Oxidation Stability of Camellia Oil During Refining

In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.

Natural product curcumin-based coordination nanoparticles for treating osteoarthritis via targeting Nrf2 and blocking NLRP3 inflammasome

Oxidative stress leads to chondrocyte apoptosis and extracellular matrix(ECM)degradation,thus contributing to the pathogenesis of osteoarthritis(OA).Herein,curcumin with remarkable antioxidant and anti-inflammatory activities has been employed as an organic ligand to coordinate ferric ions for enhancing the water-solubility and biocompatibility of natural product curcumin.The obtained iron-curcumin-based coordination nanoparticles(Fe-Cur NPs)exhibit great water-solubility and efficient reactive oxygen/nitrogen species(ROS/RNS)scavenging ability.In vitro chondrocyte evaluation experiments indicated that the intracellular ROS/RNS induced by interleukin 1β(IL-1β)could be efficiently scavenged by these Fe-Cur NPs and oxidative-stressinduced cell death could be preserved as well.In addition,post intra-articular(i.a.)injection into OA rat joints,Fe-Cur NPs could greatly inhibit OA progression via activating the nuclear factor-erythroid 2 related factor-2(Nrf2)and inhibiting nod-like receptor protein-3(NLRP3)inflammasome activation in primary rat chondrocytes,as well as decrease the production of matrix degrading proteases and other inflammatory mediators.The efficient antioxidation and anti-inflammation performance of Fe-Cur NPs endow them as a promising nanoplatform for treatment of various inflammatory diseases,and more detailed researches will be conducted in the future.

Antioxidant and antifungal activities of two spices of mangrove plant extract

Objective:To evaluate the antifungal and the radical scavenging capacity related to antioxidant potential of ethanol and water extracts of leaves of Rhizophora mucronata(R.mucronata)and Avicennia marina(A.marina)mangrove plant species against five postharvest pathogenic bacteria.Methods:In vitro assessment of antioxidant and antifungal activities was evaluated in this present study for both aqueous and ethanol extracts prepared from leaves of A.marina and R.mucronata.The antioxidant activities of these mangroves were evaluated by using reducing power and 1,1-diphenyl-2-picrylhydrazyl assays with butylated hydroxytoluene and L-(+)-ascorbic acid as standards.Results:The result showed that the antioxidant activities of all extracts increased with increasing concentration of extracts.However,the ethanol extracts of both species showed the highest antioxidant activities.Antimicrobial tests were then carried out by the disk diffusion method.The ethanol extracts of both species showed antifungal activities on Penicillium purpurogenum,Penicillium chrysogenum,Penicillium notatum,Aspergillus niger,Alternaria alternata and Penicillium italicum.However,none of the water extracts exhibited antifungal activity on the studied fungi.Among all the pathogens,tested Aspergillus flavus was the most resistant fungi.Different concentrations of extracts from A.marina and R.mucronata showed different amounts of control against tested fungal strains.Conclusions:This study indicated that mangrove species has natural antioxidant and antifungal properties.