The Effect of Hydroalcoholic Calendula Officinalis Extract on Androgen-Induced Polycystic Ovary Syndrome Model in Female Rat

Abstract

Background: Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in women of reproductive age, and the major cause of infertility. Today, using medicinal plants instead of chemical drugs could be an alternative treatment option for PCOS. The purpose of this study was to determine the effect of Calendula officinalis hydroalcoholic extract on PCOS in rats.

Method: 60 female adult rats were randomly divided into six groups, including control, sham, PCOS group, and treated PCOS groups receiving hydroalcoholic extract of Calendula officinalis with different dosages of 200, 500, and 1000 mg/kg. PCOS was induced by subcutaneous injection of DHEA 6 mg/100 g bw for 35 days. For two weeks, the extract was taken orally. The serum glucose, insulin, sex hormone levels, and oxidative status were measured at the end of the experiment. The ovaries were dissected for histomorphometric and pathological analysis.

Results: When compared to the control and sham groups, the PCOS group showed a significant increase in glucose, insulin, testosterone, and malondialdehyde (MDA) concentrations, cystic and atretic follicles, and thickness of the theca and tunica albuginea layers, and a significant decrease in LH concentration, total antioxidant capacity, corpus luteum, antral follicles, and oocyte diameter. The mean concentration of FSH, on the other hand, did not change significantly. A trend of improvement was found in the treated groups with high doses of Calendula officinalis extract.

Conclusion: In rats with PCOS and nonovulation, Calendula officinalis hydroalcoholic extract improved oxidative stress, restored folliculogenesis, and increased ovulation.

Figure 1

Rat model exhibiting both ovarian and characteristics of polycystic ovarian syndrome.

Figure 2

Stages of the estrous cycles.

Figure 3

Fasting blood glucose (a), insulin (b), HOMA-IR (c), MDA (d), and TAC (e) levels in the experimental groups. According to one-way ANOVA (post hoc: Tukey) analysis which was used for intergroup comparisons, groups with the same letters were not significantly different at α = 0.05 (P ≥ 0.05). However, dissimilar letters indicate a significant difference (P < 0.05). Data are presented as mean ± SEM(n = 7).

Figure 4

Estrous cycle pattern in the control, sham, PCOS, PCOS+Cal200, PCOS+Cal500, and PCOS+Cal1000 groups (receiving hydroalcholic extract of Calendula officinalis with dosages of 200, 500, and 1000 mg/kg). The results of eight representative rats from each group are shown. P: proestrous; E: estrous; M: metestrous; D: diestrous.

Figure 5

The bar graph of the number of primordial (a), unilaminar (b), multilaminar (c), antral (d), graafian (e), corpus luteum (f), atretic (g), and cystic follicles (h). The significant differences are exhibited on each column. (A–D) According to one-way ANOVA (post hoc: Tukey) analysis which was used for intergroup comparisons, groups with same superscripts were not significantly different at α = 0.05 (P ≥ 0.05). However, dissimilar letters indicate a significant difference (P < 0.05).

Figure 6

The bar graph of the corpus luteum diameter (a), thickness of tunica albugina (b), antral follicle diameter (c), thickness of theca layer (d), granulosa layer (e), thickness of the zona pellucida (f), and oocyte diameter (g). The significant differences are shown on each column. (A–D) According to one-way ANOVA (post hoc: Tukey) analysis which was used for intergroup comparisons, groups with same superscripts were not significantly different at α = 0.05 (P ≥ 0.05). However, dissimilar letters indicate a significant difference (P < 0.05).

Figure 7

Light photomicrograph of the ovarian tissue in the control (a, g), sham (b, h), PCOS (c, i), PCOS+Cal200 (d, k), PCOS+Cal500 (e, l), and PCOS+Cal1000 groups (f, l) (H&E staining). (a–f) Magnification 40 and (g–l) magnification 100. The antral follicle (S), graafian (G), cystic follicle (Cy), atretic follicle (A), and corpus luteum (C.L); the arrow sings in the above images show the unilaminar and multilaminar follicles.