Restoration of Spermatogenesis Using a New Combined Herbal Formula of Epimedium koreanum Nakai and Angelica gigas Nakai in an Luteinizing Hormone-Releasing Hormone Agonist-Induced Rat Model of Male Infertility.

PURPOSE: We investigated the protective effect of a mixture of 2 herbal extracts, KH-465, which consisted of Epimedium koreanum Nakai and Angelica gigas Nakai, on spermatogenesis in a luteinizing hormone-releasing hormone (LHRH) agonist-induced rat model of male infertility. MATERIALS AND METHODS: Seventy-five 12-week-old male Sprague-Dawley rats were randomly divided into 5 groups, containing 15 rats each: a normal control group that received no treatment and 4 experimental groups (I, II, III, and IV) in which an LHRH agonist was administered for 4 weeks to induce spermatogenic failure. Group I received distilled water, and groups II, III, and IV received 200 mg/kg/day of KH-465, 400 mg/kg/day KH-465, and depo-testosterone for 4 weeks, respectively. Weight changes of the testis and epididymis, sperm count motility, and levels of testosterone (T), free T, follicle-stimulating hormone (FSH), luteinizing hormone (LH), superoxide dismutase (SOD), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were estimated. RESULTS: Body, testis, and epididymis weight showed no significant differences among the control and experimental groups. Treatment with KH-465 increased the sperm count and motility. Serum hormone levels of T, free T, and FSH were not significantly different in the experimental groups, while the LH level was higher than in the LHRH agonist-induced control group, but not to a significant extent. Levels of SOD were higher and 8-OHdG were lower in the groups that received KH-465 than in the LHRH agonist-induced control group. CONCLUSIONS: Our results suggest that KH-465 increased sperm production via reducing oxidative stress and had a positive effect in a male infertility model.

Escherichia coli 6-pyruvoyltetrahydropterin synthase ortholog encoded by ygcM has a new catalytic activity for conversion of sepiapterin to 7,8-dihydropterin.

The putative gene (ygcM) of Escherichia coli was verified in vitro to encode the ortholog of 6-pyruvoyltetrahydropterin synthase (PTPS). Unexpectedly, the enzyme was found to convert sepiapterin to 7,8-dihydropterin without any cofactors. The enzymatic product 7,8-dihydropterin was identified by HPLC and mass spectrometry analyses, suggesting a novel activity of the enzyme to cleave the C6 side chain of sepiapterin. The optimal activity occurred at pH 6.5-7.0. The reaction rate increased up to 3.2-fold at 60-80 degrees C, reflecting the thermal stability of the enzyme. The reaction required no metal ion and was activated slightly by low concentrations (1-5 mM) of EDTA. The apparent K(m) value for sepiapterin was determined as 0.92 mM and the V(max) value was 151.3 nmol/min/mg. The new catalytic function of E. coli PTPS does not imply any physiological role, because sepiapterin is not an endogenous substrate of the organism. The same activity, however, was also detected in a PTPS ortholog of Synechocystis sp. PCC 6803 but not significant in Drosophila and human enzymes, suggesting that the activity may be prevalent in bacterial PTPS orthologs.

Functional investigation of a gene encoding pteridine glycosyltransferase for cyanopterin synthesis in Synechocystis sp. PCC 6803.

A gene (slr1166) putatively encoding pteridine glycosyltransferase was disrupted with a kanamycin resistance cassette in Synechocystis sp. PCC 6803, which produces cyanopterin. The deduced polypeptide from slr1166 consisted of 354 amino acid residues sharing 45% sequence identity with UDP-glucose:tetrahydrobiopterin alpha-glucosyltransferase (BGluT) isolated previously from Synechococcus sp. PCC 7942. The knockout mutant was unable to produce cyanopterin but only 6-hydroxymethylpterin-beta-galactoside, verifying that slr1166 encodes a pteridine glycosyltransferase, which is responsible for transfer of the second sugar glucuronic acid in cyanopterin synthesis. The mutant was affected in its intracellular pteridine content and growth rate, which were 74% and 80%, respectively, of wild type, demonstrating that the second sugar residue is still required for quantitative maintenance of cyanopterin. This supports the previous suggestion that glycosylation may contribute to high cellular concentration of pteridine compounds.