Research Article |
Corresponding author: Sahar Mohammed Ahmed ( sahar_hamad@uomustansiriyah.edu.iq ) Academic editor: Magdalena Kondeva-Burdina
© 2024 Sahar Mohammed Ahmed, Yassir M. K. Al-Mulla Hummadi, Huda Jaber Waheed.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ahmed SM, Al-Mulla Hummadi YMK, Waheed HJ (2024) A seed extract of Mucuna pruriens reduced male reproductive endocrine disruptions in rats induced by chlorpromazine. Pharmacia 71: 1-10. https://doi.org/10.3897/pharmacia.71.e132062
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Current research aims to assess the therapeutic impact of Mucuna pruriens seed extract on PROTAMIN (PRM) I and II gene expression and hormones in chlorpromazine-induced endocrine disruptions and reproductive toxicity in male rats. Thirty male Wistar rats were categorized into five groups: the negative control group, rats that received distilled water for 52 days; the induction group, rats that received (20 mg/kg) of chlorpromazine for 52 days; and three treatment groups that were pretreated with chlorpromazine (similar to the induction group) that received a low, medium, and high dose of Mucuna pruriens (500, 1000, and 2000 mg/kg, respectively). Serum samples were collected to measure testosterone, FSH (follicular stimulating hormone), LH (luteinizing hormone), and prolactin serum levels using the ELISA technique. Tissue samples were collected to measure PRM I and II gene expression and for histopathological study. The PRM I and II genes were significantly downregulated in the chlorpromazine-treated group. These genes were also significantly upregulated in Mucuna pruriens-treated groups. The Mucuna pruriens-treated groups revealed a significant rise in serum LH, testosterone, and FSH concentrations, decreased serum prolactin, and improved histology of testicular damage compared to the induction group. In conclusion, the endocrine disruption and hormonal changes induced by chlorpromazine improved when Mucuna pruriens was administered, improving the impairment in gene expression and hormones.
chlorpromazine, Mucuna pruriens, PRM I, PRM II, endocrine disruption, reproductive toxicity
Endocrine-disrupting chemicals (EDC) are exogenous substances that possess the potential to disrupt hormonal balance and normal endocrine system functioning, which may have a negative impact on both the reproduction and health of humans and animals (
EDCs include synthetic antipsychotic drugs, which are used for the management of psychosis (
Protamines (PRM) are the most common nucleoproteins in mature sperm that replace histones during spermiogenesis, provide DNA packaging in sperm, and chromatin condensation of sperm, which protects the genetic integrity of the paternal genome as it passes through the male and female reproductive tracts (
Mucuna pruriens, a member of the Fabaceae family, is widespread worldwide in tropical and subtropical regions (
The current study aims to evaluate the effect of Mucuna pruriens seed extracts on the PRM I and II gene expressions in chlorpromazine-induced endocrine disruptions and reproductive system damage in male rats.
All compounds and kits used in this study were pure: chlorpromazine (99.98% purity) (Sanofi, French), Mucuna pruriens seeds (Echemi, China), PRM I, PRM II (Alph DNA, Canada), LH, FSH, testosterone, and prolactin ELISA Kit (MyBioSource, USA). A botanist from the Department of Pharmacognosy—College of Pharmacy—Mustansiriyah University verified Mucuna pruriens seeds.
100 grams of the Mucuna pruriens seed were defatted using 399 ml of acetone by shaking for 48 hours at room temperature (25 ± 2 °C). The solution was then filtered, and the solid material was taken. The defatted materials were extracted using equal proportions of water: ethanol solution (1:1 ratio) with 0.1% ascorbic acid (1500 ml) by shaking for 12 hours; the resultant solution was filtered, and the filtrate was obtained and dried. The dried powder was further examined after dissolving in hot water using TLC (TLC plates were run in n-butanol-n-propanol-water-acetic acid (3:3:2:1), and spots were visualized by ninhydrin reagent (300 mg dissolved in 100 ml n-butanol and 3 ml acetic acid). Yielding is presented in Table
Male Wistar rats weighing 150–200 g were used. The rats were housed in large, comfortable cages. For 12 days, they were allowed to acclimate in a controlled environment, including temperature and humidity. They were also allowed food and water ad libitum.
Thirty male rats were allocated randomly into five groups (n = 6). The groups were characterized as follows: Group 1 (negative control) rats received distilled water orally by gastric gavage for 52 days. Group 2 (induction group) rats received 20 mg/kg chlorpromazine orally by gastric gavage once daily for 52 days (
Group 3 (low-dose Mucuna pruriens) induction with chlorpromazine (20 mg/kg, orally) once daily for 52 days, starting in day 23, rats treated with Mucuna pruriens at a dose of 500 mg/kg orally by gastric gavage once daily till day 52. Group 4 (medium-dose Mucuna pruriens) induction with chlorpromazine (20 mg/kg, orally) once daily for 52 days, starting in day 23, rats treated with Mucuna pruriens at a dose of 1,000 mg/kg orally by gastric gavage once daily till day 52. Group 5 (high-dose Mucuna pruriens) induction with chlorpromazine (20 mg/kg, orally) once daily for 52 days, starting on day 23, rats treated with Mucuna pruriens at a dose of 2,000 mg/kg orally by gastric gavage once daily till day 52 (
The experiment started on 11 October 2023, and ended on 14 December 2023, in the animal house of the Pharmacology and Toxicology Department at the College of Pharmacy—Mustansiriyah University.
Each testis was separated into two parts: one for histopathological study and preserved in 10% neutral buffered formalin (NBF) to protect the tissue structure from autolysis; the second part of testicular tissues was preserved in TRIzol and stored at -20 °C for gene expression assays.
To measure PRM I (F: GGCGAGATGCTCTTGAAGTC, R: TAGCACCATGGCCAGATACC) and PRM II (F: GATCCTGTGAAGCCTCTTGC, R: TCCTGACCTCCTGGCACTAT) gene expression using the real-time quantitative polymerase chain reaction (RT-PCR) method. This method involved testicular tissue isolation, total RNA extraction using TRIzol and purification, and complementary DNA (cDNA) synthesis using a one-step genomic DNA (gDNA) removal and a cDNA synthesis kit. Total cDNA (24 µL) was amplified in real-time PCR (including 10 µL of Perfect Start Green qPCR Super Mix with 2 µL of primers prepared from forward and reverse solutions and 4 µL of cDNA and 4 µL of nuclease-free water). The amplification conditions were pre-denaturation at 94 °C for 30 sec by one cycle, denaturation at 94 °C for 10 sec by 35 cycles, annealing at 58 °C for 15 sec by 35 cycles, extension at 72 °C for 20 sec by 35 cycles, and melting curve 70 °C–95 °C for 1 sec by one cycle. The 2-∆∆ct method is the relative quantification method most frequently found in software packages for qPCR experiments. This method uses the threshold cycle (CT) information generated from a qPCR system to calculate relative gene expression in target and reference samples, using Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (F: CAACGGATACATTGGGGGTA, R: AGAACATCATCCCTGCATCC) as a reference gene (
For measurement of LH, FSH, testosterone, and prolactin levels, first blood samples were withdrawn from the heart apex (left ventricle) by a 5 ml syringe with gauge 23 needles, then put in the gel tubes and left for 15 minutes to clot at room temperature, then centrifuged for 15 minutes at 3000 RPM. The collected serum was divided into portions in Eppendorf tubes (1.5 ml). They were stored at -20 °C (
The study was approved by the Research Ethical Committee of the College of Pharmacy, Mustansiriyah University, approval number 32, reference number 121, date: 23 June 2023.
Variables followed a normal distribution and were analyzed using ANOVA with a post-hoc Tukey test. For the data’s non-normal distribution, the Kruskal-Wallis and post hoc Dunn tests were employed to compare groups. The data are displayed as the average value plus or minus the standard error mean (SEM). The data underwent analysis using GraphPad Prism 10.2, which was utilized to generate graphs and figures. P ≤ 0.05 was regarded as statistically significant.
For sample size computation, program G Power was utilized (
Fig.
Regarding the PRM II gene expression, there was a significant downregulation (0.60 ± 0.11 fold) of PRM II in the induction group compared to the control group. When treated with 500 mg of Mucuna pruriens, the mean PRM I fold of expression (1.12 ± 0.22) showed a significant difference compared to the induction group. Similarly, the groups that were given 1000 mg and 2000 mg of Mucuna pruriens significantly upregulated (1.80 ± 0.05 and 1.82 ± 0.35 fold, respectively) compared to the induction group, which was not statistically significant compared to the control group.
A significant decrease (0.37 ± 0.02 IU/L) in serum FSH concentration was observed in the induction group compared to the control group (0.80 ± 0.01 IU/L). All tested groups of Mucuna pruriens showed significantly higher FSH levels than the induction group. In contrast, only a high-dose group of Mucuna pruriens showed no significant difference compared to the control group (Fig.
A significant decrease (0.85 ± 0.03 IU/L) in serum LH concentration was observed in the induction group compared to the control group. All tested groups of Mucuna pruriens showed significantly higher LH levels than the induction group. In contrast, both medium- and high-dose groups of Mucuna pruriens showed no significant difference compared to the control group (Fig.
A significant decrease (9.53 ± 0.3 nmol/L) in serum testosterone levels was observed in the induction group compared to the control group. All tested groups of Mucuna pruriens showed significantly higher testosterone levels than the induction group. In contrast, all doses of Mucuna pruriens showed no significant difference compared to the control group (Fig.
A significant increase (1.63 ± 0.01 IU/L) in serum prolactin levels was observed in the induction group compared to the control group. All tested groups of Mucuna pruriens showed significantly lower prolactin levels than the induction group. In contrast, all doses of Mucuna pruriens showed no significant difference compared to the control group (Fig.
The histopathological figures of the testicle in the control group revealed a normal appearance with a uniform shape and regular outline of seminiferous tubules, a normal appearance of germinal epithelial cells, normal testicular interstitial vascular elements, and normal cytoarchitecture. The magnification of seminiferous tubules showed a normal appearance of luminal spermatozoa cell contents, normal primary with secondary spermatocytes, normal spermatogonium cells, myoid cells, and normal interstitial Leydig cells (Fig.
Histopathological sections of tests, (A) control group; (B) induction group; showing severe orchitis characterized by reduced size seminiferous tubules with irregular outline content, little patches of spermatogenic cells in 100× (asterisk), line of spermatogonium cells with severing degeneration and necrosis of other types of germinal epithelial cells (red arrow), and luminal necrotic tissue (asterisk) at 400×; (C) group 3; (D) group 4; (E) group 5. H and E stain (100× and 400× magnification).
The histopathology of the induction group testicle revealed severe toxic orchitis characterized by moderate atrophy of seminiferous tubules associated with little patches of spermatogenic cells due to arrested spermatogenesis and an irregular outline of tubules. The magnification of figures revealed a few spermatogonium cells with severe degeneration and necrosis of other types of germinal epithelial cells with marked nuclear pyknosis, and the lumen of tubules showed necrotic tissue (Fig.
Treatment with 500 mg of Mucuna pruriens revealed a normal appearance with slightly normal-sized seminiferous tubules, a normal appearance of germinal epithelial cells, and a normal testicular interstitium. The magnification of the figures revealed normal spermatogenesis with a normal appearance of spermatogonium cell lines, normal primary lines with secondary spermatocyte lines, and normal maturation stages of spermatids (Fig.
Treatment with 1000 mg of Mucuna pruriens revealed a normal appearance with the normal size of seminiferous tubules, the normal appearance of germinal epithelial cells, and a normal testicular interstitium. The germinal epithelium showed a normal appearance of the spermatogonium cell line, a few normal primaries with a secondary spermatocytes and Sertoli cells, and a normal maturation stage of spermatids. Few figures revealed the normal size of seminiferous tubules with mild microcirculation, vascular congestion with dilation, interstitial edema, and thickening of the testicular interstitium (Fig.
Treatment with 2000 mg of Mucuna pruriens revealed a normal appearance and size of seminiferous tubules, a normal appearance of germinal epithelial cells, and a normal testicular interstitium. The magnification of the figures revealed the normal appearance of the spermatogonium cell line, the normal primary line with a secondary spermatocytes line, and the normal maturation stage of spermatids. Few figures revealed slight hypertrophy of seminiferous tubules, with a normal appearance of germinal epithelial cells and little figures of microcirculation within the cell line of spermatogonium cells and normal testicular interstitium (Fig.
Certain medications are considered EDCs, capable of disrupting endocrine homeostasis and exacerbating male infertility problems (
The present study demonstrates a notable reduction in the PRM I and PRM II gene expressions in the group treated with chlorpromazine compared to the control. These results agree with previous studies (
Male infertility is linked to changes in PRM I and PRM II protamine expression. Protamines are post-meiotic nuclear proteins; during the late haploid phase of spermatogenesis, histones are replaced by protamines, which play a role in preserving the DNA of sperm and condensing the head of the sperm (
FSH and testosterone regulate the mechanism of chromatin condensation during spermiogenesis (
In this study, groups that were treated with Mucuna pruriens demonstrated highly significant PRM I and PRM II gene expression up-regulation; this could be attributed to the seed of Mucuna pruriens containing L-Dopa as its active substance, which stimulates GnRH (gonadotropin-releasing hormone) secretion and enhances male reproductive function. This, in turn, stimulates the secretion of LH and FSH from the pituitary gland anterior portion; elevated FSH, LH, and testosterone serum levels stimulate spermatogenesis (
The current research’s outcomes also stated that chlorpromazine treatment produced psycho-neuroendocrine changes. These changes are shown by neurochemical imbalance, hormonal alteration, induced hypothalamic and pituitary neuronal degenerations, and testicular endocrine and exocrine derangements.
Hormones preserve and regulate the male reproductive system (
Dopamine D2 receptors on lactotroph cells in the anterior pituitary gland are inhibited by chlorpromazine. Dopamine is crucial for prolactin secretion and tonic inhibition, and its inhibition by chlorpromazine leads to increased prolactin levels in rats. Elevated prolactin levels then suppress the release of GnRHs from the hypothalamic axis. This lowers LH, testosterone, and FSH levels, which are responsible for hypogonadism, decreased libido, and infertility in males (
The histopathological study of testicular tissue in the induction group treated with chlorpromazine revealed damage to the seminiferous tubular and spermatogonium cells with severing degeneration and germinal epithelial cell necrosis with nuclear pyknosis, which agreed with previous studies (
This study demonstrated a significant decrease in the level of reproductive hormones associated with increased degenerative lesions in the testes and oxidative stress. Chlorpromazine decreased the stimulation of GnRH, so the reduction in serum LH with a consequent reduction in testosterone levels was associated with an increased index of abnormal sperm and degeneration of the seminiferous tubules that cause arrest in the maturation of sperm from hypo spermatogenesis to absent spermatogenesis. Also, a reduction in serum LH levels directly affects Leydig cells, leading to hypertrophy of these cells (
Oxidative stress plays an important role in reproductive disorders. Spermatozoa are highly vulnerable to oxidative stress due to the high content of polyunsaturated fatty acids (PUFA) in the plasma membrane. Excessive ROS and its metabolites damage lipids, proteins, and sperm DNA either directly or indirectly through the activation of sperm caspases and the production of endonuclease (
Interestingly, the testis sections in treatment groups with Mucuna pruriens show improved histo-morphologic integrity of the testis. Mucuna pruriens can potentially increase FSH, LH, and testosterone levels by activating the pituitary-testicular axis and improving Leydig cell damage. It also contains many bioactive constituents that act as antioxidants that suppress ROS production and increase free-radical scavenging before they interact with the plasma membrane of sperm, reducing membrane damage and restoring of spermatogenesis, which agrees with previous studies (
This study has confirmed the endocrine disorders and reproductive toxicity generated by chlorpromazine (synthetic antipsychotic drugs). Chlorpromazine causes hormonal disruption and alterations in the signaling pathways of PRM I and II genes responsible for spermatogenesis. The administration of Mucuna pruriens seed improved male reproductive function associated with chlorpromazine by elevating testosterone, FSH, and LH serum levels and controlling the PRM I and II signaling pathways in animal models.