Sulfated polysaccharides from seaweed as a supplement to Prochilodus brevis sperm freezing medium

BACKGROUND

Using sulfated polysaccharides (SP) in fish sperm freezing medium promotes cell maintenance.

OBJECTIVE

To evaluate the effect of different SP concentrations, extracted from two seaweeds (Gracilaria domingensis and Ulva fasciata), as a supplement to the sperm freezing medium of Prochilodus brevis.

MATERIALS AND METHODS

Five semen pools were diluted in a solution composed of 5% glucose, 10 % dimethyl sulfoxide (DMSO) and different SP concentrations (0, 0.5, 1.0, 1.5, 2.0, 2.5 or 3.0 mg/mL). The samples were cryopreserved and, after 7 days, rewarmed and analyzed for morphology, plasma membrane integrity, DNA integrity, mitochondrial activity and sperm kinetics [total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), and wobble (WOB)].

RESULTS

There was no interaction between seaweed and SP concentrations. Similar effects were observed with SP extracted from the two seaweeds, regardless of concentration. When comparing the SP concentrations, regardless of the seaweed, 1.0 mg/mL SP showed better results for VCL and VSL. For VAP and WOB, 1.0 mg/mL SP showed better results, but differed from 3.0 mg/mL. LIN followed the same pattern, but differed from SP at 2.5 and 3.0 mg/mL. For progressive motility, 1.0 mg/mL G. domingensis showed superior results compared to the control. For mitochondrial activity, G. domingensis was superior to U. fasciata, regardless of concentration. The lowest concentrations (0.5 and 1.0 mg/mL) showed the best results, regardless of the seaweed. However, the control was superior to all treatments tested.

CONCLUSION

G. domingensis SP at the lowest concentrations might be a potential supplement to the P. brevis freezing medium. doi.org/10.54680/fr22210110412.

Effect of different vitamin E levels on lipid peroxidation in streptozotocin-diabetic rats

Administration of streptozotocin is used to induce diabetes in experimental models, causing a selective destruction of pancreatic beta islet cells associated with generation of free radicals. Supplementation with antioxidant vitamins such as vitamin E is a protective factor against free radicals. The objective of this study was to determine the effect of administration of a diet supplemented with, or deficient in vitamin E to streptozotocin diabetic rats, controlled or not with insulin, on plasma glucose, hepatic vitamin E and hepatic thiobarbituric acid reactive substance (TBARS) levels before streptozotocin and 24 hours and one and two weeks after drug administration. Deficiency of vitamin E alone increased TBARS levels, and streptozotocin elevated TBARS two times in deficient groups, regardless of insulin control. In rats supplemented with vitamin E, a reduction of plasma glucose and liver vitamin E was observed two weeks after streptozotocin administration (p < 0.05). In conclusion, vitamin E supplementation probably protected against lipoperoxidation and contributed to the absence of elevation of plasma glucose levels, and vitamin E deficiency produced an increase in hepatic TBARS levels in streptozotocin diabetic rats.