessed using the Cochrane risk of bias tool. Meta-analysis was performed using RevMan 5.2. Efficacy evaluation is based on the changes in the National Institutes of Health Stroke Scale (NIHSS) and mRS scores from baseline to 10-14 days after treatment, as well as the proportion of patients achieving a modified Rankin Scale (mRS) score of 0-1 at 90 days. Safety evaluation is based on the incidence of adverse events during treatment or within 3 months.ResultsThe meta-analysis included 54 studies. For efficacy evaluation: 1. Compared with the control group, the edaravone dexborneol (ED) treatment group showed a reduction in NIHSS score of 2.27, which was statistically significant (I 2 = 93%, MD = -2.27, 95% CI:-2.61 to-1.94, p I 2 = 91%, MD = -1.92, 95% CI:-2.30 to-1.54, p I 2 = 94%, MD = -2.76, 95% CI: -3.72 to -1.79, p I 2 = 80%, MD = -3.50, 95% CI: -4.76 to -2.24, p = 0.04). Patients with higher baseline NIHSS scores may have more pronounced functional improvement after ED treatment. 2. At 2 weeks after treatment, the ED group showed a reduction in mRS score of 0.93 compared with the control group, with statistical significance (I 2 = 98%, MD = -0.93, 95% CI:-1.23 to-0.63, p I 2 = 57%, RR = 1.10, 95% CI: 1.02 to 1.18, p = 0.01). The results indicate a statistically significant functional improvement at 90 days after ED treatment for acute cerebral infarction. Therefore, ED may achieve both short-term and long-term neurological improvement in acute ischemic stroke. For safety evaluation, there was no statistically significant difference in the incidence of adverse events between the ED group and the control group (RR = 0.99, 95% CI: 0.95 to 1.03, p = 0.60).ConclusionThis meta-analysis provides evidence supporting the efficacy and safety of Edaravone Dexborneol for both short- and long-term treatment of acute ischemic stroke. It significantly reduced NIHSS and mRS scores at 10-14 days post-treatment and increased the proportion of patients achieving an mRS score of 0-1 at 90 days. Patients with higher baseline NIHSS scores may derive greater prognostic benefit from edaravone dexborneol therapy. Future multicenter, large-sample clinical studies are still needed to further validate the efficacy and safety of Edaravone Dexborneol.