ABSTRACT
Phycoerythrin (PE) is a natural protein-pigment complex with a strong pink color, but it is sensitive to thermal and light variations. In this study, PE was extracted from Porphyra haitanensis in a yield of 0.2% (w/w). The phycoerythrin hydrolysates (PEH) (3-10 kDa) were prepared by enzymatic hydrolysis of PE with bromelain (8000 U/g) at 47 °C for 30 min, with a degree of hydrolysis (DH) of 11.57 ± 0.39% and a color degradation rate of 7.98 ± 0.39%. The physicochemical properties of PEH were evaluated. The UV and fluorescence spectra indicated that bromelain changed the microenvironment around phycoerythrobilin (PEB). The infrared spectrum revealed that the bromelain hydrolysis increased the α-helix content of PEH. The scanning electron microscope showed that bromelain destroyed the dense and smooth structure of PE, resulting in irregular porous structures. The radical scavenging activities of DPPH and ABTS of PEH were increased relative to that of PE (p < 0.05). The thermal (50-80 °C)-, UV (0.5-3 h)-, visible light irradiation (2-8 h)-, and metal ion exposing stabilities of PEH were significantly improved (p < 0.05). This study provides a potential scheme for overcoming the sensitivity of PE to thermal and light variations and facilitates PEH as a natural colorant ingredient in food and pigment applications.
ABSTRACT
Aluminum (Al) has been linked to the development of some cardiovascular diseases and mung bean is a functional food with the ability to detoxify. We aimed to evaluate the preventive effect and possible underlying mechanisms of the mung bean polyphenol extract (MPE) on Al-induced cardiotoxicity. Control, AlCl3 (171.8 mg Al per kg body weight), MPE + AlCl3 (Al-treatment plus 200 mg MPE per kg body weight), and a group of MPE per se were used. Al intake induced a significant increase of serum CK and LDH activity and the level of Na+, Ca2+, malondialdehyde and advanced oxidation protein products in the AlCl3-treated rats' heart tissue. Administration of MPE significantly improved the integrity and normal ion levels of heart tissue, and attenuated oxidative damage and the accumulation of Al in Al-treated rats. MPE significantly inhibited Al-induced increase of myocardial p-JNK, cytoplasmic NF-κB, cytochrome C, and caspase-9 protein expressions. Therefore, these results showed that MPE has a cardiac protective effect against Al-induced biotoxicity through ROS-JNK and NF-κB-mediated caspase pathways. Furthermore, the stability constant for the vitexin-Al complex was analyzed (log K = log K1 + log K2 = 4.91 + 4.85 = 9.76). We found that MPE-mediated protection against Al-cardiotoxicity is connected both with MPE antioxidant and chelation properties.
Subject(s)
Aluminum Compounds/toxicity , Calcium/metabolism , Cardiotoxicity/drug therapy , Chlorides/toxicity , MAP Kinase Kinase 4/metabolism , NF-kappa B/metabolism , Phaseolus/chemistry , Plant Extracts/administration & dosage , Polyphenols/administration & dosage , Reactive Oxygen Species/metabolism , Aluminum Chloride , Animals , Cardiotoxicity/etiology , Cardiotoxicity/genetics , Cardiotoxicity/metabolism , Caspase 9/genetics , Caspase 9/metabolism , Heart/drug effects , Humans , MAP Kinase Kinase 4/genetics , Male , Malondialdehyde/metabolism , Myocardium/metabolism , NF-kappa B/genetics , Oxidative Stress/drug effects , Rats , Rats, Wistar , Signal Transduction/drug effectsABSTRACT
By the methods of bioassay, this paper studied the allelopathic effects of different concentrations root exudates from the eggplants grafted with different stocks and at different growth stages. The results showed that compared with that of own-rooted eggplant, the root exudates from grafted eggplants promoted the seed germination and seedling growth of eggplants, and, in comparing with the control (water), they increased the germination rate and plant height by 29.1% and 37.1%, respectively. The seed germination and root length of eggplants was increased at lower concentrations root exudates, but decreased at higher concentrations. The germination rate was increased up to 50% above control at 0.04 g x ml(-1), and the inhibition of root length was up to 30.3% at 0.24 g x ml(-1). The promotion effect of the root exudates from late growth stage grafted eggplants on seed germination was less than that from other growth stage grafted eggplants. Own-rooted eggplant had an intensified inhibitory effect at its late growth stage. Grafting was one of the effective methods for relieving the continuous cropping obstacles caused by autotoxicity.