Nanoparticulate versus conventional losartan: Protective effects against CCl4-induced testicular oxidative stress and fibrosis in rats

• Both conventional and nanoparticle forms of Losartan effectively mitigate carbon tetrachloride (CCl₄)-induced testicular toxicity in rats by reducing oxidative stress and fibrosis. • Losartan nanoparticles (LP-NPs) showed superior efficacy compared to conventional Losartan in restoring testicular weight, sperm count, motility, and testosterone levels. • LP-NPs significantly reduced oxidative stress markers (MDA) and enhanced antioxidant activity (GSH, SOD). • LP-NPs downregulated fibrosis markers (α-SMA, TIMP1). • The findings highlight the potential of Losartan, particularly in nanoparticle form, as a promising therapeutic agent for protecting against environmental toxin-induced male reproductive dysfunction. Environmental and pharmaceutical toxicants have contributed to a decline in human fertility. Carbon tetrachloride (CCl₄), a widely used industrial compound, is known to induce oxidative stress and fibrosis in various tissues, including the testes, leading to impaired male reproductive function. Losartan, an angiotensin II receptor antagonist, has shown potential in mitigating oxidative stress and fibrosis. However, the comparative efficacy of ordinary Losartan versus its nanoparticle form (LP-NPs) in alleviating CCl₄-induced testicular toxicity remains unexplored. This study aimed to evaluate the protective effects of ordinary and nanoparticle forms of Losartan against CCl₄-induced testicular toxicity, focusing on oxidative stress, fibrosis, and reproductive function in rats. Twenty-four male Sprague Dawley rats were divided into four groups: control, CCl₄-treated, CCl₄ + ordinary Losartan (10 mg/kg), and CCl₄ + LP-NPs (10 mg/kg). CCl₄ was administered intraperitoneally (1 mL/kg) twice weekly for six weeks, followed by four weeks of Losartan treatment. Testicular weight, sperm parameters (count, motility, morphology), testosterone levels, oxidative stress markers (MDA, GSH, SOD), and fibrosis markers (Sirius Red, α-SMA, TIMP1) were assessed. Histopathological and molecular analyses were performed to evaluate structural and gene expression changes. CCl₄ significantly reduced testicular weight (1.69 g vs. control, p < 0.001), sperm count (79.07 ± 6.67 vs. 127.2 ± 9.02, p < 0.001), and testosterone levels (1.78 ± 0.45 ng/mL vs. control, p < 0.001), while increasing oxidative stress (MDA: p < 0.001) and fibrosis markers (α-SMA, TIMP1: p < 0.001). Both ordinary Losartan and LP-NPs ameliorated these effects, but LP-NPs showed superior efficacy. LP-NPs significantly increased testicular weight (1.53 g, p < 0.001), sperm count (116.48 ± 11.81, p < 0.001), and testosterone levels (2.36 ± 0.03 ng/mL, p < 0.05) compared to ordinary Losartan. Additionally, LP-NPs more effectively reduced oxidative stress (MDA: p < 0.05) and fibrosis markers (α-SMA, TIMP1: p < 0.001) and improved seminiferous tubule diameter ( p < 0.05). Both ordinary and nanoparticle forms of Losartan attenuated CCl₄-induced testicular toxicity by reducing oxidative stress and fibrosis, with LP-NPs demonstrating superior efficacy in improving reproductive function and histological structure. These findings suggest that Losartan, particularly in nanoparticle form, is a promising therapeutic candidate for mitigating testicular damage caused by environmental toxins.