Role of curcumin on beta-amyloid protein, tau protein, and biochemical and oxidative changes in streptozotocin-induced diabetic rats.

Diabetes is one of the most common endocrine metabolic diseases and is associated with the accumulation of beta-amyloid plaques in the brain. Amyloid beta (Aß) and abnormal tau proteins are effective in the development of Alzheimer's disease. The aim of this study is to investigate the therapeutic and protective effects of curcumin on beta-amyloid (Aß) accumulation and tau protein expression levels, as well as biochemical and oxidative changes in streptozotocin-induced diabetes in rats. The study comprised five groups, each consisting of eight rats: control, diabetic, curcumin, curcumin during diabetic induction, and curcumin post-diabetic induction. Groups 2 and 4 were administered a single dose of 45 mg/kg streptozotocin on day 1, while group 5 received it on day 28. Curcumin was orally administered via gavage at a dose of 100 mg/kg/day for 35 days to the third, fourth, and fifth groups. At the end of the trial (day 35), blood sugar levels and insulin resistance were similar between the control and curcumin-treated groups but significantly higher in the diabetic groups (P < 0.05). The protective effect of curcumin is tested during induction and active diabetes. The results indicated that diabetic rats displayed increased levels of Aß, tau protein, and total oxidant capacity (TOS) compared to the curcumin-treated groups. Additionally, the total antioxidant capacity (TAS) levels were lower in the diabetic rats (P < 0.05). Aß protein levels are lower in both the serum and brain of rats with active diabetes and treated with curcumin compared to control rats (P > 0.05). In addition, serum TAS levels were higher in rats treated with curcumin following the induction of diabetes than pre-induction of diabetes (P > 0.05). The TOS levels in the serum were higher in the rats treated with curcumin during active diabetes compared to the rats treated prior to the induction of diabetes (P < 0.05). However, no significant difference was observed in the brain. The above results show that curcumin has an effect on reducing oxidative stress caused by diabetes and increasing antioxidant activity.

Protective Effects of Boric Acid Taken in Different Ways on Experimental Ovarian Ischemia 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.

Nonylphenol Exposure-Induced Oocyte Quality Deterioration Could be Reversed by Boric Acid Supplementation in Rats.

In this study, we reported boric acid's protective effects on the quality of nonylphenol (NP)-exposed oocytes. Female rats were classified into 4 groups: control, boric acid, NP, and NP+boric acid. Histopathological studies and immunohistochemical analysis of anti-müllerian hormone (AMH), mechanistic target of rapamycin (mTOR), Sirtuin1 (SIRT1), stem cell factor (SCF) studies were done. The comet assay technique was utilized for DNA damage. The ELISA method was used to determine the concentrations of oxidative stress indicators (SOD, CAT, and MDA), ovarian hormone (INH-B), and inflammation indicators (IL-6 and TNF-α). Boric acid significantly reduced the histopathological alterations and nearly preserved the ovarian reserve. With the restoration of AMH and SCF, boric acid significantly improved the ovarian injury. It downregulated SIRT1 and upregulated the mTOR signaling pathway. It provided DNA damage protection. Ovarian SOD, CAT levels were decreased by boric acid. Boric acid co-administration significantly reduced NP's MDA, IL-6, and TNF-activities. This results imply that boric acid has a protective role in ovarian tissue against NP-mediated infertility.

An evaluation of the effects on the ovaries of hyperbaric oxygen therapy in a rat model of premature ovarian failure created with cyclophosphamide.

Objective: To evaluate hyperbaric oxygen therapy (HBO) based on ovarian histology, total antioxidant status (TAS), total oxidant status (TOS), and anti-müllerian hormone (AMH), in the ovarian insufiency (POI) model created with cyclophosphamide (CYP). Materials and Methods: The rats were separated into 3 groups of the control group (n=6), the CYP group (n=6), and the CYP+HBO group (n=6). The rats in the CYP group and the CYP+HBO group were injected intraperitoneally with 200 mg/kg CYP on day 1, followed by 8 mg/kg/day for 14 days to create POI. From the 15th day onwards, the rats in the CYP+HBO group were placed in a hyperbaric cabin and exposed to 100% oxygen at 2.4 atm pressure for one h, and were then returned to their cages at the end of the hour. Results: A statistically significant decrease was determined in the primordial and primary follicle counts in the CYP group compared with the control group (p<0.05). In the CYP+HBO group, a statistically significant increase was determined in the primordial and primary follicle counts (p<0.05). The serum AMH levels were seen to be significantly decreased in the CYP group compared with both the control group and the CYP+HBO groups. The HBO was seen to decrease TOS and increase TAS. Conclusion: HBO could be an alternative treatment to minimize the effect of ovarian follicle loss caused by CYP, which is used for treating tumors that commonly occur in young females of reproductive age.