Dolichandrone serrulata flower extract ameliorates male reproductive damages in type 2 diabetic rats

Dolichandrone serrulata flower (DSF) has been believed to reduce blood glucose in hyperglycaemic persons with sub-fertility but its effect on improvement of male reproductive impairment has never been elucidated scientifically. This study attempted to investigate the hypoglycaemic effects of DSF on male reproductive damages in type 2 diabetes mellitus (T2DM) rats. Adult Sprague Dawley rats were divided into four groups (control, T2DM, DSF200 + T2DM and DSF600 + T2DM; n = 10/each). Control rats received low-fat diet for 14 days before saline injection while streptozocin (50 mg/kg BW) induced T2DM groups received high-fat diet and were orally administered with DSF (200 and 600 mg/kg BW) for 28 days. At the end, fasted blood glucose (FBG), malondialdehyde (MDA), testosterone, sperm quality, histology and protein expressions were examined. The result showed that DSF decreased high FBG and testicular MDA and increased testosterone levels of T2DM-treated rats. Low-sperm quality and histological malfunction were ameliorated in DSF-treated group. There was significant decrease in the expression of androgen receptor, heat-shock 70 and steroidogenic acute regulatory proteins of T2DM-treated rats. Our study demonstrated changes of six bands (116, 51, 45, 39, 35 and 29 kDas) of tyrosine-phosphorylated proteins. In conclusion, DSF could reduce the FBGand ameliorate the reproductive damages in male T2DM rats.     

Alterations of morphology and phosphorylated protein expression in the seminal vesicles of diabetic mice

Although many studies reported the detrimental effects of type 1 and 2 diabetes mellitus (T1DM and T2DM) on testis, reproductive parameter changes in DM seminal vesicles have never been documented. This study aimed to examine the morphology, biochemical levels and tyrosine phosphorylation in seminal vesicles of T1DM and T2DM mice. Fifty‐six male C57BL/6 mice were divided into four groups (n = 14/each): T1DM control, T1DM, T2DM control and T2DM. T1DM mice were daily injected of streptozotocin (STZ; 40 mg/kg BW) for 5 days. T2DM mice received high‐fat diet for 14 days prior to STZ injection at a single dose (85 mg/kg BW). At the end of experiments (days 36 and 72), magnesium (MG) and fructosamine (FRA) levels, and phosphorylated protein expression in seminal vesicle were examined. The results showed that seminal and prostate weights and MG and FRA levels of T1DM animals were significantly increased as compared to T2DM mice. Some seminal histopathologies and decreased epithelial height were observed in both DM groups. Significantly, a 72‐kDa phosphorylated protein expression was increased in DM seminal vesicle. We concluded that changes of biochemical components and phosphorylated proteins in seminal vesicle of T1DM and T2DM mice may be associated with low‐quality seminal plasma.     

Effect of chronic stress on expression and secretion of seminal vesicle proteins in adult rats

Chronic stress (CS) is known to affect men's health especially fertility by reducing semen quality. Although the effects of CS on testicular function and sperm parameters are documented, changes of substances and secreting proteins in the seminal vesicle (SV) have never been reported. This study aimed to demonstrate the alterations of contents and expressions of proteins in seminal vesicle fluid (SVF) under CS. Fourteen adult rats were divided into control and CS groups (n = 7/each). Control rats were not exposed to stressor, while the CS animals were immobilised by restraint cage (4 hr/day) and followed by forced swimming (15 min/day) for consecutive 60 days. Biochemical substances and malondialdehyde (MDA) level in SVF were examined. Expressions of heat-shock protein 70 (Hsp70), caspases (Casp) 3 and 9, and tyrosine-phosphorylated (TyrPho) proteins were investigated in seminal vesicle tissue (SVT) and SVF. It was found that CS caused reductions of seminal epithelial height and secreted substance levels. Significantly, MDA levels in SVF and expressions of Hsp70, Casp and TyrPho proteins were increased in of CS animals. It was concluded that CS affected seminal secretion. Low quality of CS seminal plasma may associate with increase of MDA and expressions of secreted proteins.     

The effect of Dolichandrone serrulata (wall. ex DC.) Seem. flower extract containing antioxidant capacity and terpenoids on the male reproductive system

Although the fruit extract of Dolichandrone genus was shown to inhibit spermatogenesis, the reproductive toxicity of Dolichandrone serrulata flowers (DSFs) is not documented. Recent study aimed to evaluate the sub-chronic toxicity of DSF on male reproductive system. Antioxidant capacity and total phenolic contents of DSF extract were determined using Folin–Ciocalteu's, 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. The terpenoid components were determined using nuclear magnetic resonance spectrum. Adult male rats were treated orally with DSF (100, 300 or 600 mg/kg) for 48 days. Histopathology of testis and epididymis was observed. Sperm concentration, viability, acrosome status and morphology were also examined. Expressions of heat shock protein 70 (Hsp70), tyrosine-phosphorylated (TyrPho) proteins, androgen receptor (AR) and steroidogenic acute regulatory (StAR) protein in testis were investigated. Results showed that DSF contained phenolic compounds and terpenoids (phytoandrogens; rengyolone and cleroindicin B). No reproductive histopathology was observed in DSF-treated rats. Although DSF decreased the serum testosterone level, the sperm qualities were not affected. Particularly, sperm concentration of DSF-treated animals was significantly increased. DSF changed the testicular TyrPho proteins but the expression of AR, StAR or Hsp70 was not altered. In conclusion, DSF possesses antioxidant capacity with no toxicity on male reproductive system.