Toxicology and pathology of female reproductive tract

Reproductive and developmental safety evaluation of Thymelaea hirsuta (L.) leaves aqueous extract in Wistar albino rats

ETHNOPHARMACOLOGICAL RELEVANCE

The popularity of herbal medicine is expanding globally due to the common belief that herbal products are natural and nontoxic. Thymelaea hirsuta leaves are traditionally used for the treatment of recurrent abortion in humans and animals. However, a lack of safety evaluation of the plant, particularly in pregnant women, raises serious concerns regarding its potential embryotoxic effects.

AIM OF THE STUDY

Therefore, the present study investigated the safety of Thymelaea hirsuta leaves aqueous extract (THLE) during pregnancy and lactation following maternal rat treatment.

MATERIALS AND METHODS

THLE phytochemical compounds were identified using high-performance liquid chromatography (HPLC). THLE was orally administered to pregnant rats and lactating dams at dosages of 0, 250, 500, and 1000 mg/kg/day. At the end of the study, dam s' and pups' body weights, serum biochemical and hematological indices, and histopathological changes were investigated. For the fetal observation and histopathological changes were also evaluated.

RESULTS

Our findings revealed that THLE is rich in different phenolic and flavonoid compounds. However, biochemical and hormonal parameters such as ALT, AST, and prolactin were significantly increased in dams treated with a higher dosage of THLE when compared to the control dams (P ≤ 0.05). Additionally, external, visceral and skeletal examinations of fetuses revealed a marked increase of malformation rates in treated fetuses.

CONCLUSIONS

The results revealed that higher oral dosing of THLE during pregnancy could affect embryonic development in rats, while lower doses are safe and can be used during pregnancy and lactation to attain its beneficial effects.

Effect of the Aqueous Extract of Chrysobalanus icaco Leaves on Maternal Reproductive Outcomes and Fetal Development in Wistar Rats

Toxicological studies on medicinal plants are essential to ensure their safety and effectiveness in treating various diseases. Despite the species Chrysobalanus icaco L. being popularly used in the treatment of several diseases due to the pharmacological properties of its bioactive compounds, there are few studies in the literature regarding its toxicity regarding reproduction. Therefore, the purpose of this study was to assess the potential embryotoxic and teratogenic effects of the aqueous extract of C. icaco leaves (AECi) on Wistar rats. Animals were given AECi at doses of 100, 200, and 400 mg/kg during the pre-implantation and organogenesis periods. Data were analyzed using ANOVA followed by Tukey's test and Kruskal-Wallis. Pregnant rats treated during the pre-implantation period showed no signs of reproductive toxicity. Rats that received AECi at 100, 200, and 400 mg/kg during organogenesis did not exhibit any signs of maternal systemic toxicity or significant differences in gestational and embryotoxic parameters. Some skeletal changes were observed in the treated groups. Therefore, it can be suggested that AECi at doses of 100, 200, and 400 mg/kg is safe for treated animals and does not induce reproductive toxicity under the experimental conditions applied, but it also caused low systemic toxicity.

Chronic exposure to low concentrations of chlorpyrifos affects normal cyclicity and histology of the uterus in female rats

Chlorpyrifos (CPF), the most used insecticide in Argentina, can act as an endocrine disruptor at low doses. We previously demonstrated that chronic exposure to CPF induces hormonal imbalance in vivo. The aim of this work was to study the effects of low concentrations of CPF (0.01 and 1 mg/kg/day) on the reproductive system of virgin adult rats. In the ovary, we studied the effects of CPF on steroidogenesis by determining steroid hormone content by RIA and CYP11 and CYP19 enzyme expression by qRT-PCR. The estrous cycle was evaluated by microscopic observation of vaginal smear, as well as by changes in uterine histology. In endometrium, we determined the fractal dimension and expression of PCNA, ERα and PR by IHC. Our results showed that chronic exposure to CPF affects ovarian steroid synthesis, causing alterations in the normal cyclicity of animals. In addition, CPF induced proliferative changes in the uterus, suggesting that it could affect reproduction or act as a risk factor in the development of uterine proliferative pathologies.

Early-life nutritional effects on the female reproductive system

There is now considerable epidemiological and experimental evidence indicating that early-life environmental conditions, including nutrition, affect subsequent development in later life. These conditions induce highly integrated responses in endocrine-related homeostasis, resulting in persistent changes in the developmental trajectory producing an altered adult phenotype. Early-life events trigger processes that prepare the individual for particular circumstances that are anticipated in the postnatal environment. However, where the intrauterine and postnatal environments differ markedly, such modifications to the developmental trajectory may prove maladaptive in later life. Reproductive maturation and function are similarly influenced by early-life events. This should not be surprising, because the primordial follicle pool is established early in life and is thus vulnerable to early-life events. Results of clinical and experimental studies have indicated that early-life adversity is associated with a decline in ovarian follicular reserve, changes in ovulation rates, and altered age at onset of puberty. However, the underlying mechanisms regulating the relationship between the early-life developmental environment and postnatal reproductive development and function are unclear. This review examines the evidence linking early-life nutrition and effects on the female reproductive system, bringing together clinical observations in humans and experimental data from targeted animal models.