Protective effect of antioxidant supplementation in sperm-preparation medium against oxidative stress in human spermatozoa.

BACKGROUND: Oxidative stress induced by reactive oxygen species (ROS) is associated with an impaired fertilization ability of spermatozoa. We investigated the effects of adding antioxidants to a sperm preparation medium on the functional parameters of the spermatozoa. METHODS: Spermatozoa were washed with Ham's F-10 media containing the antioxidants, ethylenediaminetetraacetic acid (EDTA) and catalase, at various concentrations, and then the ROS levels in sperm suspensions, and the forward motility, acrosome reaction, DNA integrity and lipid peroxidation of the spermatozoa were assessed. RESULTS: The ROS levels were significantly lower in sperm suspensions washed with the antioxidants (196 approximately 312 rlu; relative light units) than in control sperm (604 rlu, P < 0.05). The addition of 10 microM EDTA to the sperm preparation medium significantly improved the motility of the spermatozoa compared with the control group, the groups containing EDTA at other concentrations and the groups containing catalase. Catalase significantly increased the acrosome reaction rate of the spermatozoa. Both EDTA and catalase significantly decreased the DNA fragmentation rate of the spermatozoa. However, the antioxidants did not reduce lipid peroxidation. CONCLUSIONS: Supplementing sperm preparation medium with EDTA or catalase significantly improved the overall functional parameters of the spermatozoa by reducing the ROS levels.

Development of a natural preservative system using the mixture of chitosan-Inula helenium L. extract.

The aim of this study was to develop a new natural preservative system making up for the weak points of chitosan as a preservative. As reported in a previous manuscript (20th IFSCC Congress, Cannes, France, 1998), the minimum inhibitory concentrations (MICs) of water-soluble chitosan against bacteria and yeast were 0.9-3.0 mg mL(-1), whereas MICs of chitosan against Aspergillus niger were over 5.0 mg mL(-1). However, the result of recent study showed that the MICs of Inula helenium L. extract against A. niger were below 1.0 mg mL(-1). Thus, we could develop a new preservative system containing both chitosan and I. helenium L. extract named CI-mixture. MICs of CI-mixture against bacteria and fungi (yeast and mould) were 2.0-4.0 mg mL(-1). When 10.0% of the mixture (the ratio of chitosan to I. helenium L. extract = 7.5% : 2.5%) was applied to cosmetic formulae such as skin lotion, milk lotion, cream and pack, it revealed appropriate preservative efficacy. Our result of the patch test also showed that this preservative system reduced skin irritation by about 30-50%, as compared to the organic preservative system. Therefore, the good natural preservative system including chitosan and Inula helenium L. extract could be incorporated in cosmetic formulations.

Characterization of the Lactobacillus casei group and the Lactobacillus acidophilus group by automated ribotyping.

A total of 91 type and reference strains of the Lactobacillus casei group and the L acidophilus group were characterized by the automated ribotyping device Riboprinter microbial characterization system. The L. casei group was divided into five (C1-C5) genotypes by ribotyping. Among them, the strain of L. casei ATCC 334 was clustered to the same genotype group as most of L. paracasei strains and L casei JCM 1134T generated a riboprint pattern that was different from the type strain of L. zeae. These results supported the designation of L. casei ATCC 334 as the neotype strain, but were not consistent with the reclassification of L. casei JCM 1134T as L. zeae. The L. acidophilus group was also divided into 14 (A1-A11, B1-B3) genotypes by ribotyping. L. acidophilus, L. amylovorus, L. crispatus and L. gallinarum generated ribotype patterns that were distinct from the patterns produced by L. gasseri and L. johnsonii. This result confirmed previous data that the L. acidophilus group divided to two major clusters. Five strains of L. acidophilus and two strains of L. gasseri were correctly reidentified by ribotyping. Most strains belonging to the L. casei group and the L. acidophilus group were discriminated at the species level by automated ribotyping. Thus this RiboPrinter system yields rapid, accurate and reproducible genetic information for the identification of many strains.