Antiteratogenic Effects of β-Carotene in Cultured Mouse Embryos Exposed to Nicotine

The effect of a negative energy balance status on β-carotene availability in serum and follicular fluid of nonlactating dairy cows

Maternal metabolic pressure due to a cow's negative energy balance (NEB) has a negative effect on oocyte quality as a result of increased oxidative stress. In this study, we hypothesized that a NEB status may negatively affect the availability of β-carotene (bC, an antioxidant) in the micro-environment of the oocyte or follicular fluid (FF) and that daily bC supplementation can increase bC availability. We aimed to (1) determine the effect of a nutritionally induced NEB on bC concentrations in serum and FF as well as on the presence of bC metabolites, oxidative stress levels, and follicular growth in a nonlactating dairy cow model, and (2) investigate how this effect could be altered by dietary bC supplementation. Six multiparous nonlactating Holstein Friesian cows were subjected to 4 consecutive dietary treatments, 28 d each: (1) 1.2 × maintenance (M) or positive energy balance (PEB) without bC supplement (PEB-bC), (2) 1.2 × M with daily supplement of 2,000mg of bC comparable to the level of bC intake at grazing (PEB+bC), (3) 0.6 × M with 2,000mg of bC (NEB+bC), and (4) 0.6 × M (NEB-bC). At the end of each treatment, estrous cycles were synchronized and blood and FF of the largest follicle were sampled and analyzed for bC, retinol, α-tocopherol, free fatty acids, estradiol, and progesterone. Serum cholesterol, triglycerides, urea, insulin growth factor 1, growth hormone, total antioxidant status (TAS), and red blood cell glutathione (GSH) concentrations were determined as well. All cows lost body weight during both energy restriction periods and showed increased serum free fatty acid concentrations, illustrating a NEB. A dietary induced NEB reduced FF bC, but not plasma bC or plasma and FF retinol concentrations. However, bC and retinol concentrations drastically increased in both fluid compartments after bC supplementation. Follicular diameter was increased in supplemented PEB cows. Energy restriction reduced the TAS and red blood cell GSH, whereas daily bC supplementation could restore GSH concentrations, but not the TAS, to levels present in healthy PEB cows. In conclusion, daily bC supplementation can substantially improve bC and retinol availability in the oocyte's micro-environment, irrespective of the energy balance, which may affect follicular development and oocyte quality in the presence of maternal metabolic stress. This knowledge can be of importance to optimize nutritional strategies in the dairy industry to feed for optimal oocyte quality and fertility.

4-O-methylhonokiol inhibits serious embryo anomalies caused by nicotine via modulations of oxidative stress, apoptosis, and inflammation

BACKGROUND

Since the increasing smoking rate among women has resulted in higher rates of embryonic malformations, it is important to search for an efficient and inexpensive agent that can help reduce the rate of serious fetal anomalies caused by maternal cigarette smoking. In this study, the bioavailability of 4-O-methylhonokiol isolated from Magnolia officinalis was first demonstrated in the mouse embryos exposed to nicotine using a whole embryo culture system.

METHODS

Mouse embryos on embryonic day 8.5 were cultured with 1 mM nicotine and/or 4-O-methylhonokiol (1 × 10(-4) or 1 × 10(-3) μM) for 48 hr and were analyzed on the viewpoints of embryo developmental changes, oxidative damages, and apoptotic and inflammatory changes.

RESULTS

Embryos exposed to 1 mM nicotine developed not only severe morphological anomalies, increased expressions of tumor necrosis factor-α, interleukin-1β, and caspase 3 mRNAs; and elevated levels of lipid peroxidation, but also decreased levels of cytoplasmic superoxide dismutase, cytosolic glutathione peroxidase, phospholipid hydroperoxide glutathione peroxidase, hypoxia inducible factor-1α, and B-cell lymphoma-extra large mRNAs, and reduced superoxide dismutase activity. However, these parameters were significantly improved when embryos exposed to the nicotine were concurrently treated with 4-O-methylhonokiol (1 × 10(-4) or 1 × 10(-3) μM).

CONCLUSIONS

These findings indicate that 4-O-methylhonokiol reduces serious embryo anomalies caused by nicotine in mouse embryos via the modulations of oxidative stress, apoptosis, and inflammation, suggesting that 4-O-methylhonokiol may be a preventive and therapeutic agent against the dysmorphology induced by maternal smoking during pregnancy.

Effect of beta-carotene on titanium oxide nanoparticles-induced testicular toxicity in mice

OBJECTIVE

This study evaluated the protective effect of beta-carotene (BC) on titanium oxide nanoparticle (TNP) induced spermatogenesis defects in mice.

MATERIALS AND METHODS

Thirty-two NMRI mice were randomly divided into four groups. BC group received 10 mg/kg of BC for 35 days. TNP group received 300 mg/kg TNP for 35 days. TNP+BC group initially received 10 mg/kg BC for 10 days and was followed by concomitant administration of 300 mg/kg TNP for 35 days. Control group received only normal saline for 35 days. Epididymal sperm parameters, testicular histopathology, spermatogenesis assessments and testosterone assay were performed for evaluation of the TNP and BC effects on testis.

RESULTS

Serum testosterone levels were markedly decreased in TNP-intoxicated mice. Epididymal sperm parameters including sperm number, motility and percentage of abnormality were significantly changed in TNP-intoxicated mice (p < 0.01). Histopathological criteria such as epithelial vacuolization, sloughing of germ cells and detachment were significantly increased in TNP-intoxicated mice (p < 0.001). BC+TNP treatment significantly prevented these changes (p < 0.05). BC also significantly elevates testosterone levels in BC+TNP group compared to TNP-treated mice (p < 0.01).

DISCUSSION AND CONCLUSION

The results of this study demonstrated that BC improved the spermatogenesis defects in TNP-treated mice. BC had a potent protective effect against the testicular toxicity and might be clinically useful.