LDL Oxidation, Antioxidant Capacity and Growth of Cultured Grey Mullet (Mugil cephalus) Fed Dietary Sorghum Distillery Residue Pretreated with Polyethylene Glycol

Abstract

Dietary sorghum distillery residue (SDR) showed antioxidant and blood thinning effects on grey mullet during winter, but inhibited their growth. The objective of this study was to establish a preliminary treatment of the dietary SDR with polyethylene glycol (PEG), a tannin-binding agent, to enhance growth and blood antioxidant capacity of grey mullet ( Mugil cephalus ) feed. The feeding trial was carried out from June to November. The water temperature was between 25 and 30 degrees C; the specific growth rate of mullet was reduced significantly by feeding diet containing 20% SDR in comparison to fish fed the control diet or diet containing 20% SDR and PEG. In the period of October-November, the water temperature decreased to 19-25 degrees C; the specific growth rates of the 20% SDR-PEG group and the 20% SDR group were 0.13 and 0.19% day(-1), respectively, significantly higher than those fed the control diet (0.07% day(-1)). Feeding with 20% SDR or 20% SDR-PEG diets resulted in prolonged lag phase of low-density lipoprotein (LDL) oxidation compared to fish fed the control diet. The total antioxidant capacity of the plasma of the grey mullet fed 20% SDR-PEG was 1.24 mmol/L, significantly higher than those in the fish fed 20% SDR diet (0.84 mmol/L) or the control (0.72 mmol/L). In vivo observations found that preliminary treatment of SDR with PEG eliminated the endogenous undesirable growth inhibitory factors but maintained its protective effects against LDL oxidation in blood and improved the total antioxidant capacity and cold adaptation of grey mullet. The ethanol extract of SDR contained 31.9 +/- 7.8 mg/g gallic acids equivalent. The concentration needed to scavenge 50% of the DPPH radicals (IC(50)) was 0.86 mg/mL. Increased gallic acid equivalent and decreased IC(50) of DPPH scavenging activity of SDR fed to fish increased the total antioxidant capacity in blood plasma of grey mullet significantly.

Phenolic Acids Identified in Sorghum Distillery Residue Demonstrated Antioxidative and Anti-Cold-Stress Properties in Cultured Tilapia, Oreochromis mossambicus

“…6 A grey mullet fed diet containing 20% SDR resulted in significantly increased total antioxidant capacity of blood plasma and prolonged the lag phase of ex vivo tilapia LDL oxidation compared to those fed the control diet. 5 SDR extracts were found to have free-radical-scavenging and tyrosinase-inhibiting effects. 5,7 Both in vitro and ex vivo LDL oxidation of tilapia were inhibited by the hot-water extract of freshwater clam in a similar dose-dependent pattern.…”

“…3 The antioxidative properties of polyphenols allow them to suppress low-density lipoprotein (LDL) oxidation and scavenge free radicals. 4,5 Polyphenols demonstrate antioxidative activities better than vitamin C and vitamin E 4 . Grey mullet (Mugil cephalus) fed SDR improved blood fluidity and cold adaptation during winter.…”

Exploitation of Agro-Industrial Waste as Potential Source of Bioactive Compounds for Aquaculture

“…Therefore, this study might suggest that flavonoids improve the antioxidant response in Nile tilapia liver under induced stress. On the other hand, Lee et al [ 92 ] indicated that the dietary inclusion of residues from the distillation of sorghum (200 g/kg), increases the antioxidant activity and delays the oxidation process of low-density lipoproteins in the plasma of the Lysa ( Mugil cephalus ). Among the main bioactive compounds present in sorghum are phenolic acids (caffeic, ferulic and chlorogenic acids) and flavonoids (apigeninidin, luteolinidin, and naringenin), which have been directly related to its antioxidant activity [ 93 ].…”

Effects of different forages on the chemical compositions and antiosteoporotic activities of velvet antlers

“…The addition of SDR in chicken forage increases the antioxidant activities of animal organs without affecting their final body weight (Lee et al . ; Hsin et al . ).…”

“…The addition of SDR in chicken forage increases the antioxidant activities of animal organs without affecting their final body weight Hsin et al 2011). However, studies have also reported the inhibitory effect of SDR on the growth of grey mullet, cattle, chicken and rats (Larraín et al 2009;Lee et al 2009).…”