Observable Protective Activities of Quercetin on Aluminum Chloride-Induced Testicular Toxicity in Adult Male Wistar Rat

Smart Hesperidin/Chitosan Nanogel Mitigates Apoptosis and Endoplasmic Reticulum Stress in Fluoride and Aluminum-Induced Testicular Injury

Fluoride and aluminum are ubiquitous toxic metals with adverse reproductive effects. The citrus flavonoid hesperidin has protective activities but poor solubility and bioavailability. Nanoparticulate delivery systems can improve flavonoid effectiveness. We conducted this study to prepare a pH-responsive chitosan-based nanogel for hesperidin delivery and evaluate its effectiveness against sodium fluoride (NaF) and aluminum chloride (AlCl3) induced testicular toxicity in mice. The nanogel was synthesized using 2 kGy gamma irradiation, enabling a size under 200 nm and enhanced hesperidin release at pH 6 matching testicular acidity. Male mice received 200 mg/kg AlCl3 and 10 mg/kg NaF daily for 30 days. Hesperidin nanogel at 20 mg/kg was administered orally either prophylactically (pretreatment) or after intoxication (posttreatment). The results showed that AlCl3 + NaF induced severe oxidative stress, hormonal disturbance, apoptosis, and endoplasmic reticulum stress, evidenced by significant changes in the studied parameters and testicular histological damage. Hesperidin nanogel administration significantly inhibited oxidative stress markers, restored luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels, and alleviated tissue damage compared to the intoxicated group. It also downregulated the expression level of pro-apoptotic genes Bax, caspase-3, caspase-9, and P38MAPK, while upregulating the expression level of the anti-apoptotic BCL2 gene. Endoplasmic reticulum stress sensors PERK, ATF6, and IRE-α were also downregulated by the nanogel. The chitosan-based nanogel enhanced the delivery and efficacy of poorly bioavailable hesperidin, exhibiting remarkable protective effects against AlCl3 and NaF reproductive toxicity. This innovative nanosystem represents a promising approach to harnessing bioactive phytochemicals with delivery challenges, enabling protective effects against chemical-induced testicular damage.

Reactive Oxygen Species-Mediated Mitophagy and Cell Apoptosis are Involved in the Toxicity of Aluminum Chloride Exposure in GC-2spd

Aluminum chloride is an inorganic polymeric coagulant commonly found in daily life and various materials. Although male reproductive toxicity has been associated with AlCl3 exposure, the underlying mechanism remains unclear. This study aimed to examine the impact of AlCl3 exposure on mitophagy and mitochondrial apoptosis in testicular tissue and mouse spermatocytes. Reactive oxygen species (ROS) and ATP levels were measured in GC-2spd after AlCl3 exposure using a multifunctional enzyme labeler. The changes in mitochondrial membrane potential (MMP) and TUNEL were observed through confocal laser microscopy, and the expression of proteins associated with mitophagy and apoptosis was analyzed using Western blot. Our results demonstrated that AlCl3 exposure disrupted mitophagy and increased apoptosis-related protein expression in testicular tissues. In the in vitro experiments, AlCl3 exposure induced ROS production, suppressed cell viability and ATP production, and caused a decrease in MMP, leading to mitophagy and cell apoptosis in GC-2spd cells. Intervention with N-acetylcysteine (NAC) reduced ROS production and partially restored mitochondrial function, thereby reversing the resulting mitophagy and cell apoptosis. Our findings provide evidence that ROS-mediated mitophagy and cell apoptosis play a crucial role in the toxicity of AlCl3 exposure in GC-2spd. These results contribute to the understanding of male reproductive toxicity caused by AlCl3 exposure and offer a foundation for future research in this area.

Effect of Sempervivum tectorum Extract on Some Biomarkers of Reproductive Function and Levels of Some Trace Elements in Male Rats Exposed to Aluminum

Aluminum, a contentious trace element found in the environment, has been demonstrated to have harmful effects on both humans and animals. In contrast, Sempervivum tectorum, an evergreen plant, has been found to offer numerous beneficial effects for both humans and animals. Therefore, this study aims to assess the protective effect of S. tectorum on certain reproductive biomarkers in male rats exposed to aluminum. Thirty-five Wistar rats were randomly divided into five groups: NTC (no-treatment control) received distilled water; NC (negative control) received drinking water containing 1 mg/L aluminum sulfate (AS); E1 received 1 mg/L AS along with an 8% S. tectorum extract; PC (positive control) received only 8% S. tectorum extract; E2 received 1 mg/L AS for three months followed by 8% extract for one month. The study analyzed testosterone, LH, FSH, body weight, and the histological structure of the testis, epididymis, and prostate, as well as the levels of zinc, manganese, copper, and iron in these organs. Significant decreases in body weight, testis, and epididymis size were observed in the aluminum-exposed groups compared to the control, whereas these decreases were not significant in the S. tectorum-treated groups compared to the control. Aluminum exposure led to significant decreases in testosterone and LH levels, with FSH levels showing a nonsignificant decrease in males, which were mitigated significantly by the administration of the plant extract. Histological analysis revealed alterations in the testis, epididymis, and prostate of the AS-exposed groups, including necrosis of seminiferous tubule epithelium and Leydig cells in the testis, and basal epithelial necrosis in the epididymis and prostate. Aluminum levels increased in all organs studied, while levels of zinc, copper, iron, and manganese decreased, showing a negative and significant correlation with aluminum levels. The aqueous extract of S. tectorum demonstrated a protective effect on certain studied biomarkers in male rats affected by aluminum exposure.

Mechanism and impact of heavy metal-aluminum (Al) toxicity on male reproduction: Therapeutic approaches with some phytochemicals

Heavy metals are ubiquitous environmental toxicants that have been known to have a serious effect on human and animal health. Aluminum (Al) is a widely distributed metal in nature. Al exposure has a detrimental impact on human fertility. This review focused on Al-induced male reproductive toxicity and the potential therapeutic approaches with some phytochemicals. Data from the literature showed that Al exposure is accompanied by a drastic decline in blood levels of FSH, LH, and testosterone, reduced sperm count, and affected sperm quality. Al exposure at high levels can cause oxidative stress by increasing ROS and RNS production, mediated mainly by downregulating Nrf2 signaling. Moreover, several investigations demonstrated that Al exposure evoked inflammation, evidenced by increased TNF-α and IL-6 levels. Additionally, substantial evidence concluded the key role of apoptosis in Al-induced testicular toxicity mediated by upregulating caspase-3 and downregulating Bcl2 protein. The damaging effects of Al on mitochondrial bioenergetics are thought to be due to the excessive generation of free radicals. This review helps to clarify the main mechanism involved in Al-associated testicular intoxication and the treatment strategy to attenuate the notable harmful effects on the male reproductive system. It will encourage clinical efforts to target the pathway involved in Al-associated testicular intoxication.

N-Acetylcysteine May Regulate Altered Meteorin-Like Levels in Testicular Tissue due to Aluminum Exposure

Aluminum (AL) is a heavy metal known to have toxic effects on the reproductive system. It is known that N-acetylcysteine (NAC), which has an antioxidant effect, is a useful chelator for heavy metals. This study aimed to determine whether NAC may reduce AL-induced oxidative stress, inflammation, and germ cell apoptosis in testicular tissues and its effects on meteorin-like (METRNL) levels, which are known to play a role in energy metabolism. In this experimental study, 28 Sprague-Dawley male rats were randomly divided into 4 groups (n = 7): control, AL (30 mg/kg/day AL), AL + NAC (30 mg/kg/day AL + 150 mg/kg/day NAC), and NAC (150 mg/kg/day NAC). All AL and NAC applications were performed intraperitoneally for 14 days. At the end of the experiment, the effects of AL and/or NAC applications on testicular tissue were examined histomorphometrically, histopathologically, immunohistochemically, and biochemically. It was determined that AL exposure caused histomorphometric and histopathological changes, oxidative stress, apoptosis of germ cells, and inflammation in testicular tissues. In addition, AL caused an increase in METRNL levels. It was determined that NAC treatment significantly reduced the negative effects of AL. NAC therapy may be a protective strategy in reproductive toxicity due to AL exposure.

Naringenin ameliorates aluminum toxicity-induced testicular dysfunctions in mice by suppressing oxidative stress and histopathological alterations

Environmental aluminum intoxication has shown increasingly alarming negative consequences on reproductive health. This needs mechanistic exploration and preventive management using medicines like herbal supplementation. The ameliorative effects of naringenin (NAR) against AlCl3-induced reproductive toxicity were thus evaluated in this study by assessing testicular dysfunction in albino male mice. A group of mice was treated with AlCl3 (10 mg/kg b.w./day) and then with NAR (10 mg/kg b.w./day) for a total of sixty-two days. Results show that treatment of AlCl3 significantly reduced the body weight and testis weight of mice. AlCl3 caused oxidative damage in mice as evidenced by an increase in the concentration of nitric oxide, advanced oxidation of protein product, protein carbonylation, and lipid peroxidation. Furthermore, diminished activity of antioxidant moieties included superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione, and oxidized glutathione. Several histological changes, such as spermatogenic cell degeneration, germinal epithelium detachment, and structural abnormalities in seminiferous tubules, were observed in AlCl3-treated mice. Oral administration of NAR was found to restore body weight and testes weight and ameliorated reproductive dysfunctions. NAR decreased oxidative stress, replenished the antioxidant defense system, and improved histopathological alterations in the AlCl3-treated testes. Therefore, the present study suggests that the supplementation of NAR may be a beneficial strategy to mitigate AlCl3-induced reproductive toxicity and testicular dysfunction.

Ameliorative effects of quercetin against hepatic toxicity of oral sub-chronic co-exposure to aluminum oxide nanoparticles and lead-acetate in male rats

The present study was designed to evaluate the probable ameliorative role of quercetin (QCN) against oxidative hepatotoxicity induced by aluminum oxide nanoparticles (Al2O3NPs) with a diameter < 30 nm and lead acetate (Pb) co-exposure in adult male Sprague–Dawley rats. Rats were weighed and allocated to seven groups (n = 10 each) and were treated orally via orogastric gavage for 60 successive days: rats of the 1st group were kept as control given distilled water (1 ml/kg), rats of the 2nd group received 2 ml/kg BW/day corn oil; rats of the 3rd group were administered 20 mg/kg BW QCN/day; rats of the 4th group received 100 mg/kg BW Al2O3NPs; rats of the 5th group received 50 mg/kg BW Pb; rats of the 6th group co-received Al2O3NPs and Pb at the same previous doses; and rats of the 7th group were co-administered Al2O3NPs, Pb, and QCN at the same previous doses. At the end of the experiment, serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total, direct, indirect bilirubin, triglycerides, total cholesterol, HDL, VLDL, and LDL were estimated. The hepatic oxidative stress biomarkers as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx), were also evaluated. Finally, the histopathological and histomorphometric evaluations and the residues of Al and Pb in hepatic tissues were assessed. Al2O3NPs and/or Pb exposure significantly elevated lipid peroxidation levels and considerably altered the hepatic biochemical parameters; nevertheless, QCN significantly reduced hepatic enzymes compared to toxicant exposed groups. Additionally, QCN significantly improved Al2O3NPs-afforded liver tissue damage, as established in microscopic findings on the liver in the group treated with Al2O3NPs + Pb. Conclusively, QCN could be a candidate natural agent to safeguard the liver versus the co-harmful impacts of Al2O3NPs and Pb toxicity.

Aqueous extract of bay leaf (Laurus nobilis) ameliorates testicular toxicity induced by aluminum chloride in rats

Background and Aim

Human exposure to aluminum is inevitable, and one of the most adverse health effects of aluminum is a decrease in male fertility rates. Therefore, this study investigated the ameliorative effects of an aqueous extract from Laurus nobilis-bay leaf (BL) on aluminum chloride (AlCl₃)-induced testicular toxicity in rats.

Materials and Methods

Twenty-four Wistar rats were divided into four groups (n = 6, each group): The control (group 1) received normal saline; Group 2 animals were intraperitoneally administered with 30 mg/kg body weight (BW) AlCl₃; and Groups 3 and 4 were co-administered AlCl₃ with 125 or 250 mg/kg BW of BL extract, respectively, for 21 days. Testes, epididymis, and blood samples were collected. Testicular plasma enzyme activity was measured using a spectrophotometric assay, while concentrations of inflammatory biomarkers were determined using enzyme-linked immunosorbent assay kits.

Results

There was a significant increase (p < 0.05) in testicular enzyme activity in the group treated with AlCl₃. However, there was no significant (p > 0.05) difference in testicular enzyme activity in groups co-administered AlCl₃ and BL extract as compared with that in control. There was a significant (p < 0.05) increase in testicular nitrite concentration in the AlCl₃-treated group, whereas the administration of BL extract significantly (p < 0.05) decreased nitrite concentration in Groups 3 and 4. Furthermore, the administration of BL extracts increased sperm count and improved the morphology of the testes in AlCl₃-treated rats. Flavonoids, phenolic compounds, alkaloids, tannin, glycosides, saponin, anthraquinones, and steroids were identified in BL extract, with alkaloids and glycosides being the most abundant.

Conclusion

Aqueous extract from BL ameliorated the toxic effect of AlCl₃ and exhibited anti-inflammatory properties by inhibiting nitrite production while improving sperm count and morphology in AlCl₃-treated rats. The bioactivity of the extract may be attributed to the presence of a wide range of phytochemicals. Therefore, BL aqueous extract could be a promising source of novel compounds with male fertility-promoting and anti-inflammatory properties.

The consequence and mechanism of dietary flavonoids on androgen profiles and disorders amelioration

Androgen is a kind of steroid hormone that plays a vital role in reproductive system and homeostasis of the body. Disrupted androgen balance serves as the causal contributor to a series of physiological disorders and even diseases. Flavonoids, as an extremely frequent family of natural polyphenols, exist widely in plants and foods and have received great attention when considering their inevitable consumption and estrogen-like effects. Mounting evidence illustrates that flavonoids have a propensity to interfere with androgen synthesis and metabolism, and also have a designated improvement effect on androgen disorders. Therefore, flavonoids were divided into six subclasses based on the structural feature in this paper, and the literature about their effects on androgens published in the past ten years was summarized. It could be concluded that flavonoids have the potential to regulate androgen levels and biological effects, mainly by interfering with the hypothalamic-pituitary-gonadal axis, androgen synthesis and metabolism, androgen binding with its receptors and membrane receptors, and antioxidant effects. The faced challenges about androgen regulation by flavonoids masterly include target mechanism exploration, individual heterogeneity, food matrixes interaction, and lack of clinical study. This review also provides a scientific basis for nutritional intervention using flavonoids to improve androgen disorder symptoms.