150 Administration of naproxen has adverse effects on murine late folliculogenesis and fertility

Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to treat acute pain, from clinical pathologies such as rheumatoid arthritis to intermittent pain such as menstrual cramps. NSAIDs work by inhibiting the cyclooxygenase enzyme, which, in turn, inhibits prostaglandins, decreasing inflammation. Its use is done without a focused analysis on female ovarian and reproductive health. In this scenario, the objective of the present work was to investigate the effects of the use of naproxen on the female fertility of C57BL6 mice. The animals were divided in three groups: Control, Naproxen Low, and Naproxen High, and submitted to the following procedures: drug application, daily weighting; quantification of follicles, oocytes, and corpus luteum. The drug administration consisted in 10 mg/kg of naproxen to the Naproxen Low group and 50 mg/kg to the Naproxen High group; the Control group received the vehicle (PBS) for eight consecutive days. This study was divided into two experiments in order to observe multiple aspects of the ovary. All quantitative data were tested for normality using D’Agostino & Pearson and Shapiro-Wilk tests. Three-way parametric data were run by Newman-Keuls test. All statistical analyses were made using GraphPad 8.0.1. In the first experiment (n = 6 per group; Control, Naproxen Low, Naproxen High) the weight (15 ± 0.5 Control, 15 ± 0.7 Naproxen Low, 16 ± 0.6 Naproxen High; P = 0.587) was not altered by the drug. The animals were killed by the end of the eighth day of application and their ovaries were collected and prepared for histology. Naproxen Low and High groups had fewer antral follicles than the control group (22 ± 4 Control, 10 ± 2 Naproxen Low, 6 ± 1 Naproxen High; P = 0.0013). In the second experiment, more animals were acquired (n = 10 per group; Control, Naproxen Low, Naproxen High), treated with the same dosages as the first group and submitted to a superovulation assay. During the eight days of the drug and vehicle administration, the animals were given equine chorionic gonadotrophin 48 h and human chorionic gonadotrophin 14 h before euthanasia. The ovaries were collected, and fewer oocytes were observed in the Naproxen High group (15 ± 2 Control, 11 ± 5 Naproxen Low, 0.4 ± 0.2 Naproxen High; P < 0.0001) when compared with the other groups. After oocyte counting, the ovaries were prepared for histology. In the histological analysis, the Naproxen High group showed fewer secondary (29 ± 4 Control, 28 ± 3 Naproxen Low, 16 ± 2 Naproxen High; P = 0.022) and antral follicles (23 ± 2 Control, 16 ± 3 Naproxen Low, 10 ± 3 Naproxen High; P = 0.041). Other observations included a lesser number of corpora lutea in both treated groups (18 ± 3 Control, 11 ± 0.4 Naproxen Low, 6 ± 1 Naproxen High; P = 0.001) and a greater number of failed ovulations (unerupted antral follicles with expanded cumulus cells) in the Naproxen High group (3 ± 1 Control, 0.8 ± 0.4 Naproxen Low, 8 ± 2 Naproxen High; P = 0,002). This work brought new data to the literature on the influence of a known drug already established on the market regarding female fertility with unprecedented results and opens the possibility for new studies.

This research was supported by CAPES, FAPEMIG, and CNPq.