Endogenous antioxidant defense induction by melon superoxide dismutase reduces cardiac hypertrophy in spontaneously hypertensive rats

RNA-seq transcriptome and pathway analysis of the medicinal mushroom Lignosus tigris (Polyporaceae) offer insights into its bioactive compounds with anticancer and antioxidant potential

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal mushrooms belonging to the Lignosus spp., colloquially known as Tiger Milk mushrooms (TMMs), are used as traditional medicine by communities across various regions of China and Southeast Asia to enhance immunity and to treat various diseases. At present, three Lignosus species have been identified in Malaysia: L. rhinocerus, L. tigris, and L. cameronensis. Similarities in their macroscopic morphologies and the nearly indistinguishable appearance of their sclerotia often lead to interchangeability between them. Hence, substantiation of their traditional applications via identification of their individual bioactive properties is imperative in ensuring that they are safe for consumption. L. tigris was first identified in 2013. Thus far, studies on L. tigris cultivar sclerotia (Ligno TG-K) have shown that it possesses significant antioxidant activities and has greater antiproliferative action against selected cancer cells in vitro compared to its sister species, L. rhinocerus TM02®. Our previous genomics study also revealed significant genetic dissimilarities between them. Further omics investigations on Ligno TG-K hold immense potential in facilitating the identification of its bioactive compounds and their associated bioactivities.

AIM OF STUDY

The overall aim of this study was to investigate the gene expression profile of Ligno TG-K via de novo RNA-seq and pathway analysis. We also aimed to identify highly expressed genes encoding compounds that contribute to its cytotoxic and antioxidant properties, as well as perform a comparative transcriptomics analysis between Ligno TG-K and its sister species, L. rhinocerus TM02®.

MATERIALS AND METHODS

Total RNA from fresh 3-month-old cultivated L. tigris sclerotia (Ligno TG-K) was extracted and analyzed via de novo RNA sequencing. Expressed genes were analyzed using InterPro and NCBI-Nr databases for domain identification and homology search. Functional categorization based on gene functions and pathways was performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Clusters of Orthologous Genes (COG) databases. Selected genes were subsequently subjected to phylogenetic analysis.

RESULTS

Our transcriptomics analysis of Ligno TG-K revealed that 68.06% of its genes are expressed in the sclerotium; 80.38% of these were coding transcripts. Our analysis identified highly expressed transcripts encoding proteins with prospective medicinal properties. These included serine proteases (FPKM = 7356.68), deoxyribonucleases (FPKM = 3777.98), lectins (FPKM = 3690.87), and fungal immunomodulatory proteins (FPKM = 2337.84), all of which have known associations with anticancer activities. Transcripts linked to proteins with antioxidant activities, such as superoxide dismutase (FPKM = 1161.69) and catalase (FPKM = 1905.83), were also highly expressed. Results of our sequence alignments revealed that these genes and their orthologs can be found in other mushrooms. They exhibit significant sequence similarities, suggesting possible parallels in their anticancer and antioxidant bioactivities.

CONCLUSION

This study is the first to provide a reference transcriptome profile of genes expressed in the sclerotia of L. tigris. The current study also presents distinct COG profiles of highly expressed genes in Ligno TG-K and L. rhinocerus TM02®, highlighting that any distinctions uncovered may be attributed to their interspecies variations and inherent characteristics that are unique to each species. Our findings suggest that Ligno TG-K contains bioactive compounds with prospective medicinal properties that warrant further investigations.

CLASSIFICATION

Systems biology and omics.

Atractylenolide II ameliorates myocardial fibrosis and oxidative stress in spontaneous hypertension rats

BACKGROUND

Hypertension is a well-recognized risk factor for cardiovascular, which is also a critical factor in causing myocardial fibrosis (MF).

OBJECTIVE

The study aimed to explore the effect of Atractylenolide II (ATL-II) on MF and oxidative stress in spontaneous hypertension rats (SHR).

METHODS

The body weight of rats after injection of ATL-II was quantitatively analyzed. The left ventricular function of SHR was evaluated by Echocardiographic. HE staining, Masson trichrome staining, left ventricular mass index (LVMI) and immunofluorescence was applied to investigate the effects of ATL-II on MF. RT qPCR was used to detect the Collagen I, α-SMA, Fibronectin, and Vimentin mRNA expression levels in myocardial slices. The effect ATL-II on cardiomyocyte apoptosis was detected by TUNEL staining and western blot. An immunohistochemistry assay was conducted to detect α-SMA protein and TGF-β1 protein. The contents of H2O2, GSH-PX, SOD, and MDA were measured by colorimetry.

RESULTS

ATL-II could dose-dependently improve the BW of SHRs (P< 0.05) and enhance myocardial function. Moreover, ATL-II effectively reduced cardiomyocyte apoptosis in SHRs. Alternatively, ATL-II could inhibit the Collagen I, α-SMA, Fibronectin, and Vimentin mRNA and protein expression levels in SHRs. ATL-II could ameliorate oxidative stress by improving the activities of SOD and GSH-PX and lowering the contents of H2O2 and MDA in ATL-II-treated SHRs, which reach about 80%.

CONCLUSION

ATL-II could exert an inhibiting effect on MF and oxidative stress in SHRs. Hence, ATL-II may hold promise for the treatment of MF and oxidative stress in Spontaneous Hypertension.

Oxidative Stress, Antioxidants and Hypertension

As a major cause of morbidity and mortality globally, hypertension remains a serious threat to global public health. Despite the availability of many antihypertensive medications, several hypertensive individuals are resistant to standard treatments, and are unable to control their blood pressure. Regulation of the renin-angiotensin-aldosterone system (RAAS) controlling blood pressure, activation of the immune system triggering inflammation and production of reactive oxygen species, leading to oxidative stress and redox-sensitive signaling, have been implicated in the pathogenesis of hypertension. Thus, besides standard antihypertensive medications, which lower arterial pressure, antioxidant medications were tested to improve antihypertensive treatment. We review and discuss the role of oxidative stress in the pathophysiology of hypertension and the potential use of antioxidants in the management of hypertension and its associated organ damage.

Carboxymethyl-glucan from Saccharomyces cerevisiae reduces blood pressure and improves baroreflex sensitivity in spontaneously hypertensive rats

Carboxymethyl-glucan (CMG) is a derivative of β-d-glucan extracted from Sacharomyces cerevisae. This polymer presents improved physicochemical properties and shows health benefits, such as immunomodulation, antioxidant, anti-inflammatory, anti-tumor, and antiplatelet activities, and improved vascular function. However, studies concerning the effect of administration of CMG on the cardiovascular parameters, mainly in the field of hypertension, are scarce. This study aimed to investigate the effect of administration of CMG in spontaneously hypertensive rats (SHR) and normotensive rats (WKY) models. Normotensive and hypertensive animals received CMG at doses of 20 mg kg-1 and 60 mg kg-1 for four weeks. Then, weight gain, lipid profile, renal function, blood pressure, cardiac hypertrophy, baroreflex sensitivity, and sympathetic tone were evaluated. Oral administration of CMG influenced weight gain and cholesterol levels, and significantly reduced urea in the hypertensive animals. It decreased blood pressure levels and cardiac hypertrophy, improved baroreflex response, and reduced the influence of sympathetic tone. The results demonstrate the antihypertensive effect of CMG through improvement in baroreflex sensitivity via sympathetic tone modulation.

Superoxide Dismutase Administration: A Review of Proposed Human Uses

Superoxide dismutases (SODs) are metalloenzymes that play a major role in antioxidant defense against oxidative stress in the body. SOD supplementation may therefore trigger the endogenous antioxidant machinery for the neutralization of free-radical excess and be used in a variety of pathological settings. This paper aimed to provide an extensive review of the possible uses of SODs in a range of pathological settings, as well as describe the current pitfalls and the delivery strategies that are in development to solve bioavailability issues. We carried out a PubMed query, using the keywords "SOD", "SOD mimetics", "SOD supplementation", which included papers published in the English language, between 2012 and 2020, on the potential therapeutic applications of SODs, including detoxification strategies. As highlighted in this paper, it can be argued that the generic antioxidant effects of SODs are beneficial under all tested conditions, from ocular and cardiovascular diseases to neurodegenerative disorders and metabolic diseases, including diabetes and its complications and obesity. However, it must be underlined that clinical evidence for its efficacy is limited and consequently, this efficacy is currently far from being demonstrated.

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.

The Effects of Trimetazidine on QT-interval Prolongation and Cardiac Hypertrophy in Diabetic Rats

Background

Trimetazidine (TMZ) is an anti-ischemic drug. In spite of its protective effects on cardiovascular system, there is no scientific study on the usefulness of TMZ treatment for prolonged QT interval and cardiac hypertrophy induced by diabetes.

Objectives

To evaluate the effects of TMZ on QT interval prolongation and cardiac hypertrophy in the diabetic rats.

Methods

Twenty-four male Sprague-Dawley rats (200-250 g) were randomly assigned into three groups (n = 8) by simple random sampling method. Control (C), diabetic (D), and diabetic administrated with TMZ at 10 mg/kg (T10). TMZ was administrated for 8 weeks. The echocardiogram was recorded before isolating the hearts and transfer to a Langendorff apparatus. Hemodynamic parameters, QT and corrected QT interval (QTc) intervals, heart rate and antioxidant enzymes were measured. The hypertrophy index was calculated. The results were evaluated by one-way ANOVA and paired t-test using SPSS (version 16) and p < 0.05 was regarded as significant.

Results

The diabetic rats significantly indicated increased hypertrophy, QT and QTc intervals and decreased Left ventricular systolic pressure (LVSP), Left ventricular developed pressure (LVDP), rate pressure product (RPP), Max dp/dt, and min dp/dt (±dp/dt max), heart rate, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase in the heart. Treatment with TMZ in the diabetic animals was significantly improved these parameters in comparison to the untreated diabetic group.

Conclusions

TMZ improves QTc interval prolongation and cardiac hypertrophy in diabetes.

A Specific Melon Concentrate Exhibits Photoprotective Effects from Antioxidant Activity in Healthy Adults

Skin is the largest body organ and the first barrier to exogenous threats. This organ is constantly exposed to external factors such as ultraviolet radiation, which induces many adverse effects including sunburn, depigmentation, photo aging, photo immune suppression, and even skin cancer. Antioxidants seem to be good candidates in order to reduce ultraviolet-mediated damages and to prevent the health consequences of ultraviolet exposure. The present investigation aims to further characterize the potential skin photoprotective effects of a food supplementation and a topical administration of a melon concentrate alone or in combination. A clinical study assessing the Minimal Erythema Dose (MED) was first set up to evaluate photoprotection. Afterward, an independent in vitro study was performed on human skin explants from a donor to evaluate the effect of the melon concentrate at different levels including on the sunburn cells formation and on the endogenous antioxidant enzymes and its influence on melanin. Clinical study results demonstrate that melon concentrate application and/or supplementation increased MED. It also increased the endogenous antioxidant enzymes and reduced sunburn cells and melanin level on irradiated skin explants. Therefore, it is suggested that melon concentrate administration (oral and/or topical) could be a useful strategy for photoprotection due to its antioxidant properties.

Dietary supplementation with a specific melon concentrate reverses vascular dysfunction induced by cafeteria diet

Background

Obesity-related metabolic syndrome is associated with high incidence of cardiovascular diseases partially consecutive to vascular dysfunction. Therapeutic strategies consisting of multidisciplinary interventions include nutritional approaches. Benefits of supplementation with a specific melon concentrate, enriched in superoxide dismutase (SOD), have previously been shown on the development of insulin resistance and inflammation in a nutritional hamster model of obesity.

Objective

We further investigated arterial function in this animal model of metabolic syndrome and studied the effect of melon concentrate supplementation on arterial contractile activity.

Design and results

The study was performed on a hamster model of diet-induced obesity. After a 15-week period of cafeteria diet, animals were supplemented during 4 weeks with a specific melon concentrate (Cucumis melo L.) Contractile responses of isolated aorta to various agonists and antagonists were studied ex vivo. Cafeteria diet induced vascular contractile dysfunction associated with morphological remodeling. Melon concentrate supplementation partially corrected these dysfunctions; reduced morphological alterations; and improved contractile function, especially by increasing nitric oxide bioavailability and expression of endogenous SOD.

Conclusions

Supplementation with the specific melon concentrate improves vascular dysfunction associated with obesity. This beneficial effect may be accounted for by induction of endogenous antioxidant defense. Such an approach in line with nutritional interventions could be a useful strategy to manage metabolic syndrome–induced cardiovascular trouble.

Diet supplementation with a specific melon concentrate improves oviduct antioxidant defenses and egg characteristics in laying hens

The objectives of this study were to investigate the effects of a specific melon concentrate on oviduct antioxidant defenses and egg characteristics of laying hens.Lohmann Brown hens were assigned to 2 treatment groups (n = 16 in each). One group was supplemented with the melon concentrate (26 mg/kg of feed) during 6 wk. The other group was composed of untreated hens, which served as control. Eggs were collected, weighed (yolk, albumen, shell), and analyzed (Haugh unit and albumen pH relevant for egg freshness) at the end of the supplementation period. Antioxidant status was evaluated in the oviduct measuring antioxidant enzymes by western blotting.This study demonstrated that the melon concentrate could ameliorate egg weight, and particularly yolk contribution to egg weight and egg shell weight. An increase in endogenous antioxidant defenses in the oviduct after this melon concentrate supplementation could explain the better egg characteristics. The improvement of egg quality, due to melon concentrate, may have important economic implications for future breeding programs, particularly if these effects generalize from hens to other poultry species, or even other livestock animal species.

Relaxin and atrial natriuretic peptide pathways participate in the anti-fibrotic effect of a melon concentrate in spontaneously hypertensive rats

BACKGROUND

In spontaneously hypertensive rats (SHR), a model of human essential hypertension, oxidative stress is involved in the development of cardiac hypertrophy and fibrosis associated with hypertension. Dietary supplementation with agents exhibiting antioxidant properties could have a beneficial effect in remodeling of the heart. We previously demonstrated a potent anti-hypertrophic effect of a specific melon (Cucumis melo L.) concentrate with antioxidant properties in spontaneously hypertensive rats. Relaxin and atrial natriuretic peptide (ANP) were reported to reduce collagen deposition and fibrosis progression in various experimental models.

OBJECTIVE

The aim of the present investigation was to test the hypothesis that, beside reduction in oxidative stress, the melon concentrate may act through relaxin, its receptor (relaxin/insulin-like family peptide receptor 1, RXFP1), and ANP in SHR.

DESIGN AND RESULTS

The melon concentrate, given orally during 4 days, reduced cardiomyocyte size (by 25%) and totally reversed cardiac collagen content (Sirius red staining) in SHR but not in their normotensive controls. Treatment with the melon concentrate lowered cardiac nitrotyrosine-stained area (by 45%) and increased by 17-19% the cardiac expression (Western blot) of superoxide dismutase (SOD) and glutathione peroxidase. In addition, plasma relaxin concentration was normalized while cardiac relaxin (Western blot) was lowered in treated SHR. Cardiac relaxin receptor level determined by immunohistochemical analysis increased only in treated SHR. Similarly, the melon concentrate reversed the reduction of plasma ANP concentration and lowered its cardiac expression.

CONCLUSIONS

The present results demonstrate that reversal of cardiac fibrosis by the melon concentrate involves antioxidant defenses, as well as relaxin and ANP pathways restoration. It is suggested that dietary SOD supplementation could be a useful additional strategy against cardiac hypertrophy and fibrosis.

Protective effect of myostatin gene deletion on aging-related muscle metabolic decline

While myostatin gene deletion is a promising therapy to fight muscle loss during aging, this approach induces also skeletal muscle metabolic changes such as mitochondrial deficits, redox alteration and increased fatigability. In the present study, we evaluated the effects of aging on these features in aged wild-type (WT) and mstn knockout (KO) mice. Moreover, to determine whether an enriched-antioxidant diet may be useful to prevent age-related disorders, we orally administered to the two genotypes a melon concentrate rich in superoxide dismutase for 12 weeks. We reported that mitochondrial functional abnormalities persisted (decreased state 3 and 4 of respiration; p<0.05) in skeletal muscle from aged KO mice; however, differences with WT mice were attenuated at old age in line with reduced difference on running endurance between the two genotypes. Interestingly, we showed an increase in glutathione levels, associated with lower lipid peroxidation levels in KO muscle. Enriched antioxidant diet reduced the aging-related negative effects on maximal aerobic velocity and running limit time (p<0.05) in both groups, with systemic adaptations on body weight. The redox status and the hypertrophic phenotype appeared to be beneficial to KO mice, mitigating the effect of aging on the skeletal muscle metabolic remodeling.

Dietary supplementation with a superoxide dismutase-melon concentrate reduces stress, physical and mental fatigue in healthy people: a randomised, double-blind, placebo-controlled trial

Background: We aimed to investigate effects of superoxide dismutase (SOD)-melon concentrate supplementation on psychological stress, physical and mental fatigue in healthy people. Methods: A randomized, double-blind, placebo-controlled trial was performed on 61 people divided in two groups: active supplement (n = 32) and placebo (n = 29) for 12 weeks. Volunteers were given one small hard capsule per day. One capsule contained 10 mg of SOD-melon concentrate (140 U of SOD) and starch for the active supplement and starch only for the placebo. Stress and fatigue were evaluated using four psychometric scales: PSS-14; SF-36; Stroop tests and Prevost scale. Results: The supplementation with SOD-melon concentrate significantly decreased perceived stress, compared to placebo. Moreover, quality of life was improved and physical and mental fatigue were reduced with SOD-melon concentrate supplementation. Conclusion: SOD-melon concentrate supplementation appears to be an effective and natural way to reduce stress and fatigue. Trial registration: trial approved by the ethical committee of Poitiers (France), and the ClinicalTrials.gov Identifier is NCT01767922.