Short-term assessment of toxicological aspects, oxidative and inflammatory response to dietary melon superoxide dismutase in rats

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 superoxide dismutase-rich melon pulp concentrate on inflammation, antioxidant status and growth performance of challenged post-weaning piglets

Piglets can often suffer impaired antioxidant status and poor immune response during post-weaning, especially when chronic inflammation takes place, leading to lower growth rates than expected. Oral administration of dietary antioxidant compounds during this period could be a feasible way to balance oxidation processes and increase health and growth performance. The aim of the trial was to study the effects of an antioxidant feed supplement (melon pulp concentrate) that contains high concentration of the antioxidant superoxide dismutase (SOD) on inflammation, antioxidant status and growth performance of lipopolysaccharide (LPS) challenged weaned piglets. In total, 48 weaned piglets were individually allocated to four experimental groups in a 2×2 factorial design for 29 days. Two different dietary treatments were adopted: (a) control (CTR), fed a basal diet, (b) treatment (MPC), fed the basal diet plus 30 g/ton of melon pulp concentrate. On days 19, 21, 23 and 25 half of the animals within CTR and MPC groups were subjected to a challenge with intramuscular injections of an increasing dosage of LPS from Escherichia coli (serotype 0.55:B5) (+) or were injected with an equal amount of PBS solution (-). Blood samples were collected at the beginning of the trial and under the challenge period for interleukin 1β, interleukin 6, tumour necrosis factor α, haptoglobin, plasma SOD activity, total antioxidant capacity, reactive oxygen species, red blood cells and plasma resistance to haemolysis, and 8-oxo-7, 8-dihydro-2'-deoxyguanosine. Growth performance was evaluated weekly. A positive effect of melon pulp concentrate was evidenced on total antioxidant capacity, half-haemolysis time of red blood cells, average daily gain (ADG) and feed intake, while LPS challenge increased pro-inflammatory cytokines and haptoglobin serum concentrations, with a reduced feed intake and gain : feed (G : F). The obtained results show that oral SOD supplementation with melon pulp concentrate ameliorates the total antioxidant capacity and the half-haemolysis time in red blood cell of post-weaning piglets, with positive results on growing performance.

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.

Inhalation of Talc Induces Infiltration of Macrophages and Upregulation of Manganese Superoxide Dismutase in Rats

Talc is a mineral that is widely used in cosmetic products, antiseptics, paints, and rubber manufacturing. Although the toxicological effects of talc have been studied extensively, until now no detailed inhalation study of talc focusing on oxidative stress has been done. This repeated 4 weeks whole-body inhalation toxicity study of talc involved Sprague-Dawley rats. Male and female groups of rats were exposed to inhaled talc at 0, 5, 50, and 100 mg/m(3) for 6 hours daily, 5 days/week for 4 weeks. The objective was to identify the 4-week inhalation toxicity of talc and investigate antioxidant activity after exposure to talc. There were no treatment-related symptoms or mortality in rats treated with talc. Glucose (GLU) was decreased significantly in male rats exposed to 50 and 100 mg/m(3) of talc. Histopathological examination revealed infiltration of macrophages on the alveolar walls and spaces near the terminal and respiratory bronchioles. In male and female rats exposed to 100 mg/m(3) talc, expression of superoxide dismutase 2, a typical biological indicator of oxidative damage, was significantly increased. Thus, inhalation of talc induces macrophage aggregations and oxidative damage in the lung.

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.

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

We assessed the influence of SODB, a melon superoxide dismutase (SOD), on left ventricular (LV) hypertrophy in SHR. SODB (4 or 40U SOD) was given orally for 4 or 28 days to SHR. For each treatment period, LV weight index (LVWI) and cardiomyocytes size were measured. SOD, glutathione peroxidase (GPx) and catalase expressions, and LV production and presence of superoxide anion were determined. Pro-inflammatory markers were also measured. SODB reduced LVWI and cardiomyocytes size after 4 or 28 days. Cardiac SOD and GPx increased by 30-40% with SODB. The presence but not production of superoxide anion was significantly reduced by SODB. No effect of SODB was detected on inflammatory status in any group. The beneficial effect of SODB on cardiac hypertrophy seems to be related to the stimulation of endogenous antioxidant defense, suggesting that SODB may be of interest as a dietary supplementation during conventional antihypertensive therapy.

Cafeteria diet induces obesity and insulin resistance associated with oxidative stress but not with inflammation: improvement by dietary supplementation with a melon superoxide dismutase

Oxidative stress is involved in obesity. However, dietary antioxidants could prevent oxidative stress-induced damage. We have previously shown the preventive effects of a melon superoxide dismutase (SODB) on oxidative stress. However, the mechanism of action of SODB is still unknown. Here, we evaluated the effects of a 1-month curative supplementation with SODB on the liver of obese hamsters. Golden Syrian hamsters received either a standard diet or a cafeteria diet composed of high-fat, high-sugar, and high-salt supermarket products, for 15 weeks. This diet resulted in insulin resistance and in increased oxidative stress in the liver. However, inflammatory markers (IL-6, TNF-α, and NF-κB) were not enhanced and no liver steatosis was detected, although these are usually described in obesity-induced insulin resistance models. After the 1-month supplementation with SODB, body weight and insulin resistance induced by the cafeteria diet were reduced and hepatic oxidative stress was corrected. This could be due to the increased expression of the liver antioxidant defense proteins (manganese and copper/zinc superoxide dismutase, catalase, and glutathione peroxidase). Even though no inflammation was detected in the obese hamsters, inflammatory markers were decreased after SODB supplementation, probably through the reduction of oxidative stress. These findings suggest for the first time that SODB could exert its antioxidant properties by inducing the endogenous antioxidant defense. The mechanisms underlying this induction need to be further investigated.

Superoxide dismutase administration, a potential therapy against oxidative stress related diseases: several routes of supplementation and proposal of an original mechanism of action

Oxidative stress, involved in many diseases, is defined as an impaired balance between reactive oxygen species (ROS) production and antioxidant defences. Antioxidant enzymes such as superoxide dismutase (SOD) play a key role in diminishing oxidative stress. Thus, the removal of ROS by exogenous SODs could be an effective preventive strategy against various diseases. The poor bioavailability of exogenous SODs has been criticized. However, improvements in SOD formulation may overcome this limitation and boost interest in its therapeutic properties. Here, we provide a review of animal and human studies about SODs supplementation in order to evaluate their therapeutic value. Protective effects have been observed against irradiation, carcinogenesis, apoptosis and neurodegeneration. SODs administration has also been reported to alleviate inflammatory, infectious, respiratory, metabolic and cardiovascular diseases and genitourinary and fertility disorders, raising the question of its mechanism of action in these diverse situations. Some authors have shown an increase in endogenous antioxidant enzymes after exogenous SODs administration. The induction of endogenous antioxidant defence and, consequently, a decrease in oxidative stress, could explain all the effects observed. Further investigations need to be carried out to test the hypothesis that SODs supplementation acts by inducing an endogenous antioxidant defence.