Diabetic cardiomyopathy is one of the major mortality risk factors among diabetic patients worldwide. It has been established that most of the cardiac structural and functional alterations in the diabetic cardiomyopathy condition resulted from the hyperglycemia-induced persistent oxidative stress in the heart, resulting in the maladaptive responses of inflammation and apoptosis. Flavonoids, the most abundant phytochemical in plants, have been reported to exhibit diverse therapeutic potential in medicine and other biological activities. Flavonoids have been widely studied for their effects in protecting the heart against diabetes-induced cardiomyopathy. The potential of flavonoids in alleviating diabetic cardiomyopathy is mainly related with their remedial actions as anti-hyperglycemic, antioxidant, anti-inflammatory, and anti-apoptotic agents. In this review, we summarize the latest findings of flavonoid treatments on diabetic cardiomyopathy as well as elucidating the mechanisms involved.

Monosodium glutamate (MSG) is widely used in food preparation industry and has been consumed regularly. Previous studies had reported on effects of MSG when given at extremely high dosages, the results are not applicable to human equivalent intake. Therefore, the present study aimed to evaluate the effect of MSG on sperm quality and changes in reproductive organs of adult male rats when taken at average human daily intake (ADI). Twenty-four adult male rats were randomly assigned into three groups; NC (Normal control), MSG60 and MSG120 where MSG was given orally at 60 mg/kg and 120 mg/kg to each respective group. All treatments were conducted for 28 consecutive days. MSG at estimated ADI of 120 mg/kg body weight resulted in a significant drop in sperm quality (p < 0.05) when compared to both control and MSG60 groups. A significant decrease in the weight of reproductive organs was also apparent (p < 0.05). Moreover, oxidative status evaluation showed that treatment of MSG induces oxidative stress in the testis, more severely at a dose of 120 mg/kg body weight. These findings are supported by alterations in the observed histology of reproductive organs. This study shows that an intake dose of 120 mg/kg body weight MSG could cause significant damage to the reproductive system.

Background: Nicotine is a major toxic and hazardous component of cigarette smoke, and it has been widely used in nicotine replacement therapy (NRT). This study was aimed to investigate the effects of chronic low-dose nicotine on sperm characteristics and reproductive organ integrity in adolescent male Sprague-Dawley rats.Methods: Twelve rats were equally divided into two groups. Group I received normal saline, and group II received 0.6 mg/kg body weight nicotine intraperitoneally for 28 consecutive days. At the end of the experimental period, sperm was collected for sperm characteristic evaluation, and the testes and prostate were isolated for biochemical and morphological analysis. The effects of nicotine on the body and reproductive organ weights of the animals were evaluated.Results: Chronic nicotine treatment significantly (P < 0.05) altered the sperm count, motility, viability, and morphology, and remarkably increased the malondialdehyde (P < 0.001) and advanced oxidation protein product (P < 0.05) levels in the testes and prostate of nicotinetreated group compared to control group. Moreover, nicotine caused a significant decrease (P < 0.05) in the superoxide dismutase activity of the testes. No significant differences were observed in the reduced glutathione level in both of the testes and prostate of nicotine group compared with control group. Nicotine also induced histopathological alteration in the testes.Conclusion: A low-dose nicotine exposure at 0.6 mg/kg caused detrimental effects on sperm characteristics and induced oxidative stress in the testes and prostate.

As the powerhouse of the cells, mitochondria play a very important role in ensuring that cells continue to function. Mitochondrial dysfunction is one of the main factors contributing to the development of cardiomyopathy in diabetes mellitus. In early development of diabetic cardiomyopathy (DCM), patients present with myocardial fibrosis, dysfunctional remodeling and diastolic dysfunction, which later develop into systolic dysfunction and eventually heart failure. Cardiac mitochondrial dysfunction has been implicated in the development and progression of DCM. Thus, it is important to develop novel therapeutics in order to prevent the progression of DCM, especially by targeting mitochondrial dysfunction. To date, a number of studies have reported the potential of phenolic acids in exerting the cardioprotective effect by combating mitochondrial dysfunction, implicating its potential to be adopted in DCM therapies. Therefore, the aim of this review is to provide a concise overview of mitochondrial dysfunction in the development of DCM and the potential role of phenolic acids in combating cardiac mitochondrial dysfunction. Such information can be used for future development of phenolic acids as means of treating DCM by alleviating the cardiac mitochondrial dysfunction.

Previous studies found that Kelulut Honey produced by Trigona spp. bees is able to prevent oxidative damage in various pathological conditions.  Thus, the present study aimed to determine whether Kelulut Honey could prevent the sperm and testicular damage in streptozotocin-induced diabetic rats. Male Adult male Sprague-Dawley rats were divided into four groups: Non-Diabetic (NDM), Non-Diabetic with Kelulut Honey supplementation (NDMKH), Diabetic without supplementation (DM) and Diabetic with Kelulut Honey supplementation (DMKH).  Kelulut honey was given at the dose of 2.0 g/kg weight daily via gavage for 28 consecutive days. Results showed that sperm quality produced by diabetic rats supplemented with Kelulut honey significantly improved compared to the diabetic control groups (p<0.05). SOD activity and GSH level increased significantly (p<0.05) whereas PC and MDA levels significantly decreased in sperm and testis of DMKH rats when compared to DM rats (p<0.05). Histological observation showed obvious increase in spermatozoa in the lumen of epididymis and increased spermatogenic cells density in the testis of DMKH group.  In conclusion, Kelulut Honey has a potential in preventing the damage of sperm and testis in diabetic rats.

Cardiovascular disease is the most common cause of death among diabetic patients worldwide. Hence, cardiovascular wellbeing in diabetic patients requires utmost importance in disease management. Recent studies have demonstrated that protein kinase C activation plays a vital role in the development of cardiovascular complications via its activation of mitogen-activated protein kinase (MAPK) cascades, also known as PKC-MAPK pathways. In fact, persistent hyperglycaemia in diabetic conditions contribute to preserved PKC activation mediated by excessive production of diacylglycerol (DAG) and oxidative stress. PKC-MAPK pathways are involved in several cellular responses, including enhancing oxidative stress and activating signalling pathways that lead to uncontrolled cardiac and vascular remodelling and their subsequent dysfunction. In this review, we discuss the recent discovery on the role of PKC-MAPK pathways, the mechanisms involved in the development and progression of diabetic cardiovascular complications, and their potential as therapeutic targets for cardiovascular management in diabetic patients.

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids’ ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy.

Oxidative stress plays a critical role in diabetes-induced complications including injurious effect on male reproductive organ. Hibiscus sabdariffa Linn. or roselle possesses antioxidant properties and widely used to treat various diseases. The study was aimed to evaluate the effect of H. sabdariffa polyphenol-rich extract (HPE) from the calyces towards male reproductive organs in diabetic rats. Twenty-four male rats were divided into three groups; (i) normal nondiabetic (NDM), (ii) diabetic (DM) and (iii) diabetic treated with HPE (DM + HPE) groups. Diabetes was induced with streptozotocin (60 mg/kg, single i.p.). HPE (100 mg/kg) was administrated by forced feeding for 28 consecutive days before being sacrificed to harvest their reproductive organs. Results showed that superoxide dismutase (SOD) and catalase (CAT) activities as well as gluthathione (GSH) levels in the testis homogenate of DM + HPE group were significantly higher (p < 0.05) compared to DM group. Meanwhile, significantly lower levels of malondialdehyde (MDA) and protein carbonyl (PC) were observed in DM + HPE group compared to DM group. The histological observation showed morphological alteration of the testis in DM group, which was impeded following supplementation of HPE. In conclusion, this suggests that HPE supplementation is able to prevent oxidant injury of testis of diabetic rats.