Mangiferin protects against ‭intestinal ischemia/reperfusion-induced ‭liver injury: ‬‬Involvement of PPAR-‭γ, GSK-3β and Wnt/β-catenin pathway‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

Modulation of the Oxidative Stress and ICAM-1/TLR4/NF-Κβ Levels by Metformin in Intestinal Ischemia/Reperfusion Injury in Rats

Metformin, a biguanide drug, is used for its antihyperglycemic effects. The purpose of the present study was to investigate the effects of metformin on the experimental model of intestinal ischemia-reperfusion (I/R) injury. Ischemia was induced by superior mesenteric artery occlusion followed by reperfusion. Metformin was administered orally by gavage at doses of 50, 100 or 200 mg/kg for one week before the surgery. Rats were divided to five groups (n = 8 for each): Sham control group; I/R control group; Metformin50 treated I/R group; Metformin100 treated I/R group; and Metformin200 treated I/R group. Tissue levels of malondialdehyde (MDA), glutathione (GSH), myeloperoxidase (MPO) activity, intercellular adhesion molecule-1 (ICAM-1), toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as histological analysis were evaluated. Metformin treatment decreased the levels of MDA in 100 and 200 mg/kg doses besides lowering the MPO activity and ICAM-1 levels in all doses. Metformin also reduced NF-κB levels at dose of 200 mg/kg and improved histopathological scores at doses of 100 and 200 mg/kg. The treatment with metformin can prevent I/R-induced intestinal injury through down-regulating ICAM-1 and NF-κB levels, reducing oxidative stress, and lowering neutrophil accumulation. We propose that metformin could be a therapeutic agent in intestinal I/R.

Geraniol modulates inflammatory and antioxidant pathways to mitigate intestinal ischemia-reperfusion injury in male rats

Intestinal ischemia-reperfusion injury (IIR/I) significantly increases morbidity and mortality. This study examines the therapeutic effects of geraniol (GNL), which is noted for its anti-inflammatory and antioxidant properties, on intestinal I/R injury in rats. Forty-nine male Wistar-Albino rats were divided into seven groups. After 30 min of ischemia and subsequent reperfusion for either 1 or 6 h, intestinal and hepatic tissues were analyzed. Biochemical assessments measured malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), and nitric oxide (NO) activities. Inflammatory and apoptotic markers were evaluated using qRT-PCR and ELISA, and apoptotic cell rates were determined by flow cytometry. GNL treatment significantly protected intestinal and hepatic tissues, enhancing antioxidant enzyme activity and normalizing MDA and NO activities. It demonstrated notable anti-inflammatory effects at 100 and 200 mg/kg doses, reducing TNF-α, IL-1β, and IL-6 levels while decreasing tissue MPO content. GNL also increased Bcl-2 levels and decreased Bax levels, indicating anti-apoptotic effects. Serum activities of ALT, AST, and creatine kinase were lower in GNL-treated rats, and flow cytometry showed a reduction in apoptotic cells. GNL effectively mitigated oxidative stress and histopathological damage from intestinal I/R injury by reducing pro-apoptotic markers and increasing anti-apoptotic markers, highlighting its protective effects.

Mangiferin Induces Post-Implant Osteointegration in Male Diabetic Rats

Background and Objectives: Hyperglycemia is known to undermine the osteointegration process of implants. In this study, the effects of mangiferin (MF) on the post-implant osteointegration process in a type-II diabetes model were investigated molecularly and morphologically. Materials and Methods: Sprague Dawley male rats were divided into three groups: control, diabetes, and diabetes + MF. All animals were implanted in their tibia bones on day 0. At the end of the 3-month experimental period, the animals' blood and the implant area were isolated. Biochemical measurements were performed on blood samples and micro-CT, qRT-PCR, histological, and immunohistochemical measurements were performed on tibia samples. Results: MF significantly improved the increased glucose, triglyceride-VLDL levels, and liver enzymes due to diabetes. By administering MF to diabetic rats, the osteointegration percentage and bone volume increased while porosity decreased. DKK1 and BMP-2 mRNA expressions and OPN, OCN, and OSN mRNA-protein expressions increased by MF administration in diabetic rats. Additionally, while osteoblast and osteoid surface areas increased with MF, osteoclast and eroded surface areas decreased. Conclusions: The findings of our study indicate that MF will be beneficial to the bone-repairing process and osteointegration, which are impaired by type-II diabetes.

Curcumin suppresses the Wnt/β-catenin signaling pathway by inhibiting NKD2 methylation to ameliorate intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening condition with no effective treatment currently available. Curcumin (CCM), a polyphenol compound in Curcuma Longa, reportedly has positive effects against intestinal I/R injury. However, the mechanism underlying the protective effect of CCM against intestinal I/R injury has not been fully clarified. To determine whether the protective effect of CCM was mediated by epigenetic effects on Wnt/β-catenin signaling, the effect of CCM was examined in vivo and in vitro. An intestinal I/R model was established in Sprague-Dawley (SD) rats with superior mesenteric artery occlusion, and Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) for in vivo simulation of I/R. The results showed that CCM significantly reduced inflammatory, cell apoptosis, and oxidative stress induced by I/R insult in vivo and in vitro. Western blot analysis showed that CCM preconditioning reduced the protein levels of β-catenin, p-GSK3β, and cyclin-D1 and increased the protein level of GSK3β compared with the I/R group. Overexpressing β-catenin aggravated H/R injury, and knocking down β-catenin relieved H/R injury by improving intestinal permeability and reducing the cell apoptosis. Moreover, Naked cuticle homolog 2(NKD2) mRNA and protein levels were upregulated in the CCM-pretreated group. 5-aza-2'-deoxycytidine (5-AZA) treatment improved intestinal epithelial barrier impairment induced by H/R. Besides, the protein levels of total β-catenin, phosphor-β-catenin and cyclin-D1 were reduced after overexpressing NKD2 in Caco-2 cells following H/R insult. In conclusion, Our study suggests that CCM could attenuate intestinal I/R injury in vitro and in vivo by suppressing the Wnt/β-catenin signaling pathway via inhibition of NKD2 methylation.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

A Mango Leaf Extract (Zynamite®) Combined with Quercetin Has Exercise-Mimetic Properties in Human Skeletal Muscle

Zynamite PX^®, a mango leaf extract combined with quercetin, enhances exercise performance by unknown molecular mechanisms. Twenty-five volunteers were assigned to a control (17 males) or supplementation group (8 males, receiving 140 mg of Zynamite^® + 140 mg quercetin/8 h for 2 days). Then, they performed incremental exercise to exhaustion (IE) followed by occlusion of the circulation in one leg for 60 s. Afterwards, the cuff was released, and a 30 s sprint was performed, followed by 90 s circulatory occlusion (same leg). Vastus lateralis muscle biopsies were obtained at baseline, 20 s after IE (occluded leg) and 10 s after Wingate (occluded leg), and bilaterally at 90 s and 30 min post exercise. Compared to the controls, the Zynamite PX^® group showed increased basal protein expression of Thr²⁸⁷-CaMKIIδ_D (2-fold, p = 0.007) and Ser⁹-GSK3β (1.3-fold, p = 0.005) and a non-significant increase of total NRF2 (1.7-fold, p = 0.099) and Ser⁴⁰-NRF2 (1.2-fold, p = 0.061). In the controls, there was upregulation with exercise and recovery of total NRF2, catalase, glutathione reductase, and Thr²⁸⁷-CaMKIIδ_D (1.2-2.9-fold, all p < 0.05), which was not observed in the Zynamite PX^® group. In conclusion, Zynamite PX^® elicits muscle signaling changes in resting skeletal muscle resembling those described for exercise training and partly abrogates the stress kinases responses to exercise as observed in trained muscles.

Mangiferin for the Management of Liver Diseases: A Review

The liver is a digestive and metabolic organ, and several factors can induce liver damage, which is a severe threat to human health. As a natural polyphenolic compound, mangiferin belongs to xanthone glucoside and mainly exists in many plants, such as mango. It is notorious that mangiferin has remarkable pharmacological activities such as anti-inflammatory, anti-tumor, antioxidative stress, antiviral and so on. Emerging evidence indicates the therapeutic benefits of mangiferin against liver disease, including liver injury, nonalcoholic fatty liver disease, alcoholic liver disease, liver fibrosis, and hepatocellular carcinoma. This review aims to summarize the possible underlying signaling mediated by mangiferin in liver disease treatment and the available findings of mangiferin, which can be used to treat different liver diseases and may contribute to mangiferin as a therapeutic agent for liver disease in humans.

Rebamipide protects against experimentally induced intestinal ischemia/reperfusion-promoted liver damage: Impact on SIRT1/β-catenin/FOXO1and NFκB signaling

Rebamipide (Reba) is a well-known gastroprotective agent. However, its potential protective efficacy against intestinal ischemia/reperfusion (I/R)-induced liver injury remains elusive. Therefore, this study aimed to assess the modulatory effect of Reba on SIRT1/β-catenin/FOXO1-NFκB signaling cascade. Thirty-two male Wistar albino rats were randomized into four groups: G1 (sham): rats were subjected to surgical stress without I/R, GII (I/R): rats were subjected to 60 min/4-h I/R, GIII (Reba + I/R): rats received Reba 100 mg/kg/day, p.o. for three weeks, then were subjected to 60 min/4-h I/R, and GIV (Reba + EX527 + I/R): rats received Reba (100 mg/kg/day p.o.) + EX527 (10 mg/kg/day, ip) for three weeks before I/R. Reba pretreatment decreased the serum levels of ALT and AST, improved I/R-induced histological alterations of both intestine and liver, increased hepatic Silent information regulator 1 (SIRT1) expression/content, β-catenin expression/immunoreactivity, and FOXO1 expression, while suppressed NF-κB p65 expression/protein content. In addition, Reba increased hepatic total antioxidant capacity (TAC), while suppressed malondialdehyde (MDA), tumor necrosis factor (TNFα), and caspase-3 activity. Furthermore, Reba inhibited BAX expression, while upregulated Bcl-2 expression. Reba exhibited a plausible protective effect against intestinal I/R-mediated liver injury by modulating SIRT1/β-catenin/FOXO1-NFκB signaling mechanisms.

The Cardioprotective Effect of Corosolic Acid in the Diabetic Rats: A Possible Mechanism of the PPAR-γ Pathway

The study was conducted to determine whether corosolic acid could protect the myocardium of diabetic rats from damage caused by isoproterenol (ISO) and, if so, how peroxisome proliferator-activated receptor gamma (PPAR-γ) activation might contribute into this protection. Diabetes in the rats was induced by streptozotocin (STZ), and it was divided into four groups: the diabetic control group, diabetic rats treated with corosolic acid, diabetic rats treated with GW9662, and diabetic rats treated with corosolic acid plus GW9662. The study was carried out for 28 days. The diabetic control and ISO control groups showed a decrease in mean arterial pressure (MAP) and diastolic arterial pressure (DAP) and an increase in systolic arterial pressure (SAP). The rat myocardium was activated by corosolic acid treatment, which elevated PPAR-γ expression. A histopathological analysis showed a significant reduction in myocardial damage by reducing myonecrosis and edema. It was found that myocardial levels of CK-MB and LDH levels were significantly increased after treatment with corosolic acid. By decreasing lipid peroxidation and increasing endogenous antioxidant levels, corosolic acid therapy showed a significant improvement over the ISO diabetic group. In conclusion, our results prove that corosolic acid can ameliorate ISO-induced acute myocardial injury in rats. Based on these results, corosolic acid seems to be a viable new target for the treatment of cardiovascular diseases and other diseases of a similar nature.

Possible Implication of Nrf2, PPAR-γ and MAPKs Signaling in the Protective Role of Mangiferin against Renal Ischemia/Reperfusion in Rats

Mangiferin (Mang) is a known glucosylxanthone that has proven its shielding effect against ischemia/reperfusion (Is/R). However, its full underlying mechanistic perspective against renal Is/R induced lesions is not fully revealed. Consequently, the purpose of this study is to track further non-investigated modulatory signals of Mang against the renal Is/R model involving nuclear factor erythroid 2-related factor (Nrf)2/heme oxygenase (HO)-1, peroxisome proliferator-activated receptor (PPAR)-γ/nuclear factor (NF)-κB, p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) signaling. To ratify our aim, Mang was administrated (20 mg/kg, i.p for seven days) before the induction of bilateral Is/R. Mechanistic maneuver revealed that Mang balanced oxidative state via increasing the expression of the antioxidant Nrf2/HO-1 cue with subsequent enhancement of GSH besides MDA lessening. Additionally, Mang enhanced PPAR-γ mRNA expression and declined p-p38 MAPK and p-JNK expression with concomitant NF-κB downsizing leading to iNOS/NOx and TNF-α rebating. Furthermore, the Mang anti-apoptotic trait was affirmed by enriching Bcl-2 expression as well as decreasing Bax and caspase-3 expression. All these potentials were in the line with the molecular docking results and the improved histopathological findings and renal function biomarkers. Consequently, Mang provided plausible protective mechanisms against renal Is/R-related events, possibly by amending oxidative status, inflammatory mediators, and apoptotic cell death through the involvement of Nrf2, PPAR-γ, MAPK, JNK, and NF-κB signaling.

A promising drug combination of mangiferin and glycyrrhizic acid ameliorates disease severity of rheumatoid arthritis by reversing the disturbance of thermogenesis and energy metabolism

BACKGROUND

Activation of immune system in rheumatoid arthritis (RA) consumes amount of energy, and the energy metabolic signals may be a potential target for RA therapy. Baihu-Guizhi decoction (BHGZD) achieves satisfactory therapeutic effects in RA in clinics by recovering the adjacent articular cartilage and bone destruction, and abnormal articular temperature. However, its pharmacological material basis and molecular mechanisms have not been fully elucidated.

PURPOSE

This study focused on exploring the potential acting mechanism of BHGZD against RA, and identifying its main bioactive compounds (BACs) of the combination of mangiferin and glycyrrhizic acid.

METHODS

Key putative targets of BHGZD acting on adjuvant-induced arthritis (AIA)-M rats were screened by the transcriptomic profiling of the whole blood cells and synovium tissues collected from rats in normal control, AIA-M model and AIA-M-BHGZD treatment groups. Then, BACs of BHGZD against RA were identified using Ultra Performance Liquid Chromatography-Mass spectrum/Mass spectrum, molecular docking, surface plasmon resonance and pharmacokinetic analysis. In vivo experiments based on AIA-M rats and in vitro experiments based on 3T3-L1 preadipocytes were performed to verify the pharmacological effects of BACs against RA and the corresponding mechanisms.

RESULTS

PKA-ADCY5-PPARγ-PGC 1α-UCP1-PRDM16 signal axis was demonstrated to be the candidate targets of BHGZD against RA and was involved in maintaining the balance of thermogenesis and energy metabolism, according to the transcriptional regulatory network analysis based on "herbs-putative targets-disease interaction network". Then, mangiferin from Rhizoma Anemarrhenae and glycyrrhizic acid from Radix Glycytthizae were identified as the main BACs of BHGZD against RA due to their highly accumulation in the blood in vivo, strong binding affinities with the two candidate targets of BHGZD against RA-ADCY5 and PPARγ, as well as the in vivo and in vitro strong regulation effects on energy metabolism disturbance.

CONCLUSIONS

These findings offer evidence that the combination of mangiferin and glycyrrhizic acid from BHGZD may be a promising candidate drug for RA therapy, and also provide an important reference for the development and modernization of traditional Chinese formulae.

Mechanism Involved in Acute Liver Injury Induced by Intestinal Ischemia-Reperfusion

Intestinal ischemia-reperfusion (I/R) is a common pathophysiological process, which can occur in many conditions such as acute enteric ischemia, severe burns, small intestinal transplantation, etc,. Ischemia-reperfusion of the intestine is often accompanied by distal organ injury, especially liver injury. This paper outlined the signal pathways and cytokines involved in acute liver injury induced by intestinal I/R: the NF-κB Signaling Pathway, the P66shc Signaling Pathway, the HMGB1 Signaling Pathway, the Nrf2-ARE Signaling Pathway, the AMPK-SIRT-1 Signaling Pathway and other cytokines, providing new ideas for the prevention and treatment of liver injury caused by reperfusion after intestinal I/R.

Peripheral arterial disease: Effects of ethanolic extracts of seed kernels of mango (Mangifera indica .L) on acute hind limb ischemia-reperfusion injury in diabetic rats

Background and aim

Hind limb ischemia is one of the peripheral arterial diseases affecting majority of the people with atherosclerosis, diabetes and chronic cigarette smokers. Hind limb ischemic-reperfusion injury is also one of the exacerbating events in these peoples, resulting in hind limb dysfunction. The aim of this study was to identify the effects of ethanolic extracts of mangifera indica (EEMI) on reversing hind limb dysfunction in diabetic rats with acute hind limb ischemia-reperfusion injury.

Experimental procedure

Unilateral femoral artery ligated diabetic rats were orally fed with EEMI (0.2 and 0.4 g/kg) for 14 days. At the end of the study, plasma levels of pro-inflammatory cytokines and relevant biochemical parameters were measured. The isolated gastrocnemius muscles were used for gene expression and histopathological studies.

Results

There was a significant reduction (p < 0.05) in the plasma levels of pro-inflammatory cytokines, nitric oxide, malondialdehyde; and the expression levels of mRNA of induced nitric oxide synthase and intercellular adhesion molecule -1; and increase in anti-inflammatory cytokine, in isolated gastrocnemius muscles of animals treated with 0.2 and 0.4 g/kg of EEMI in comparison to disease control. In addition, histopathological study of gastrocnemius muscle and hind limb function test indicated the recovery of tissue damage from ischemic reperfusion at 0.2 and 0.4 g/kg of EEMI in comparison to disease control.

Conclusion

We conclude that 14-day EEMI treatment of rats with acute hind limb ischemia/reperfusion in diabetic rats recovered from ischemic/reperfusion injury by modulating (decreasing) oxidative stress and inflammation.

Anwulignan Ameliorates the Intestinal Ischemia/Reperfusion

Anwulignan is one of the monomer compounds in the lignans from Schisandra sphenanthera In this study, we observed the effect of anwulignan on intestinal ischemia/reperfusion (II/R) injury in male Sprague-Dawley rats and explored the underlying mechanisms. The results showed that pretreatment with oral anwulignan could significantly increase the mesenteric blood microcirculatory flow velocity; relieve the congestion and pathologic injury of jejunum; enhance the autonomic tension of jejunum smooth muscle and its reactivity to acetylcholine; increase the activities of superoxide dismutase, catalase, glutathione S-transferase, and choline acetyltransferase; increase the contents of acetylcholine and glutathione in the serum or jejunal tissue; decrease the activities of myeloperoxidase, protein kinase C, and nicotinamide adenine dinucleotide phosphate oxidase; reduce the contents of malondialdehyde, 8-hydroxy-2-deoxyguanosine, nicotinamide adenine, reactive oxygen species, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β; increase the expression levels of muscarinic receptor 3, PI3K, phosphorylation protein kinase B, p-GSK3β Ser9, Nrf2, p-Nrf2, heme oxygenase (decycling) 1, and b-cell lymphoma 2 in the jejunal tissue; and decrease the expression levels of p-GSK3β Tyr216, kelch-like ECH-associated protein 1, Bax, and cleaved caspase-3, suggesting that anwulignan can ameliorate II/R-induced jejunal tissue injury in rats and that the mechanism may be related to its activating the PI3K/protein kinase B pathway and then regulating the Nrf2/Anti-oxidative Response Element signaling pathway and the expression of apoptosis-related proteins to play antioxidant and antiapoptotic roles. SIGNIFICANCE STATEMENT: Anwulignan can significantly reduce jejunal tissue injury and the production of inflammatory factors in rats with intestinal ischemia-reperfusion injury, improve the antioxidant capacity, and reduce the apoptosis of jejunal tissue, and it has the effect of significantly improving intestinal ischemia-reperfusion injury in rats, suggesting that anwulignan may be used as a potential drug for the prevention and treatment of intestinal ischemia-reperfusion injury or a resource for the development of health food.

Mangiferin mitigates di-(2-ethylhexyl) phthalate-induced testicular injury in rats by modulating oxidative stress-mediated signals, inflammatory cascades, apoptotic pathways, and steroidogenesis

Di-(2-ethylhexyl) phthalate (DEHP) is an endocrine disruptor that causes reproductive defects in male animal models. This study was conducted to explore the plausible modulatory effects of mangiferin (MF) against DEHP-induced testicular injury in rats. Thirty-two adult male albino rats were allocated into four groups. Two groups were given DEHP (2 g/kg/day, p.o) for 14 days. One of these groups was treated with MF (20 mg/kg/day, i.p) for 7 days before and 14 days after DEHP administration. A vehicle-treated control was included, and another group of rats was given MF only. Results revealed that MF treatment suppressed oxidative testicular injury by amplifying the mRNA expression of nuclear factor-erythroid 2 related factor-2 (Nrf2) and increasing hemoxygenase-1 (HO-1), glutathione, and total antioxidant capacity (TAC) levels. This treatment also enhanced superoxide dismutase activity, but it decreased malondialdehyde and nitric oxide levels. MF had an anti-inflammatory characteristic, as demonstrated by the downregulation of the mRNA of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The content of tumor necrosis factor-alpha also decreased. MF modulated the apoptotic pathway by suppressing the mRNA of cytochrome c (Cyt c), Fas ligand content, Bax IHC expression, caspase-3 activity and cleaved caspase-3 IHC expression. It also upregulated the expression levels of heat-shock protein 70 (HSP70) and B-cell lymphoma 2. Moreover, MF upregulated the mRNA expression levels of HSP70 and c-kit and enriched the content of steroidogenic acute regulatory (StAR) protein, which were reflected in serum testosterone levels. This result indicated that MF played crucial roles in steroidogenesis and spermatogenesis. Besides, the activities of testicular marker enzymes, namely, acid and alkaline phosphatases, and lactate dehydrogenase, significantly increased. Histopathological observations provided evidence supporting the biochemical and molecular measurements. In conclusion, MF provided protective mechanisms against the DEHP-mediated deterioration of testicular functions partially through its antioxidant, anti-inflammatory, and anti-apoptotic properties. It also involved the restoration of steroidogenesis and spermatogenesis through the modulation of Nrf2/HO-1, NF-κB/Cyt c/HSP70, and c-Kit signaling cascades.

PPARγ in Ischemia-Reperfusion Injury: Overview of the Biology and Therapy

Ischemia-reperfusion injury (IRI) is a complex pathophysiological process that is often characterized as a blood circulation disorder caused due to various factors (such as traumatic shock, surgery, organ transplantation, burn, and thrombus). Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. Theoretically, IRI can occur in various tissues and organs, including the kidney, liver, myocardium, and brain, among others. The advances made in research regarding restoring tissue perfusion in ischemic areas have been inadequate with regard to decreasing the mortality and infarct size associated with IRI. Hence, the clinical treatment of patients with severe IRI remains a thorny issue. Peroxisome proliferator-activated receptor γ (PPARγ) is a member of a superfamily of nuclear transcription factors activated by agonists and is a promising therapeutic target for ameliorating IRI. Therefore, this review focuses on the role of PPARγ in IRI. The protective effects of PPARγ, such as attenuating oxidative stress, inhibiting inflammatory responses, and antagonizing apoptosis, are described, envisaging certain therapeutic perspectives.

Intestinal ischemic reperfusion injury: Recommended rats model and comprehensive review for protective strategies

Intestinal ischemic reperfusion injury (IIRI) is a life-threatening condition with high morbidity and mortality in the clinic. IIRI was induced by intestinal ischemic diseases such as, small bowel transplantation, aortic aneurysm surgery, and strangulated hernias. Although related mechanisms have not been fully elucidated, during the last decade, researches have demonstrated that many factors are crucial in the pathological process, including oxidative stress (OS), epithelial barrier function disorder, and so on. Rats model, as the most applied animal IIRI model, provides specific targets for researches and therapeutic strategies. Moreover, various treatment strategies such as, anti-oxidative stress, anti-apoptosis, and anti-inflammation, have shown promising effects in alleviating IIRI. However, current researches cannot solve the clinical problems of IIRI, and specific treatment strategies are still needed to be exploited. This review focuses on a recommended experimental IIRI rat model and understanding of the involved mechanisms such as, OS, gut bacteria translocation, apoptosis, and necroptosis, aim at providing novel ideas for therapeutic strategies of IIRI.

Mangiferin alleviates endoplasmic reticulum stress in acute liver injury by regulating the miR-20a/miR-101a-Nrf2 axis

This study aimed to investigate the mechanism of mangiferin on regulating endoplasmic reticulum (ER) stress in acute liver injury. The mouse model of acute liver injury was established by injection of LPS/D-GalN. The primary mouse hepatocytes were stimulated with LPS to induce the in vitro model. The effect of miR-20a/101a on the luciferase activity of Nrf2 3'-UTR was assessed by luciferase reporter assay. Mangiferin improved the liver function, inhibited the oxidative stress and ER stress and down-regulated the expressions of miR-20a and miR-101a in LPS/D-GalN-induced mice and LPS-induced hepatocytes. The knockdown of miR-20a and miR-101a co-operatively alleviated ER stress of LPS-induced hepatocytes. miR-20a and miR-101a both targeted Nrf2 and the over-expression of miR-20a or miR-101a decreased Nrf2 protein level, while their silences increased Nrf2 protein level. The silence of miR-20a and miR-101a promoted Nrf2 expression and inhibited the ER stress in LPS-induced hepatocytes, while the knockdown of Nrf2 reversed these effects. The over-expression of miR-20a and miR-101a eliminated the effects of mangiferin on Nrf2 protein level and ER stress in LPS-induced hepatocytes and Nrf2 over-expression altered these trends. Our findings suggest that mangiferin alleviates ER stress in acute liver injury by regulating the miR-20a/miR-101a-Nrf2 axis.

The effects of amantadine on lung tissue in lower limb ischemia/reperfusion injury model in rats

Background

This study aims to evaluate the effect of amantadine on lung tissue of after lower limb ischemia/reperfusion injury in rats.

Methods

A total of 24 Wistar rats were divided into four equal groups including six rats in each: sham group (Group S), amantadine group (Group A), ischemia/reperfusion group (Group I/R), and ischemia/reperfusion + amantadine group (Group I/R-A). All groups underwent a midline abdominal incision. In Groups I/R and I/R-A, the infrarenal abdominal aorta was clamped for 120 min and, then, reperfused for 120 min after removal of the clamp. Amantadine hydrochloride 45 mg/kg was administered intraperitoneally to the rats of Groups A and Group I/R-A 15 min before surgery. At the end of reperfusion period (240 min), all rats were sacrificed, and their lung tissues were obtained. Lung tissue catalase and superoxide dismutase activities and glutathione S-transferase and malondialdehyde levels were analyzed. Lung tissues were examined histopathologically.

Results

Catalase activity was lower in Groups A, I/R, and I/R-A compared to Group S. Superoxide dismutase activity was higher in Group I/R than Group S. Superoxide dismutase activity in Groups I/R-A and A decreased, compared to Groups S and I/R. Glutathione S-transferase levels decreased in Groups I/R and A, compared to Group S. Glutathione S-transferase levels in Group I/R-A were higher than Groups I/R and A. The highest level of malondialdehyde was found in Group I/R and the lowest level was found in Group I/R-A. According to histopathological examination, infiltration scores were significantly lower in Group S than Groups I/R and I/R-A (p=0.009 and p=0.011, respectively). The alveolar wall thickening scores in Group I/R were also significantly higher than Groups S and Group A (p=0.001 and p=0.001, respectively).

Conclusion

Lung tissue can be affected histopathologically by ischemia/ reperfusion injury and this injury can be reversed by amantadine administration.

Cilostazol mitigates mesenteric ischemia/reperfusion-induced lung lesion: Contribution of PPAR-γ, NF-κB, and STAT3 crosstalk

AIMS

Cilostazol (Cilo), a phosphodiesterase-III inhibitor, has signified its efficacy against different ischemia/reperfusion (IS/RE) models. Nevertheless, it has not fully illuminated its potential effect against intestinal IS/RE-induced lung injury. Consequently, the study was fashioned to evaluate the feasible mechanism of action of Cilo against intestinal IS/RE-induced lung injury.

MAIN METHODS

Wistar rats were treated with Cilo (0.1 g/kg, p.o.) or with a vehicle for 14 days prior to IS/RE, induced by clamping of the superior mesenteric artery for 30 min with subsequent clamp removal for 2 h.

KEY FINDINGS

The mechanistic study disclosed that Cilo protected the two studied organs, viz., lung, and intestine partially by intensifying the expression/content of PPAR-γ accompanied by reducing the expression/content of NF-қB-p65 and STAT3. In addition to normalizing MDA, iNOS, and NOx, the Cilo antioxidant power was confirmed by intensifying tissues content of the total antioxidant capacity. With regard to the anti-inflammatory effect, Cilo reduced the effects of TNF-α, IL-6, and ICAM-1, which were reflected in MPO activity. Furthermore, Cilo had an anti-apoptotic attribute demonstrated by enhancing Bcl-2 content and lessening caspase-3 level.

SIGNIFICANCE

Cilo provided conceivable protective mechanisms to modulate events concomitant with mesenteric IS/RE partly by modulating oxidative stress, inflammation, and apoptosis feasibly via the participation of PPAR-γ, STAT3, and NF-κB p65 signaling pathways.

A pervasive scientific overview on mangiferin in the prevention and treatment of various diseases with preclinical and clinical updates

Natural products are increasing used in preventing and treating various diseases. Mangiferin belongs to the xanthone family, and has potential antiangiogenic, anticancer, immunomodulatory and anti-inflammatory activity along with the antioxidant activity. It is also used in the treatment of cardiac problem, diabetes and neurodegenerative disease. Finding of various researchers proves that mangiferin has a broad spectrum therapeutic application. Motive of this review is to describe the various studies performed on mangiferin for its different pharmacological activities. It also discusses various challenges associated with mangiferin such as stability and bioavailability. Strategies and approaches to improve bioavailability of mangiferin have also been discussed. Both research and review articles were used to write the manuscript. They were collected from various search engines like Pub Med, Science Direct and Google Scholar, using keywords like mangiferin, polyphenol, bioavailability enhancement, solubility enhancement, and antioxidant. Mangiferin being a potent antioxidant is effective in the treatment of various diseases. With novel drug delivery approaches we can overcome poor solubility and bioavailability problem which eventually can result to better utilisation of mangiferin in treating a variety of diseases and make mangiferin a revolutionary drug.

Mangiferin Attenuates LPS/D-GalN-Induced Acute Liver Injury by Promoting HO-1 in Kupffer Cells

Acute liver injury and its terminal phase, hepatic failure, trigger a series of complications, including hepatic encephalopathy, systematic inflammatory response syndrome, and multiorgan failure, with relatively high morbidity and mortality. Liver transplantation is the ultimate intervention, but the shortage of donor organs has limited clinical success. Mangiferin (MF), a xanthone glucoside, has been reported to have excellent anti-inflammatory efficacy. Here, a lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury mouse model was established to investigate the protective role of MF and the underlying mechanisms of action. Pretreatment with MF improved survival, decreased serum aminotransferase activities, and inhibited hepatic TNF-α production in LPS/D-GalN-challenged mice. Through Kupffer cell (KC) deletion by GdCl₃ and KC adoptive transfer, KCs were confirmed to be involved in these beneficial effects of MF. MF reduced LPS-mediated TNF-α production via the suppression of the TLR4/NF-κB signaling pathway in vitro. MF promoted HO-1 expression, but the knockdown of HO-1 prevented TNF-α inhibition, suggesting that the damage-resistance effects of HO-1 occurred via the suppression of TNF-α synthesis. When HO-1-silenced KCs were transferred to the liver with KC deletion, the protective effect of MF against LPS/D-GalN-induced acute liver injury was reduced, illustrating the role of KC-derived HO-1 in the anti-injury effects of MF. Collectively, MF attenuated acute liver injury induced by LPS/D-GalN via the inhibition of TNF-α production by promoting KCs to upregulate HO-1 expression.

Mangiferin ameliorates placental oxidative stress and activates PI3K/Akt/mTOR pathway in mouse model of preeclampsia

Preeclampsia is an inflammatory disease which can induce oxidative stress in placenta. Oxidative stress in preeclampsia is regulated by the phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. Mangiferin, an anti-oxidative molecule, is reported to ameliorate oxidative stress in the kidney and brain through activating the PI3K/Akt/mTOR pathway. We aimed to investigate the effects of mangiferin in a mouse model of preeclampsia, which was induced by phosphatidylserine/dioleoyl-phosphatidycholine (PS/PC) from day 5 to 17 of pregnancy. The female pregnant mice were divided into five groups according to drug treatment. Animals received mangiferin orally at doses of 10, 20, 40 mg/kg/day from day 0.5 to 17. In preeclampsia mouse model, elevated systolic blood pressure and proteinuria were ameliorated by mangiferin treatment. Mangiferin attenuated fms-like tyrosine kinase-1 and placental growth factor expression and oxidative stress in both blood and placenta of preeclampsia mice. The suppressed PI3K/Akt/mTOR pathway in placenta was activated by mangiferin treatment. This study demonstrates that mangiferin ameliorates placental oxidative stress and activates PI3K/Akt/mTOR pathway in a mouse model of preeclampsia.

Bergenin Exerts Hepatoprotective Effects by Inhibiting the Release of Inflammatory Factors, Apoptosis and Autophagy via the PPAR-γ Pathway

Objective

Hepatic ischemia reperfusion (IR) limits the development of liver transplantation technology. The aim of this study was to explore the protective effects of Bergenin on hepatic IR, particularly the elimination of reactive oxygen species (ROS) and activation of the peroxisome proliferators activated receptor γ (PPAR-γ) pathway.

Methods

Initial experiments were performed to confirm the non-toxicity of Bergenin. Mice were randomly divided into sham, IR, and IR + Bergenin (10, 20 and 40 mg/kg) groups, and serum and tissue samples were obtained at 2, 8 and 24 h for detection of liver enzymes (ALT and AST), inflammatory factors (TNF-α, IL-6 and IL-1β), ROS, cell death markers (Bcl-2, Bax, Beclin-1 and LC3) and related important pathways (PPAR-γ, P38 MAPK, NF-κB p65 and JAK2/STAT1).

Results

Bergenin reduced the release of ROS, down-regulated inflammatory factors, and inhibited apoptosis and autophagy. Additionally, expression of PPAR-γ-related genes was increased and phosphorylation of P38 MAPK, NF-κB p65 and JAK2/STAT1-related proteins was decreased in Bergenin pre-treatment groups in a dose-dependent manner.

Conclusion

Bergenin exerts hepatic protection by eliminating ROS, affecting the release of inflammatory factors, and influencing apoptosis- and autophagy-related genes via the PPAR-γ pathway in this model of hepatic IR injury.

Cytoprotective Effects of Mangiferin and Z-Ligustilide in PAH-Exposed Human Airway Epithelium in Vitro

According to World Health Organisation (WHO) air pollution increases the risk of cardiovascular disorders, respiratory diseases, including COPD, lung cancer and acute respiratory infections, neuro-degenerative and other diseases. It is also known that various phytochemicals may mitigate such risks. This study tested if phytochemicals mangiferin (MNG) and Z-ligustilide (Z-LG) may protect PAH-exposed human lung bronchial epithelial cells (BEAS-2B). Organic PAH extract was obtained from the urban fine PM with high benzo(a)pyrene content collected in Eastern European mid-sized city during winter heating season. Cell proliferation traits and levels of intracellular oxidative stress were examined. Effect of MNG (0.5 µg/mL) alone or in combination with PAH on bronchial epithelium wound healing was evaluated. Both phytochemicals were also evaluated for their antioxidant properties in acellular system. Treatment with MNG produced strong cytoprotective effect on PAH-exposed cells (p < 0.01) while Z-LG (0.5 µg/mL) exhibited strong negative effect on cell proliferation in untreated and PAH-exposed cells (p < 0.001). MNG, being many times stronger antioxidant than Z-LG in chemical in vitro assays (p < 0.0001), was also able to decrease PAH-induced oxidative stress in the cell cultures (p < 0.05). Consequently MNG ameliorates oxidative stress, speeds up wound healing process and restores proliferation rate in PAH-exposed bronchial epithelium. Such protective effects of MNG in air pollution affected airway epithelium stimulate further research on this promising phytochemical.

Extract of Aquilaria crassna leaves and mangiferin are vasodilators while showing no cytotoxicity

The leaves of Aquilaria spp. promote “physiological balance”, and are “cardiotonic and provide blood nourishment”. In Asia, these leaves are increasingly consumed as tea and claimed to provide benefits to cardiovascular function, albeit without any scientific proof. Therefore, this study sought to evaluate the action of Aquilaria crassna leaf aqueous extract (AE) on vascular function and vascular smooth muscle cytotoxicity. AE and a main constituent, mangiferin were investigated for their vasorelaxation of rat mesenteric arteries and aortae in vitro. Acute cytotoxicity of AE (0.1–1000 μg/ml) and mangiferin (0.1–100 μM) on rat enzymatically isolated vascular smooth muscle cells was assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. AE dilated rat mesenteric arteries (EC₅₀∼107 μg/ml, E_max∼95%) more than aorta (EC₅₀∼265 μg/ml, E_max∼76%, p < 0.05).

AE-induced vasodilation in mesenteric artery was reduced by endothelial removal (EC₅₀∼202 μg/ml, p < 0.05), incubation with endothelial nitric oxide synthase (eNOS) (100 μM, L-NAME) (EC₅₀∼309 μg/ml, p < 0.05), and partly reduced by L-type Ca²⁺ channel blockade at higher concentrations. Likewise, mangiferin (1–100 μM) dilated the mesenteric artery more potently than the aorta. However, its maximum relaxation was less than with AE (41% in the mesenteric artery and <10% in the aorta). Isolated vascular smooth muscle cells incubated in AE or mangiferin for 1 h showed no cytotoxicity. Thus, AE is a vasorelaxant while being free of acute cytotoxicity towards vascular smooth muscle, thus potentially ameliorating human vascular dysfunction.

In Vitro Bioaccessibility and Effect of Mangifera indica (Ataulfo) Leaf Extract on Induced Dyslipidemia

Cardiovascular diseases (CVDs) are the leading causes of death in the world, and epidemiological evidence points to dietary habits, stress, and obesity as major risk factors promoting pathological conditions like atherosclerosis, hypertension, and thrombosis. Current therapeutic approaches for CVDs rely on lifestyle changes and/or the use of drug agents. However, since the efficacy of such interventions is often limited by poor compliance and/or significant side effects, continued research on new preventive and therapeutic approaches is much needed. Our study is aimed to determine the bioaccessibility, total content of phenolic compounds, and antioxidant capacity (DPPH·, ABTS^·+) of a methanolic extract from Mangifera indica L. leaves (MEM), and its lipid-lowering effect on an induced dyslipidemia model in Wistar rats. Our results showed that mangiferin is the main component of MEM. The extract showed a total content of polyphenol compounds of 575.28 gallic acid equivalents per dry matter basis (GAE/g db), antioxidant activity 77.68 μmol Trolox equivalents per gram (TE/g) db as measured by DPPH· and 20,630 μmol TE/g db by ABTS^·+, and 12% of phenolic compounds were bioaccessible, and 100 mg/kg of MEM reduced hyperlipidemia levels induced in Wistar rats. Further study on the potential use of MEM as a nutraceutical to prevent CVDs in high-fat diet consumers is required.

Protective effects of hydrogen rich water on the intestinal ischemia/reperfusion injury due to intestinal intussusception in a rat model

This study aimed to investigate the protective effects of hydrogen rich water on the intestinal ischemia/reperfusion (I/R) injury in a rat intestinal intussusception (II) model. Ninety Sprague-Dawley rats were randomly assigned into three groups (n = 30 per group). In sham group, rats received laparotomy, and the intestine was exposed for 15 minutes without II. In I/R + saline group and I/R + hydrogen group, rats received II after laparotomy and then intestine was relocated 8 hours later, followed by immediately intraperitoneal injection of normal saline and hydrogen rich water (HRW) (5 mL/kg), respectively. One hour later, the intestine was collected for hematoxylin-eosin staining and immunohistochemistry for apoptotic cells and 8-oxo-deoxyguanosine, and blood was harvested for detection of tumor necrosis factor-α, malondialdehyde and superoxide dismutase. Hematoxylin-eosin staining showed the intestinal mucosa was significantly damaged in I/R + saline group, which was markedly attenuated after HRW treatment. The serum tumor necrosis factor-α content increased significantly in I/R + saline group, but HRW treatment reduced serum tumor necrosis factor-α content as compared to I/R + saline group (P < 0.05). Serum malondialdehyde content and 8-oxo-deoxyguanosine positive cells in the intestine increased dramatically after II, but HRW significantly reduced them in I/R+hydrogen group (P < 0.05). In addition, superoxide dismutase activity reduced markedly and apoptotic cells increased in I/R + saline group as compared to sham group, but they HRW increased superoxide dismutase activity and reduced apoptotic cells significantly in I/R + hydrogen group (P < 0.05). Our results indicate hydrogen rich water is able to attenuate II induced intestinal I/R injury via inhibiting intestinal inflammation, attenuating intestinal/serum oxidative stress and reducing apoptotic intestinal cells.