Induction of lipid peroxidation in human fibroblasts by the antioxidant propyl gallate in combination with copper(II)

Effect of ethyl gallate and propyl gallate on dextran sulfate sodium (DSS)-induced ulcerative colitis in C57BL/6 J mice: preventive and protective

OBJECTIVE AND DESIGN

Inflammatory bowel disease (IBD) is an idiopathic inflammatory condition of the digestive system marked by oxidative stress, leukocyte infiltration, and elevation of inflammatory mediators. In this study, we demonstrate the protective effect of ethyl gallate (EG), a phytochemical, and propyl gallate (PG), an anti-oxidant, given through normal drinking water (DW) and copper water (CW) in various combinations, which had a positive effect on the amelioration of DSS-induced ulcerative colitis in C57BL/6 J mice.

MATERIALS AND METHODS

We successfully determined the levels of proinflammatory cytokines and anti-oxidant enzymes by ELISA, tracked oxidative/nitrosative stress (RO/NS) by in vivo imaging (IVIS) using L-012 chemiluminescent probe, disease activity index (DAI), and histopathological and morphometric analysis of colon in DSS-induced colitis in a model.

RESULTS

The results revealed that oral administration of ethyl gallate and propyl gallate at a dose of 50 mg/kg considerably reduced the severity of colitis and improved both macroscopic and microscopic clinical symptoms. The level of proinflammatory cytokines (TNF-α, IL-6, IL-1β, and IFN-γ) in colonic tissue was considerably reduced in the DSS + EG-treated and DSS + PG-treated groups, compared to the DSS alone-treated group. IVIS imaging of animals from the DSS + EG and DSS + PG-treated groups showed a highly significant decrease in RO/NS species relative to the DSS control group, with the exception of the DSS + PG/CW and DSS + EG + PG/CW-treated groups. We also observed lower levels of myeloperoxidase (MPO), nitric oxide (NO), and lipid peroxidation (LPO), and restored levels of GST and superoxide dismutase (SOD) in DSS + EG-DW/CW, DSS + PG/DW, and DSS + EG + PG/DW groups compared to DSS alone-treated group. In addition, we showed that the EG, PG, and EG + PG treatment significantly reduced the DAI score, and counteracted the body weight loss and colon shortening in mice compared to DSS alone-treated group. In this 21-day study, mice were treated daily with test substances and were challenged to DSS from day-8 to 14.

CONCLUSION

Our study highlights the protective effect of ethyl gallate and propyl gallate in various combinations which, in pre-clinical animals, serve as an anti-inflammatory drug against the severe form of colitis, indicating its potential for the treatment of IBD in humans. In addition, propyl gallate was investigated for the first time in this study for its anti-colitogenic effect with normal drinking water and reduced effect with copper water.

Pharmacokinetic and toxicological overview of propyl gallate food additive

The progressive use of food additives in "ultra-processed" food has increased attention to them. Propyl gallate (PG) is an essential synthetic preservative that commonly used in food, cosmetics, and pharmacies as an antioxidant. This study aimed to outline the existing evidence on the toxicological studies of PG including its physicochemical properties, metabolism, and pharmacokinetics effects. The methods include updated searches for the relevant databases. The EFSA has evaluated the use of PG in food industry. It establishes an acceptable daily intake (ADI) of 0.5 mg/kg bw per day. Based on exposure assessment, it can be concluded that at the current level of use, PG is not of safety concern.

Bioactive compounds, antioxidant capacity and antitumoral activity of ethanolic extracts from fruits and seeds of Eugenia involucrata DC

Eugenia involucrata DC. (Myrtaceae) is a native tree species from Brazil that has been scarcely studied. We investigated the phenolic composition, the antioxidant capacity and the antitumoral activity of ethanolic extracts from fruits (FE) and seeds (SE) of E. involucrata. Six anthocyanins were identified by UPLC-PDA/MS/MS in FE, being four derived from cyanidin, and the other ones derived from delphinidin and pelargonidin. Using HPLC-PDA, FE presented a larger number of phenolic compounds (epicatechin, catechin, rutin, ellagic acid, myricetin and quercetin) than SE, which did not show myricetin and quercetin. However, SE showed higher total phenolic content and generally stronger in vitro antioxidant capacity than FE, except that only FE exhibited superoxide radical scavenging activity, which may be attributed to the anthocyanins present in fruits. Additionally, only SE exhibited antitumoral activity in a pancreatic cancer cell line (PANC-1). The antitumoral mechanisms involved imbalance of antioxidant status, alteration of mitochondrial membrane potential, cytoskeleton disassembly and induction of cell death by apoptosis and necrosis. Compared to the standard antitumoral drug gemcitabine, SE exhibited higher antitumoral efficacy and selectivity index. The highest concentration of total phenolics and of specific phenolic compounds bearing antitumoral properties may be related to the antitumoral activity of SE. Our results corroborate previous data of E. involucrata as an important source of bioactive compounds and provide, for the first time, evidences of in vitro antitumoral potential of its seeds on pancreatic cancer cell line.

EGFR-dependent signalling reduced and p38 dependent apoptosis required by Gallic acid in Malignant Mesothelioma cells

The unrestrained EGFR signalling contributes to malignant phenotype in a number of cancers including Malignant Mesotheliomas. Present study was designed to evaluate EGFR-dependent anti-proliferative and apoptotic effects of Gallic acid in transformed Mesothelial (MeT-5A) and Malignant Mesothelioma (SPC212) cells. Gallic acid reduced the viability of Malignant Mesothelioma cells in a concentration and time-dependent manner. However, viability of mesothelial cells reduced only at high concentration and longer time periods. Gallic acid restrained the activation of EGFR, ERK1/2 and AKT proteins and down regulated expression of Cyclin D and Bcl-2 genes, but upregulated the expression of p21 gene in EGF-induced SPC212 cells. GA-induced transitory G1 arrest and triggered mitochondrial and death receptor mediated apoptosis, which requires p38MAPK activation. The data provided here indicate that GA is able to inhibit EGFR dependent proliferation and survival signals and induces p38 pathway dependent apoptosis in Malignant Mesothelioma cells. On the basis of these experimental findings it is worthwhile to investigate further the biological activity of Gallic acid on other Mesothelioma cell lines harbouring aberrant EGFR signals.

Anti-inflammatory activity of n-propyl gallate through down-regulation of NF-κB and JNK pathways

The present study aimed to assess anti-inflammatory activity and underlying mechanism of n-propyl gallate, the n-propyl ester of gallic acid. n-Propyl gallate was shown to contain anti-inflammatory activity using two experimental animal models, acetic acid-induced permeability model in mice, and air pouch model in rats. It suppressed production of nitric oxide and induction of inducible nitric oxide synthase and cyclooxygenase-2 in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. It was able to diminish reactive oxygen species level elevated in the LPS-stimulated RAW264.7 macrophage cells. It also suppressed gelatinolytic activity of matrix metalloproteinase-9 enhanced in the LPS-stimulated RAW264.7 macrophage cells. It inhibited inhibitory κB-α degradation and enhanced NF-κB promoter activity in the stimulated macrophage cells. It was able to suppress phosphorylation of c-Jun NH(2)-terminal kinase 1/2 (JNK1/2) and activation of c-Jun promoter activity in the stimulated macrophage cells. In brief, n-propyl gallate possesses anti-inflammatory activity via down-regulation of NF-κB and JNK pathways.

Quantitative determination of Amaryllidaceae alkaloids from Galanthus reginae-olgae subsp. vernalis and in vitro activities relevant for neurodegenerative diseases

In the present work the qualitative and quantitative analysis of Amaryllidaceae-type alkaloids in the aerial parts and bulbs of Galanthus reginae-olgae Orph. subsp. vernalis Kamari is presented for the first time using GC-MS analysis. The alkaloids galanthamine, lycorine, and tazettine were identified in both extracts while crinine and neronine were found only in the bulbs. The yield of alkaloid fraction from bulbs (36.8%) is very high compared to the yield from aerial parts (9.34%). Lycorine was the major component in both fractions. The antioxidant potential was determined by three complementary methods. The preparations to reduce the stable free radical DPPH to the yellow-colored 1,1-diphenyl-2-picrylhydrazyl with IC(50) values of 39 and 29 mug/mL for MeOH extracts from aerial parts and bulbs, respectively. The higher activity was given by EtOAc fraction of aerial parts with IC(50) of 10 mug/mL. This activity is probably due to the presence in EtOAc fraction of polar compounds such as polyphenols. The fraction exhibited a significant antioxidant capacity also in the beta-carotene-linoleic acid test system. A higher level of antioxidant activity was observed for EtOAc fraction from bulbs with IC(50) of 10 mug/mL after 30 min and 9 mug/mL after 60 min of incubation. In contrast, the fraction from bulbs performed poorly in the lipid peroxidation liposomes assay. Significant activity was obtained for dichloromethane fraction from aerial parts (IC(50) of 74 mug/mL). The major abundance of alkaloid in dichloromethane fraction may be responsible of the bulbs anti-cholinesterase highest activity (38.5%) at 0.5 mg/mL.

Biological properties of different extracts of twoSeneciospecies

This study reports on the antioxidant, anti-diabetic and cytotoxic properties of different extracts of two Senecio species, Senecio vulgaris and Senecio inaequidens. Leaves of the latter are used as food in specific populations of Southern of Africa. Both investigated species of Senecio were found to possess different biological activities. S. inaequidens extracts possess a greater antioxidant activity in comparison with S. vulgaris. Highly significant and dose-dependent performance was obtained with the methanolic and dichloromethane extracts of S. vulgaris and the n-hexane extract of S. inaequidens regarding cytotoxic activity on cancer cell lines, while none of the extracts demonstrated activity on normal cell line MRC-5. Both Senecio species also show appreciable alpha-amylase inhibition, particularly the methanolic and dichloromethane extracts, and this may confer anti-diabetic properties on the extract.

Antioxidant, alpha-amylase inhibitory and brine-shrimp toxicity studies on Centaurea centaurium L. methanolic root extract

Free radical scavenging activity of the methanolic extract of the roots of Centaurea centaurium L. (Asteraceae) and its phenolic, non-polar and water fractions was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The phenolic fraction showed high radical-scavenging activity with DPPH (IC(50) of 57 microg mL(-1)) and potent antioxidant properties both on lipid peroxidation and beta-carotene bleaching (IC(50) of 195 and 5 microg mL(-1), respectively). The n-hexane fraction of the extract showed the highest inhibitory activity against alpha-amylase with an IC(50) of 158 microg mL(-1). In this fraction, the most abundant constituents were the fatty acids: 11,14-eicosadienoic acid methyl ester, 9-octadecenoic acid methyl ester and 9-octadecenoic acid. Various terpenes, e.g. cypirene, alpha-zingiberene, beta-farnesene, beta-santalene, beta-bisabolene, beta-himachalene and azulene were also present. The LC(50) against the brine shrimp nauplii for the methanolic extract was found to be 44.05 microg mL(-1), whilst LC(50) values for the polyphenolic, lipophilic and water fractions were found to be 157.44, 25.98 and 152.81 microg mL(-1), respectively.

In vivo anti-inflammatory and in vitro antioxidant activities of Mediterranean dietary plants

Five hydroalcoholic extracts of edible plants from Calabria region (Italy) used in local traditional medicine for the treatment of inflammatory diseases were evaluated for their in vivo topical anti-inflammatory activity (inhibition of croton oil-induced ear oedema in mice) and in vitro antioxidant and antiradical properties (inhibition of linoleic acid oxidation and bovine brain liposomes peroxidation, DPPH radical scavenging). All the extracts showed an anti-inflammatory effect: 300 microg/cm(2) provoked oedema reductions ranging from 21 to 27%. All the extracts exerted also radical scavenging and/or antioxidant properties, the most active plant being Mentha aquatica L. (Lamiaceae) which contained the highest amount of phenolics (337 mg/g) and of flavonoids (15.75 mg/g). Moreover, the content and the composition of sterols were assessed by GC-MS in the examined plants Borago officinalis L. (Boraginaceae) contained the highest number of sterols.

In vitro activities of Citrus medica L. cv. Diamante (Diamante citron) relevant to treatment of diabetes and Alzheimer's disease

The present study showed for the first time the in vitro properties (antioxidant, hypoglycaemic and anticholinesterase) of Citrus medica L. cv. Diamante which belongs to the Rutaceae family. The n-hexane extract of Diamante citron peel is characterized by the presence of monoterpenes and sesquiterpenes. The most abundant constituents were two monoterpenes: limonene and gamma-terpinene. The extract showed significant antioxidant activity that was carried out using different assays (DPPH test, beta-carotene bleaching test and bovine brain peroxidation assay). Oxidative damage, caused by the action of free radicals, may initiate and promote the progression of a number of chronic diseases, including diabetes and Alzheimer's disease. Diamante citron peel extract showed hypoglycaemic activity and an anticholinesterase effect.

Comparative chemical composition and antioxidant activities of wild and cultivated Laurus nobilis L. leaves and Foeniculum vulgare subsp. piperitum (Ucria) coutinho seeds

The chemical composition and antioxidant activities of wild and cultivated Laurus nobilis leaves and Foeniculum vulgare subsp. piperitum seeds were determined. Differences were found in the total phenolic content of fennel. GC-MS analysis of the non polar fractions showed a different composition between wild and cultivated plants. Cultivated laurel had a high content of terpenes such as linool, alpha-terpinol, alpha-terpinyl acetate, thymol, caryophyllene, aromandrene, selinene, farnesene, and cadinene, while wild laurel had a high content of eugenol and methyl eugenol, vitamin E, and sterols. The antioxidant potential of the extracts was determined using three complementary methods. Wild plants showed greater radical scavenging activity than the cultivated plants. The extracts also exhibited a significant antioxidant capacity also in the beta-carotene-linoleic acid test system. A high level of antioxidant activity was observed in wild laurel (IC50 = 1 microg/ml). Significant antioxidant activity measured in bovine brain was observed in wild laurel.

Antioxidant and cytotoxic activities of methanolic extract and fractions from Senecio gibbosus subsp. gibbosus (GUSS) DC

The aim of this study was to evaluate the in vitro antioxidant and cytotoxic activities of the methanolic extract and fractions of Senecio gibbosus subsp. gibbosus aerial parts. The antioxidant activity was assessed by means of two different tests: (1) bleaching of the stable 2,2-diphenyl-1-picrylhydrazil (DPPH) radical; and (2) lipid peroxidation of liposomes which were prepared from bovine brain extract. In both tests used methanolic extract and AcOEt fraction showed a significant antioxidant effect. The cytotoxic activity of the methanolic extract and fractions was carried out using the SRB assay. The methanolic extract demonstrated a good cytotoxic activity against human breast cancer cell line (MCF-7) and human prostate cancer cell line (LNCaP). Dichloromethane and AcOEt fractions showed the greatest cytotoxic activity, particularly on LNCaP cell line.

Comparative radical scavenging and antidiabetic activities of methanolic extract and fractions from Achillea ligustica ALL

The yield of methanolic extract and total phenol and non polar content of flowered parts from Achillea ligustica ALL. are reported. GC-MS analysis of the non polar fraction showed that the triterpene moretenol was the major constituent (17.228%) followed by stigmast-6-en-3beta-ol, veridiflorol and beta-amyrin (7.524%, 5.078% 4.470%, respectively). The antioxidant activities of the methanolic extract and its fractions from A. ligustica were carried out using two different in vitro assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and lipid peroxidation of liposomes assay. Methanolic extract showed higher radical scavenging activity on DPPH (IC50 of 50 microg/ml). This activity is probably due to the phenolic fraction which shown an IC50 value of 22 microg/ml. A different result was obtained from the methanolic extract on the lipid peroxidation of liposomes (IC50 of 416 microg/ml). The alpha-amylase inhibition assay was applied to evaluate antidiabetic activity. The methanolic extract showed weak activity (28.18% at 1 mg/ml) while the n-hexane fraction showed 74.96% inhibition at 250 microg/ml.

In Vitro Antioxidant Effect and Inhibition of .ALPHA.-Amylase of Two Varieties of Amaranthus caudatus Seeds

This study reports on the biological properties, antioxidant and antidiabetic, of two varieties of Amaranthus caudatus seeds, Oscar blanco and Victor red. Oil, squalene and phenolic contents were also determined. Seeds of both investigated varieties were found to possess very different levels of squalene (2.2% in Oscar blanco variety and 7.5% in Victor red variety). Although the antioxidant activity of A. caudatus var. Oscar blanco and A. caudatus var. Victor red statistically did not differ significantly from each other (IC50 values of ethyl acetate extracts were 0.50 mg/ml and 0.62 mg/ml, respectively), significant differences were noticed in relation to antidiabetic activity (inhibition of alpha-amylase, EC 3.2.1.1) of methanolic extracts that showed 50.5% for A. caudatus var. Oscar blanco and 28% for A. caudatus var. Victor red at concentration of 25 microg/ml.

Reactive oxygen species and UV-B: effect on cyanobacteria

Reactive oxygen species (ROS) are involved in the damage and response of cyanobacteria to UV-B irradiation. In cyanobacteria, there are several targets for the potentially toxic ROS such as lipids, DNA and protein. The damage to photosynthetic apparatus induces the inhibition of photosynthesis that is mediated partially by ROS. UV-B-induced oxidative stress and oxidative damage increases with irradiation time and can be reversed after long-term irradiation. This raises the interesting question of whether cyanobacteria can acclimatize to the present UV-B stress. On one hand, ROS may also act as signal molecules and mediate the genetic regulation of photosynthetic genes and the induction of antioxidant enzymes. On the other hand, the efficient defense and repair system allows cyanobacteria to recover from the oxidative damage under moderate UV-B irradiation. In addition, the following methods are discussed: the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), used to detect oxidative stress induced by UV-B; thiobarbituric acid reactive substances (TBARS), used to determine lipid peroxidation in cyanobacteria; fluorimetric analysis of DNA unwinding (FADU), used to quantify DNA strand breaks induced by ROS formation under UV-B stress.

Antioxidant activity of methanolic extract of Hypericum triquetrifolium Turra aerial part

The antioxidant activity of the methanol extract of Hypericum triquetrifolium Turra (Hypericaceae) aerial part and of flavonoids isolated therein, I3,II8-biapigenin, quercetin-3-O-galactoside, kaempferol-3-O-glycoside, (-)-epicatechin and hypericin, was evaluated. The IC(50) resulted between 0.062 and 1 mg/ml.