Overview of Cosmetic Efficacy Evaluation Methods Based on Antioxidant Mechanisms

Ultraviolet(UV),ozone(O_(3)),and particulate matter(PM)in air pollutants in the external environment can induce skin aging through oxidative mechanisms such as free radicals,lipid peroxidation,and protein oxidation.Antioxidant cosmetics can be used to defend against oxidative damage caused by the external environment to the skin.In China,the claimed cosmetics need to be managed according to new efficacy cosmetics,but there are currently few reports on the evaluation methods for such new efficacy cosmetics.The efficacy evaluation methods of cosmetics with antioxidant mechanisms under UV,O_(3),and PM models were reviewed,and the skin damage caused by UV,O_(3),and PM were introduced.Suggestions for the application of each model in the efficacy evaluation of antioxidant cosmetics and raw materials were given to provide ideas for new efficacy claims and technical references for establishing a new efficacy evaluation system.

Drought-Mediated Modulation in Metabolomic Profiling of Nigella Sativa Leaf, Growth, Ecophysiology and Antioxidants

Abiotic stresses,including drought,have been found to affect the growth and medicinal quality of numerous herbs.The proposed study aims to study the effects of different drought regimes on the metabolic profile,growth,ecophysiology,cellular antioxidants,and antioxidant potential of Nigella sativa(Black cumin)leaf.Forty-day-old seedlings of N.sativa were exposed to three regimes of drought(control,moderate and high)for a week.UPLCMS/MS metabolic profile of the leaf reveals the presence of more than a hundred metabolites belonging to anthocyanins,chalcones,dihydro flavonoids,flavonoids,flavanols,flavones,flavonoid carbonoside,isoflavones,etc.Drought was found to alter the contents of identified metabolites.Drought stress-induced oxidative stress and increased production of hydrogen peroxide and superoxide anions.Physiological changes,activities of antioxidant enzymes,contents of antioxidants,and proline were significantly high under drought to protect against the low water regimes.Furthermore,stressed leaf extract had higher antioxidant potential.Thus,N.sativa leaf bears multiple metabolic pathways and can tolerate a higher degree of drought or osmotic stress.

Plant phenolic extracts for the quality protection of frying oil during deep frying:Sources,effects,and mechanisms

Protection of frying oil from deterioration by adding plant phenolic extracts to guarantee the quality of fried foods becomes the primary approach to promote the sustainable development of deep frying.Therefore,sources,antioxidant effects,and mechanisms of plant phenolic extracts recently applied in the quality protection of frying oil as well as challenges for the actual use of these extracts are comprehensively reviewed in this study.Spices,herbs,berries,tea leaves,and fruit and vegetable wastes are common sources for preparing phenolic extracts showing comparative antioxidant capacity referring to the synthetic antioxidants.The general effect of using these natural antioxidants is the improvement of thermal stability to extend the shelf life of frying oil and thus the modification of edible quality of fried foods.Specifically,the increases in common quality attributes and amount of hazardous products and the oxidative reduction of unsaturated triacylglycerols without negatively influencing the sensory quality are inhibited when suitable plant extracts are applied.The incorporation of plant phenolic extracts other than synthetic counterparts in frying oil has been demonstrated as a potential method to improve the frying performance of oils.However,challenges for the scale application of plant phenolic extracts,such as the purity,thermal stability,and antioxidant timing,are still needed to be further investigated.

Antioxidant Protection Mechanisms Reveal Significant Response in Drought-Induced Oxidative Stress in Some Traditional Rice of Assam, India

Drought tolerance levels and antioxidant protection mechanisms were evaluated for 21 traditional rice varieties of Assam, India, along with Sahbhagi Dhan （drought tolerant） and IR64 （drought sensitive） as controls. Drought was imposed in hydroponic culture with polyethylene glycol 6000 （PEG6000） that was initially standardized with different concentrations. All the rice varieties showed apparent decreases in growth characteristics under drought stress （initially at 15% for 7 d followed by 20% PEG6000 for 7 d in Yoshida medium）. On the basis of standard evaluation score （SES）, eight rice varieties showed high drought tolerance which were carried forward for further biochemical analyses. Based on different morpho- physiological parameters, SN03 （Bora）, SN04 （Prosad Bhog）, SN05 （Kola Joha）, SN06 （Helash Bora）, SN08 （Salihoi Bao）, SN12 （Kola Amona）, SN20 （Ronga Bora） and SN21 （Sok-Bonglong） were identified as promising drought tolerant varieties. The non-enzymatic antioxidants activities viz., glutathione, ascorbate and enzymatic antioxidant activities such as superoxide dismutase （SOD）, catalase （CAT）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX）, glutathione reductase （GR） in shoots and roots of all the selected varieties revealed significant level of protection mechanisms as compared with controls. Enhancement in activities of the overall antioxidant enzymes including SOD, GPX, CAT, GR and APX under drought stress reflects their role in the adaptation process under water stress.

Transcriptomes of Litopenaeus vannamei reveal modulation of antioxidant system induced by dietary archaeal carotenoids

Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.

Evaluation of Stabilization Performances of Antioxidants in Poly(ether ether ketone)

Two types of antioxidants（a primary antioxidant and a secondary antioxidant） were used to improve the stability of poly（ether ether ketone）（PEEK）. The effects of the antioxidants on the properties of PEEK and the stabilization mechanism were investigated by some characterization methods, such as rheometer, thermogravimetric ana- lysis（TGA）, universal tester and electron spin resonance（ESR）. The results indicate that the efficiency of the phosphorous antioxidant（DS） in improving the stability of PEEK was better than that of the phenolic antioxidant（DN） in both melting stability and thermal stability, and the thermal stability of PEEK sample containing 0.07%（mass fraction） DS was the best among all the samples due to the decrease of the free radicals density, as proven by ESR measurement. Additionally, no obvious changes could be observed in mechanical properties of PEEK containing antioxidants compared to those of virgin PEEK.

Theoretical and experimental study on the inhibition of jet fuel oxidation by diarylamine

Antioxidants addition is believed as a facile and effective way to improve jet fuel thermal oxidation stability.However,amine antioxidants,as one of the most important antioxidants,have not received sufficient attention in the field of jet fuel autoxidation yet.Herein,the inhibition efficiency and mechanism of decane and exo-tetrahydrodicyclopentadiene(THDCPD)oxidation by di-4-tert-butylphenylamine(diarylamine)was experimentally and theoretically investigated.The results show that diarylamine can significantly inhibit decane oxidation but is less efficient for THDCPD oxidation,which is attributed to the higher energy barrier of retro-carbonyl-ene reaction(rate-determining step)in THDCPD than that in decane during diarylamine regeneration.However,the addition of diarylamine will cause undesirable color change after accelerated oxidation and produce slightly more deposits during high-temperature thermal oxidative stress for both decane and THDCPD.The results provide significant implications for the future design of effective antioxidant additives for high-performance jet fuel.

Phenolic compounds of green tea: Health benefits and technological application in food

Green tea has been an important beverage for humans since ancient times, widely consumed and considered to have health benefits by traditional medicine in Asian countries. Green tea phenolic compounds are predominately composed of catechin derivatives, although other compounds such as flavonols and phenolic acids are also present in lower proportion. The bioactivity exerted by these compounds has been associated with reduced risk of severe illnesses such as cancer, cardiovascular and neurodegenerative diseases. Particularly, epigallocatechin gallate has been implicated in alteration mechanisms with protective effect in these diseases as indicated by several studies about the effect of green tea consumption and mechanistic explanation through in vitro and in vivo experiments. The biological activity of green tea phenolic compounds also promotes a protective effect by antioxidant mechanisms in biological and food systems, preventing the oxidative damage by acting over either precursors or reactive species. Extraction of phenolic compounds influences the antioxidant activity and promotes adequate separation from green tea leaves to enhance the yield and/or antioxidant activity. Application of green tea phenolic compounds is of great interest because the antioxidant status of the products is enhanced and provides the product with additional antioxidant activity or reduces the undesirable changes of oxidative reactions while processing or storing food.In this scenario, meat and meat products are greatly influenced by oxidative deterioration and microbial spoilage, leading to reduced shelf life. Green tea extracts rich in phenolic compounds have been applied to increase shelf life with comparable effect to synthetic compounds, commonly used by food industry. Green tea has great importance in general health in technological application, however more studies are necessary to elucidate the impact in pathways related to other diseases and food applications.