Antioxidant properties of Klunzinger's mullet (Liza klunzingeri) protein hydrolysates prepared with enzymatic hydrolysis using a commercial protease and microbial hydrolysis with Bacillus licheniformis.

Antioxidant activity of Klunzinger's mullet (Liza klunzingeri) muscle hydrolysates obtained using Bacillus licheniformis fermentation and enzymatic hydrolysis was determined. Hydrolysates obtained after 6 days of fermentation with B. licheniformis showed the highest free radical scavenging activity, metal chelating ability and ferric reducing antioxidant power (FRAP) (P ≤ 0.05). Microbial fermentation led to a higher percentage of small peptides and higher solubility compared with Alcalase hydrolysis (P ≤ 0.05). Hydrolysates showing the highest antioxidant properties attenuated serum, liver, and kidney oxidative stress biomarkers in male Wister rats stressed by carbon tetrachloride (P ≤ 0.05). At 300 mg/kg oral administration, hydrolysates increased serum, renal, and hepatic total antioxidant capacity (TAC) (P ≤ 0.05) and reduced their elevated levels of malondialdehyde (MDA), nitric oxide (NO•), and serum liver enzymes (AST, ALP, and ALT) (P ≤ 0.05). The hydrolysates were able to ameliorate hepatic damage by reducing necrosis, fatty changes, and inflammation. Results showed the antioxidant and hepato-toxic protective activities of Klunzinger's mullet muscle hydrolysates obtained using microbial fermentation, which may, therefore, potentially be considered as a functional food ingredient.

Therapeutic Effects of Oleuropein in Improving Seizure, Oxidative Stress and Cognitive Disorder in Pentylenetetrazole Kindling Model of Epilepsy in Mice.

Prolonged epileptic seizures are the cause of neuronal death and brain damage. Lesions in different regions of the brain can lead to memory loss and cognitive disorders. It is therefore essential to seek out new neuroprotective drugs. Our aim was to investigate the therapeutic effects of oleuropein in improving seizure, oxidative stress, and cognitive disorder in pentylenetetrazole (PTZ) kindling model of epilepsy in mice. Mice were randomized to four groups; negative control group intraperitoneally receiving PTZ for 10 days, oleuropein group receiving oleuropein (20 mg/kg) 30 min before PTZ administration, positive control group receiving diazepam 30 min before PTZ administration and flumazenil group receiving flumazenil and then oleuropein 30 min before PTZ administration. Epilepsy severity was investigated after final administration of PTZ. Then hippocampal tissues were removed and stored at -70 °C until measurements of the interleukin-1 (IL-1) and glutamate transporter 1 (GLT-1) gene expression were conducted. Oleuropein treatment caused a significant increase in seizure latency and a significant decrease in total frequencies of head ticks, head and upper limbs seizures, the whole body seizures, frequent spinning and jumping and tonic seizures in PTZ receiving mice. IL-1 expression decreased in oleuropein group and GLT-1 levels did not change significantly in this group. Oleuropein treatment caused significant improvement of passive avoidance memory in PTZ receiving mice in shuttle box. Oleuropein can decrease PTZ-induced seizures and memory disorders due to its antioxidant and anti-inflammatory properties and is thus recommended to be used for production of anti-epileptic drugs.

The protective effect of Liza klunzingeri protein hydrolysate on carbon tetrachloride-induced oxidative stress and toxicity in male rats.

OBJECTIVES: Today, consumers are looking for food products providing health benefits in addition to meeting the basic nutritional needs of the body. This study aimed to evaluate the antioxidant and cytotoxic effects of Liza klunzingeri protein hydrolysate both in vivo and in vitro. MATERIALS AND METHODS: Fish protein hydrolysate (FPH) was prepared using enzymatic hydrolysis with papain. In vitro antioxidant activity was assessed using five different antioxidant assays. The cytotoxic effect on 4T1 cell line was evaluated using the MTT assay. The distribution of the molecular weight of FPH was measured using HPLC. In the in vivo study, CCl4-exposed Wistar rats were orally treated with FPH (150, 300, and 600 mg/kg) or gallic acid (50 mg/kg) for 28 consecutive days. RESULTS: Enzymatic hydrolysis gave hydrolysate rich in low molecular weight peptides (<1000 Da) with strong free radicals (ABTS, DPPH, and OH) scavenging activity and cytotoxicity. Treatment of CCl4-exposed rats with all doses of FPH significantly lowered serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). FPH at doses of 300 and 600 mg/kg significantly decreased lipid peroxidation and improved total antioxidant capacity in serum, liver, and kidney of the CCl4 exposed rats. All doses of L.klunzingeri protein hydrolysate reduced CCl4-induced nitric oxide production of the kidney. Liver histopathological damage caused by CCl4 also ameliorated with all doses of FPH. CONCLUSION: L. klunzingeri protein hydrolysate can be considered as a functional food to alleviate oxidative stress.

Antioxidant and cytotoxic properties of protein hydrolysates obtained from enzymatic hydrolysis of Klunzinger's mullet (Liza klunzingeri) muscle

Today, consumers are looking for functional foods that promote health and prevent certain diseases in addition to provide nutritional requirements. This study aimed to evaluate the antioxidant and cytotoxic properties of Liza klunzingeri protein hydrolysates. Fish protein hydrolysates (FPHs) were prepared from L. klunzingeri muscle using enzymatic hydrolysis with papain at enzyme/substrate ratios of 1:25 and 1:50 for 45, 90 and 180 min. The antioxidant activities of the FPHs were investigated through five antioxidant assays. The cytotoxic effects on 4T1 carcinoma cell line were also evaluated. The amino acid composition and molecular weight distribution of the hydrolysate with the highest antioxidant activity were determined by HPLC. All six FPHs exhibited good scavenging activity on ABTS (IC50=0.60-0.12 mg/mL), DPPH (IC50= 3.18-2.08 mg/mL), and hydroxyl (IC50=4.13-2.07 mg/mL) radicals. They also showed moderate Fe+2 chelating capacity (IC50=2.12-12.60 mg/mL) and relatively poor ferric reducing activity (absorbance at 70 nm= 0.01-0.15, 5 mg/mL). In addition, all hydrolysates showed cytotoxic activities against the 4T1 cells (IC50=1.62-2.61 mg/mL). 94.6% of peptide in hydrolysate with the highest antioxidant activity had molecular weight less than 1,000 Da. L. klunzingeri protein hydrolysates show significant antioxidant and anticancer activities in vitro and are suggested to be used in animal studies.