Antioxidant Constituents Research Articles

Global Profiling of the Antioxidant Constituents in Chebulae Fructus Based on an Integrative Strategy of UHPLC/IM-QTOF-MS, MS/MS Molecular Networking, and Spectrum-Effect Correlation.

An integrative strategy of UHPLC/IM-QTOF-MS analysis, MS/MS molecular networking (MN), in-house library search, and a collision cross-section (CCS) simulation and comparison was developed for the rapid characterization of the chemical constituents in Chebulae Fructus (CF). A total of 122 Constituents were identified, and most were phenolcarboxylic and tannic compounds. Subsequently, 1,3,6-tri-O-galloyl-β-d-glucose, terflavin A, 1,2,6-tri-O-galloyl-β-d-glucose, punicalagin B, chebulinic acid, chebulagic acid, 1,2,3,4,6-penta-O-galloyl-β-d-glucose, and chebulic acid, among the 23 common constituents of CF, were screened out by UPLC-PDA fingerprinting and multivariate statistical analyses (HCA, PCA, and OPLS-DA). Then, Pearson's correlation analysis and a grey relational analysis were performed for the spectrum-effect correlation between the UPLC fingerprints and the antioxidant capacity of CF, which was finally validated by an UPLC-DPPH• analysis for the main antioxidant constituents. Our study provides a global identification of CF constituents and contributes to the quality control and development of functional foods and preparations dedicated to CF.

Antioxidant, cytotoxic properties, and chemical constituents of soil Streptomyces spp. isolated from Muna Islands, Southeast Sulawesi, Indonesia

Soil Streptomyces are filamentous Gram-positive bacteria which were the biggest producer of remarkable bioactive compounds with multiple biological roles. This study aimed to assess the antioxidant and cytotoxic activities of crude extract derived from 3 soil Streptomyces strains, namely APM-7, APM-11, and APM-21, which was isolated from Muna Islands, Southeast Sulawesi as well as profiling its compounds using gas chromatography and mass spectrometry (GC-MS). The results indicated that the ethyl acetate extract of APM-7 strain showed the most antioxidant potential with an IC50 value for both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) of 31.61 and 57.91 μg/mL, respectively. Interestingly, this corresponding extract exhibited the highest total phenolic content (TPC) and total flavonoid content (TFC) values of 41.74 mg GAE/g extract and 32.51 mg QE/g extract. The cytotoxic effect of APM-7 extract (100 μg/mL) against human breast carcinoma cells (MCF-7) was found as having the best with the inhibition value of 81.31%. GC-MS analysis of APM-7 extract revealed 12 peaks which included some dominant compounds, including isophorone and Bis (2-ethylhexyl) phthalate which might be responsible for the antioxidant and cytotoxic properties. Our results indicate that the Streptomyces sp. strain APM-7 could be developed as medically useful compounds.

Cyanidin-3-O-glucoside from blueberry anthocyanin extracts protects ARPE-19 cells against high glucose damage via REDD1/GSK3β pathway

The retinal pigment epithelium (RPE) serves dual roles: it acts as a selective barrier and also as a regulator for the photoreceptor layer situated above it. The RPE is considered a crucial target for halting the development and progression of diabetic retinopathy (DR). This study focuses on understanding the protective role of blueberry anthocyanin extracts (BAEs), particularly its anti-oxidant constituent, cyanidin-3-O-glucoside (C3G), against damage to RPE cells induced by high glucose (HG) levels. The findings revealed that the BAEs mitigated damage to HG-induced ARPE-19 cells by decreasing the intracellular reactive oxygen species (ROS) levels, which improved cell morphology and cell viability (p < 0.01). Importantly, these cytoprotective effects were linked to the C3G rich in BAEs. The underlying mechanism may involve C3G interrupting the ROS generation feedback loop by downregulating REDD1 expression, which in turn enhanced the retinal Nrf2 antioxidant response to HG through the promotion of the GSK3β phosphorylation at Ser-9. Moreover, C3G suppressed VEGFA expression by inhibiting REDD1 levels in HG-induced ARPE-19 cells, subsequently preventing an increase in vascular permeability. In conclusion, this study suggested that the C3G relieved HG-induced oxidative stress damage in ARPE-19 cells via REDD1/GSK3β pathway and inhibited an increase in vascular permeability by downregulating VEGFA expression. These insights could shed light on how this natural bioactive compound can help manage HG-associated eye disorders like DR.

Changes in bioactive compounds, antioxidant activity, and polyphenols of red beetroots dehydrated in oven, microwave, and infrared systems

AbstractBackroundThe antioxidant capacity of red beetroot has an important role in promoting human health and preventing degenerative diseases and cancer. Beetroot and colorful root vegetables are rich in phenol compounds with antioxidant properties.ResultsIn this study, changes in total phenolic and flavonoid amounts and antioxidant activities and phenolic constituents of red beets heated in oven, microwave (MW), and infrared (IR) systems were investigated. The total phenolic and flavonoid contents of the red beetroots heated in oven, MW, and IR were determined between 327.85 (IR) and 619.27 mg GAE/100 g (oven) to 674.03 (IR) and 1089.24 mg/100 g (MW), respectively. Also, the antioxidant activity values of dehydrated red beet samples varied between 0.02 (IR) and 4.73 mmol/kg (Oven). The values of total phenolic, total flavonoid values, and antioxidant activities of the red beet samples were most affected by infrared. Gallic acid and 3,4‐dihydroxybenzoic acid amounts of red beet samples were identified between 47.54 (Oven) and 438.65 mg/100 g (MW) to 15.98 (IR) and 45.44 mg/100 g (MW), respectively. Also, the highest p‐coumaric acid (8.50 mg/100 g), ferulic acid (6.26 mg/100 g), resveratrol (2.55 mg/100 g), quercetin (4.69 mg/1000 g), cinnamic acid (0.21 mg/100 g), and kaempferol (0.64 mg/100 g) were established in red beets dehydrated in MW system.ConclusionWhen the red beet is desired to be rich in total phenolic and total flavonoid components, conventional and microwave oven cooking should be preferred, respectively. The phenolic components of the red beets dehydrated in the microwave were found to be high (except caffeic acid) compared with oven and IR.

Dragon fruit farming by-products as an important source of several glycosylated flavonoids

Plants are globally used as an alternative for conventional drugs in treatment of many diseases. A significant proportion of medicinal properties of plants is addressed to antioxidant constituents as flavonoids and phenolic acids. The genus Selenicereus, known as dragon fruit, has about 15 species of epiphytic or hemiepiphytic cactus with hotspots in the tropical region of Mexico. Recently, these plants have been the focus of pharmacological studies due to the antioxidant activity of its fruits. Although many studies have investigated the biological activities of fruits, few studies investigated the chemical constituents and biological activities of cladodes. Despite the little knowledge about cladodes, it has been already observed to have higher antioxidant activities and other biological activities than the fruits. Besides this, cladodes are by-products resulting from the year-round pruning. Another important point about studies involving dragon fruit is that none of them identify the variety that is being used. As it is a commercial plant, it has many varieties created by artificial selection and hybridization such as many other food plants. In this study we found that varieties from the same species showed quantitative and qualitative differences in the metabolite profile using LC-MS. Metabolite profile from Cerrado (Selenicereus setaceus) was closer to Branca (Selenicereus undatus) than Thick King (S. setaceus), as well as Golden (S. undatus) was closer to Thick King than Branca. These results show that it is essential to identify varieties that are being used in the studies, whereas studies that attempt to replicate the experiments or use these plants for phytopreparations are prone to mislead.

A Comparative Analysis of Chemical Constituents and Antioxidant Effects of Dendrobium fimbriatum Hook Fractions with Different Polarities.

The aim of this study was to investigate the chemical composition and antioxidant capacity of various polar fractions obtained from Dendrobium fimbriatum Hook (DH). First, a 90% ethanol-aqueous extract of DH (CF) was subjected to sequential fractionation using different organic solvents, resulting in the isolation of a methylene chloride fraction (DF), an ethyl acetate fraction (EF), an n-butanol fraction (BF), and a remaining water fraction (WF) after condensation. Additionally, the CF was also subjected to column chromatography via a D101 macroreticular resin column, eluted with ethanol-aqueous solution to yield six fractions (0%, 20%, 40%, 60%, 80%, and 100%). UPLC-Q-Exactive Orbitrap-MS/MS analysis identified a total of 47 chemical compounds from these polar fractions, including fatty acids, amino acids, phenolic acids, flavonoids, organic heterocyclic molecules, and aromatic compounds. Moreover, DF, EF, and the 60%, 80%, and 100% ethanol-aqueous fractions had higher total phenol content (TPC) and total flavonoid content (TFC) values and greater 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS-) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging abilities. In H2O2-induced HepG2 cells, the aforementioned fractions could increase the activities of antioxidative enzymes NAD(P)H: quinone oxidoreductase 1 (NQO1), superoxide dismutase (SOD), heme oxygenase-1 (HO-1) and catalase (CAT), stimulate glutathione (GSH) synthesis by increasing the activities of glutamic acid cysteine ligase (GCL) and glutathione synthetase (GS), regulate GSH metabolism by increasing glutathione peroxidase (GSH-Px) and glutathione reductase (GR) activities, and reduce levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Furthermore, the antioxidative stress effect of the DH fractions was found to be positively correlated with the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) protein and the presence of antioxidative chemical constituents. In conclusion, this study highlights the efficacy of both liquid-liquid extraction and macroporous resin purification techniques in the enrichment of bioactive compounds from natural food resources. The comprehensive analysis of chemical constituents and antioxidant effects of different polar fractions from Dendrobium fimbriatum Hook contributes to the understanding of its potential application in functional foods and nutraceuticals.

Dietary Olive Leaf Extract Differentially Modulates Antioxidant Defense of Normal and Aeromonas hydrophila-Infected Common Carp (Cyprinus carpio) via Keap1/Nrf2 Pathway Signaling: A Phytochemical and Biological Link.

Olive leaves are an immense source of antioxidant and antimicrobial bioactive constituents. This study investigated the effects of dietary incorporation of olive leaf extract (OLE) on the growth performance, hematobiochemical parameters, immune response, antioxidant defense, histopathological changes, and some growth- and immune-related genes in the common carp (Cyprinus carpio). A total of 180 fish were allocated into four groups with triplicate each. The control group received the basal diet without OLE, while the other three groups were fed a basal diet with the OLE at 0.1, 0.2, and 0.3%, respectively. The feeding study lasted for 8 weeks, then fish were challenged with Aeromonas hydrophila. The results revealed that the group supplied with the 0.1% OLE significantly exhibited a higher final body weight (FBW), weight gain (WG%), and specific growth rate (SGR) with a decreased feed conversion ratio (FCR) compared to the other groups (p < 0.05). An increase in immune response was also observed in the fish from this group, with higher lysosome activity, immunoglobulin (IgM), and respiratory burst than nonsupplemented fish, both before and after the A. hydrophila challenge (p < 0.05). Similarly, the supplementation of the 0.1% OLE also promoted the C. carpio's digestive capacity pre- and post-challenge, presenting the highest activity of protease and alkaline phosphatase (p < 0.05). In addition, this dose of the OLE enhanced fish antioxidant capacity through an increase in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and decreased hepatic lipid peroxidation end products (malondialdehyde-MDA), when compared to the control group, both pre- and post-infection (p < 0.05). Concomitantly with the superior immune response and antioxidant capacity, the fish fed the 0.1% OLE revealed the highest survival rate after the challenge with A. hydrophila (p < 0.05). A significant remarkable upregulation of the hepatic sod, nrf2, and protein kinase C transcription levels was detected as a vital approach for the prevention of both oxidative stress and inflammation compared to the infected unsupplied control group (p < 0.05). Interestingly, HPLC and UPLC-ESI-MS/MS analyses recognized that oleuropein is the main constituent (20.4%) with other 45 compounds in addition to tentative identification of two new compounds, namely oleuroside-10-carboxylic acid (I) and demethyl oleuroside-10-carboxylic acid (II). These constituents may be responsible for the OLE exerted potential effects. To conclude, the OLE at a dose range of 0.66-0.83 g/kg w/w can be included in the C. carpio diet to improve the growth, antioxidant capacity, and immune response under normal health conditions along with regulating the infection-associated pro-inflammatory gene expressions, thus enhancing resistance against A. hydrophila.

Bioassay-guided isolation of the antioxidant constituent from Kaempferia rotunda L.

Abstract. Aryantini D, Astuti P, Yuniarti N, Wahyuono S. 2023. Bioassay-guided isolation of the antioxidant constituent from Kaempferia rotunda L. Biodiversitas 24: 3641-3648. Kaempferia rotunda L. contains various phytochemical compounds with various biological activities and has been widely utilized in traditional medicine. This research focused on exploring bioactive compounds in the ethanol extract of Kaempferia rotunda using radical scavenging (1,1-Diphenyl-2-picrylhydrazyl) bioassay-guided isolation. Initially, the powdered material of K. rotunda was macerated with 70% ethanol and filtered, and the filtrate was evaporated in vacuo to make concentrated ethanol extract. The concentrated ethanol extract was then triturated gradually with increasing polarity of solvents (n-hexane, ethyl acetate, ethanol) to give n-hexane (HSF), ethyl acetate (EASF), ethanol (ESF), and residue (ISF) fractions. Each fraction was tested by DPPH bioassay with quercetin as the positive control to determine the active fraction. The active fraction (ESF) was further fractionated by Vacuum Liquid Chromatography (VLC) using a mobile gradient phase starting from ethyl acetate 100%, acetone 100%, and methanol 100% tomake3 sub-fractions (F1, F2, F3),respectively. The DPPH radical scavenging bioassay showed that F1 was the most active, containing bioactive compound detected by TLC visualized by DPPH. Based on spectroscopic and literature data comparison, this compound was isolated, purified, and identified ascrotepoxide. Crotepoxide displayed IC50of 38.91±0.59 (ABTS), 47.45±0.60 (DPPH),and 26.74±1.23 (FRAP) µg/mL.

Analysis of Antioxidant Constituents of Filtering Infusions from Oak (Quercus sideroxyla Bonpl. and Quercus eduardii Trel.) and Yerbaniz (Tagetes lucida (Sweet) Voss) as Monoamine Oxidase Inhibitors.

The antioxidant constituents of ancestral products with ethnobotanical backgrounds are candidates for the study of filtering infusions to aid in pharmacotherapies focused on the treatment of depression and anxiety. Monoamine oxidase A (MAO-A) is an enzyme that regulates the metabolic breakdown of serotonin and noradrenaline in the nervous system. The goal of this study was to evaluate in vitro and in silico the effect of antioxidant constituents of filtering infusions from yerbaniz (Tagetes lucida (Sweet) Voss) and oak (Quercus sideroxyla Bonpl. and Quercus eduardii Trel.) as monoamine oxidase inhibitors. Materials were dried, ground, and mixed according to a simplex-centroid mixture design for obtaining infusions. Differential analysis of the phenolic constituent's ratio in the different infusions indicates that among the main compounds contributing to MAO-A inhibition are the gallic, chlorogenic, quinic, and shikimic acids, quercetin glucuronide and some glycosylated derivatives of ellagic acid and ellagic acid methyl ether. Infusions of Q. sideroxyla Bonpl. leaves, because of their content (99.45 ± 5.17 µg/mg) and synergy between these constituents for MAO-A inhibition (52.82 ± 3.20%), have the potential to treat depression and anxiety. Therefore, future studies with pharmacological approaches are needed to validate them as therapeutic agents with applications in mental health care.

Determination of the contents of bioactive compounds in St. John’s wort (Hypericum perforatum): Comparison of commercial and wild samples

Abstract St. John’s wort (Hypericum perforatum) is a medicinal plant with a rich history of traditional use. It has been shown to possess a range of beneficial health properties, including antioxidant and anti-inflammatory activities. In this study, the content of flavonoids and the antioxidant activity of commercially available dried and wild-grown samples were analyzed using the LC–MS/MS method. In addition, these samples were evaluated for their functional constituents, such as phenolic acids (ferulic, caffeic, chlorogenic, and gallic acids), quercetin, rutin, pseudohypericin, and hypericin using the liquid chromatography tandem mass spectrometry method. The most important antioxidant constituents in the samples analyzed were polyphenols with chlorogenic acid as the predominant compound. The content of the most important biocomponents with antidepressant activity was also analyzed. The results suggest that wild plants exposed to more stress factors have higher amount of compounds with antidepressant effects than plants grown in controlled conditions.

Hypoglycemic activities of flowers of Xanthoceras sorbifolia and identification of anti-oxidant components by off-line UPLC-QTOF-MS/MS-free radical scavenging detection

ObjectiveTo identify phytochemical constituents present in the extract of flowers of Xanthoceras sorbifolia and evaluate their anti-oxidant and anti-hyperglycemic capacities. MethodsThe AlCl3 colorimetric method and Prussian Blue assay were used to determine the contents of total flavonoids and total phenolic acids in extraction layers, and the bioactive layers was screened through anti − oxidative activity in vitro. The Waters ACQUITY UPLC system and a Waters ACQUITY UPLC BEH C18 column (2.0 mm × 150 mm, 5 μm) were used to identify the ingredients. And anti-oxidative ingredients were screened by off-line UPLC-QTOF-MS/MS-free radical scavenging. The ameliorative role of it was further evaluated in a high-fat, streptozotocin-induced type 2 diabetic rat model and the study was carried out on NADPH oxidase (PDB ID: 2CDU) by molecular docking. ResultsCombined with the results of activity screening in vitro, the anti − oxidative part was identified as the ethyl acetate layer. A total of 24 chemical constituents were identified by liquid chromatography-mass spectrometry in the ethyl acetate layer and 13 main anti-oxidative active constituents were preliminarily screened out through off-line UPLC-QTOF-MS/MS-free radical scavenging. In vivo experiments showed that flowers of X. sorbifolia could significantly reduce the blood glucose level of diabetic mice and alleviate liver cell damage. Based on the results of docking analysis related to the identified phytocompounds and oxidase which involved in type 2 diabetes, quercetin 3-O-rutinoside, kaempferol-3-O-rhamnoside, isorhamnetin-3-O-glucoside, and isoquercitrin showed a better inhibitory profile. ConclusionThe ethyl acetate layer was rich in flavonoids and phenolic acids and had significant anti-oxidant activity, which could prevent hyperglycemia. This observed activity profile suggested X. sorbifolia flowers as a promising new source of tea to develop alternative natural anti-diabetic products with a high safety margin.

Recovery of Bioactive Compounds from Calabrian Bergamot Citrus Waste: Selection of Best Green Extraction

The purpose of this study was to select the best green extraction technique to recover the bioactive compounds in Calabrian Bergamot waste (Pomace). Different experimental variables such as solvent, time, and temperature were tested and the main physicochemical characteristics and antioxidant activity and constituents, such as total flavonoids, individual flavonoids, and limonoids (UHPLC-DAD) were analyzed. Later, the best extraction methodology was applied to characterize the individual portions that compose the bergamot pomace (albedo/pulp, seeds, and juice) of three different Calabrian cultivars: Fantastico, Femminello, and Castagnaro. Results of this study evidence that bergamot waste possesses a high antioxidant content that can be potentially used for further applications in the food industry.

Phytochemical, Antioxidant and Anti-diabetic Potentials of the Ethanol Leave Extracts of four Medicinal Plants

For many years, medicinal plants have been a resource for healing in several local communities around the world and the phytochemicals in them such as flavonoids, alkaloids, phenolic, tannins, and terpenoids are attributed to their many medicinal values. Vernonia amydalina, Senna alata, Jatropha curcas, and Grewia pubescens are important plants with immense value. In this study, phytochemical screening, antioxidant analysis and the potential anti-hyperglycemic properties of the plants was investigated in-vitro. The ethanol leave extracts of the plants were subjected to qualitative phytochemical screening and tannin, flavonoids and phenol quantification. Ferric reducing antioxidant power and DPPH radical inhibition of the extracts was done by spectrophotometric method while the anti-diabetic potential was analyzed through the in-vitro α-amylase and α-glucosidase inhibition. Phytochemicals detected in the ethanol leave extracts of the four plants are tannins, flavonoids, phenolics, terpenoids, steroids, alkaloids, cardiac glycosides, and saponins. Flavonoids, phenols, and tannin content were highest in Senna alata (0.27±0.0.002 mg: mg of rutin per g of extract, 10.63±0.0.017 mg: mg of gallic acid per g of extract, and 6.72±0.06 mg/g respectively) followed by V. amygdalina (0.20±00.002 mg: mg of rutin per g of extract, 8.27±0.0.017 mg: mg of gallic acid per g of extract, and 7.98±0.03 mg/g respectively). While the least content of all was found in the extracts of Jatropha curcas. Concentration dependent and statistically significant difference was observed in both the FRAP and DPPH radical inhibition of all the extracts. Senna alata showed the strongest reducing power followed by the V. amygdalina. Both Senna alata and V. amygdalina showed DPPH radical inhibition that is not significantly (p&gt;0.05) different from that of trolox. α-amylase and α-glucosidase inhibition was also demonstrated in a concentration dependent manner. In both the α-amylase and α-glucosidase inhibition, V. amygdalina and S. alata exhibited the most significant inhibitory properties among the plant extracts. The overall result in this study suggested that V. amygdalina, S. alata with the highest content of the phytochemicals, and antioxidant activities are potential source of antioxidant constituents and might be useful for the management of diseases such as diabetes.

A Review Article: Free Radical and Replacement Synthetic Antioxidant by Natural Antioxidant

Free radical may be responsible of several pathophysiology disease for threatening human life, and they are produced from endogenous and exogenous sources. Using the balanced amount of nutritious diet lead to a good health, may be neutralizing or scavenging free radicals by antioxidants compounds. daily diet have large number of vitamin A, E and C, carotenoids, polyphenols, etc. as natural antioxidants, the main bases of them are fruits, cereals, vegetables, and beverages. Enzymatic and non-enzymatic antioxidant substances are two different kinds that lessen the reactions of free radicals. In order to protect itself from reactive oxygen species, the human body uses an enzyme antioxidant. The two kinds of non-enzymatic antioxidants are natural antioxidants and synthetic antioxidants. The aim of this review is to knowledge a reasons which causes the free radical and balance them by natural antioxidant constituents, and replacement synthetic antioxidant by natural antioxidant, due to daily diet have large amounts from natural antioxidants, and natural antioxidants more effective than synthetic antioxidants, in additional they occurrence in nature and more inexpensive.

Phytochemical Screening of Nyctanthes arbor-tristis Plant Extracts and Their Antioxidant and Antibacterial Activity Analysis.

Nyctanthes arbor-tristis, alias "Vishnu Parijat," is a medicinal plant used to treat various inflammation-associated ailments and to combat innumerable infections in the traditional system of medicine. In the present study, we collected the samples of N. arbor-tristis from the lower Himalayan region of Uttarakhand, India, and carried out their molecular identification through DNA barcoding. To examine the antioxidant and antibacterial activities, we prepared the ethanolic and aqueous extracts (from flowers and leaves) and performed their phytochemical analysis by using different qualitative and quantitative approaches. The phytoextracts showed marked antioxidant potential, as revealed by a comprehensive set of assays. The ethanolic leaf extract showed marked antioxidant potential towards DPPH, ABTS, and NO scavenging (IC50 = 30.75 ± 0.006, 30.83 ± 0.002, and 51.23 ± 0.009 μg/mL, respectively). We used TLC-bioautography assay to characterize different antioxidant constituents (based on their Rf values) in the chromatograms ran under different mobile phases. For one of the prominent antioxidant spots in TLC bioautography, GC-MS analysis identified cis-9-hexadecenal and n-hexadecanoic acid as the major constituents. Furthermore, in antibacterial study, the ethanolic leaf extract showed marked activity against Aeromonas salmonicida (113.40 mg/mL of extract was equivalent to 100 μg/mL of kanamycin). In contrast, the ethanolic flower extract showed considerable antibacterial activity against Pseudomonas aeruginosa (125.85 mg/mL of extract ≡100 μg/mL of kanamycin). This study presents the phylogenetic account and unravels the antioxidant-related properties and antibacterial potential of N. arbor-tristis.

A TLC-direct bioassay method for detection of anti-lipid peroxidation constituents from fruits of Perilla frutescens

A practical TLC-direct bioassay method was established for screening and evaluating antioxidant activity. The method was based on series of reactions. Irradiation of linoleic acid with UV 254 nm produced lipid peroxides. Upon heating, the peroxides were converted into malondialdehyde, which combined with thiobarbituric acid to a red pigment with a maximum absorption at 535 nm. Following a TLC separation, substance with anti-lipid peroxidation activity showed white spots/zones against red background on the TLC plate. The proposed method was established by the dot blot test, and validated with respect to selectivity, sensitivity, linearity, precision, and recovery after optimizing key experimental parameters. In an exemplary screening for antioxidant constituents from Perilla fruits, two active zones were discovered and tentatively characterized as salviaflaside and rosmarinic acid by TLC-interface-ESI-MS, respectively. Further verification by HPTLC-bioassay-guided-isolation was carried out and in addition to salviaflaside and rosmarinic acid, also luteolin 5-O-β-d-glucopyranoside and 3′-dehydroxyl-rosmarinic acid-3-O-β-D-glucoside were discovered to show prominent anti-lipid peroxidation activity.

Isolation and identification of antioxidant constituents from the flowers of Salvia miltiorrhiza

A new salvianolic acid derivative, (7′E)-(7S, 8S)-salvianolic acid V (1), together with four previously described compounds (2-5) were obtained from the n-butanol fraction of Salvia miltiorrhiza flowers. Their structures were established by a series of spectroscopic methods, and the absolute configuration of 1 was determined by electronic circular dichroism (ECD) calculation. Salvianolic acids (1) and phenolic acids (2-4) showed stronger DPPH free radical scavenging abilities and certain protective effects against H2O2-induced human skin fibroblast (HSF) cells oxidative damage, in which compound 1 (IC50 7.12 μM) possessed more noticeable free radical scavenging activity than the positive control vitamin C (IC50 14.98 μM).

Linum corymbulosum Protects Rats against CCl4-Induced Hepatic Injuries through Modulation of an Unfolded Protein Response Pathway and Pro-Inflammatory Intermediates.

Liver fibrosis is a major pathological feature of chronic liver disease and effective therapies are limited at present. The present study focuses on the hepatoprotective potential of L. corymbulosum against carbon tetrachloride (CCl4)-induced liver damage in rats. Analysis of Linum corymbulosum methanol extract (LCM) using high-performance liquid chromatography (HPLC) revealed the presence of rutin, apigenin, catechin, caffeic acid and myricetin. CCl4 administration lowered (p < 0.01) the activities of antioxidant enzymes and reduced glutathione (GSH) content as well as soluble proteins, whereas the concentration of H2O2, nitrite and thiobarbituric acid reactive substances was higher in hepatic samples. In serum, the level of hepatic markers and total bilirubin was elevated followed by CCl4 administration. The expression of glucose-regulated protein (GRP78), x-box binding protein-1 total (XBP-1 t), x-box binding protein-1 spliced (XBP-1 s), x-box binding protein-1 unspliced (XBP-1 u) and glutamate-cysteine ligase catalytic subunit (GCLC) was enhanced in CCl4-administered rats. Similarly, the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemo attractant protein-1 (MCP-1) was strongly increased with CCl4 administration to rats. Co-administration of LCM along with CCl4 to rats lowered (p < 0.05) the expression of the above genes. Histopathology of the liver showed hepatocyte injury, leukocyte infiltration and damaged central lobules in CCl4-treated rats. However, LCM administration to CCl4-intoxicated rats restored the altered parameters towards the levels of control rats. These outcomes indicate the existence of antioxidant and anti-inflammatory constituents in the methanol extract of L. corymbulosum.

Mitigation of Paeoniae Radix Alba extracts on H2O2-induced oxidative damage in HepG2 cells and hyperglycemia in zebrafish, and identification of phytochemical constituents.

Paeoniae Radix Alba (PRA), as a Traditional Chinese Medicine, is widely used in Chinese cuisine due to high health-benefits and nutrition, but the effect of different polarity of solvents on the extraction of antioxidant and hypoglycemic constituents, as well as the major active compounds remain unclear. In this research, 40, 70, and 95% ethanol were firstly applied to extract the polyphenols from PRA, the extraction yields, total phenolics, and total flavonoids content, free radical scavenging ability, α-glucosidase inhibition ability, and anti-glycation ability of extracts were evaluated spectroscopically. The oxidative damage protection, hypoglycemic activity, and alleviation on peripheral nerve damage were evaluated by H2O2-induced HepG2 cells and hyperglycemic zebrafish models. UPLC-QTOF-MS/MS was used to identify the major chemical constituents. The results showed that 40, 70, and 95% ethanol exhibited insignificant difference on the extraction of phenolics and flavonoids from PRA. All extracts showed promising DPPH⋅ and ABTS⋅+ scavenging ability, α-glucosidase inhibition and anti-glycation ability. In addition, PRA extracts could restore the survival rate of HepG2 cells induced by H2O2, and alleviate the oxidative stress by reducing the content of MDA and increasing the levels of SOD, CAT, and GSH-Px. The 70% ethanol extract could also mitigate the blood glucose level and peripheral motor nerve damage of hyperglycemic zebrafish. Thirty-five compounds were identified from 70% ethanol extract, gallotannins, gallic acid and its derivatives, and paeoniflorin and its derivatives were the dominant bioactive compounds. Above results could provide important information for the value-added application of PRA in functional food and medicinal industry.

Bioactive constituents from Flacourtia vogelii Hook.f. (Flacourtiaceae)

The chemical investigation of the methanolic root extract of Flacourtia vogelii led to the isolation of a new arylbenzoate derivative, vogelinal (1), together with thirteen known compounds (2–14). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antioxidant, antifungal and antibacterial activities. Compound 7 exhibited the highest antioxidant potential, with RSa 50 of 11.80 ± 2.13 µg/mL, RSa 50 of 42.60 ± 6.32 µg/mL and RC50 of 51.60 ± 7.71 µg/mL for the DPPH, ABTS and FRAP assay, respectively. Compound 13 displayed weak antifungal effect with MIC value of 125 μg/mL against Candida parapsilosis. Compound 8 showed weak antibacterial effect with MIC value of 125 μg/mL, against Shigella dysenteria. The present study, conclude that this species could be a promising source of antioxidant and antibacterial constituents.