Potential therapeutic effects of Ulva lactuca water fraction on monosodium glutamate-induced testicular and prostatic tissue damage in rats

Male infertility is considered one of the most critical health problems that are expected to expand worldwide. Ulva lactuca is a species of green seaweeds which is known to be a rich source of many important nutrients. Accordingly, this study is designated to investigate the therapeutic role of Ulva lactuca water fraction (UL) against monosodium glutamate (MSG)-induced male reproductive system disorders in male rats. Ulva lactuca methanolic crude extract was prepared firstly, and then water-dissolved compounds of this crude methanolic extract were separated. Ulva lactuca water fraction active phenolic compounds were determined using high-performance liquid chromatography (HPLC). Thirty-two male rats were divided equally into four groups; male infertility was induced in sixteen experimental animals by MSG at dose of 15 mg/Kg for 45 days. Eight infertile animals were treated with 100 mg/Kg of Ulva lactuca water fraction for 30 days. The rest of the animals were divided into two control groups; one control group (eight animals) was used to study the effect of UL on healthy rats at dose of 100 mg/Kg for 30 days and healthy control group (eight animals). Semen quality parameters (concentration and motility ratio), serum testosterone, prostate-specific antigen (PSA), and phosphatases were estimated by using standard protocols. Moreover, prooxidants and endogenous antioxidant enzymes were measured in prostate and testis homogenates. In addition, relative expression of pro-inflammatory genes (inducible nitric oxide synthase (i-NOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha alpha (TNF-alpha), and tumor protein (P53)) were assessed in testicular and prostatic tissues. Finally, histological alterations were measured by hematoxylin and eosin (H&E) stain. Results revealed that Ulva lactuca water fraction contains active phenolic constituents responsible for its antioxidant bioactivity. Oral administration of MSG significantly induced histological alterations. Oxidative stress was observed with elevated levels of nitric oxide (NO), thiobarbituric acid reactive substances (TBARS), and xanthine oxidase (XO) activity in both testis and prostate tissues. MSG adversely affected prostate function via elevation of PSA, prostatic acid phosphatases (PAPs), and total acid phosphatases (TAPs). In addition, it upregulated pro-inflammatory genes in testis and prostate tissues. Meanwhile, MSG reduced serum testosterone, semen quality, and antioxidant enzyme activities (glutathione peroxidase (GPx), glutathione-s-transferase (GST), and superoxide dismutase (SOD)). Treatment with UL notably ameliorated the state of oxidative stress and downregulated the expression of pro-inflammatory gene markers. This study highlighted the potential efficacy of Ulva lactuca water fraction on MSG-induced male infertility in rats.