Elucidation of the liver proteome in response to an antioxidant intake in rabbits

Abstract

Abstract Background Antioxidant intakes are one of the most cherished dietary approaches for the management of oxidative stress-induced liver damages. These antioxidants exist as the bioactive compounds present in plants and other natural sources functioning in varieties of ways from acting as direct scavengers of the free radicals to acting as the modifiers of genes and proteins expressions. Chlorella vulgaris is one of such antioxidants; it is a unicellular microalga and a rich source of polyphenols which has been reported for its capacity of reducing oxidative stress by upregulation of antioxidant genes. However, there are scarce reports on its effect on antioxidant protein expressions and functions in the liver. This situation necessitates untargeted proteomic profiling of the liver due to the antioxidant intakes as carried out in this present study. Sixteen laboratory weaner rabbits of 8 weeks old with initial average bodyweight of 1060 ± 29.42 g were randomly divided into two groups (n = 8 per group); the first group served as control while the second served as the treatment group were used for this study. Results After a period of 120 days daily consumption of 500 mg of Chlorella vulgaris biomass per kg bodyweight of the rabbit models, the animals were sacrificed and their livers were harvested followed by protein extraction for the untargeted proteomic profiling using LC-MS/Orbitrap Fusion Tribrid™ peptides quantifier and sequencer. Also, there was an assessment of the oxidative stress biomarkers in the liver and serum of the rabbits. Five-hundred and forty-four (544) proteins were identified out of which 204 were unique to the control, 198 were unique to the treatment group, while 142 were common to both groups of the rabbits. Antioxidant proteins commonly found in both groups were upregulated in the treatment group and were significantly associated with oxidative stress-protective activities. There was a reduction in oxidative stress biomarkers of the supplemented group as indicated by the assessment of the liver malondialdehyde concentrations (p < 0.05), total antioxidant capacities (p < 0.05), and antioxidant enzyme activities (p < 0.05). Similarly, these biomarkers were significantly reduced in the serum of the supplemented rabbits (p < 0.05). Conclusion The study concluded that Chlorella vulgaris is an antioxidant agent that could be suitable for reducing liver oxidative stress damage and it is a potential drug candidate for protecting the liver against oxidative stress damages as revealed in the rabbit models.