Investigation of the anti-oxidative and anti-inflammatory effects of melatonin on experimental liver damage by radiation

Melatonin mitigated methotrexate-induced hepatotoxicity through interrelated biological processes

BACKGROUND

Hepatotoxicity associated with methotrexate (MTX) is mainly due to disruption of redox balance and development of oxidative injury to hepatocytes. Melatonin (MLT) is a potent antioxidant and regulates wide range of biological functions, processes and utilized as adjuvant for number of medical applications. The current study investigated the mitigating effect of MLT on the MTX-induced hepatotoxicity.

METHODS AND RESULTS

Adult male rats received MLT (25 mg/kg, orally) for seven days flowed by single injection of MTX (20 mg/kg, ip) then treat with MLT continued for additional 7 days. The present result showed MLT treatment mitigated histopathological changes in the liver that associated with normalization of ALT and AST activity as well as bilirubin, albumin and alfa-fetoprotein levels in serum of MLT + MTX-treated rat to comparable control level. MLT treatment significantly reduced MDA content and myeloperoxidase activity while enhanced the activity of superoxide dismutase, catalase and glutathione content in the liver indicating the empowerment of the antioxidant status. Amelioration of MLT-induced oxidative stress resulted in a reduction in the inflammatory response due to antioxidant restoration and inhibited apoptosis indicated by downregulation of caspase-3 expression. The replenishment of antioxidant content powers the defense system of the hepatocytes. As a result, apoptosis is reduced which might be due to the ability of MLT protect DNA integrity thus maintaining hepatocyte functions and structure. Consequently, liver histology was protected.

CONCLUSIONS

In summary, MLT modulates liver function and structure by orchestrating linked processes, including redox balance, inflammatory response, suppression of caspase-3, and DNA damage.

Enhanced kidney damage induced by increasing nonylphenol doses: impact on autophagy-related proteins and proinflammatory cytokines in rats

Nonylphenol (NP) is an organic pollutant and endocrine disruptor chemical that has harmful effects on the environment and living organisms. This study looked at whether kidney tissues subjected to increasing doses of nonylphenol generated alterations in histopathologic, pro-inflammatory, and autophagic markers. Fifty rats were divided into five groups of ten each: group I: healthy group, II: control (corn oil), group III: 25 μl/kg NP, group IV: 50 μl/kg NP, group V: 75 μl/kg NP. The kidney tissue samples were obtained for histopathological, immunohistochemical, and biochemical analyses. The histological deteriorations observed in all NP groups included tubular epithelial cell degeneration, inflammation areas, and hemorrhage. The immunohistochemical investigations showed that NP significantly elevated the autophagy markers (Beclin-1, LC3A/B, p62), pro-inflammatory cytokines (TNF-α, IL-6), HIF-1α, and eNOS in group III, IV and V compared with group I and II. The biochemical analysis also revealed that pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) increased in correlation with the NP doses, but only IL-1β reached statistical significance in NP treated rats kidney tissue. The biochemical findings have been confirmed by the histological studies. The damage to renal tissue caused by NP exposure may worsen it by increasing inflammatory and autophagic markers.

Protective Effects of Boric Acid Taken in Different Ways on Experimental Ovarian İschemia and Reperfusion

Ovarian ischemia is a gynecological emergency that occurs as a result of ovarian torsion, affects women of reproductive age, and reduces ovarian reserve. The current study was designed to investigate the effect of boric acid taken in different ways on histopathological changes, autophagy, oxidative stress, and DNA damage caused by ischemia and reperfusion in the ovary of adult female rats. We established seven groups of 70 adult female rats: untreated control, intraperitoneal boric acid group (IpBA), oral boric acid group (OBA), ischemia/reperfusion group (ischemia/2 h reperfusion; OIR), ischemia/reperfusion and local boric acid group (OIR + LBA), ischemia/reperfusion and intraperitoneal boric acid group (OIR + IpBA), and ischemia/reperfusion and oral boric acid group (OIR + OBA). On the 31st day of the experimental procedure, both ovaries were harvested for histologic (hematoxylen and eosin and Masson trichrom), biochemical (ELISA and AMH, MDA, SOD, and CAT analyses), and comet evaluation. In the OIR group, hemorrhage, edema, inflammation, and diminished follicle reserve were seen in the ovary. Boric acid treatment reduced the ovarian ischemia/reperfusion damage, and the follicles exhibited similar morphological features to the control group. Moreover, boric acid treatment decreased the levels of Hsp70, NF-KB, COX-2, and CD31, which increased as a result of OIR. On the other hand, SCF and AMH levels, which decreased as a result of OIR, increased with boric acid treatment. The levels of autophagy markers (Beclin-1, LC3, and p62) reached values close to those of the control group. According to the biochemical findings, it was concluded that boric acid is also effective on oxidative stress, and the AMH level was particularly high in the OIR + OBA group, consistent with the immunohistochemical staining result. In addition, it was observed that the DNA damage caused by OIR reached values close to those of the control group, especially in the OBA after OIR. This study showed the therapeutic effects of boric acid on OIR injuries; thus, boric acid may be a potential therapeutic agent for ovarian protection and fertility preservation in cases that may cause ovarian torsion.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.