The neuroprotective effects of melatonin against diabetic neuropathy: A systematic review of non-clinical studies

Modulating oxidative stress, apoptosis, and mitochondrial dysfunctions on cardiotoxicity induced by aluminum phosphide pesticide using resveratrol

The agricultural fumigant pesticide aluminum phosphide (AlP) is cardiotoxic. Water causes AlP to emit phosphine gas, a cardiac toxin that affects heart function and causes cardiogenic shock. AlP poisoning's high fatality rate is due to cardiotoxicity. This study examines how resveratrol reduces oxidative stress, mitochondrial activity, and apoptosis in human cardiac myocyte (HCM) cells. After determining the optimal doses of resveratrol using the MTT test, HCM cells were subjected to a 24-h treatment of resveratrol following exposure to AlP (2.36 μM). The levels of reactive oxygen species (ROS), superoxide dismutase (SOD) activity, mitochondrial swelling, mitochondrial cytochrome c release, and mitochondrial membrane potential (MMP) in HCM cells were investigated. Also, the expression of Bax and Bcl-2, caspace-3 activity, and apoptosis were assessed. The present investigation revealed that AlP substantially increased the level of ROS and decreased SOD activation, which were significantly modulated by resveratrol in a dose-dependent manner. Moreover, AlP induced an elevation of mitochondrial swelling, cytochrome c release, and MMP collapse. Co-administration of resveratrol significantly reduced above mitochondrial markers. AlP also significantly upregulated BAX and downregulated Bcl-2 expression, elevated caspace-3 activity, and apoptosis. Resveratrol co-administration was able to meaningfully modulate the mentioned parameters and finally reduce apoptosis. In conclusion, resveratrol, via its pleotropic properties, significantly demonstrated cytoprotective effects on HCM cytotoxicity induced by AlP.

Astrocyte response to melatonin treatment in rats under high-carbohydrate high-fat diet

The involvement of consumption of high-carbohydrate high-fat (HCHF) diet in cognitive impairment is attributed, at least in part, to the activation of astrocytes, which contributes to the development of neuroinflammation, oxidative stress, and subsequent cognitive deficits. This study aimed to assess the influence of melatonin on cognitive impairment and astrogliosis induced by the HCHF diet in rats. Male Wistar rats were fed an HCHF diet for eight weeks to induce obesity and metabolic syndrome. Subsequently, they received oral melatonin treatment for four weeks at doses of 5 mg/kg, 10 mg/kg, and 30 mg/kg, alongside the HCHF diet. Cognitive function was evaluated using the Y-maze test, while the levels of proinflammatory cytokines, oxidative stress, and the number glial fibrillary acidic protein (GFAP) positive cells were assessed in the hippocampi and hypothalamus. The consumption of the HCHF diet resulted in weight gain, hyperlipidemia, impaired glucose tolerance, cognitive decline, neuroinflammation, oxidative stress damage, and astrogliosis in rats. Although melatonin treatment did not demonstrate beneficial effects on blood glucose and lipid metabolism, it improved the impaired working memory caused by the HCHF diet. Melatonin exhibited a dose-dependent reduction of astrogliosis, neuroinflammation, and lipid peroxidation while restored superoxide dismutase in the hippocampus and hypothalamus of HCHF diet-treated rats. These findings provide evidence that melatonin inhibits astrocyte activation, thereby attenuating inflammation and minimizing oxidative stress damage induced by the HCHF diet.

The Effects of Apigenin in the Treatment of Diabetic Nephropathy: A Systematic Review of Non-clinical Studies

PURPOSE

Diabetes is one of the important and growing diseases in the world. Among the most common diabetic complications are renal adverse effects. The use of apigenin may prevent the development and progression of diabetes-related injuries. The current study aims to review the effects of apigenin in the treatment of diabetic nephropathy.

METHODS

In this review, a systematic search was performed based on PRISMA guidelines for obtaining all relevant studies on "the effects of apigenin against diabetic nephropathy" in various electronic databases up to September 2022. Ninety-one articles were obtained and screened in accordance with the predefined inclusion and exclusion criteria. Seven eligible articles were finally included in this review.

RESULTS

The experimental findings revealed that hyperglycemia led to the decreased cell viability of kidney cells and body weight loss and an increased kidney weight of rats; however, apigenin administration had a reverse effect on these evaluated parameters. It was also found that hyperglycemia could induce alterations in the biochemical and renal function-related parameters as well as histopathological injuries in kidney cells or tissue; in contrast, the apigenin administration could ameliorate the hyperglycemia-induced renal adverse effects.

CONCLUSION

The results indicated that the use of apigenin could mitigate diabetes-induced renal adverse effects, mainly through its antioxidant, anti-apoptotic, and anti-inflammatory activities. Since the findings of this study are based on experimental studies, suggesting the use of apigenin (as a nephroprotective agent) against diabetic nephropathy requires further clinical studies.

The cardioprotective effects of cerium oxide nanoparticles against the poisoning generated by aluminum phosphide pesticide: Controlling oxidative stress and mitochondrial damage

BACKGROUND

Aluminum phosphide (AlP) is a well-known toxic compound used as an agricultural pesticide to prevent insect damage to stored crops. However, even if just a small amount was consumed, it caused lasting harm to the human body and, in acute concentrations, death. The current study employed cerium oxide nanoparticles (CeO2 NPs) to reduce oxidative stress and various harmful outcomes of AlP poisoning.

METHODS

Following finding effective concentrations of CeO2 NPs via MTT assay, Human Cardiac Myocyte (HCM) cells were pre-treated with CeO2 NPs for 24 h. After that, they were exposed to 2.36 μM AlP. The activity of oxidative stress and mitochondrial biomarkers, including mitochondrial swelling, mitochondrial membrane potential, and cytochrome c release, were evaluated in HCM cells. Finally, the population of apoptotic and necrotic cells was assessed via flow cytometry.

RESULTS

After 24 h, data revealed that all tested concentrations of CeO2 NPs were safe, and 25 and 50 μM of that were selected as effective concentrations. Oxidative stress markers (malondialdehyde, protein carbonyl, superoxide dismutase, and catalase) showed that CeO2 NPs could successfully decrease AlP poisoning due to their antioxidant characteristics. Mitochondrial markers were also recovered by pre-treatment of HCM cells with CeO2 NPs. Furthermore, pre-treating with CeO2 NPs could compensate for the reduction of live cells with AlP and cause a diminishing in the population of early and late apoptotic cells.

CONCLUSION

As a result, it is evident that CeO2 NPs, through the recovery of oxidative stress and mitochondrial damages caused by AlP, reduce apoptosis and have therapeutic potentials on HCM cells.

Tanshinone-IIA mediated neuroprotection by modulating neuronal pathways

The progression of neurological diseases is mainly attributed to oxidative stress, apoptosis, inflammation, and trauma, making them a primary public concern. Since no drugs can stop these neurological disorders from happening, active phytochemical intervention has been suggested as a possible treatment. Among the several phytochemicals being studied for their potential health advantages, tanshinone-IIA (Tan-IIA ) stands out due to its wide range of therapeutic effects. Tan-IIA, derived from the Salvia miltiorrhiza plant, is a phenanthrenequinone. The pharmacological characteristics of Tan-IIAagainst various neurodegenerative and neuropsychiatric illnesses have led researchers to believe that the compound possesses neuroprotective potential. Tan-IIA has therapeutic potential in treating neurological diseases due to its capacity to cross the blood-brain barrier and its broad range of activities. In treating neurological disorders, Tan-IIA has been shown to have neuroprotective effects such as anti-apoptotic, anti-inflammatory, BBB protectant, and antioxidant properties. This article concisely summarises the latest scientific findings about the cellular and molecular aspects of Tan-IIA neuroprotection in relation to various neurological diseases. The results of preclinical studies on Tan-IIA provide insight into its potential application in future therapeutic development. This molecule rapidly establishes as a prominent bioactive compound for clinical research.

A Systematic Review of the Chemo/Radioprotective Effects of Melatonin against Ototoxic Adverse Effects Induced by Chemotherapy and Radiotherapy

BACKGROUND

Although chemotherapy and radiotherapy are effective in cancer treatment, different adverse effects induced by these therapeutic modalities (such as ototoxicity) restrict their clinical use. Co-treatment of melatonin may alleviate the chemotherapy/radiotherapy-induced ototoxicity.

OBJECTIVE

In the present study, the otoprotective potentials of melatonin against the ototoxicity induced by chemotherapy and radiotherapy were reviewed.

METHODS

According to the PRISMA guideline, a systematic search was carried out to identify all relevant studies on "the role of melatonin against ototoxic damage associated with chemotherapy and radiotherapy" in the different electronic databases up to September 2022. Sixty-seven articles were screened based on a predefined set of inclusion and exclusion criteria. Seven eligible studies were finally included in this review.

RESULTS

The in vitro findings showed that cisplatin chemotherapy significantly decreased the auditory cell viability compared to the control group; in contrast, the melatonin co-administration increased the cell viability of cisplatin-treated cells. The results obtained from the distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) tests demonstrated a decreased amplitude of DPOAE and increased values of ABR I-IV interval and ABR threshold in mice/rats receiving radiotherapy and cisplatin; nevertheless, melatonin co-treatment indicated an opposite pattern on these evaluated parameters. It was also found that cisplatin and radiotherapy could significantly induce the histological and biochemical changes in the auditory cells/tissue. However, melatonin co-treatment resulted in alleviating the cisplatin/radiotherapy-induced biochemical and histological changes.

CONCLUSION

According to the findings, it was shown that melatonin co-treatment alleviates the ototoxic damage induced by chemotherapy and radiotherapy. Mechanically, melatonin may exert its otoprotective effects via its anti-oxidant, anti-apoptotic, and anti-inflammatory activities and other mechanisms.