Honokiol protects rats against eccentric exercise-induced skeletal muscle damage by inhibiting NF-kappaB induced oxidative stress and inflammation

Chitosan/siRNA nanoparticles targeting PARP-1 attenuate Neuroinflammation and apoptosis in hyperglycemia-induced oxidative stress in Neuro2a cells

Hyperglycemia induces an excessive production of superoxide by the mitochondria's electron-transport chain triggers several pathways of injury contributing to the development of diabetic complications. This increase in oxidative and nitrosative stress triggers the activation of PARP-1, a nuclear enzyme, through mechanisms such as DNA damage. siRNA-chitosan nanoparticles were formed based on electrostatic interaction, their particle size, zeta potential, STEM, and cellular uptake were characterized. Neuro2a cells were treated with low glucose (LG) and high glucose (HG) for 24 and 48 h. Neuro2a cells were pre-treated with negative siRNA, naked siRNA, siRNA-Lipofectamine™300, and ChNPs-5. qRT-PCR was used to analyze the expression of regulatory, inflammatory, and apoptotic biomarkers. The siRNA-chitosan complex at the weight ratio 1:3000 were approximately uniform spheres with particle size 150.5 nm and a positive zeta potential of about +41.5 mV. The uptake of FITC-labeled nanoparticles into Neuro2a cells was visualized using fluorescence microscopy with no significant cytotoxicity compared to the control cells. High glucose stimulation of Neuro2a cells increased PARP1 expression, and with siRNA-ChNP (1:3000) treatment, significant inhibition of PARP1 expression is observed that consequently reversed the expression of regulatory genes like SIRT1, FOXO1, FOXO3, and p53. PARP-1 inhibition reduced HG-induced inflammatory response, including NF-kB, IL6, IL1β, TNFα, iNOS, and TGF-β expression, and HG-induced apoptosis response, such as Cas-3, Cas-9, BAK, BAX, and AIF expression. This study highlights the crucial role of siRNA delivery via ChNPs and PARP-1 inhibition in hyperglycemia-induced oxidative stress in Neuro2a cells and PARP-1 inhibition may be a feasible strategy for the treatment of hyperglycemia-induced oxidative stress.

NAD+ homeostasis and its role in exercise adaptation: A comprehensive review

Nicotinamide adenine dinucleotide (NAD+) is a crucial coenzyme involved in catalyzing cellular redox reactions and serving as a substrate for NAD+-dependent enzymes. It plays a vital role in maintaining tissue homeostasis and promoting healthy aging. Exercise, a well-established and cost-effective method for enhancing health, can influence various pathways related to NAD+ metabolism. Strategies such as supplementing NAD+ precursors, modulating NAD+ synthesis enzymes, or inhibiting enzymes that consume NAD+ can help restore NAD+ balance and improve exercise performance. Various overlapping signaling pathways are known to play a crucial role in the beneficial effects of both NAD+ and exercise on enhancing health and slowing aging process. Studies indicate that a combined strategy of exercise and NAD+ supplementation could synergistically enhance athletic capacity. This review provides an overview of current research on the interactions between exercise and the NAD+ network, underscoring the significance of NAD+ homeostasis in exercise performance. It also offers insights into enhancing exercise capacity and improving aging-related diseases through the optimal use of exercise interventions and NAD+ supplementation methods.

Beneficial effect of honokiol and magnolol on polyol pathway and oxidative stress parameters in the testes of diabetic rats

In diabetes hyperglycemia, excessive production of free radicals and present oxidative stress lead to many complications in the body, including male reproductive system disorders. To prevent the development of diabetic complications in the testes resulting from them, it seems beneficial to include compounds considered as natural antioxidants. Honokiol and magnolol are neolignans obtained from magnolia bark, which possess proven antioxidant properties. The aim of this study was to evaluate the effect of honokiol and magnolol on the parameters of oxidative stress, polyol pathway and glycation products in the testes as well as on selected biochemical parameters in the blood serum of rats with type 2 diabetes. The study was conducted on mature male Wistar rats with high fat diet and streptozotocin-induced type 2 diabetes. Neolignans-treated rats received honokiol or magnolol orally at the doses of 5 or 25 mg/kg, respectively, for 4 weeks. Parameters related to glucose and lipid homeostasis, basic serological parameters and sex hormones level in the serum as well as polyol pathway parameters, antioxidant enzyme activity, endogenous antioxidants level, sumaric parameters for oxidative stress and oxidative damage in the testes were estimated. Oral administration of honokiol and magnolol turned out to be beneficial in combating the effects of oxidative stess in the testes, but showed no favorable effects on serum biochemical parameters. Additionally, magnolol compared to honokiol revealed more advantageous impact indicating the reversal of the effects of diabetic complications in the male reproductive system and counteracted oxidative stress damages and polyol pathway disorders in the testes.

The potential role of upregulated PARP-1/RIPK1 expressions in amikacin-induced oxidative damage and nephrotoxicity in Wistar rats

This study aimed to investigate the gene expression levels associated with nephrotoxic action of amikacin, as well as the post-treatment effect of diuretics on its nephrotoxic effects. Sixty male rats were divided equally into six groups, including the control group receiving saline intra-peritoneally (ip), and the five treated groups including therapeutic and double therapeutic dose groups, injected ip (15 and 30 mg/kg b.wt./day) respectively for seven days, and another two rat groups treated as therapeutic and double therapeutic dose groups then administered the diuretic orally for seven days and the last group received amikacin ip at a rate of 15 mg/kg/day for seven days, then given free access to water without diuretics for another seven days and was kept as a self-recovery group. Amikacin caused kidney injury, which was exacerbated by the double therapeutic dose, as evidenced by abnormal serum renal injury biomarkers, elevated renal MDA levels, inhibition of renal catalase and SOD enzyme activities, with renal degenerative and necrotic changes. Moreover, comet assays also revealed renal DNA damage. Interestingly, amikacin administration markedly elevated expression levels of the PARP-1, RIP1, TNF-α, IL-1β, and iNOS genes as compared to the control group. However, compared to the self-recovery group, post-amikacin diuretic treatment modulates amikacin-induced altered findings and alleviates amikacin nephrotoxic effects more efficiently. Our findings suggested the potential role of PARP-1 and RIPK1 expressions that influence the expression of proinflammatory cytokines such as IL-1β and TNF-α by exaggerating oxidative stress which may contribute to the pathogenesis of amikacin-induced nephrotoxicity.

Sirtuin3 confers protection against acute pulmonary embolism through anti-inflammation, and anti-oxidative stress, and anti-apoptosis properties: participation of the AMP-activated protein kinase/mammalian target of rapamycin pathway

An increasing number of studies have suggested that oxidative stress and inflammation play momentous roles in acute pulmonary embolism (APE). Honokiol, a bioactive biphenolic phytochemical substance, is known for its strong anti-oxidative and anti-inflammatory effects, and it served as an activator of sirtuin3 (SIRT3) in the present study. The purposes of the study were to explore the effects of honokiol on APE rats and investigate whether the function of honokiol is mediated by SIRT3 activation. In the study, the rats received a right femoral vein injection of dextran gel G-50 particles (12 mg/kg) to establish the APE model and were subsequently administered honokiol and/or a selective SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine (3-TYP; 5 mg/kg) intraperitoneally. The results showed that SIRT3 activation by honokiol attenuated the loss in lung function, ameliorated the inflammatory response and oxidative damage, and inhibited apoptosis in lung tissues of the rats with APE but that this was reversed by 3-TYP. In addition, we found that the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway might be activated by honokiol but restrained by 3-TYP. These results indicated that honokiol was capable of suppressing the adverse effects of APE and that this was diminished by SIRT3 suppression, implying that activation of SIRT3 might serve as a therapeutic method for APE.

Synthesis, Quality Control and Preliminary Activity Evaluation of a New Compound HM475

Based on the principle of molecular splicing and theory of traditional Chinese medicine pairs, a new multi-active compound (HM475) was synthesized by connecting metformin with honokiol, and its structure was characterized, which not only reduced the toxicity of raw materials, but also maintained the original activity, and had a certain significance in research and innovation. At the same time, quality control and preliminary activity evaluation were carried out, and the effect of HM475 on neuroinflammation was further explored, which provided a new idea for drug development of neurodegenerative diseases.

Inhibition of poly (ADP-ribose) Polymerase-1 (PARP-1) improves endothelial function in pulmonary hypertension

Endothelial dysfunction is critical in the pulmonary vasculature during pulmonary hypertension (PH). Moreover, in PH, increased inflammation and oxidative/nitrosative stress cause DNA damage, activating poly (ADP-ribose) polymerase-1 (PARP-1). Meloche et al. (2014) and our previous research have shown that inhibiting PARP-1 is protective in PH and associated RV hypertrophy. However, the role of PARP-1 in pulmonary arterial endothelial dysfunction has not been explored completely. Therefore, the current study aims to investigate the involvement of PARP-1 in endothelial dysfunction associated with PH. Hypoxia (1% O2) was used to induce a PH-like phenotype in human pulmonary artery endothelial cells (HPAECs), and PARP-1 inhibition was achieved via siRNA (60 nM). For the in vivo study, male Sprague Dawley rats were administered monocrotaline (MCT; 60 mg/kg, SC, once) to induce PH, and 1, 5-isoquinolinediol (ISO; 3 mg/kg) was administered daily intraperitoneally to inhibit PARP-1. PARP-1 inhibition decreased proliferation and inflammation, as well as improved mitochondrial dysfunction in hypoxic HPAECs. Furthermore, PARP-1 inhibition also promoted apoptosis by increasing DNA damage in hypoxic HPAECs. In addition, inhibition of PARP-1 reduced cell migration, VEGF expression, and tubule formation in hypoxic HPAECs. In in vivo studies, PARP-1 inhibition by ISO significantly decreased the RVP and RVH as well as improved endothelial function by increasing the pulmonary vascular reactivity and expression of p-eNOS in MCT-treated rats.

Shenhuang Plaster Application Improves Gastrointestinal Motility in Mice with Postoperative Ileus through Intestinal Microbiota

Postoperative ileus (POI) is a common surgical complication, and its incidence remains high. Shenhuang Plaster (SHP) is a famous traditional Chinese medicine with a definite curative effect on postoperative intestinal dysfunction; however, the mechanisms involved in these effects are unclear. Accordingly, in this study, we constructed a POI mouse model and used the intestinal flora as the target to explore the regulatory effect of SHP on gastrointestinal motility. The results illustrated that SHP applied at the Shenque acupoint promoted the recovery of gastrointestinal motility, relieved intestinal villus atrophy and basal damage caused by POI, protected the integrity of intestinal tissue morphology, and alleviated the inflammatory response in the intestinal tissue of POI model mice. In addition, we clarified the role of the intestinal flora in the occurrence and development of POI, further evaluated the changes in the intestinal flora in each group of mice, and analysed the regulatory effect of SHP on the intestinal flora in mice with POI. The results suggested that SHP might improve gastrointestinal motility disorder in POI mice by effectively regulating intestinal flora.

Mechanisms of eccentric contraction-induced muscle damage and nutritional supplementations for mitigating it

Eccentric contraction (ECC) often results in large and long-lasting force deficits accompanied by muscle soreness, primarily due to muscle damage. In this sense, exercises that involve ECC are less desirable. Paradoxically, exercise training that includes a substantial eccentric phase leads to a more powerful activation of the genes responsible for skeletal muscle remodeling (e.g., hypertrophy) than other types of training that emphasize a concentric or isometric phase. Therefore, effective strategies that lessen ECC-induced muscle damage will be of interest and importance to many individuals. The purpose of this brief review is to highlight the published literature on the effects of ECC and/or nutritional supplementations on proteins, lipids, metabolic and ionic changes, and enzyme activities in skeletal muscles subjected to an acute bout of ECC. First, we discuss the potential mechanisms by which ECC causes muscle damage. Previous findings implicate a Ca²⁺ overload-oxidative modification pathway as one possible mechanism contributing to muscle damage. Thereafter, the efficacy of two nutritional supplementations, i.e., L-arginine and antioxidant, is discussed because L-arginine and antioxidant would be expected to ameliorate the adverse effects of Ca²⁺ overload and oxidative modification, respectively. Of these, L-arginine ingestion before ECC seems likely to be the effective strategy for mitigating ECC-related proteolysis. More studies are needed to establish the effectiveness of antioxidant ingestion. The application of effective strategies against muscle damage may contribute to improvements in health and fitness, muscle function, and sports performance.

Immediate Effect of Dry Needling on the Viscoelastic Properties of a Trigger Point on the Infraspinatus Muscle Measured with MyotonPRO

Purpose: This article investigates the immediate effects of a dry needling (DN) puncture on the viscoelastic properties (tone, stiffness, elasticity) of a trigger point (TP) in the infraspinatus muscle in non-traumatic chronic shoulder pain. Method: Forty-eight individuals with non-traumatic chronic shoulder pain were recruited. The presence of a TP in the infraspinatus muscle was confirmed by a standardized palpatory exam. The viscoelastic properties were measured with a MyotonPRO device at baseline (T1), immediately after DN (T2), and 30 minutes later (T3). A DN puncture was applied to the TP to obtain a local twitch response while performing the technique. Results: Analyses of variance showed significant decreases in tone ( p < 0.001) and stiffness ( p = 0.003) across time after the DN technique. Post hoc tests revealed a significant reduction in tone and stiffness from T1 to T2 ( p ≤ 0.004) and no significant changes from T2 to T3 ( p ≥ 0.10). At T3, only stiffness remained significantly lower compared to T1 ( p = 0.013). Conclusions: This study brings new insights on the immediate mechanical effect of DN on tone and stiffness of TPs. Whether these effects are associated with symptom improvement and long-term effects still needs to be verified.

Honokiol Inhibits Atrial Metabolic Remodeling in Atrial Fibrillation Through Sirt3 Pathway

Background and Purpose: Atrial metabolic remodeling plays a critical role in the pathogenesis of atrial fibrillation (AF). Sirtuin3 (Sirt3) plays an important role in energy homeostasis. However, the effect of Sirt3 agonist Honokiol (HL) on AF is unclear. Therefore, the aim of this study is to determine the effect of HL on atrial metabolic remodeling in AF and to explore possible mechanisms.

Experimental Approach: irt3 and glycogen deposition in left atria of AF patients were examined. Twenty-one rabbits were divided into sham, P (pacing for 3 weeks), P + H treatment (honokiol injected with pacing for 3 weeks). The HL-1 cells were subjected to rapid pacing at 5 Hz for 24 h, in the presence or absence of HL and overexpression or siRNA of Sirt3 by transfection. Metabolic factors, circulating metabolites, atrial electrophysiology, ATP level, and glycogens deposition were detected. Acetylated protein and activity of its enzymes were detected.

Key Results: Sirt3 was significantly down-regulated in AF patients and rabbit/HL-1cell model, resulting in the abnormal expression of its downstream metabolic key factors, which were significantly restored by HL. Meanwhile, AF induced an increase of the acetylation level in long-chain acyl-CoA dehydrogenase (LCAD), AceCS2 and GDH, following decreasing of activity of it enzymes, resulting in abnormal alterations of metabolites and reducing of ATP, which was inhibited by HL. The Sirt3 could regulate acetylated modification of key metabolic enzymes, and the increase of Sirt3 rescued AF induced atrial metabolic remodeling.

Conclusion and Implications: HL inhibited atrial metabolic remodeling in AF via the Sirt3 pathway. The present study may provide a novel therapeutical strategy for AF.

PARkinson's: From cellular mechanisms to potential therapeutics

Our understanding of the progression and mechanisms underlying the onset of Parkinson's disease (PD) has grown enormously in the past few decades. There is growing evidence suggesting that poly (ADP-ribose) polymerase 1 (PARP-1) hyperactivation is involved in various neurodegenerative disorders, including PD, and that poly (ADP-ribose) (PAR)-dependent cell death is responsible for neuronal loss. In this review, we discuss the contribution of PARP-1 and PAR in the pathological process of PD. We describe the potential pathways regulated by the enzyme, review clinically relevant PARP-1 inhibitors as potential disease-modifying therapeutics for PD, and outline important factors that need to be considered for repurposing PARP-1 inhibitors for use in PD.

Role for Plant-Derived Antioxidants in Attenuating Cancer Cachexia

Cancer cachexia is the progressive muscle wasting and weakness experienced by many cancer patients. It can compromise the response to gold standard cancer therapies, impair functional capacity and reduce overall quality of life. Cancer cachexia accounts for nearly one-third of all cancer-related deaths and has no effective treatment. The pathogenesis of cancer cachexia and its progression is multifactorial and includes increased oxidative stress derived from both the tumor and the host immune response. Antioxidants have therapeutic potential to attenuate cancer-related muscle loss, with polyphenols, a group of plant-derived antioxidants, being the most widely investigated. This review describes the potential of these plant-derived antioxidants for treating cancer cachexia.

Honokiol: A review of its pharmacological potential and therapeutic insights

BACKGROUND

Honokiol is a pleiotropic compound which been isolated from Magnolia species such as Magnolia grandiflora and Magnolia dealbata. Magnolia species Magnolia grandiflora is used in traditional medicine for the treatment of various diseases.

PURPOSE

The objective of this review is to summarize the pharmacological potential and therapeutic insights of honokiol.

STUDY DESIGN

Honokiol has been specified as a novel alternative to treat various disorders such as liver cancer, neuroprotective, anti-spasmodic, antidepressant, anti-tumorigenic, antithrombotic, antimicrobial, analgesic properties and others. Therefore, this study designed to represent the in-depth therapeutic potential of honokiol.

METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, PubMed, Google Scholar, and Scopus, were performed using the keywords 'Honokiol', 'Health Benefits' and 'Therapeutic Insights' as the keywords for primary searches and secondary search terms were used as follows: 'Anticancer', 'Oxidative Stress', 'Neuroprotective', 'Antimicrobial', 'Cardioprotection', 'Hepatoprotective', 'Anti-inflammatory', 'Arthritis', 'Reproductive Disorders'.

RESULTS

This promising bioactive compound presented an wide range of therapeutic and biological activities which include liver cancer, neuroprotective, anti-spasmodic, antidepressant, anti-tumorigenic, antithrombotic, antimicrobial, analgesic properties, and others. Its pharmacokinetics has been established in experimental animals, while in humans, this is still speculative. Some of its mechanism for exhibiting its pharmacological effects includes apoptosis of diseased cells, reduction in the expression of defective proteins like P-glycoproteins, inhibition of oxidative stress, suppression of pro-inflammatory cytokines (TNF-α, IL-10 and IL-6), amelioration of impaired hepatic enzymes and reversal of morphological alterations, among others.

CONCLUSION

All these actions displayed by this novel compound could make it serve as a lead in the formulation of drugs with higher efficacy and negligible side effects utilized in the treatment of several human diseases.

Honokiol: A naturally occurring lignan with pleiotropic bioactivities

Honokiol is the dominant biphenolic compound isolated from the Magnolia tree, and has long been considered as the active constituent of the traditional Chinese herb, 'Houpo', which is widely used to treat symptoms due to 'stagnation of qi'. Pharmacological studies have shown that honokiol possesses a wide range of bioactivities without obvious toxicity. Honokiol protects the liver, kidneys, nervous system, and cardiovascular system through reducing oxidative stress and relieving inflammation. Moreover, honokiol shows anti-diabetic property through enhancing insulin sensitivity, and anti-obese property through promoting browning of adipocytes. In vivo and in vitro studies indicated that honokiol functions as an anti-cancer agent through multiple mechanisms: inhibiting angiogenesis, promoting cell apoptosis, and regulating cell cycle. A variety of therapeutic effects of honokiol may be associated with its physiochemical properties, which make honokiol readily cross the blood brain barrier and the blood-cerebrospinal fluid barrier, with high bioavailability. In the future, more clinical researches on honokiol are needed to fully authenticate its therapeutic values.

Orange peel extract reduces the inflammatory state of skeletal muscle after downhill running via an increase in IL-1RA

It has been reported that orange peel extract (OPE) and the 4 major polymethoxyflavones (PMFs) in OPE have a protective effect against downhill running (DR)-induced skeletal muscle inflammation. However, the mechanism is not well understood. We investigated the potential of OPE and PMF compounds for increasing anti-inflammatory cytokine levels. The plasma interleukin-1 receptor antagonist (IL-1RA) level was increased 1 and 8 h after OPE administration in rats. Nobiletin induced the secretion of IL-1RA from C2C12 myotubes. In the inflammatory state of skeletal muscle after DR, OPE administration reduced nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) expression, NF-κB-DNA binding, and monocyte chemotactic protein-1 mRNA levels, but these effects were all abrogated by the intravenous administration of IL-1RA neutralizing antibody. These results indicated that OPE reduces skeletal muscle inflammatory state after DR via an increase in IL-1RA, and that IL-1 receptor signaling is important for skeletal muscle inflammation after DR.

Magnoliae Cortex Alleviates Muscle Wasting by Modulating M2 Macrophages in a Cisplatin-Induced Sarcopenia Mouse Model

Cachexia causes high mortality, low quality of life, and rapid weight loss in cancer patients. Sarcopenia, a condition characterized by the loss of muscle, is generally present in cachexia and is associated with inflammation. M2 macrophages, also known as an anti-inflammatory or alternatively activated macrophages, have been shown to play a role in muscle repair. Magnoliae Cortex (M.C) is a widely used medicinal herb in East Asia reported to have a broad range of anti-inflammatory activities; however, the effects of M.C on sarcopenia and on M2 macrophage polarization have to date not been studied. This study was designed to investigate whether the oral administration of M.C could decrease cisplatin-induced sarcopenia by modulating M2 macrophage polarization in mice. C57BL/6 mice were injected intraperitoneally with cisplatin (2.5 mg/kg) to mimic chemotherapy-induced sarcopenia. M.C extract (50, 100, and 200 mg/kg) was administered orally every 3 days (for a total of 12 times). M.C (100 and 200 mg/kg) significantly alleviated the cisplatin-induced loss of body mass, skeletal muscle weight, and grip strength. In addition, M.C increased the expression of M2 macrophage markers, such as MRC1, CD163, TGF-β, and Arg-1, and decreased the expression of M1-specific markers, including NOS2 and TNF-α, in skeletal muscle. Furthermore, the levels of like growth factor-1(IGF-1), as well as the number of M2a and M2c macrophages, significantly increased in skeletal muscle after M.C administration. M.C did not interfere with the anticancer effect of cisplatin in colon cancer. Our results demonstrated that M.C can alleviate cisplatin-induced sarcopenia by increasing the number of M2 macrophages. Therefore, our findings suggest that M.C could be used as an effective therapeutic agent to reverse or prevent cisplatin-induced sarcopenia.

Polymethoxyflavones in orange peel extract prevent skeletal muscle damage induced by eccentric exercise in rats

Polymethoxyflavones (PMFs) contained in the peel of citrus fruits have anti-inflammatory, anticancer, and antidepressant effects. However, their effects on skeletal muscle are unknown. We investigated whether PMFs could prevent skeletal muscle damage induced by eccentric exercise in rats. Downhill running for 90 min increased the levels of the inflammatory cytokines, monocyte chemotactic protein-1 (MCP-1), and interleukin-1β (IL-1β) in skeletal muscles, especially in vastus lateralis, and the plasma creatine kinase levels. These increases were attenuated by a single oral administration of orange peel extract (OPE) 30 min before downhill running. A mixture of nobiletin, sinensetin, 3,5,6,7,8,3',4'-heptamethoxyflavone, and tangeretin, which are the major PMFs of OPE, also showed similar effects on muscle damage. These results suggest that OPE has a protective effect against eccentric exercise-induced skeletal muscle damage, and that the effects may be attributed to the 4 major PMFs.

Magnolia officinalis Reduces Inflammation and Damage Induced by Recurrent Status Epilepticus in Immature Rats

BACKGROUND

Neuroinflammation induced in response to damage caused by status epilepticus (SE) activates the interleukin (IL)1-β pathway and proinflammatory proteins that increase vulnerability to the development of spontaneous seizure activity and/or epilepsy.

OBJECTIVES

The study aimed to assess the short-term anti-inflammatory and neuroprotective effects of Magnolia officinalis (MO) on recurrent SE in immature rats.

METHODS

Sprague-Dawley rats at PN day 10 were used; n = 60 rats were divided into two control groups, SHAM and KA, and two experimental groups, MO (KA-MO) and Celecoxib (KA-Clbx). The anti-inflammatory effect of a single dose of MO was evaluated at 6 and 24 hr by Western blotting and on day 30 PN via a subchronic administration of MO to assess neuronal preservation and hippocampal gliosis by immunohistochemistry for NeunN and GFAP, respectively.

RESULTS

KA-MO caused a decrease in the expression of IL1-β and Cox-2 at 6 and 24 h post-treatment, a reduction in iNOS synthase at 6 and 24 hr post-treatment and reduced neuronal loss and gliosis at postnatal day 30, similar to Clbx.

CONCLUSION

The results indicating that Magnolia officinalis is an alternative preventive treatment for early stages of epileptogenesis are encouraging.

The Challenge by Multiple Environmental and Biological Factors Induce Inflammation in Aging: Their Role in the Promotion of Chronic Disease

The aging process is driven by multiple mechanisms that lead to changes in energy production, oxidative stress, homeostatic dysregulation and eventually to loss of functionality and increased disease susceptibility. Most aged individuals develop chronic low-grade inflammation, which is an important risk factor for morbidity, physical and cognitive impairment, frailty, and death. At any age, chronic inflammatory diseases are major causes of morbimortality, affecting up to 5-8% of the population of industrialized countries. Several environmental factors can play an important role for modifying the inflammatory state. Genetics accounts for only a small fraction of chronic-inflammatory diseases, whereas environmental factors appear to participate, either with a causative or a promotional role in 50% to 75% of patients. Several of those changes depend on epigenetic changes that will further modify the individual response to additional stimuli. The interaction between inflammation and the environment offers important insights on aging and health. These conditions, often depending on the individual's sex, appear to lead to decreased longevity and physical and cognitive decline. In addition to biological factors, the environment is also involved in the generation of psychological and social context leading to stress. Poor psychological environments and other sources of stress also result in increased inflammation. However, the mechanisms underlying the role of environmental and psychosocial factors and nutrition on the regulation of inflammation, and how the response elicited for those factors interact among them, are poorly understood. Whereas certain deleterious environmental factors result in the generation of oxidative stress driven by an increased production of reactive oxygen and nitrogen species, endoplasmic reticulum stress, and inflammation, other factors, including nutrition (polyunsaturated fatty acids) and behavioral factors (exercise) confer protection against inflammation, oxidative and endoplasmic reticulum stress, and thus ameliorate their deleterious effect. Here, we discuss processes and mechanisms of inflammation associated with environmental factors and behavior, their links to sex and gender, and their overall impact on aging.

Impaired exercise performance is independent of inflammation and cellular stress following genetic reduction or deletion of selenoprotein S

Selenoprotein S (Seps1) can be protective against oxidative, endoplasmic reticulum (ER), and inflammatory stress. Seps1 global knockout mice are less active, possess compromised fast muscle ex vivo strength, and, depending on context, heightened inflammation. Oxidative, ER, and inflammatory stress modulates contractile function; hence, our aim was to investigate the effects of Seps1 gene dose on exercise performance. Seps1^-/- knockout, Seps1^-/+ heterozygous, and wild-type mice were randomized to 3 days of incremental, high-intensity treadmill running or a sedentary control group. On day 4, the in situ contractile function of fast tibialis anterior (TA) muscles was determined. Seps1 reduction or deletion compromised exercise capacity, decreasing distance run. TA strength was also reduced. In sedentary Seps1^-/- knockout mice, TA fatigability was greater than wild-type mice, and this was ameliorated with exercise. Whereas, in Seps1^+/- heterozygous mice, exercise compromised TA endurance. These impairments in exercise capacity and TA contractile function were not associated with increased inflammation or a dysregulated redox state. Seps1 is highly expressed in muscle fibers and blood vessels. Interestingly, Nos1 and Vegfa mRNA transcripts were decreased in TA muscles from Seps1^-/- knockout and Seps1^-/+ heterozygous mice. Impaired exercise performance with Seps1 reduction or deletion cannot be attributed to heightened cellular stress, but it may potentially be mediated, in part, by the effects of Seps1 on the microvasculature.

Supplementation with a Bioactive Melon Concentrate in Humans and Animals: Prevention of Oxidative Damages and Fatigue in the Context of a Moderate or Eccentric Physical Activity

Exercise is recognized to provide both physical and psychological health benefits. However, oxidative stress can occur and induce muscular damages. SOD B^®; M is a melon concentrate, well known to counteract oxidative stress and prevent its side effects. The present study aimed to evaluate the potential of the melon concentrate in the context of both a strong and isolated effort associated with deleterious effects, and a moderate and regular physical activity considered as beneficial. First, a preclinical study was set up on rats to evaluate its potential on the prevention of damages induced by an eccentric exercise. Secondly, the combined effect of the melon concentrate and a regular standardized physical training was studied on the overall physical condition of healthy subjects in a randomized, double-blind, placebo-controlled trial. Repeated measures Analysis of Variance (ANOVA), student’s t test and Mann–Whitney test were used for statistical analyses. Melon concentrate helped to prevent gastrocnemius damages induced by the eccentric exercise. It allowed a reduction of fibrosis by approximately 38% and a reduction of Tumor Necrosis Factor- α (TNF-α) plasma level by 28%. This supplementation also induced a rearrangement of myosin fibers and an increase in PGC-1α plasma level. In the clinical study, melon concentrate was able to decrease oxidative stress and C-Reactive protein (CRP) plasma level. Besides, magnesium (Mg) plasma level was higher in the context of a regular training performed by healthy subjects supplemented with the melon concentrate. Therefore, the melon concentrate allowed a better adaptation to effort linked to PGC-1α activation: a regulator of energy metabolism. The antioxidant properties of the melon concentrate and its ability to mobilize magnesium also suggest that the supplementation could induce a better resistance to fatigue and recovery during regular physical activity.

Nutritional and Pharmacological Interventions to Expedite Recovery Following Muscle-Damaging Exercise in Older Adults: A Narrative Review of the Literature

Exercise-induced muscle damage (EIMD) manifests as muscle soreness, inflammation, and reductions in force generating capacity that can last for several days after exercise. The ability to recover and repair damaged tissues following EIMD is impaired with age, with older adults (≥50 years old) experiencing a slower rate of recovery than their younger counterparts do for the equivalent exercise bout. This narrative review discusses the literature examining the effect of nutritional or pharmacological supplements taken to counter the potentially debilitating effects of EIMD in older adults. Studies have assessed the effects of nonsteroidal anti-inflammatory drugs, vitamin C and/or E, or higher protein diets on recovery in older adults. Each intervention showed some promise for attenuating EIMD, but, overall, there is a paucity of available data in this population, and more studies are required to determine the influence of nutrition or pharmacological interventions on EIMD in older adults.

Dietary CCPS from bitter gourd attenuates sodium arsenite induced female reproductive ailments cum infertility in wistar rats: anti-inflammatory and anti-apoptotic role

This investigation explored a dietary therapy of pectic polysaccharide (CCPS) (2 mg/ Kg BW) against female repro-toxicity and infertility triggered by sodium arsenite (As3+) (10 mg/ Kg BW) in Wistar rats. The isolated CCPS consists of D-galactose and D-methyl galacturonate with a molar ratio of 1: 4. FTIR spectral analysis of CCPS and CCPS- sodium arsenite (As3+) complex indicated a possible chelating property of CCPS in presence of binding sites (OH-/COOH) for As3+. Series of negatively charged galacturonate residues in CCPS provide better potential for cation chelation. CCPS significantly mitigated As3+ induced ovarian, uterine lipid peroxidation, and reactive oxygen species (ROS) generation by the restoration of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities. CCPS post-treatment enhanced ovarian steroidogenesis along with a restoration of normal tissue histoarchitecture in As3+ fed rats by regulating the estradiol receptor alpha (ER-α). CCPS suppressed anti-inflammatory properties effectively found since a down-regulation of NF-kappa B (NF-қB), pro-inflammatory tumor necrosis-α (TNF-α) and interleukin-6 (IL-6) were observed in arsenicated rats with CCPS. This study confirmed the up-regulation of uterine pro-apoptotic/ apoptotic proteins caspase-3, poly ADP ribose polymerase (PARP), proliferating cell nuclear antigen (PCNA), phospho p53 and Bax, followed by down-regulation of Bcl-2 and protein Kinase B (AKT) signaling pathway along with uterine tissue regeneration in As3+ exposed rats. Oral CCPS attenuated the above apoptotic expressional changes significantly and dietary CCPS ensured successful fertility with the birth of healthy pups in lieu of infertile condition in As3+ fed rats. Moreover, this study also supports that CCPS treatment attenuated the As3+ toxicity by modulating the S-adenosine methionine (SAM) pool components, B12, folate and homocysteine.

l-arginine ingestion inhibits eccentric contraction-induced proteolysis and force deficit via S-nitrosylation of calpain

It has been shown that calpains are involved in the proteolysis of muscle proteins that occurs with eccentric contraction (ECC) and that exogenously applied nitric oxide decreases the calpain‐mediated proteolysis. The aim of this study was to examine the effects of ingestion of l‐arginine (ARG), a nitric oxide precursor, on ECC‐related calpain activation. In the first and second experiments, male Wistar rats were given ARG in water for 7 days starting from 3 days before the ECC protocol (average ingestion, ~600 mg kg‐body wt⁻¹ day⁻¹). Tibialis anterior muscles underwent 200 repeated ECCs and, subsequently, were excised 3 days later. Whole muscle analyses (the first experiment) revealed that ARG attenuated ECC‐induced force deficit and autolysis of calpain‐1, and increased the amounts of S‐nitrosylated calpain‐1. Regarding ryanodine receptor (RyR) and dihydropyridine receptor (DHPR), ECC‐induced proteolysis was completely inhibited by ARG, whereas the inhibition was partial for junctophilin‐1 (JP1). Skinned fiber analyses (the second experiment) showed that ARG also inhibited ECC‐elicited reductions in the ratio of depolarization‐induced to maximum Ca²⁺‐activated force. In the third experiment, homogenates of rested muscles were treated with S‐nitrosylating agent, S‐nitrosoglutathione (GSNO), and/or high Ca²⁺ concentration ([Ca²⁺]). Treatment with high [Ca²⁺] and without GSNO produced proteolysis of RyR, DHPR, and JP1. On the other hand, treatment with high [Ca²⁺] and GSNO caused complete inhibition of RyR and DHPR proteolysis and partial inhibition of JP1 proteolysis. These results indicate that ARG ingestion can attenuate ECC‐induced proteolysis of Ca²⁺ regulatory proteins and force deficit by decreasing calpain activation via S‐nitrosylation.

Poly(ADP-Ribose) Polymerases in Host-Pathogen Interactions, Inflammation, and Immunity

The literature review presented here details recent research involving members of the poly(ADP-ribose) polymerase (PARP) family of proteins. Among the 17 recognized members of the family, the human enzyme PARP1 is the most extensively studied, resulting in a number of known biological and metabolic roles. This review is focused on the roles played by PARP enzymes in host-pathogen interactions and in diseases with an associated inflammatory response. In mammalian cells, several PARPs have specific roles in the antiviral response; this is perhaps best illustrated by PARP13, also termed the zinc finger antiviral protein (ZAP). Plant stress responses and immunity are also regulated by poly(ADP-ribosyl)ation. PARPs promote inflammatory responses by stimulating proinflammatory signal transduction pathways that lead to the expression of cytokines and cell adhesion molecules. Hence, PARP inhibitors show promise in the treatment of inflammatory disorders and conditions with an inflammatory component, such as diabetes, arthritis, and stroke. These functions are correlated with the biophysical characteristics of PARP family enzymes. This work is important in providing a comprehensive understanding of the molecular basis of pathogenesis and host responses, as well as in the identification of inhibitors. This is important because the identification of inhibitors has been shown to be effective in arresting the progression of disease.

Neuroprotective effects of honokiol: from chemistry to medicine

The incidence of neurological disorders is growing in developed countries together with increased lifespan. Nowadays, there are still no effective treatments for neurodegenerative pathologies, which make necessary to search for new therapeutic agents. Natural products, most of them used in traditional medicine, are considered promising alternatives for the treatment of neurodegenerative diseases. Honokiol is a natural bioactive phenylpropanoid compound, belonging to the class of neolignan, found in notable amounts in the bark of Magnolia tree, and has been reported to exert diverse pharmacological properties including neuroprotective activities. Honokiol can permeate the blood brain barrier and the blood-cerebrospinal fluid to increase its bioavailability in neurological tissues. Diverse studies have provided evidence on the neuroprotective effect of honokiol in the central nervous system, due to its potent antioxidant activity, and amelioration of the excitotoxicity mainly related to the blockade of glutamate receptors and reduction in neuroinflammation. In addition, recent studies suggest that honokiol can attenuate neurotoxicity exerted by abnormally aggregated Aβ in Alzheimer's disease. The present work summarizes what is currently known concerning the neuroprotective effects of honokiol and its potential molecular mechanisms of action, which make it considered as a promising agent in the treatment and management of neurodegenerative diseases. © 2017 BioFactors, 43(6):760-769, 2017.

Anti-aging effect of fullerenol on skin aging through derived stem cells in a mouse model

Fullerenol is similar to graphite in terms of structure. In the present study, the anti-aging effect of fullerenol on skin through derived stem cells in a mouse model was assessed and the potential mechanism of fullerenol was investigated. The anti-aging effect of fullerenol effectively inhibited the retention rate of transplanted adipose-derived stem cells and increased the thickness of the dermal portion of skin and collagen ratio in mice. The effect of fullerenol on the proliferation of stem cells was observed. Treatment with fullerenol effectively promoted the mRNA expression of Runt-related transcription factor 2, alkaline phosphatase and osteocalcin in a mouse model of skin aging induced by D-galactose. However, fullerenol treatment effectively suppressed the protein expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) and increased forkhead box protein O1 (FoxO1) protein expression in the mice model of skin aging induced by D-galactose. These results demonstrate that the anti-aging effect of fullerenol on skin through derived stem cells may be mediated in mice via the PPAR-γ/FoxO1 signaling pathway.

Poly(ADP-Ribose)Polymerase-1 in Lung Inflammatory Disorders: A Review

Asthma, acute lung injury (ALI), and chronic obstructive pulmonary disease (COPD) are lung inflammatory disorders with a common outcome, that is, difficulty in breathing. Corticosteroids, a class of potent anti-inflammatory drugs, have shown less success in the treatment/management of these disorders, particularly ALI and COPD; thus, alternative therapies are needed. Poly(ADP-ribose)polymerases (PARPs) are the post-translational modifying enzymes with a primary role in DNA repair. During the last two decades, several studies have reported the critical role played by PARPs in a good of inflammatory disorders. In the current review, the studies that address the role of PARPs in asthma, ALI, and COPD have been discussed. Among the different members of the family, PARP-1 emerges as a key player in the orchestration of lung inflammation in asthma and ALI. In addition, PARP activation seems to be associated with the progression of COPD. Furthermore, PARP-14 seems to play a crucial role in asthma. STAT-6 and GATA-3 are reported to be central players in PARP-1-mediated eosinophilic inflammation in asthma. Interestingly, oxidative stress-PARP-1-NF-κB axis appears to be tightly linked with inflammatory response in all three-lung diseases despite their distinct pathophysiologies. The present review sheds light on PARP-1-regulated factors, which may be common or differential players in asthma/ALI/COPD and put forward our prospective for future studies.

Variations in Oxidative Stress Levels in 3 Days Follow-up in Ultramarathon Mountain Race Athletes

Spanidis, Y, Stagos, D, Orfanou, M, Goutzourelas, N, Bar-or, D, Spandidos, D, and Kouretas, D. Variations in oxidative stress levels in 3 days follow-up in ultramarathon mountain race athletes. J Strength Cond Res 31(3): 582-594, 2017-The aim of the present study was the monitoring of the redox status of runners participating in a mountain ultramarathon race of 103 km. Blood samples from 12 runners were collected prerace and 24, 48, and 72 hours postrace. The samples were analyzed by using conventional oxidative stress markers, such as protein carbonyls (CARB), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) in plasma, as well as glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. In addition, 2 novel markers, the static oxidation-reduction potential marker (sORP) and the capacity oxidation-reduction potential (cORP), were measured in plasma. The results showed significant increase in sORP levels and significant decrease in cORP and GSH levels postrace compared with prerace. The other markers did not exhibit significant changes postrace compared with prerace. Furthermore, an interindividual analysis showed that in all athletes but one sORP was increased, whereas cORP was decreased. Moreover, GSH levels were decreased in all athletes at least at 2 time points postrace compared with prerace. The other markers exhibited great variations between different athletes. In conclusion, ORP and GSH markers suggested that oxidative stress has existed even 3 days post ultramarathon race. The practical applications from these results would be that the most effective markers for short-term monitoring of ultramarathon mountain race-induced oxidative stress were sORP, cORP, and GSH. Also, administration of supplements enhancing especially GSH is recommended during ultramarathon mountain races to prevent manifestation of pathological conditions.

Plasma and adipose tissue level of angiopoietin-like 7 (ANGPTL7) are increased in obesity and reduced after physical exercise

Objective

ANGPTL7 is a member of the Angiopoietin-like (ANGPTL) protein family that is composed of eight proteins (1–8). Increasing evidence is associating ANGPTL proteins to obesity and insulin resistance. The biological role of ANGPTL7 is yet to be understood except for a recently proposed role in the pathophysiology of glaucoma. This study was designed to shed light on the function of ANGPTL7 in obesity and its modulation by physical exercise as well as its potential association with lipid profile.

Methods

A total of 144 subjects were enrolled in this study and finished three months of physical exercise. The participants were classified based on their BMI, 82 subjects were non-obese and 62 obese. ANGPTL7 levels in plasma and adipose tissue were measured by ELISA, RT-PCR and immunohistochemistry.

Results

In this study, we showed that ANGPTL7 level was increased in the plasma of obese subjects (1249.05± 130.39 pg/mL) as compared to non-obese (930.34 ± 87.27 pg/mL) (p-Value = 0.032). ANGPTL7 Gene and protein expression levels in adipose tissue also showed over two fold increase. Physical exercise reduced circulating level of ANGPTL7 in the obese subjects to 740.98± 127.18 pg/mL, (p-Value = 0.007). ANGPTL7 expression in adipose tissue was also reduced after exercise. Finally, ANGPTL7 circulating level showed significant association with TG level in the obese subjects (R² = 0.183, p-Value = 0.03).

Conclusion

In conclusion, our data shows for the first time that obesity increases the level of ANGPTL7 in both plasma and adipose tissue. Increased expression of ANGPTL7 might play a minor role in the regulation of TG level in obese subjects either directly or through interaction with other ANGPTL protein members. Physical exercise reduced the level of ANGPTL7 highlighting the potential for targeting this protein as a therapeutic target for regulating dyslipidemia.

Role of calpain in eccentric contraction-induced proteolysis of Ca2+-regulatory proteins and force depression in rat fast-twitch skeletal muscle

The aim of this study was to examine the in vivo effects of eccentric contraction (ECC) on calpain-dependent proteolysis of Ca2+-regulatory proteins and force production in fast-twitch skeletal muscles. Rat extensor digitorum longus muscles were exposed to 200 repeated ECC in situ and excised immediately [recovery 0 (REC0)] or 3 days [recovery 3 (REC3)] after cessation of ECC. Calpain inhibitor (CI)-treated rats were intraperitoneally injected with MDL-28170 before ECC and during REC3. Tetanic force was markedly reduced at REC0 and remained reduced at REC3. CI treatment ameliorated the ECC-induced force decline but only at REC3. No evidence was found for proteolysis of dihydropyridine receptor (DHPR), junctophilin (JP)1, JP2, ryanodine receptor (RyR), sarcoplasmic reticulum Ca2+-ATPase (SERCA)1a, or junctional face protein-45 at REC0. At REC3, ECC resulted in decreases in DHPR, JP1, JP2, RyR, and SERCA1a. CI treatment prevented the decreases in DHPR, JP1, and JP2, whereas it had little effect on RyR and SERCA1a. These findings suggest that DHPR, JP1, and JP2, but not RyR and SERCA1a, undergo calpain-dependent proteolysis in in vivo muscles subjected to ECC and that impaired function of DHPR and/or JP might cause prolonged force deficits with ECC.

NEW & NOTEWORTHY Calpain-dependent proteolysis is one of the contributing factors to muscle damage that occurs with eccentric contraction (ECC). It is unclear, however, whether calpains account for proteolysis of Ca2+-regulatory proteins in in vivo muscles subjected to ECC. Here, we provide evidence that dihydropyridine receptor and junctophilin, but not ryanodine receptor and sarcoplasmic reticulum Ca2+-ATPase, undergo calpain-dependent proteolysis.

Mechanisms underpinning protection against eccentric exercise-induced muscle damage by ischemic preconditioning

Eccentric exercise training is effective for increasing muscle mass and strength, and improving insulin sensitivity and blood lipid profiles. However, potential muscle damage symptoms such as prolonged loss of muscle function and delayed onset of muscle soreness may restrict the use of eccentric exercise, especially in clinical populations. Therefore, strategies to reduce eccentric exercise-induced muscle damage (EIMD) are necessary, and an extensive number of scientific studies have tried to identify potential intervention modalities to perform eccentric exercises without adverse effects. The present paper is based on a narrative review of current literature, and provides a novel hypothesis by which an ischemic preconditioning (IPC) of the extremities may reduce EIMD. IPC consists of an intermittent application of short-time non-lethal ischemia to an extremity (e.g. using a tourniquet) followed by reperfusion and was discovered in clinical settings in an attempt to minimize inflammatory responses induced by ischemia and ischemia-reperfusion-injury (I/R-Injury) during surgery. The present hypothesis is based on morphological and biochemical similarities in the pathophysiology of skeletal muscle damage during clinical surgery and EIMD. Even though the primary origin of stress differs between I/R-Injury and EIMD, subsequent cellular alterations characterized by an intracellular accumulation of Ca²⁺, an increased production of reactive oxygen species or increased apoptotic signaling are essential elements for both. Moreover, the incipient immune response appears to be similar in I/R-Injury and EIMD, which is indicated by an infiltration of leukocytes into the damaged soft-tissue. Thus far, IPC is considered as a potential intervention strategy in the area of cardiovascular or orthopedic surgery and provides significant impact on soft-tissue protection and downregulation of undesired excessive inflammation induced by I/R-Injury. Based on the known major impact of IPC on skeletal muscle physiology and immunology, the present paper aims to illustrate the potential protective effects of IPC on EIMD by discussing possible underlying mechanisms.

Effects of the foot strike pattern on muscle activity and neuromuscular fatigue in downhill trail running

Minimizing musculo-skeletal damage and fatigue is considered paramount for performance in trail running. Our purposes were to investigate the effects of the foot strike pattern and its variability on (a) muscle activity during a downhill trail run and (b) immediate and delayed neuromuscular fatigue. Twenty-three runners performed a 6.5-km run (1264 m of negative elevation change). Electromyographic activity of lower-limb muscles was recorded continuously. Heel and metatarsal accelerations were recorded to identify the running technique. Peripheral and central fatigue was assessed in knee extensors (KE) and plantar flexors (PF) at Pre-, Post-, and 2 days post downhill run (Post2d). Anterior patterns were associated with (a) higher gastrocnemius lateralis activity and lower tibialis anterior and vastus lateralis activity during the run and (b) larger decreases in KE high-frequency stimulus-evoked torque Post and larger decrements in KE MVC Post2d. High patterns variability during the run was associated with (a) smaller decreases in KE Db100 Post and MVC Post2d and (b) smaller decreases in PF MVC Post and Post2d. Anterior patterns increase the severity of KE peripheral fatigue. However, high foot strike pattern variability during the run reduced acute and delayed neuromuscular fatigue in KE and PF.

Honokiol protects against renal ischemia/reperfusion injury via the suppression of oxidative stress, iNOS, inflammation and STAT3 in rats

Honokiol is the predominant active ingredient in the commonly used traditional Chinese medicine, Magnolia, which has been confirmed in previous studies to exhibit anti-oxidation, antimicrobial, antitumor and other pharmacological effects. However, its effects on renal ischemia/reperfusion injury (IRI) remain to be elucidated. The present study aimed to examine the effects of honokiol on renal IRI, and to investigate its potential protective mechanisms in the heart. Male adult Wistar albino rats were induced into a renal IRI model. Subsequently, the levels of serum creatinine, blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), and the levels of serum nitrite and the kidney nitrite were examined in the IRI group. The levels of oxidative stress, inducible nitric oxide synthase (iNOS), inflammatory factors and caspase-3 were evaluated using a series of commercially available kits. The levels of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and the protein expression levels of STAT3 were determined using western blotting. Pretreatment with honokiol significantly reduced the levels of serum creatinine, BUN, ALT, AST and ALP, and the level of nitrite in the kidney of the IRI group, compared with the control group. The levels of malondialdehyde, the activity of myeloperoxidase, and the gene expression and activity of iNOS were reduced in the IRI rats, compared with the sham-operated rats, whereas the levels of superoxide dismutase and catalase were increased following treatment with honokiol in the IRI rats. In addition, the expression levels of tumor necrosis factor-α and interleukin-6 in the IRI rats were increased by honokiol. Treatment with honokiol suppressed the protein expression levels of p-STAT3 and caspase-3 in the IRI rats. These findings indicated that honokiol protects against renal IRI via the suppression of oxidative stress, iNOS, inflammation and STAT3 in the rat.

Assessment of eccentric exercise-induced oxidative stress using oxidation-reduction potential markers

The aim of the present study was to investigate the use of static (sORP) and capacity ORP (cORP) oxidation-reduction potential markers as measured by the RedoxSYS Diagnostic System in plasma, for assessing eccentric exercise-induced oxidative stress. Nineteen volunteers performed eccentric exercise with the knee extensors. Blood was collected before, immediately after exercise, and 24, 48, and 72 h after exercise. Moreover, common redox biomarkers were measured, which were protein carbonyls, thiobarbituric acid-reactive substances, total antioxidant capacity in plasma, and catalase activity and glutathione levels in erythrocytes. When the participants were examined as one group, there were not significant differences in any marker after exercise. However, in 11 participants there was a high increase in cORP after exercise, while in 8 participants there was a high decrease. Thus, the participants were divided in low cORP group exhibiting significant decrease in cORP after exercise and in high cORP group exhibiting significant increase. Moreover, only in the low cORP group there was a significant increase in lipid peroxidation after exercise suggesting induction of oxidative stress. The results suggested that high decreases in cORP values after exercise may indicate induction of oxidative stress by eccentric exercise, while high increases in cORP values after exercise may indicate no existence of oxidative stress.

Honokiol downregulates Kruppel-like factor 4 expression, attenuates inflammation, and reduces histopathology after spinal cord injury in rats

STUDY DESIGN

Randomized experimental study.

OBJECTIVE

To investigate the neuroprotective effect of honokiol (HNK) on rats subjected to traumatic spinal cord injury (SCI) and the molecular mechanisms.

SUMMARY OF BACKGROUND DATA

Inflammation contributes to the secondary injury to the spinal cord. Honokiol has been used as a neuroprotective agent because of its strong antioxidant and anti-inflammatory properties. Kruppel-like factor 4 (Klf4) is a newly identified critical target for the anti-inflammatory effect of HNK. Whether HNK can inhibit inflammatory response in rat model of SCI through mediating the expression of Klf4 has yet to be elucidated.

METHODS

Eighty-four adult female Sprague-Dawley rats were randomly divided into 4 groups as sham, SCI, SCI + Vehicle (0.1% propylene glycol in saline, intraperitoneally), and SCI + HNK (20 mg/kg, intraperitoneally) groups. The influences of HNK on the proinflammatory cytokines, microglial activation, neutrophil infiltration, histological changes, and improvement in motor function were assessed.

RESULTS

In the SCI group, proinflammatory cytokines, microglial activation, neutrophil infiltration, and Klf4 expression levels were increased compared with the sham group (P < 0.001). HNK intervention downregulated the expression of Klf4, reduced the production of proinflammatory cytokines, inhibited microglial activation, and neutrophil infiltration (P < 0.05). Furthermore, HNK also reduced histopathology and improved functional outcome after traumatic SCI.

CONCLUSION

HNK reduces secondary tissue damage and improves locomotor function recovery after SCI through suppressing inflammatory response, and can be used as a potential therapeutic agent for SCI.

LEVEL OF EVIDENCE

NA.

Hypoxia-inducible factor-1 modulates the expression of vascular endothelial growth factor and endothelial nitric oxide synthase induced by eccentric exercise

The present study investigated the effects of acute and chronic eccentric exercise on the hypoxia-inducible factor (HIF)-1α activation response and the concomitant modulation of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) expression in rat skeletal muscle. Twenty-four male Wistar rats were randomly assigned to three experimental groups: rested control group, acutely exercised group after an intermittent downhill protocol for 90 min, and acutely exercise group with a previous eccentric training of 8 wk. HIF-1α activation, VEGF and eNOS gene expression, protein content, and promoter activation were assessed in vastus lateralis muscle biopsies. Acute eccentric exercise induced a marked activation of HIF-1α and resulted in increased VEGF and eNOS mRNA level and protein concentration. The binding of HIF-1α to the VEGF and eNOS promoters, measured by a chromatin immunoprecipitation assay, was undetectable in rested rats, whereas it was evident in acutely exercised animals. Acute exercise also increased myeloperoxidase, toll-like receptor-4, tumor necrosis factor-α, and interleukin-1β protein content, suggesting a contribution of proinflammatory stimuli to HIF-1α activation and VEGF overexpression. All of these effects were partially abolished by training. Moreover, training resulted in an increased capillary density. In summary, our findings indicate that eccentric exercise prompts an HIF-1α response in untrained skeletal muscle that contributes to the upregulation of VEGF and eNOS gene expression and is attenuated after an eccentric training program.

Evaluation of two novel antioxidants with differential effects on curcumin-induced apoptosis in C2 skeletal myoblasts; involvement of JNKs

Excessive levels of reactive oxygen species (ROS) result in numerous pathologies including muscle disorders. In essence, skeletal muscle performance of daily activities can be severely affected by the redox imbalances occurring after muscular injuries, surgery, atrophy due to immobilization, dystrophy or eccentric muscle contraction. Therefore, research on the potential beneficial impact of antioxidants is of outmost importance. In this context, aiming at further exploring the mechanisms of action of our newly synthesized antioxidant compounds (AK1 and AK2) in a skeletal muscle experimental setting, we initially investigated their scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and subsequently assessed their effect on the viability of C2 skeletal myoblasts in the presence of two pro-oxidants: H2O2 and curcumin (MTT assay). Interestingly, while both compounds reversed the detrimental effect of H2O2, only AK2 was cytoprotective in curcumin-treated C2 cells. We next confirmed the immediate activation of extracellular signal-regulated kinases (ERKs) and the more delayed activation profile of c-Jun NH2-terminal kinases (JNKs) in C2 skeletal myoblasts exposed to curcumin, by Western blotting. In correlation with the aforementioned results, only AK2 blocked the curcumin-induced activation of JNKs pathway. Furthermore, JNKs were revealed to mediate curcumin-induced apoptosis in C2 cells and only AK2 to effectively suppress it (by detecting its effect on poly(ADP-ribose) polymerase fragmentation). Overall, we have shown that two similar in structure novel antioxidants confer differential effects on C2 skeletal myoblasts viability under oxidative stress conditions. This result may be attributed to these antioxidants respective diverse mode of interaction with the signaling effectors involved in the observed responses. Future studies should further evaluate the mechanism of action of these compounds in order to support their potential application in therapeutic protocols against ROS-related muscle disorders.

A contralateral repeated bout effect attenuates induction of NF-κB DNA binding following eccentric exercise

We investigated the existence of contralateral repeated bout effect and tested if the attenuation of nuclear factor-kappa B (NF-κB; an important regulator of muscle inflammation) induction following eccentric exercise is a potential mechanism. Thirty-one healthy men performed two bouts of knee extension eccentric exercise, initially with one leg and then with the opposite leg 4 wk later. Vastus lateralis muscle biopsies of both exercised and control legs were taken 3 h postexercise. Knee extension isometric and isokinetic strength (60°/sec and 180°/sec) were measured at baseline, pre-exercise, immediately postexercise, and 1/day for 5 days postexercise. Serum creatine kinase (CK) activity and muscle soreness were assessed at baseline and 1/day for 5 days postexercise. NF-κB (p65) DNA-binding activity was measured in the muscle biopsies. Isometric strength loss was lower in bout 2 than in bout 1 at 24, 72, and 96 h postexercise ( P < 0.05). Isokinetic strength (60°/s and 180°/s) was reduced less in bout 2 than in bout 1 at 72 h postexercise ( P < 0.01). There were no significant differences between bouts for postexercise CK activity or muscle soreness. p65 DNA-binding activity was increased following eccentric exercise (compared with the control leg) in bout 1 (122.9% ± 2.6%; P < 0.001) and bout 2 (109.1% ± 3.0%; P < 0.05). Compared with bout 1, the increase in NF-κB DNA-binding activity postexercise was attenuated after bout 2 ( P = 0.0008). Repeated eccentric exercise results in a contralateral repeated bout effect, which could be due to the attenuated increase in NF-κB activity postexercise.

The magnolia bioactive constituent 4-O-methylhonokiol protects against high-fat diet-induced obesity and systemic insulin resistance in mice

Obesity is caused by a combination of both genetic and environmental risks. Disruption in energy balance is one of these risk factors. In the present study, the preventive effect on high-fat diet- (HFD-) induced obesity and insulin resistance in mice by Magnolia bioactive constituent 4-O-methylhonokiol (MH) was compared with Magnolia officinalis extract BL153. C57BL/6J mice were fed by normal diet or by HFD with gavage-administered vehicle, BL153, low-dose MH, and high-dose MH simultaneously for 24 weeks, respectively. Either MH or BL153 slightly inhibited body-weight gain of mice by HFD feeding although the food intake had no obvious difference. Body fat mass and the epididymal white adipose tissue weight were also mildly decreased by MH or BL153. Moreover, MH significantly lowered HFD-induced plasma triglyceride, cholesterol levels and activity of alanine transaminase (ALT), liver weight and hepatic triglyceride level, and ameliorated hepatic steatosis. BL153 only significantly reduced ALT and liver triglyceride level. Concurrently, low-dose MH improved HFD-induced hyperinsulinemia and insulin resistance. Furthermore, the infiltration of mast cells in adipose tissue was decreased in MH or in BL153 treatment. These results suggested that Magnolia bioactive constituent MH might exhibit potential benefits for HFD-induced obesity by improvement of lipid metabolism and insulin resistance.

Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity

AIM

Daidzein (4',7-dihydroxyisoflavone) is an isoflavone exiting in many herbs that has shown anti-inflammation activity. The aim of this study was to investigate the mechanism underlying its anti-inflammatory action in murine lung epithelial cells.

METHODS

C57BL/6 mice were intranasally exposed to TNF-α to induce lung inflammation. The mice were injected with daidzein (400 mg/kg, ip) before TNF-α challenge, and sacrificed 12 h after TNF-α challenge, and lung tissues were collected for analyisis. In in vitro studies, murine MLE-12 epithelial cells were treated with TNF-α (20 ng/mL). The expression of pro-inflammatory chemokine Cxcl2 mRNA and NF-κB transcriptional activity were examined using real-time PCR and a dual reporter assay. Protein poly-adenosine diphosphate-ribosylation (PARylation) was detecyed using Western blotting and immunoprecipitation assays.

RESULTS

Pretreatment of the mice with daidzein markedly attenuated TNF-α-induced lung inflammation, and inhibited Cxcl2 expression in lung tissues. Furthermore, daidzein (10 μmol/L) prevented TNF-α-induced increases in Cxcl2 expression and activity and NF-κB transcriptional activity, and markedly inhibited TNF-α-induced protein PARylation in MLE-12 cells in vitro. In MLE-12 cells co-transfected with the PARP-1 expression plasmid and NF-κB-luc (or Cxcl2-luc) reporter plasmid, TNF-α markedly increased NF-κB (or Cxcl2) activation, which were significantly attenuated in the presence of daidzein (or the protein PARylation inhibitor PJ 34). PARP-1 activity assay showed that daidzein (10 μmol/L) reduced the activity of PARP-1 by ∼75%.

CONCLUSION

The anti-inflammatory action of daidzein in murine lung epithelial cells seems to be mediated via a direct interaction with PARP-1, which inhibits RelA/p65 protein PARylation required for the transcriptional modulation of pro-inflammatory chemokines such as Cxcl2.

Pharmacokinetics of honokiol after intravenous guttae in beagle dogs assessed using ultra-performance liquid chromatography-tandem mass spectrometry

A simple, rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of honokiol in beagle dog plasma after intravenous guttae. With addition of the internal standard magnolol, plasma samples were precipitated with methanol and separated on a Shim-pack XR-ODS II (2.0 × 100 mm, 2.2 µm) with isocratic elution of methanol and water (80:20) solution at a flow rate of 0.2 mL/min. A good separation of honokiol was achieved within 3.5 min. Quantification was performed on a Waters Quattro Premier XE triple quadrupole mass spectrometer with electrospray ionization inlet in the negative multiple reaction monitoring mode. Good linearity was obtained over the concentration range of 5.12-15580 ng/mL (r(2) > 0.998). Intra- and inter-day precisions were <13.10%, and accuracy ranged from 89.21 to 99.92%. The lower limit of quantification for honokiol was 5.12 ng/mL, and honokiol was stable under various conditions (three freeze-thaw cycles, short-term temperature, post-preparative and long-term temperature conditions.). This validated method was successfully applied to the pharmacokinetic study of honokiol in dogs by intravenous guttae.