Effects of diabetes and phyto-therapeutic treatment on male reproductive function in the Wistar rat.

Abstract

The negative impact of diabetes mellitus on male fertility highlights the need to find effective treatments. Historically, sage, whose Latin name "salvia", derived from the word “salvare” (to save), underscores its long-standing reputation for medicinal properties. Thus, our study aimed to assess the effects of Salvia balansae Noë ex Coss flower aqueous extract (FAE) on the reproductive function of diabetic rats based on behavioral, hormonal, cytological (spermogram), and histological approaches. Total phenolic and flavonoid content, quantification of phytochemicals by ultrahigh performance liquid chromatography (UHPLC)–electrospray ionization (ESI)–tandem mass spectrometry (MS/MS) method, and in vitro antioxidant capacity, in vivo anti-inflammatory property and acute toxicity of FAE extract were elucidated. For the in vivo study, male Wistar rats were divided into four groups: a normoglycemic control and treated group with FAE (200 mg/kg b.w. by gavage), and two different groups were given a single dose of streptozotocin (40 mg/kg b.w. by intraperitoneal injection). These groups were divided into: hyperglycemic control and hyperglycemic + 200 mg/kg b.w/day of FAE by gavage for 12 weeks. This study was based on different analyses: behavioral (elevated plus maze (EPM), sexual incentive motivation test (SIM), and a mating behavior test), hormonal (serum testosterone levels), cytological examination of spermatic parameters (count, motility, morphology, and viability) and histological investigation of the testicular structure. Our study indicates that FAE contained a large amount of phenolic compounds and flavonoids, thirteen constituents were quantified; cynaroside (3,8 mg analyte/g extract) was the main compound, followed by rosmarinic acid (3,145 mg analyte/g extract), thus confirming its high antioxidant capacity, reflected by the DPPH IC50 values of 31.06 ± 0.12 μg/mL, along with FRAP A0.5 values of 27.93 ± 1.04 μg/mL. Acute toxicity tests of FAE demonstrated a substantial safety margin, as no toxicity was observed at doses up to 2 g/kg. Additionally, a significant anti-inflammatory effect was shown through carrageenan-induced plantar edema tests in rats, with a maximum inhibition of 88.06% observed at 6 hours. When administered at a dose of 200 mg/kg to diabetic rats, FAE significantly improved blood glucose levels (P < 0.001). There were also notable increases in body and testicular weights (P < 0.001). Furthermore, anxiety levels were reduced (P < 0.01), and sexual motivation was enhanced (P < 0.001). The treatment also led to improved sexual interactions, evidenced by an increased frequency of male-female interactions (P < 0.001) and decreased latency times (P < 0.001). Additionally, testicular histological changes (degeneration of the germinal epithelium, presence of cellular debris, reduction in the size and number of germ cells, decrease in sperm density, and apoptosis), abnormal sperm and morphometric parameters (P < 0.001), and a significant drop in serum testosterone levels (P < 0.001) were noted in diabetic rats. All these altered parameters were restored and normalized by our FAE at a dose of 200 mg/kg (P < 0.001). The present work demonstrates the therapeutic potential of Salvia balansae flowers in enhancing reproductive function in diabetic rats, potentially through its antioxidant, anti-inflammatory, antihyperglycemic, and aphrodisiac properties