Antioxidant Effects of Irisin in Liver Diseases: Mechanistic Insights

Oxidative stress is a crucial factor in the development of various liver diseases. Irisin, a metabolic hormone discovered in 2012, is mainly produced by proteolytic cleavage of fibronectin type III domain containing 5 (FNDC5) in skeletal muscles. Irisin is induced by physical exercise, and a rapidly growing body of literature suggests that irisin is, at least partially, responsible for the beneficial effects of regular exercise. The major biological function of irisin is believed to be involved in the maintenance of metabolic homeostasis. However, recent studies have suggested the therapeutic potential of irisin against a variety of liver diseases involving its antioxidative function. In this review, we aim to summarize the accumulating evidence demonstrating the antioxidative effects of irisin in liver diseases, with an emphasis on the current understanding of the potential molecular mechanisms.

Gastroprotective and Antioxidative Effects of the Traditional Thai Polyherbal Formula Phy-Blica-D against Ethanol-Induced Gastric Ulcers in Rats

Phy-Blica-D is a traditional Thai polyherbal formula that has reduced oxidative stress in non-communicable diseases. However, evidence supporting the gastroprotective effects of Phy-Blica-D has not been previously reported. Therefore, this study aimed to evaluate the gastroprotective effects of Phy-Blica-D against gastric ulcers in rats and investigate the potential underlying mechanism. To estimate the possible mechanisms of action, we examined the levels of oxidative stress markers, such as reactive oxygen species (ROS) and malondialdehyde (MDA), as well as antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH). According to our results, rats treated with only 80% ethanol (vehicle group) exhibited significant increases in their ulcer area and ulcer index (UI). Moreover, the levels of ROS and MDA markedly increased in the vehicle group compared with the normal control group. Daily oral administration of Phy-Blica-D (500 and 1000 mg/kg) for 7 days not only significantly decreased the ulcer area and UI, but also remarkably decreased the ROS and MDA levels in gastric tissue. Gastric ulcers induced by ethanol had significantly decreased antioxidant enzyme activities (CAT and SOD) and non-enzymatic antioxidant (GSH), whereas pretreatment with Phy-Blica-D significantly improved the activities of CAT, SOD, and GSH. Moreover, after exposure to ethanol, the rats exhibited a significantly increased level of inducible nitric oxide synthase (iNOS), which was reduced after treatment with Phy-Blica-D. These findings suggest that Phy-Blica-D potentially exerts its gastroprotective effects by suppressing oxidative stress and stimulating antioxidant enzymes, which is one of the causes of destruction of cell membranes, and it is involved in the pathogenesis of acute gastric ulcers induced by ethanol.

Active sites of peptide from Arg-Ser-Ser protect against oxidative stress in HepG2 cells

Peptide Arg-Ser-Ser (RSS) was derived from Lactobacillus amylolyticus co-incubated with edible <i>Dendrobium aphyllum</i>. Here, we further examined the antioxidative effects of RSS in HepG2 cells subjected to 2,2-azobis(2-methylpropanimidamidine) dihydrochloride-induced oxidative stress. RSS protected cells by eliminating the level of reactive oxygen species (ROS). The protein expression of antioxidant enzymes, Nrf2 and Keap1 determined by western blot, indicated that RSS might maintain cellular homeostasis by directly scavenging free radicals instead of by enzymatic system. Furthermore, quantum chemistry calculations and a characterization of electronic-related properties showed that the highest occupied molecular orbital energy distribution was on arginine residue. Pre-treatment with RSS with the active site methylated resulted in increased ROS levels, thereby verifying that N₂-H₃ is the active site for antioxidant activity. Our findings provide valuable insights into the antioxidant activity of RSS and a basis for developing antioxidant functional foods.

Fermented Oyster Extract Attenuated Dexamethasone-Induced Muscle Atrophy by Decreasing Oxidative Stress

It is well known that oxidative stress induces muscle atrophy, which decreases with the activation of Nrf2/HO-1. Fermented oyster extracts (FO), rich in γ-aminobutyric acid (GABA) and lactate, have shown antioxidative effects. We evaluated whether FO decreased oxidative stress by upregulating Nrf2/HO-1 and whether it decreased NF-κB, leading to decreased IL-6 and TNF-α. Decreased oxidative stress led to the downregulation of Cbl-b ubiquitin ligase, which increased IGF-1 and decreased FoxO3, atrogin1, and Murf1, and eventually decreased muscle atrophy in dexamethasone (Dexa)-induced muscle atrophy animal model. For four weeks, mice were orally administered with FO, GABA, lactate, or GABA+Lactate, and then Dexa was subcutaneously injected for ten days. During Dexa injection period, FO, GABA, lactate, or GABA+Lactate were also administered, and grip strength test and muscle harvesting were performed on the day of the last Dexa injection. We compared the attenuation effect of FO with GABA, lactate, and GABA+lactate treatment. Nrf2 and HO-1 expressions were increased by Dexa but decreased by FO; SOD activity and glutathione levels were decreased by Dexa but increased by FO; NADPH oxidase activity was increased by Dexa but decreased by FO; NF-κB, IL-6, and TNF-α activities were increased by Dexa were decreased by FO; Cbl-b expression was increased by Dexa but restored by FO; IGF-1 expression was decreased by Dexa but increased by FO; FoxO3, Atrogin-1, and MuRF1 expressions were increased by Dexa but decreased by FO. The gastrocnemius thickness and weight were decreased by Dexa but increased by FO. The cross-sectional area of muscle fiber and grip strength were decreased by Dexa but increased by FO. In conclusion, FO decreased Dexa-induced oxidative stress through the upregulation of Nrf2/HO-1. Decreased oxidative stress led to decreased Cbl-b, FoxO3, atrogin1, and MuRF1, which attenuated muscle atrophy.

Allicin protects against renal ischemia–reperfusion injury by attenuating oxidative stress and apoptosis

Background Studies have demonstrated that allicin may play critical roles in the procession of ischemia–reperfusion(I/R) injury. The purpose of this study was to investigate the protective effects of allicin on renal I/R injury by attenuating oxidative stress and apoptosis. Methods To establish a model of renal I/R, the right kidney underwent 12 h reperfusion after 45 min ischemia, allicin was administered intraperitoneally at concentrations of 40, 50 or 60 mg/kg. NRK-52E cells were treated with allicin at concentrations of 1, 3 or 5 μM in 24 h hypoxia/ 6 h reoxygenation(H/R) treatments. Indicators of HE, oxidative stress, apoptosis were measured to evaluate the effect of aliicin on renal I/R injury. Results Allicin protected renal I/R injury by ameliorating histological injury and decreasing the oxidative stress in renal tissues. Meanwhile, allicin significantly downregulated the expression of Bax and caspase-3, upregulated the expression of Bcl-2 in I/R renal tissues and H/R treated NRK-52E cells. Conclusions Allicin may exert anti-apoptotic and antioxidative effects to promote renal function recovery in I/R renal tissues and H/R treated NRK-52E cells. Taken together, allicin may be a potential novel therapy option for future renal injury protection.

Evaluation of the Anti-Shigellosis Activity of Dietary Isothiocyanates in Galleria mellonella Larvae

Cruciferous vegetables, widely present in daily diets, are a rich source of organosulfur compounds with proven health benefits, especially chemopreventive or antioxidative effects. Isothiocyanate derivatives (ITCs) exhibit a broad spectrum of biological and pharmacological activity and recently, their antibacterial properties have been of particular importance. Here, we have focused on the anti-shigellosis activity of sulforaphane (SFN) and phenethyl ITC (PEITC). The genus Shigella causes gastroenteritis in humans, which constitutes a threat to public health. Production of a potent Stx toxin by S. dysenteriae type 1 results not only in more severe symptoms but also in serious sequela, including the hemolytic uremic syndrome. Here, we present evidence that two aliphatic and aromatic ITCs derivatives, SFN and PEITC, have an effective antibacterial potency against S. dysenteriae, also negatively regulating the stx gene expression. The molecular mechanism of this effect involves induction of the global stress-induced stringent response. ITCs also inhibit bacterial virulence against the Vero and HeLa cells. We present evidence for the therapeutic effect of sulforaphane and phenethyl ITC against a S. dysenteriae infection in the Galleria mellonella larvae model. Thus, our results indicate that isothiocyanates can be effectively used to combat dangerous bacterial infections.

Chemical Constituents of the Leaves of Diospyros kaki (Persimmon)

Diospyros kaki (persimmon) leaves have long been utilized as traditional medicine for the treatment of ischemic stroke, angina, and hypertension and as a healthy beverage and cosmetic for anti-aging. This study aimed to isolate as many compounds as possible from an ethanol extract of the persimmon leaves to identify the biologically active compounds. The antioxidative effect of the ethyl acetate layer from the ethanol extract of the persimmon leaves was demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and online high-performance liquid chromatography-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (HPLC-ABTS) analysis. A new flavonoid, kaempferol-3-O-β-d-2″-coumaroylgalactoside (1), and a new natural compound, kaempferol-3-O-β-d-2″-feruloylglucoside (3) were isolated from the ethyl acetate layer, along with 25 previously known compounds, including fourteen flavonoids, one ionone, two coumarins, seven triterpenoids, and one acetophenone. Their structures were determined by the interpretation of spectrometric and spectroscopic data. All isolated compounds were rapidly evaluated using an online HPLC-ABTS assay, and of these, compounds 4–8, 11, 13, 15, and 16 clearly showed antioxidative effects. The amount of these compounds was 0.3–0.65% of the extract.

Anti-Inflammatory and Antioxidative Effects of Sumatriptan Against Doxorubicin-Induced Cardiotoxicity in Rat

The clinical use of doxorubicin as a potent chemotherapeutic agent is limited due to its dose-dependent cardiotoxicity. Oxidative stress and inflammatory pathways have a pivotal role in doxorubicin-induced cardiotoxicity. Sumatriptan, a 5-hydroxytryptamine (5-HT)1B/1D agonist that is mainly used to relieve migraine pain, has suggested exerting protective effects in numerous pathological conditions through antiinflammatory properties. The aim of the present study was to investigate the effects of sumatriptan on doxorubicin-induced cardiotoxicity and the contribution of anti-inflammation and antioxidative responses. Cardiotoxicity was induced by the administration of doxorubicin three times a week (2.5 mg/kg i.p) for two consecutive weeks on male rats. The animals were divided into four groups, including Control, Sumatriptan (0.1 mg/kg) received group, doxorubicin received group, and Doxorubicin+Sumatriptan (0.1 mg/kg) received group. Sumatriptan was administered 30 min before every injection of doxorubicin. On the last day of the second week, the body weight, mortality rate, electrocardiogram (ECG) and histopathological changes, cardiac inotropic study, and biochemical factors were evaluated. The loss of body weight, mortality rate, ECG parameters, reduction of papillary muscle contractility force as well as histopathological scores following administration of doxorubicin indicated severe cardiac damage. However, treatment with sumatriptan inhibited the functional and structural impairment induced by doxorubicin. In addition, sumatriptan could significantly reduce cardiac tissue levels of malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α), which were increased in the doxorubicin-treated rats. This study illustrated the protective effects of sumatriptan on decreasing doxorubicin-induced cardiac toxicity and mortality rate in part through inhibition of inflammatory and oxidative stress pathways.

hucMSC Conditioned Medium Ameliorate Lipopolysaccharide-Induced Acute Lung Injury by Suppressing Oxidative Stress and Inflammation via Nrf2/NF-κB Signaling Pathway

Acute lung injury (ALI) is a common clinical syndrome in the cardiac intensive care unit with a high mortality rate. Inflammation and oxidative stress have been reported to play a crucial role in the development of ALI. Previous studies have shown that human umbilical cord mesenchymal stem cells (hucMSCs) have anti-inflammatory and antioxidative effects in various diseases. However, the anti-inflammatory and antioxidative effects of the hucMSC conditioned medium (CM) on LPS-induced ALI remain unclear. Therefore, in this study, we assessed whether the hucMSC conditioned medium could attenuate LPS-induced ALI and the underlying mechanisms. Mice were randomly divided into four groups: the control group, PBS group, LPS+PBS group, and LPS+CM group. The lung histopathology and bronchoalveolar lavage fluid (BALF) were analyzed after intervention. The Nrf2/NF-κB signaling pathway and its downstream target genes were tested, and the cytokines and growth factors in CM were also measured. The results showed that CM significantly attenuated the histological alterations; decreased the wet/dry weight ratio; reduced the levels of MPO, MDA and ROS; increased SOD and GSH activity; and downregulated the level of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α. Furthermore, CM promoted the expression of Nrf2 and its target genes NQ01, HO-1, and GCLC and inhibited the expression of NF-κB and its target genes IL-6, IL-1β, and TNF-α. These effects may be closely related to the large amounts of cytokines and growth factors in the CM. In conclusion, our results demonstrated that CM could attenuate LPS-induced ALI, probably due to inhibition of inflammation and oxidative stress via the Nrf2/NF-κB signaling pathway.

The Therapeutic Potential of Cannabis in Counteracting Oxidative Stress and Inflammation

Significant growth of interest in cannabis (Cannabis sativa L.), especially its natural anti-inflammatory and antioxidative properties, has been observed recently. This narrative review aimed to present the state of the art of research concerning the anti-inflammatory activity of all classes of cannabinoids published in the last five years. Multimodal properties of cannabinoids include their involvement in immunological processes, anti-inflammatory, and antioxidative effects. Cannabinoids and non-cannabinoid compounds of cannabis proved their anti-inflammatory effects in numerous animal models. The research in humans is missing, and the results are unconvincing. Although preclinical evidence suggests cannabinoids are of value in treating chronic inflammatory diseases, the clinical evidence is scarce, and further well-designed clinical trials are essential to determine the prospects for using cannabinoids in inflammatory conditions.