Quercetin and Ferulic Acid Elicit Estrogenic Activities In Vivo and In Silico

Abstract

In this study, we examined the sub-acute toxicity of quercetin and ferulic acid and evaluated their effects on protein, cholesterol, and estrogen levels in vivo. Six groups of female Wistar rats were fed by gavage. The first and second groups represent the positive (Clomiphene citrate 10 mg/kg) and negative (NaCl 0.9%) control groups, while the other groups received quercetin and ferulic acid at doses of 5 and 10 mg/kg/day for 28 days. The sub-acute toxicity was monitored by examining the weights, biochemical parameters (AST, ALT, ALP, urea, and CREA), and histological changes in the kidneys and liver of the treated animals. Furthermore, the in vivo estrogenic effects were studied in terms of the serum and ovarian cholesterol levels, serum estradiol, and uterine proteins. Finally, Docking studies were conducted to evaluate the binding affinity of quercetin and ferulic acid for alpha and beta estrogen receptors. Results showed that both compounds were devoid of any signs of nephrotoxicity or hepatotoxicity. Additionally, quercetin and ferulic acid caused significant estrogenic effects evidenced by an increase of 8.7 to 22.48% in serum estradiol, though to a lesser amount than in the reference drug-treated group (64.21%). Moreover, the two compounds decreased the serum cholesterol levels (12.26-32.75%) as well as the ovarian cholesterol level (11.9% to 41.50%) compared to the negative control. The molecular docking in estrogen alpha and estrogen beta active sites showed high affinity of quercetin (-10.444 kcal/mol for estrogen alpha and -10.662 kcal/mol for estrogen beta) and ferulic acid (-6.377 kcal/mol for estrogen alpha and -6.3 kcal/mol for estrogen beta) to these receptors. This study provides promising insights into the potential use of quercetin as a therapeutic agent for the management of female fertility issues.

Keywords: docking study; estrogenic activity; female infertility; ferulic acid; quercetin; sub-acute toxicity.

Figure 1

The impact of quercetin and ferulic acid on weight gain was assessed before and after a 28-day treatment period. The superscript letters indicate significant differences at a p-value of less than 0.05 between the treatments. The values provided represent the mean ± standard error of the mean. The negative control group was administered NaCl 0.9%, while the C.C. group received clomiphene citrate, the F.A. group received ferulic acid, and the Q. group received quercetin.

Figure 2

Effect of quercetin and ferulic acid on liver (A,B) and kidney (C,D) parameters. The letters in superscript indicate the significant difference at p < 0.05 between treatments. Negative control (NaCl 0.9%), F.A. (Ferulic Acid), Q. (Quercetin).

Figure 3

Liver histopathological sections were stained with hematoxylin–eosin–safran at a magnification of ×40: (A) represent the negative control (NaCl 0.9%); (B) represent the reference group treated with clomiphene citrate (10 mg/kg); (C,D) represent ferulic acid groups (5 and 10 mg/kg, respectively); (E,F) represent quercetin groups (5 and 10 mg/kg, respectively).

Figure 4

Kidney histopathological sections were stained with hematoxylin–eosin–safran at a magnification of ×40: (A) represents the negative control (NaCl 0.9%); (B) represents reference group treated with clomiphene citrate (10 mg/kg); (C,D) represent ferulic acid groups (5 and 10 mg/kg, respectively); (E,F) represent quercetin groups (5 and 10 mg/kg, respectively).

Figure 5

Impact of quercetin and ferulic acid on (A) ovarian and (B) uterine weights was assessed in comparison to the negative control (NaCl 0.9%) and positive control (clomiphene citrate (C.C)). The letters in superscript indicate the significant difference at p < 0.05 between treatments. The data represent the mean ± s.e.m. (n = 5). F.A. (ferulic acid), Q. (quercetin).

Figure 6

The impact of quercetin and ferulic acid on the levels of (A) serum and (B) ovarian cholesterol was assessed. The superscript letters indicate significant differences at a p-value of less than 0.05 among the treatments. The presented data represent the mean ± standard error of the mean (n = 5). Negative control (NaCl 0.9%), C.C. (clomiphene citrate), F.A. (ferulic acid), Q. (quercetin).

Figure 7

The impact of quercetin and ferulic acid on the levels of uterine proteins (A) and serum estradiol (B) were examined in comparison to the negative control (0.9% NaCl) and positive control (clomiphene citrate (C.C)). The letters in superscript indicate a significant difference at p < 0.05 between treatments. The values represent the mean ± s.e.m. F.A. (ferulic acid), Q. (quercetin).

Figure 8

Histopathological sections of rat ovaries: (A) represents the negative control (NaCl 0.9%); (B) represents the reference group treated with clomiphene citrate (10 mg/kg); (C,D) represent ferulic acid groups (5 and 10 mg/kg, respectively); (E,F) represent quercetin groups (5 and 10 mg/kg, respectively). Abbreviations: FP: Primary Follicle; FS: Secondary Follicle; TF: Tertiary Follicle; FG: Graf’s follicle; CJ: Yellow Body; arrowheads: dilated blood vessels.

Figure 9

The two-dimensional viewer of ligands in active sites. (A) represents quercetin interactions in the active sites of estrogen alpha. (B) represents quercetin interactions in the active sites of estrogen beta receptors. (C) represents ferulic acid interactions in the active sites of estrogen alpha. (D) represents ferulic acid interactions in the active sites of estrogen beta receptors.

Figure 10

The three-dimensional viewer of ligands in active sites. (A) represents quercetin interactions in the active sites of estrogen alpha. (B) represents quercetin interactions in the active sites of estrogen beta receptors. (C) represents ferulic acid interactions in the active sites of estrogen alpha. (D) represents ferulic acid interactions in the active sites of estrogen beta receptors.