Effect of the ethanolic extract from Fagara tessmannii on testicular function, sex reproductive organs and hormone level in adult male rats.

The effect of ethanolic extract of Fagara tessmannii, wide medicinal plants used on reproductive function in South Cameroon, was investigated in male rats. Twenty male sexually experienced rats (four groups) were orally treated with vehicle, 0.01, 0.1, 1 g kg(-1) BW per day of F. tessmannii (equivalent to 16.67 g, 33.33 g, 50 g, 66.66 g kg(-1) dry raw material) for 14 days, the upper limit dose without any clinical sign of toxicity was 2 g kg(-1). Fagara tessmannii extract negatively affected weight of accessory organs and significantly affected body weight gain at dose 1 g kg(-1) (P < 0.05) in treated rats. The weight of epididymis and seminal vesicle significantly decreased at low doses (0.01 g kg(-1)) while the prostate weight decreased at all doses (P < 0.05). The transit of spermatozoa in cauda epididymidis significantly increased at lower dose of 0.01 g kg(-1) (P < 0.05). In addition, F. tessmannii extract affected neither daily sperm production (DSP) and DSP per g nor sperm count in vas deferens and epididymis. The length of stages IX-I of the seminiferous tubule and serum testosterone level increased dose-dependently following 14 days of treatment (P < 0.05). The results suggest that F. tessmannii, 14 days after treatment, may improve spermatogenesis, testosterone level and sperm transit in cauda epididymidis but negatively impair reproductive organ activities.

Improved fertility in gilts and sows after artificial insemination of frozen-thawed boar semen by supplementation of semen extender with caffeine and CaCl2.

Supplementation of semen extender with caffeine and CaCl(2) for artificial insemination (AI) of fresh spermatozoa has been demonstrated to reduce recruitment of uterine polymorphonuclear leukocytes (PMNs) and the activity of phagocytosis. Here, we determined if addition of caffeine and CaCl(2) to semen extender improves the fertility of frozen-thawed boar semen. In experiment 1, gilts were cervically inseminated twice with frozen-thawed boar spermatozoa (25 x 10(8) cells per dose) suspended in Modena solution (n=7) or modified Beltsville Thawing Solution supplemented with caffeine and CaCl(2) (BCC, n=7). The gilts were slaughtered 4 h later, and their oviducts and uterine horns plus the body of the uterus were flushed to recover PMNs and non-phagocytosed spermatozoa. There was no difference in the total number of uterine PMNs between gilts inseminated with Modena solution and those inseminated with BCC (3.8 x 10(8) vs. 1.5 x 10(8) cells, respectively); however, the total number of uterine spermatozoa was higher when gilts were inseminated with BCC (40.6 x 10(6) cells) compared with those inseminated with Modena solution (1.4 x 10(6) cells, P<0.05). In experiment 2, gilts and sows were subjected to intrauterine insemination twice with frozen-thawed spermatozoa suspended (25 x 10(8) sperm per dose) in Modena (n=21) or BCC (n=21). The overall pregnancy and farrowing rates were higher in females inseminated with BCC (71.4 and 61.9%, respectively) compared with those inseminated with Modena solution (38.1 and 28.6%, respectively, P<0.05). However, no significant difference in litter size of piglets was observed between treatments (7.2 +/- 1.6 piglets for Modena solution vs. 8.2 +/- 0.9 piglets for BCC solution). In conclusion, we demonstrated that use of BCC solution for frozen-thawed boar semen produced better pregnancy and farrowing rates following AI than Modena solution, probably by reducing the phagocytosis of spermatozoa.

Biology of sperm capacitation: evidence for multiple signalling pathways.

The endpoint of in vitro/in vivo capacitation is the ability of sperm surface receptors to bind to their complementary ligands on zona pellucida, the extracellular glycocalyx that surrounds the egg, and undergo the Ca2+-dependent signal transduction. The net result is the fenestration and fusion of the sperm plasma membrane and the underlying outer acrosomal membrane at multiple sites and exocytosis of acrosomal contents. The hydrolytic action of glycohydrolases and proteinases, released at the site of sperm-zona binding, along with the enhanced thrust generated by the hyperactivated flagellar motility of the bound spermatozoon, are important factors that regulate the fertilization process. This report discusses the physiological significance of calmodulin, a 17 kDa Ca2+ sensor protein, in sperm function. The in vitro experimental approaches described in this article provide evidence strongly suggesting that calmodulin plays an important role in the priming (that is, capacitation) of mouse spermatozoa as well as in the agonist-induced acrosome reaction. In addition, we have used several calmodulin antagonists in an attempt to characterize further the morphological and biochemical changes associated with sperm capacitation. Data presented in this report suggest that calmodulin antagonists prevent capacitation by interfering with multiple regulatory pathways and do so either with or without adverse effects on sperm motility and protein tyrosine phosphorylation of sperm components.

In vitro screening of antimotility effect on human sperm with polyphenolic compounds purified from Chinese herbal medicines.

PIP: 24 kinds of pure compounds extracted from Chinese herbal medicines were studied for their effects on human sperm motility. 7 were found to inhibit sperm motility at the concentration of 2 mg/ml. These 7 substances were further investigated for their sperm motility-inhibitory effect at the concentration of 3.0 mg/ml, 4.5 mg/ml, and 6.75 mg/ml to test the dose-related response. The results showed that 5 of the 7 extracts, namely casuarinin, cinnamtannin B-1, pedunculagin, epicatchin-(4beta-8)-epicatechin-(4beta-8)-catechin, and catechin have a strong inhibitory effect on sperm motility with dose-response relationship. Since the chemical structures of these extracts have already been determined, further studies should aim at exploring the mechanisms of their antimotility effect on human sperm. It would appear that some traditional Chinese herbal medicines have the potential of becoming new and acceptable forms of male oral contraceptives in the future.^ieng

A changed responsiveness to oestrogen in ewes with clover disease.

When clover-infertile ewes are subsequently exposed to non-oestrogenic pasture, they have a reduced fertilization rate, due to an inability to store spermatozoa in the cervix, and the cervical mucus has a reduced spinnbarkeit, caused by a slower response to oestrogenic stimulation. Vaginal cell keratinization and oestrous behaviour occurred more slowly after treatment of affected ewes with oestrogen. Other changes in affected ewes suggest that phyto-oestrogens have permanent mild differentiating effects on adults. Sexual behaviour is masculinized, the cervix takes on a uterine-like appearance and the genital tract becomes permanently oestrogenized. The manner in which these changes relate to the altered responsiveness to oestrogen remains to be clarified.

Studies on the male antifertility agent gossypol acetic acid: in vitro studies on the effect of gossypol acetic acid on human spermatozoa.

PIP: The hypothesis that gossypol (an active ingredient associated with cottonseed oil) affects enzymes and other constituents of spermatozoa, resulting in alterations in motility and sperm viability after in vitro treatment, was tested using human semen samples. At a gossypol acetic acid concentration (and a 30 minute incubation) of .01 mcg, the percent motility was 71+ or -2.5 (P .01); at .1 mcg concentration, percent motility was 69+ or -4 (P .01); at 1 mcg motility was 66+ or -5 (P .005); at 10 cg, motility was 38.5+ or -3.5 (P .001). Control values for sperm motility were 77+ or -3. These investigations suggested that treatment with gossypol depletes production of adenosine triphosphate in the sperms and thus their metabolism does not proceed normally, rendering them immotile. It appears that the high vulnerability of the testis to gossypol and the uncoupling of oxidative phosphorylation in the respiratory chain of mitochondria of germ cells may be the mechanism responsible for infertility induction.^ieng