Actinopyga lecanora (A. lecanora) is classified among the edible species of sea cucumber, known to be rich in protein. Its hydrolysates were reported to contain relatively high antioxidant activity. Antioxidants are one of the essential properties in cosmeceutical products especially to alleviate skin aging. In the present study, pH, reaction temperature, reaction time and enzyme/substrate ratio (E/S) have been identified as the parameters in the papain enzymatic hydrolysis of A. lecanora. The degree of hydrolysis (DH) with antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays were used as the responses in the optimization. Analysis of variance (ANOVA), normal plot of residuals and 3D contour plots were evaluated to study the effects and interactions between parameters. The best conditions selected from the optimization were at pH 5.00, 70 °C of reaction temperature, 9 h of hydrolysis time and 1.00% enzyme/substrate (E/S) ratio, with the hydrolysates having 51.90% of DH, 42.70% of DPPH activity and 109.90 Fe2+μg/mL of FRAP activity. The A. lecanora hydrolysates (ALH) showed a high amount of hydrophobic amino acids (286.40 mg/g sample) that might be responsible for antioxidant and antityrosinase activities. Scanning electron microscopy (SEM) image of ALH shows smooth structures with pores. Antityrosinase activity of ALH exhibited inhibition of 31.50% for L-tyrosine substrate and 25.40% for L-DOPA substrate. This condition suggests that the optimized ALH acquired has the potential to be used as a bioactive ingredient for cosmeceutical applications.
Roots and leaves of the Cermela Hutan (Phyllanthus gomphocarpus Hook. F) plant were studied to determine antioxidant activity, phytochemical compounds, proportion of carbohydrate, crude protein, moisture, ash, fat, total phenolic content (TPC), and total flavonoid content (TFC).
The antioxidant properties of virgin coconut oil produced through chilling and fermentation were investigated and compared with refined, bleached and deodorized coconut oil. Virgin coconut oil showed better antioxidant capacity than refined, bleached and deodorized coconut oil. The virgin coconut oil produced through the fermentation method had the strongest scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the highest antioxidant activity based on the beta-carotene-linoleate bleaching method. However, virgin coconut oil obtained through the chilling method had the highest reducing power. The major phenolic acids detected were ferulic acid and p-coumaric acid. Very high correlations were found between the total phenolic content and scavenging activity (r=0.91), and between the total phenolic content and reducing power (r=0.96). There was also a high correlation between total phenolic acids and beta-carotene bleaching activity. The study indicated that the contribution of antioxidant capacity in virgin coconut oil could be due to phenolic compounds.
This study evaluated the in vitro antioxidant capacities of extracts from Pleurotus pulmonarius via Folin-Ciocalteu, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, metal chelating, cupric ion reducing antioxidant capacity, and lipid peroxidation inhibition assays. Extract compositions were determined by phenol-sulfuric acid; Coomassie Plus (Bradford) protein; Spectroquant zinc, copper, and manganese test assays; and liquid chromatography-tandem mass spectrometry (LC/MS/MS) and gas chromatography-mass spectrometry (GC/MS). Methanol-dichloromethane extract, water fraction, hot water, aqueous extract and hexane fraction exhibited the most potent extracts in the antioxidant activities. LC/MS/MS and GC/MS showed that the extracts contained ergothioneine, ergosterol, flavonoid, and phenolic compounds. The selected potent extracts were evaluated for their inhibitory effect against oxidation of human low-density lipoproteins and protective effects against hydrogen peroxide-induced cytotoxic injury in human aortic endothelial cells. The crude aqueous extract was deemed most potent for the prevention of human low-density lipoprotein oxidation and endothelial membrane damage. Ergothioneine might be the compound responsible for the activities, as supported by previous reports. Thus, P. pulmonarius may be a valuable antioxidant ingredient in functional foods or nutraceuticals.
Plants and plant-based products have been used for a long time for medicinal purposes. This study aimed to determine the antioxidant and anti-α-glucosidase activities of eight selected underutilized plants in Malaysia: Leucaena leucocephala, Muntingia calabura, Spondias dulcis, Annona squamosa, Ardisia elliptica, Cynometra cauliflora, Ficus auriculata, and Averrhoa bilimbi. This study showed that the 70% ethanolic extract of all plants exhibited total phenolic content (TPC) ranging from 51 to 344 mg gallic acid equivalent (GAE)/g dry weight. A. elliptica showed strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) scavenging activities, with half maximal inhibitory concentration (IC50) values of 2.17 and 49.43 μg/mL, respectively. Most of the tested plant extracts showed higher inhibition of α-glucosidase enzyme activity than the standard, quercetin, particularly A. elliptica, F. auriculata, and M. calabura extracts with IC50 values of 0.29, 0.36, and 0.51 μg/mL, respectively. A total of 62 metabolites including flavonoids, triterpenoids, benzoquinones, and fatty acids were tentatively identified in the most active plant, i.e., A. elliptica leaf extract, by using ultra-high-performance liquid chromatography (UHPLC)-electrospray ionization (ESI) Orbitrap MS. This study suggests a potential natural source of antioxidant and α-glucosidase inhibitors from A. elliptica.