Furan toxicity on testes and protective role of lycopene in diabetic rats

Mechanistic insights on lycopene usage against diabetes and associated complications

Lycopene is a tetraterpene compound belonging to carotenoids that are widely present in tomatoes and similar products. It is known as a powerful anti-oxidant and a non-provitamin A carotenoid. Lycopene has been found to effectively improve diabetes mellitus and its complications, such as cardiac complications, disorders caused by oxidative stress, and liver and neurological disorders. Furthermore, free radicals have been shown to disrupt the action of insulin by changing the physical state of the target cell membrane, while carotenoids improve insulin secretion and function in blood sugar regulation by neutralizing free radicals. It, therefore, seems that targeted clinical studies are needed to investigate the therapeutic effect of lycopene against metabolic disorders induced by diabetes. This review aims to summarize information on the sources and potential uses of lycopene and the possible mechanisms involved in the reduction of the above diseases. Its protective effects, in terms of toxicity and safety, are also discussed. The literature sources used in this review were PubMed, Google Scholar, Scopus, and Web of Science databases.

The impact of furan exposure on steroidogenesis in Leydig cells: cellular and molecular observations

BACKGROUND

Furan is an organic compound that occurs as a result of heat treatment during the processing and cooking of many food products. Furthermore, the environment contains furan in tobacco smoke and vehicle exhaust gases, and it serves as an intermediate molecule in the synthesis of various pharmaceutical and chemical agents, pesticides, and stabilizers. Studies on the male reproductive system have not been able to elucidate the pathway through which furan exerts its negative effects.

METHODS AND RESULTS

In this study, the TM3 Leydig cell line was exposed to various furan concentrations (0.03, 0.3, and 3 mM) for 24 h. In order to assess the cytotoxic effects of furan on Leydig cells, we examined cell viability, cell proliferation, and lactate dehydrogenase enzyme levels. To investigate the detrimental effects of furan on testosterone biosynthesis, quantitative analyses were conducted on cAMP and testosterone levels, as well as the expression levels of key genes and transcription factors implicated in the steroidogenic pathway. The results indicate that furan inhibited the viability and proliferation of Leydig cells and enhanced the activity of lactate dehydrogenase. Leydig cells administered to furan exhibited notable reductions in cAMP and testosterone levels. Additionally, while the expression levels of steroidogenic genes were downregulated, significant changes were detected in the expression levels of the transcription factors responsible for the regulation of these genes.

CONCLUSIONS

Consequently, our findings suggest that furan exerts inhibitory effects on steroidogenesis in Leydig cells through multiple mechanisms, ultimately leading to infertility by inducing dysfunction in Leydig cells.

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.

Assessment of the oxidative damage and apoptotic pathway related to furan cytotoxicity in cultured mouse Leydig cells

Research on heat-induced food contamination is being given more attention as a result of the health risks that have been publicly revealed in recent years. Furan is known as a colorless, combustible, heterocyclic aromatic organic molecule and is formed when food products are processed and stored. It has been established that furan, which is inevitably ingested, has a deleterious impact on human health and causes toxicity. Furan is known to have adverse effects on the immune system, neurological system, skin, liver, kidney, and fat tissue. Infertility caused by furan is a result of its damaging effects on several tissues and organs as well as the reproductive system. Although studies on the adverse effects of furan on the male reproductive system have been performed, there is no study revealing apoptosis in Leydig cells at the gene level. In this study, TM3 mouse Leydig cells were exposed to 250- and 2,500-μM concentrations of furan for 24 h. The findings demonstrated that furan decreased cell viability and antioxidant enzyme activity while increasing lipid peroxidation, reactive oxygen species, and apoptotic cell rates. Furan also increased the expression of the important apoptotic genes Casp3 and Trp53 while decreasing the expression of another pro-apoptotic gene, Bcl2, and antioxidant genes Sod1, Gpx1, and Cat. In conclusion, these results imply that furan may cause loss of cell function in mouse Leydig cells responsible for testosterone biosynthesis by impairing the efficiency of the antioxidant system, possibly by inducing cytotoxicity, oxidative stress, and apoptosis.

In silico detection of Cucurbitacin-E on antioxidant enzymes of model organism Galleria mellonella L. (Lepidoptera: Pyralidae) and variation of antioxidant enzyme activities and lipid peroxidation in treated larvae

Background

In silico studies further provided predictive binding properties of selected ligands for inhibition of target protein. In the study, molecular binding poses of Cucurbitacin-E and antioxidant enzymes (glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and acetylcholinesterase (AChE) of Galleria mellonella were determined in silico. Cucurbitacins are the most important components of Ecballium elaterium. The first cucurbitacin isolated from the plant was Cucurbitacin-E. In this study, the toxic effect of E. elaterium (L.) A. Rich. (Cucurbitaceae) fruit juice on G. mellonella (Lepidoptera: Pyralidae) larvae, which is known as a good model insect, was also detected, and its effect on antioxidant enzyme activities and lipid peroxidation was revealed.

Results

The plant fruit juice was tested on the target larvae of G. mellonella with different doses for 24 h. After the application, mortality rate, LC50, LC90 and LC99 values, the malondialdehyde (MDA) level and the activity changes of antioxidant enzymes were determined. Mortality increased with the increasing concentration of fruit juice. Also, increasing doses of essential oil caused decreasing in SOD, CAT, GST GPx, GR and AChE activities and increasing in MDA levels. As a result of in silico studies, maximum binding energy was obtained from G. mellonella CAT enzyme with Cucurbitacin E as a ligand.

Conclusions

This is the first study to demonstrate the in silico binding potential of Cucurbitacin E on G. mellonella enzymes. The results indicate that E. elaterium can be used against G. mellonella in a pest control program.

Graphical Abstract

Testicular toxicity of cisplatin in rats: ameliorative effect of lycopene and N-acetylcysteine

Lycopene (LP) and N-acetylcysteine (NAC) protective effects were assessed for testicular toxicity mediated by cisplatin (CP) in rats. Forty-nine rats were divided into 7 groups (n = 7); these groups included the control group (saline, PO), LP (10 mg/kg, PO), NAC (150 mg/kg, PO), CP (7.5 mg/kg, IP) on the 27th day of the study, LP + CP, NAC+CP, and LP + NAC + CP. Serum levels of testosterone were decreased following CP injection. Malondialdehyde (MDA) has been increased with considerable glutathione (GSH), and dismutase superoxide (SOD) and catalase (CAT) decline in the testis tissues after CP injection. CP caused severe alterations in testicular tissues and elevated caspase-3 expression. Besides that, LP and/or NAC administration improved CP-induced testicular toxicity and apoptosis, probably via their antioxidant properties.

Molecular docking and toxicity assessment of spirodiclofen: protective role of lycopene

In this study, toxic effects of spirodiclofen and protective role of lycopene against toxic effects were investigated by using physiological, cytogenetic, anatomical, and biochemical parameters. Allium cepa L. bulbs were used as test material. The bulbs were divided into six groups as one control and five application groups. Bulb in the control group was germinated with tap water, and in treatment groups, 20-mg L^-1 dose of spirodiclofen 215- and 430-mg L^-1 doses of lycopene were applied. Spirodiclofen application caused a decrease in physiological parameters such as germination percentage, root length, and weight increase. Spirodiclofen administration caused a decrease in the percentage of mitotic index (MI) and an increase in DNA fragmentation, micronucleus (MN), and chromosomal aberration (CA) frequency. Spirodiclofen application caused an increase in the level of the oxidant compound malondialdehyde (MDA), changes in the level of antioxidant enzymes, and disruption of the oxidant/antioxidant balance in the cell. Molecular interactions between spirodiclofen and antioxidant enzymes were determined by molecular docking analysis. In addition to physiological, biochemical, and genetic abnormalities, spirodiclofen also caused deformations in the anatomy of the A. cepa root tip meristematic cells. Lycopene treatment showed a protective effect by suppressing the toxic effects of spirodiclofen, causing a significant improvement in the values of selected physiological, cytogenetic, anatomical, and biochemical parameters. As a result, spirodiclofen insecticide caused toxic effects on various parameters in A. cepa, which is a eukaryotic model organism. In order to elucidate the toxicity mechanism, each parameter is associated with each other. Molecular docking method has revealed the effects of spirodiclofen on antioxidant enzymes. Lycopene application together with spirodiclofen resulted in the regression of all toxic effects and improvement in the root tissue. This result shows that lycopene has a strong protective property against spirodiclofen toxicity.

Effects of endocrine disruptor furan on reproductive physiology of Sprague Dawley rats: An F1 Extended One-Generation Reproductive Toxicity Study (EOGRTS)

The present study investigated the reproductive toxicity of furan in an Extended One-Generation Reproductive Toxicity Study in rats. Sprague Dawley F0 weaning rats (30 per sex per group) were exposed to furan orally at 0, 1, 2.5, 5, and 10 mg kg^-1 for 10 weeks (males) and 2 weeks (females) and then mated. Results of F0 indicated that in the furan-treated groups (5 mg kg^-1 and 10 mg kg^-1), body weight (bw) gain decreased during prebreed and gestational period while increased during lactation periods. F0 animals prebreeding exposure resulted in head tilt and foot splay at 10 mg kg^-1. Number of live pups at birth were decreased (p < 0.001) at 10 mg kg^-1. At postnatal day (PND) 70, a significant (p = 0.03) decrease in testosterone levels of male rats and estrogen levels of female rats (p = 0.05) was observed in 10 mg kg^-1 furan-treated group in F1 generation. Luteinizing hormone, follicle-stimulating hormone, and progesterone levels were also reduced, but their reduction was not statistically significant in all groups. In higher dose furan group (10 mg kg^-1), testicular and ovarian weights were reduced in F1 generation at PND 70, with decreased daily sperm production (p = 0.01) and disturbed estrous cyclicity (p < 0.01). Some histopathological changes were also observed in testis and ovaries in groups whose parents were previously exposed to 10 mg kg^-1 bw of furan group. Based on the above results, it is suggested that exposure to food-based contaminant furan induced remarkable changes in the F0 (parental stage) and F1 (offspring, pubertal, and adult stage) generations of Sprague Dawley rats.

Testicular toxicity of gentamicin in adult rats: Ameliorative effect of lycopene

The current study was aimed to investigate the ameliorative effect of lycopene against gentamicin-induced testicular toxicity in adult rat testes. Pretreatment with lycopene (4 mg/kg/day) significantly prevented the decrease in the absolute testes weight and relative testes weight and the reduction in sperm count, motility, viability, and daily sperm production in gentamicin (100 mg/kg/day)-treated rats. Gentamicin significantly decreased the level of serum testosterone and testicular lactate dehydrogenase-X and G6PDH activities but a marked increase was observed upon pretreatment with lycopene. Testicular caspase-3 and -9 activities were significantly increased but lycopene showed significant protection from gentamicin-induced apoptosis. Oxidative stress was induced by gentamicin treatment as evidenced by increased hydrogen peroxide level and lipid peroxidation and decreased the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and glutathione content. These alterations were effectively prevented by lycopene pretreatment. Histopathological examination showed loss of spermatogenesis and morphological abnormalities of the testis after treatment with gentamycin. These abnormalities were effectively normalized by pretreatment with lycopene. In conclusion, gentamicin decreases rat testes weight and inhibits spermatogenesis. It induces oxidative stress and apoptosis by possible mitochondrial dysfunction. These data provide insight into the mode of action of gentamicin-induced testicular toxicity and the beneficial role provided by lycopene to restore the suppressed spermatogenesis.

Let food be your medicine: nutraceutical properties of lycopene

In this review, we highlight research and clinical trials involving lycopene and its impact on human health.

Furan-induced cardiotoxicity in diabetic rats and protective role of lycopene

The objective of this current study is to search the impacts of furan and lycopene on a diabetic rat's heart. Diabetes increases prevalence with a sedentary lifestyle and obesity. Furan, a carcinogen, was detected in foods that had undergone thermal treatment. Two groups were formed, such as: the control and diabetic groups. Diabetic groups fall into four allocated groups: control, lycopene, furan, and furan + lycopene. The changes in malondialdehide levels, antioxidant enzymes' activities, and histopathology of the heart were pointed out. We observed that the changes in both the MDA level and the antioxidant enzymes' activities were due to diabetes. Furan-induced increment in MDA levels, but GST, CAT, SOD, and GPx activities showed a decrease. Lycopene influenced these changes positively. In terms of the pathological studies, changes were also observed in diabetic rats. The histological damage in the diabetic furan groups was found to be very serious. Lycopene was protective against furan that caused histopathological changes. Diabetes and furan resulted into heart damages in rats and lycopene showed preventive effects. But this was not a complete protection. PRACTICAL APPLICATIONS: Furan by product of chlorinated chemical compounds production and chemical processes including combustion, are virtually ubiquitous in the environment. Because of this, furan occur potential risk for human health. Furan is known to exist at higher levels in fatty foods, such as full-fat milk and dairy products, meat and eggs. They can accumulate in the fatty tissues of animals and humans. Diabetes increase in the prevalence of a sedentary lifestyle and obesity. Diabetes with furan-induced cardiotoxicity. Foods should not be heated over and over again, especially diabetic heart patients should stay away from this situation.

Effects of lycopene on metabolism of glycolipid in type 2 diabetic rats

Diabetes is a series of metabolic diseases, which characteristics is hyperglycemia caused by the interruption of insulin action. Lycopene is an antioxidant which has potential anti-diabetic activity but the correlative reports are rare. This study was designed to explore the influence of lycopene on metabolism of glycolipid in type 2 diabetes. The model of type2 diabetes was induced in adult male albino Sprague Dawley rats, weighing 180-220 g, feeding high fat diet for 4 weeks, then streptozotocin (25 mg/kg) was intraperitoneally injected. 1 week after, rats in diabetic group showed increasing in fasting blood glucose, lipid in blood and liver, glycosylated hemoglobin, HOMA-IR and decreasing in plasma insulin comparing with the normal control group after modeling. Oral administration of lycopene oil solution (10 mg/kg or 20 mg/kg body weight) once a day for 10 weeks can improve the above changes and make them toward to normality. The activities of oxidative enzymes SOD and GSH-Px increased and MDA decreased in pancreatic tissue of rats after the intervention of lycopene. In addition, it can also observe that lycopene can protect body weight loss from diabetic rats. These results showed that lycopene has potential effect on anti-diabetes and it can regulate the metabolism of glycolipid in diabetic rats.

Thermal processing food-related toxicants: a review

Heterocyclic aromatic amines, acrylamide, 5-hydroxymethylfurfural, furan, polycyclic aromatic hydrocarbons, nitrosamines, acrolein, chloropropanols and chloroesters are generated toxicants formed in some foodstuffs, mainly starchy and protein-rich food during thermal treatment such as frying, roasting and baking. The formation of these chemical compounds is associated with development of aromas, colors and flavors. One of the challenges facing the food industry today is to minimize these toxicants without adversely affecting the positive attributes of thermal processing. To achieve this objective, it is essential to have a detailed understanding of the mechanism of formation of these toxicants in processed foods. All reviewed toxicants in that paper are classified as probable, possible or potential human carcinogens and have been proven to be carcinogenic in animal studies. The purpose of that review is to summarize some of the most frequent occurring heat-generated food toxicants during conventional heating, their metabolism and carcinogenicity. Moreover, conventional and microwave heating were also compared as two different heat treatment methods, especially how they change food chemical composition and which thermal food toxicants are formed during specific method.

Risks for public health related to the presence of furan and methylfurans in food

The European Commission asked EFSA for a scientific evaluation on the risk to human health of the presence of furan and methylfurans (2-methylfuran, 3-methylfuran and 2,5-dimethylfuran) in food. They are formed in foods during thermal processing and can co-occur. Furans are produced from several precursors such as ascorbic acid, amino acids, carbohydrates, unsaturated fatty acids and carotenoids, and are found in a variety of foods including coffee and canned and jarred foods. Regarding furan occurrence, 17,056 analytical results were used in the evaluation. No occurrence data were received on methylfurans. The highest exposures to furan were estimated for infants, mainly from ready-to-eat meals. Grains and grain-based products contribute most for toddlers, other children and adolescents. In adults, elderly and very elderly, coffee is the main contributor to dietary exposure. Furan is absorbed from the gastrointestinal tract and is found in highest amounts in the liver. It has a short half-life and is metabolised by cytochrome P450 2E1 (CYP2E1) to the reactive metabolite, cis-but-2-ene-1,4-dialdehyde (BDA). BDA can bind covalently to amino acids, proteins and DNA. Furan is hepatotoxic in rats and mice with cholangiofibrosis in rats and hepatocellular adenomas/carcinomas in mice being the most prominent effects. There is limited evidence of chromosomal damage in vivo and a lack of understanding of the underlying mechanism. Clear evidence for indirect mechanisms involved in carcinogenesis include oxidative stress, gene expression alterations, epigenetic changes, inflammation and increased cell proliferation. The CONTAM Panel used a margin of exposure (MOE) approach for the risk characterisation using as a reference point a benchmark dose lower confidence limit for a benchmark response of 10% of 0.064 mg/kg body weight (bw) per day for the incidence of cholangiofibrosis in the rat. The calculated MOEs indicate a health concern. This conclusion was supported by the calculated MOEs for the neoplastic effects.