Ameliorative effect of fractionated low-dose gamma radiation in combination with ellagic acid on nicotine-induced hormonal changes and testicular toxicity in rats

Protective effect of Enicostemma axillare - Swertiamarin on oxidative stress against nicotine-induced liver damage in SD rats

OBJECTIVE

The current investigation was aimed to determine the hepatoprotective benefits of Swertiamarin (ST) administration against nicotine-induced hepatotoxicity in SD rats.

MATERIAL AND METHODS

A total of 48 adult male SD rats were allocated into six groups using a fully randomised approach. As a control, group I was given oral (PO) normal saline. For 65 days, the animals in groups II, III, IV, V and VI received 2.5mg/kg/day of nicotine intraperitoneally (IP), 100mg/kg/day of ST orally (PO), 200mg/kg/day of ST orally (PO), 2.5mg/kg/day of nicotine (IP)+100mg/kg/day of ST (PO), and 2.5mg/kg/day of nicotine (IP)+200mg/kg/day of ST (PO), respectively. Animals were killed on 66thday, liver tissue was removed and used for histopathological analysis as well as biochemical testing (oxidative stress parameters and liver function enzymes).

RESULTS

When compared to control animals, the animals in group II showed a substantial rise in their aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, and creatinine levels (P˂0.001). Furthermore, compared to control animals, these animals displayed enhanced hepatic oxidative stress as indicated by significantly higher Malondialdehyde (MDA) levels (P˂0.001) and lower levels of Catalase (CAT), Glutathione (GSH), Glutathione peroxidase (GSH-Px) and Superoxide dismutase (SOD) (P˂0.001). Further, more histological anomalies were seen in the liver of nicotine-treated rats compared to control rats, including significant vacuolization, poor tissue architecture, the growth of pycnotic nuclei, and dilated sinusoids. Contrary to nicotine-treated rats, the co-administration of ST and nicotine was observed to prevent the abnormalities caused by nicotine (groups V and VI).

CONCLUSION

The results of the current study show that nicotine can seriously harm liver tissue and that swertiamarin can prevent the harmful effects of nicotine on rat liver. Future research is necessary to delve deeply into the mechanisms behind swertiamarin protective impact against nicotine-induced hepatotoxicity.

Low-Dose Gamma Radiation Modulates Liver and Testis Tissues Response to Acute Whole Body Irradiation

Aim

This work aims to investigate whether the pre-exposure to low dose/low dose rate (40 mGy, 2.2 mGy/hour) γ-radiation as a priming dose can produce a protective effect against the subsequent high one (4 Gy, .425 Gy/minute).

Methods

Rats were divided into Group I (control), Group II (L); exposed to 40 mGy, Group III (H); exposed to 4 Gy, and Group IV (L+H); exposed to 40 mGy 24 hours before the exposure to 4Gy. The molecular and biochemical changes related to oxidative stress, DNA damage, apoptosis, and mitochondrial activity in the liver and testis were studied 4 hours after irradiation.

Results

Exposure to 40 mGy before 4 Gy induced a significant increase in the levels of Nrf2, Nrf2 mRNA, TAC, and mitochondrial complexes I & II accompanied by a significant decrease in the levels of LPO, 8-OHdG, DNA fragmentation, TNF-α, caspase-3, and caspase-3 mRNA compared with H group.

Conclusion

Exposure to low-dose γ-radiation before a high dose provides protective mechanisms that allow the body to survive better after exposure to a subsequent high one via reducing the oxidative stress, DNA damage, and apoptosis-induced early after irradiation. However, further studies are required to identify the long-term effects of this low dose.

Low-dose radiation-induced demethylation of 3β-HSD participated in the regulation of testosterone content

The effects of low-dose radiation (LDR, ≤0.1 Gy) on living organisms have been the hot areas of radiation biology but do not reach a definitive conclusion yet. So far, few studies have adequately accounted for the male reproductive system responses to LDR, particularly the regulation of testosterone content. Hence, this study was designed to evaluate the effects of LDR on Leydig cells and testicular tissue, especially the ability to synthesize testosterone. We found that less than 0.2-Gy ⁶⁰ Co gamma rays did not cause significant changes in the hemogram index and the body weight; also, pathological examination did not find obvious structural alterations in testis, epididymis, and other radiation-sensitive organs. Consistently, the results from in vitro showed that only more than 0.5-Gy gamma rays could induce remarkable DNA damage, cycle arrest, and apoptosis. Notably, LDR disturbed the contents of testosterone in mice serums and culture supernatants of TM3 cells and dose dependently increased the expression of 3β-HSD. After cotreatment with trilostane (Tril), the inhibitor of 3β-HSD, increased testosterone could be partially reversed. Besides, DNA damage repair-related enzymes, including DNMT1, DNMT3B, and Sirt1, were increased in irradiated TM3 cells, accompanying by evident demethylation in the gene body of 3β-HSD. In conclusion, our results strongly suggest that LDR could induce obvious perturbation in the synthesis of testosterone without causing organic damage, during which DNA demethylation modification of 3β-HSD might play a crucial role and would be a potential target to prevent LDR-induced male reproductive damage.