Abstract Aim: To evaluate the antifertility effect ofAlstonia scholaris bark extract in male rats. Methods: In male Wistar rats Alstonia scholaris bark extract was given by oral route at a dose of 200 mg/day for 60 da...Abstract Aim: To evaluate the antifertility effect ofAlstonia scholaris bark extract in male rats. Methods: In male Wistar rats Alstonia scholaris bark extract was given by oral route at a dose of 200 mg/day for 60 days. The fertility and testicular function were assessed by mating tests, sperm motility, sperm concentration, biochemical indices and testicular cell population dynamics. Results: Oral feeding with the extract at a dose of 200 mg/day for the period of 60 days did not cause body weight loss, while the weights of testes, epididymides, seminal vesicle and ventral prostate were significantly reduced. The production of step-19 spermatids was reduced by 79.6% in treated rats. The population of preleptotene and pachytene spermatocytes were decreased by 61.9% and 60.1%, respectively. Spermatogonia and Sertoli cell population were also affected. The seminiferous tubule and Leydig cell nuclear area were reduced significantly (P<0.01) when compared to the controls. Reduced sperm count and motility resulted in a total suppression of fertility. A significant fall in the protein and sialic acid content of the testes, epididymides, seminal vesicle and ventral prostate as well as glycogen content of testes were also noticed. The fructose content in the seminal vesicle was lowered whereas the testicular cholesterol was elevated as compared with the controls. The following compounds were obtained from the extract with chromatographic separation over Si-gel column: α-amyrin, β-amyrin, lupiol acetate, venenative, rhazine and yohimbine. Conclusion: At the dose level employed, Alstonia scholaris bark extract has a significant antifertility effect in male rats; the primary site of action may be post meiotic germ cells (Step 19 spermatids).展开更多
The reconstruction after peripheral nerve damage, especially for long‐segment nerve defects, remains a clinical challenge. Autologous nerve graft transplantation is an efficient method for the repair of peripheral ne...The reconstruction after peripheral nerve damage, especially for long‐segment nerve defects, remains a clinical challenge. Autologous nerve graft transplantation is an efficient method for the repair of peripheral nerve defects, but the involved com‐plications and shortcomings have greatly limited the clinical efficacy of treatments offered to patients with nerve defects. Thus, there is an urgent need to develop new therapeutic strategies and explore alternatives to autologous nerve transplantation in clinical practice, based on the knowledge of the peripheral nerve regeneration mechanism and biological histocompatibility principles. With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. In this paper, the study background of nerve conduits, their applications in clinic, status of conduit material research and construction of tissue‐engineered artificial nerves were reviewed.展开更多
文摘Abstract Aim: To evaluate the antifertility effect ofAlstonia scholaris bark extract in male rats. Methods: In male Wistar rats Alstonia scholaris bark extract was given by oral route at a dose of 200 mg/day for 60 days. The fertility and testicular function were assessed by mating tests, sperm motility, sperm concentration, biochemical indices and testicular cell population dynamics. Results: Oral feeding with the extract at a dose of 200 mg/day for the period of 60 days did not cause body weight loss, while the weights of testes, epididymides, seminal vesicle and ventral prostate were significantly reduced. The production of step-19 spermatids was reduced by 79.6% in treated rats. The population of preleptotene and pachytene spermatocytes were decreased by 61.9% and 60.1%, respectively. Spermatogonia and Sertoli cell population were also affected. The seminiferous tubule and Leydig cell nuclear area were reduced significantly (P<0.01) when compared to the controls. Reduced sperm count and motility resulted in a total suppression of fertility. A significant fall in the protein and sialic acid content of the testes, epididymides, seminal vesicle and ventral prostate as well as glycogen content of testes were also noticed. The fructose content in the seminal vesicle was lowered whereas the testicular cholesterol was elevated as compared with the controls. The following compounds were obtained from the extract with chromatographic separation over Si-gel column: α-amyrin, β-amyrin, lupiol acetate, venenative, rhazine and yohimbine. Conclusion: At the dose level employed, Alstonia scholaris bark extract has a significant antifertility effect in male rats; the primary site of action may be post meiotic germ cells (Step 19 spermatids).
文摘The reconstruction after peripheral nerve damage, especially for long‐segment nerve defects, remains a clinical challenge. Autologous nerve graft transplantation is an efficient method for the repair of peripheral nerve defects, but the involved com‐plications and shortcomings have greatly limited the clinical efficacy of treatments offered to patients with nerve defects. Thus, there is an urgent need to develop new therapeutic strategies and explore alternatives to autologous nerve transplantation in clinical practice, based on the knowledge of the peripheral nerve regeneration mechanism and biological histocompatibility principles. With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. In this paper, the study background of nerve conduits, their applications in clinic, status of conduit material research and construction of tissue‐engineered artificial nerves were reviewed.
