Effects of dietary riboflavin levels on antioxidant defense of the juvenile grouper Epinephelus coioides

Abstract

This study was conducted to evaluate the effects of dietary riboflavin on antioxidant defense in the juvenile grouper Epinephelus coioides. Graded levels of riboflavin (0.9, 1.6, 4.4, 6.7, 12.9 and 19.4 mg kg(-1) dry diet) were fed to grouper juveniles (mean weight: 14.90 +/- 0.46 g) for 12 weeks. Higher levels of liver thiobarbituric acid reactive substances (TBARS) content were observed in grouper fed low doses (0.9 and 1.6 mg kg(-1) diet) of riboflavin. Both liver glutathione reductase (GR) activity and its activation coefficient (GR-AC) poorly responded to riboflavin deficiency. In addition, other indices of the glutathione-dependent defense system, including the activities of glutathione peroxidase (GSH-PX) and glutathione-S-transferase (GST), and the content of glutathione (GSH), were also non-significantly affected by dietary riboflavin levels. However, the activities of liver superoxide dismutase (SOD) and catalase (CAT) were significantly lower in fish fed 0.9 mg kg(-1) diet, with a positive correlation between the different groups. In conclusion, the present study indicated that the juvenile grouper fed the riboflavin-unsupplemented diet was susceptible to lipid peroxidation (LPO), with lower SOD and CAT activities in the liver. However, the glutathione-dependent defense system of grouper was not affected by dietary riboflavin levels.

Dietary riboflavin requirement of fingerlingChanna punctatus(Bloch) based on growth, conversion efficiencies, protein retention, liver riboflavin storage, RNA/DNA ratio and carcass composition

“…Antioxidant property of dietary riboflavin as evident in this study has also been documented by Huang et al. (). They reported that the grouper fed a riboflavin‐unsupplemented diet was susceptible to lipid peroxidation (LPO), with lower SOD and CAT activities in the liver.…”

“…Antioxidant enzymes usually act in a coordinated manner to ensure optimal protection against oxidative stress (Hermes-Lima, 2004;Huang, Tian, Wu, Yang, & Liu, 2010). The enzymatic antioxidant includes superoxide dismutase (SOD), catalase, glutathione peroxidase and glutathione reductase, and non-enzymatic antioxidants such as glutathione (Knight, 2000;Li et al, 2014).…”

“…Previous studies indicated the accumulation of lipid peroxidation products in the liver (Taniguchi & Hara, 1983), lenses (Bates, 1991) and erythrocytes (Levin, Cogan, & Levy, 1990) in riboflavin-deficient rats, which indicated a poor antioxidant defence caused by riboflavin deficiency. Riboflavin inhibits the formation of hydroperoxides (Huang et al, 2010). The mechanism may be that riboflavin can quench free radicals through its reversion from reduced form to oxidized form (Toyosaki, 1992).…”

Ameliorative effect of riboflavin on hyperglycemia, oxidative stress and DNA damage in type-2 diabetic mice: Mechanistic and therapeutic strategies

“…# indicates significantly different from diabetic group at p 0.05. cisplatin during radiochemotherapy [28]. In a previous study, dietary riboflavin was reported to have significantly restored the antioxidant defences in a riboflavin-deficient fish compared with the control fish [29]. Moreover, some other animal studies have reported a similar effect of riboflavin on the activities of SOD and catalase in mice and rat model [30e33].…”

Iron bioavailability of different sources in juvenile grouperEpinephelus coioides

“…Grouper Epinephelus coioide , as the important economically farmed species, is widely distributed in the coastal areas of Southeast Asia and is popular with consumers for its excellent meat quality and high value in market (Pierre et al., ; Ye et al., ). Up to now, abundant nutrient researches about grouper have been reported, such as protein requirement (Shiau & Lan, ), amino acid requirement (Luo et al., ), riboflavin requirement (Huang, Tian, Wu, Yang, & Liu, ) and mineral requirement like selenium, Fe, calcium and phosphorous (Lin & Shiau, ; Ye et al., , ). Although dietary Fe has been studied before, the source was limited to FeSO 4 (Ye et al., ).…”