Effect of dietary supplementation with seaweed and polyphenols mixture on antioxidant status, concentration and motility of rabbit spermatozoa

In recent years, many studies have been focused on natural substances that could have effect on health of animals. We investigated effect of extract consisting mainly of polyphenols, brown algae and plant polysaccharides on the reproduction potential of male rabbits (New Zealand white breed) during 60 days long dietary experiment. The rabbits were divided into three groups. Control was fed a basal diet, whereas the second and third group were supplemented with seaweed and polyphenols mixture: T1 = 0.3% and T2 = 0.6% respectively. We observed that sperm concentration in both experimental groups increased in comparison to the control group. Results of the CASA analysis showed enhanced motility (C = 85.09±7.53%, T1 = 87.21±8.25%, T2 = 89.38±8.02%) and progressive motility (C = 74.28±12.6%, T1 = 79.07±13.89%, T2 = 81.28±11.37%) in experimental groups supplemented with combination of algae and polyphenols in comparison with the control group. While monitoring ferric reducing ability of plasma (FRAP), we found the highest value in T1 group, changes were insignificat. An increase in GPx activity was measured in experimental groups in comparison with the control group with major difference in T1 group. In experimental groups, we determined an increase in activity of superoxide dismutase (SOD) in comparison with control group, the difference was significant in T2 group (C = 0.26±0.11 U/mg TP; T2 = 0.31±0.09 U/mg TP). In conclusion, our studies suggest that dietary supplementation with brown seaweed and plant polyphenols mixture may be potentially useful for enhancement of sperm motility and protection against oxidative stress

Lippia citriodora (verbascoside) extract supplementation: Effect on rabbit semen quality in vivo and in vitro

Verbascoside, the main component of Lippia citriodora extract, is one of the most powerful free radical scavengers exhibiting a wide biological activity. In in vivo study 20 adult New Zealand white rabbit bucks were divided into two homogeneous groups, one control (CON) and one verbascoside-supplemented (0.1%) in feed mixture (EXP) and later in vitro effects of verbascoside on the motility aspects of rabbit spermatozoa were analysed. The spermatozoa concentration, ejaculate volume, spermatozoa motility, progressive motility, distance parameters, velocity parameters and type of spermatozoa movement were negatively affected by Lippia citriodora leaves extract after the first 4 weeks of dietary treatment, till the end of experiment (8 weeks). Four weeks after the suspension of feed additive supplementation, all spermatozoa traits values returned to the normality, and in line with CON group. For in vitro findings, ejaculates from 10 male New Zealand white bucks were collected using an artificial vagina. Then it was diluted in physiological saline solution containing different concentrations of verbascoside at the concentration of 0, 0.0024, 0.0219, 0.157, 120.0 mg/ml (Ctrl, VB1, VB2, VB3, VB4 groups, respectively), using a dilution ratio of 1: 4. The obtained data proved that verbascoside at the concentration of 0.0024 and 0.0219 mg/ml had no adverse effect on spermatozoa. Additionally, we found that verbascoside at higher concentrations (0.157 and 120.0 mg/ml) significantly altered all the motility parameters analysed in the experiment. In conclusion a possible negative effect of verbascoside supplementation into feed mixture (0.1%) on semen quality parameters in rabbit bucks as well as in vitro can be stated, obviously considering that target organs of antioxidant activities of phenylpropanoid glycosides are various. In addition it has to be emphasized that the extract showed a reversible action, since the semen traits of treated animals returned to the normality after the dietary administration period

Effects of dietary plant polyphenols and seaweed extract mixture on male-rabbit semen: Quality traits and antioxidant markers

Feed additive consisting of polysaccharides from brown seaweeds plus phenolic acid, hydroxycinnamic acids, tannins, and flavonoids from plant extracts, was used as rabbit food supplement. Main aim of the study was to determine the effect of natural mix of marine and freshwater seaweed polyphenols on selected reproductive characteristics of male rabbits during the 90-days experiment. Natural mix was incorporated in feed-pellets for rabbits in two different concentrations – 0.3% (T1 group) and 0.6% (T2 group), compared with a control group (C group). In experimental groups a significant increase of concentration of calcium during first 30 days of supplementation was found. An increase of alanine aminotransferase, glutathione peroxidase and ferric reducing ability of plasma and a decrease in aspartate aminotransferase after 90 days were recorded in the same groups. Except for that we noticed decrease of semen distance of curved line and velocity of curved line after 30 days though only while being supplemented with 0.6% proportion of seaweed polyphenols in feed mixture. Based on the results it can be stated that the natural mix in the tested levels do not show adverse effect on male rabbit reproductive parameters, and an improvement of antioxidant status was observed. The feed additives can have a very important effect on growth, health and development of animals in general as it supplies the with the much-needed minerals, nutritional substances and antioxidants, on which we focused in our study

Comparison of semen characteristics and histological structure of the testis from transgenic and non-transgenic rabbits

[EN] The aim of this study was to compare semen characteristics including sperm quantity, quality, and abnormalities, as well as histological structure of the testis of three-year old transgenic (human clotting factor, hFVIII, gene) and nontransgenic rabbits. For the experiment, 10 transgenic rabbits of F2 and F3 generations and 10 randomly selected non-transgenic males of the same breed and age were used as controls. All males were housed in individual cages, under a the same environmental conditions: photoperiod (14L:10D), temperature (18-20°C), and humidity (65-70%). Semen samples, collected once a week for 20 wk from each control and transgenic male, were analyzed by computer assited semen analysis within a few minutes following natural ejaculation into an artificial vagina. Concentration of spermatozoa was higher in the transgenic than in the non-transgenic group (P<0.001; 316.6±148.8 and 126.7±64.4¿106/ mL, respectively). Significant differences (P<0.1) between transgenic and non-transgenic males were observed also in spermatozoa motility (63.08 vs. 32.60%). Significantly higher (P<0.05) relative volume (8.08±2.89%) and diameter of testicular lumen (36.89±23.11 ¿m) were found in the transgenic animals compared to control animals (16.69±4.70%, 53.89±25.42 ¿m). Our results show that spermatozoa parameters and histological structure of the testis can be used for the characterization of male reproductive traits of older transgenic rabbits.This work was supported by the grant No: 2003 SP51/028 09 00/028 09 03 coordinated by the Slovak Academy of Science and by the grant of Ministry of Agriculture Slovak Republic (RÚVV 07-012). All experiments were approved according to ethical permission No. SK P 28004. We are grateful to Dr. Shoubadeep Roychoudhury for the English correction.Lukac, N.; Massanyi, P.; Flesarova, S.; Danko, J.; Makarevich, A.; Chrenek, P. (2009). Comparison of semen characteristics and histological structure of the testis from transgenic and non-transgenic rabbits. World Rabbit Science. 17(4):221-226. https://doi.org/10.4995/wrs.2009.64722122617

Endocrine Disruption by Heavy Metals on Steroidogenesis in Model Systems

In this study human adrenocortical carcinoma cell line NCI-H295R was used as an in vitro biological model to study the effect of heavy metals on steroidogenesis. The cell cultures were exposed to different concentrations of cadmium (1.90; 3.90; 7.80; 15.60; 31.20; 62.50 μM of CdCl2), mercury (1.0; 5.0; 25; 50; 100 μM of HgCl2), nickel (3.90; 7.80; 15.60; 31.20; 62.50; 125; 250; 500 μM of NiCl2) and compared to control. Cell viability was measured by the metabolic activity (MTT) assay for estimation of mitochondria structural integrity. Quantification of sexual steroid production directly from aliquots of the medium was performed by enzyme linked immunosorbent assay (ELISA). Cadmium decreased the release of progesterone and testosterone already at a very low concentration (1.90 μM) of CdCl2, while the cell viability remained relatively high (> 75%) up to 7.80 μM of CdCl2 and significantly (P<0.01) decreased at 15.60 μM and higher concentrations of CdCl2. Concentration-dependent depression in testosterone production was detected particularly for higher concentration of HgCl2. Progesterone production was also decreased, but at the lower concentrations (1.0 and 5.0 μM) of HgCl2 this decline was lower compared to depression of testosterone. The cell viability significantly decreased at 25 μM and higher concentration of HgCl2. Results of the our study indicate dose dependent decreases in both sexual steroid hormones by NCI-H295R cell culture following a 48 h in vitro NiCl2 exposure. The lowest concentration of progesterone was significantly (P<0.01) detected in groups with the higher doses (≥ 500 μM) of NiCl2, which elicited significant cytotoxic effect. The testosterone production was decreased as well, but this decline was more pronounced compared to depression of progesterone. These results suggest that heavy metals have detrimental effects on steroid hormone synthesis even at very low concentrations and consecutively on reproductive physiology