Screening and Evaluation of Antioxidant Activities of Selected Naphthalene Compounds / Jurnal Sains Kesihatan Malaysia

@#The antioxidant activities of twelve naphthalene compounds containing (E)-1-((3-iodophenylimino)methyl) naphthalen2-ol(NAPH1), (E)-1-((3-bromophenylimino) methyl) naphthalen-2-ol (NAPH2), E)-1-((4-bromo-2-(trifluoromethoxy)phenylimino) methyl) naphthalen-2-ol, (E)-1-((4-bromo-2-(trifluoromethoxy) phenylimino) methyl)naphthalen-2-ol(NAPH3), (E)-1-((2-methoxy-5-(trifluoromethyl) phenylimino) methyl) naphthalen-2-ol (NAPH4), (E)-1-((naphthalen-2-ylimino) methyl) naphthalen-2-ol (NAPH5), (E)-1-((2-bromo-3-methylphenylimino) methyl) naphthalen-2-ol (NAPH6),(E)-N-((2-ethoxynaphthalen-1-yl)methylene)-3-methylaniline (NAPH7), (E)-4-ethoxy-N-((2-ethoxynaphthalen-1-yl)methylene) aniline (NAPH8), (E)-N-((2-ethoxynaphthalen-1-yl) methylene) naphthalen-1-amine (NAPH9), (E)-1-(2,5-difluorophenyl)-N-((2-ethoxynaphthalen-1-yl) methylene) methanamine (NAPH10), (E)-N-((2-ethoxynaphthalen-1-yl)methylene)-4-fluoroaniline (NAPH11), (E)-N-((2-ethoxynaphthalen-1-yl)methylene)-2-ethylaniline (NAPH12) wereinvestigated in vitro by antioxidant activity (phosphomolybdenum assay), reducing power, H2O2 scavenging activity,metal chelating effects and lipid peroxidation. Scavenging activities of the naphthalen compounds were tested against1,1-diphenyl-2-picrylhydrazyl, hydroxyl and superoxide anion radicals. Most of them are potent antioxidant, radicalsuperoxide anion scavengers and in vitro inhibition of lipid peroxidation. The compounds; NAPH5, NAPH10 and NAPH12were found to exhibit promising antioxidant profiles at 10 and 50 mM concentrations. Among these, NAPH5 at higherconcentration was the most active compound in inhibiting lipid peroxidation as shown in the homogenates of kidney,heart and spleen. The presented results validate that NAPH5, NAPH10 and NAPH12 can be possessed as a source ofantioxidant potential and a rich source of synthetic antioxidant for medicinal or foods.

Native and Heated Hydrolysates of Milk Proteins and Their Capacity to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model.

Casein and whey proteins with and without heat treatment were obtained of whole milk and four commercial milks in Ecuador, and were hydrolyzed. Then, their capacity to inhibit the lipid peroxidation using the TBARS method was evaluated at concentrations of 0.02, 0.04, 0.2, and, 0.4 mg/mL. Native and heated hydrolysates of milk proteins present high inhibitions of lipid peroxidation with a dose dependent effect both in vivo and in vitro tests. Casein and whey proteins obtained from whole milk were the ones with the highest anti-oxidant activity in vitro and in vivo test. Native casein hydrolysate at 0.4 mg/mL present a value of 55.55% of inhibition of lipid peroxidation and heated casein hydrolysate at 0.4 mg/mL presents a value of 58.00% of inhibition of lipid peroxidation. Native whey protein at 0.4 mg/mL present a value of 34.84% of inhibition of lipid peroxidation, and heated whey protein at 0.4 mg/mL presents a value of 40.86% of inhibition of lipid peroxidation. Native and heated casein hydrolysates were more active than native and heated whey protein hydrolysates. Heat treatments have an effect of increasing the in vitro inhibition of lipid peroxidation of hydrolysates of milk protein. Casein and whey hydrolysates were able to inhibiting lipid peroxidation in the zebrafish larvae model. Native casein hydrolysate obtained of whole milk presents 48.35% of inhibition TBARS in vivo, this activity was higher in heated casein hydrolysate obtained of whole milk with a value of 56.28% of inhibition TBARS in vivo. Native whey protein hydrolysate obtained of whole milk presents 35.30% of inhibition TBARS, and heated whey protein hydrolysate obtained of whole milk was higher, with a value of 43.60% of inhibition TBARS in vivo.

Digestibility of Quinoa (Chenopodium quinoa Willd.) Protein Concentrate and Its Potential to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model.

Quinoa protein concentrate (QPC) was extracted and digested under in vitro gastrointestinal conditions. The protein content of QPC was in the range between 52.40 and 65.01% depending on the assay used. Quinoa proteins were almost completely hydrolyzed by pepsin at pH of 1.2, 2.0, and 3.2. At high pH, only partial hydrolysis was observed. During the duodenal phase, no intact proteins were visible, indicating their susceptibility to the in vitro simulated digestive conditions. Zebrafish larvae model was used to evaluate the in vivo ability of gastrointestinal digests to inhibit lipid peroxidation. Gastric digestion at pH 1.2 showed the highest lipid peroxidation inhibition percentage (75.15%). The lipid peroxidation activity increased after the duodenal phase. The digest obtained at the end of the digestive process showed an inhibition percentage of 82.10%, comparable to that showed when using BHT as positive control (87.13%).

A tocotrienol series with an oxidative terminal prenyl unit from Garcinia amplexicaulis.

Ten tocotrienol derivatives, i.e., amplexichromanols (1-10), were isolated from stem bark of Garcinia amplexicaulis Vieill. ex Pierre collected in Caledonia. The structures of the compounds 1-5 were determined to be chromanol derivatives substituted by a polyprenyl chain oxidized in terminal position. The remaining compounds 6-10 are the corresponding dimeric derivatives. Eleven known compounds, including xanthones, tocotrienol derivatives, triterpenes and phenolic compounds, were also isolated. Their structures were mainly determined using one and two-dimensional NMR and mass spectroscopy analysis. The compounds and some amplexichromanol molecules formerly isolated from G. amplexicaulis exhibited significant antioxidant activity against lipid peroxidation and in the ORAC assay.

Phytochemical and in vitro antioxidant evaluation of different fractions of Amaranthus graecizans subsp. silvestris (Vill.) Brenan.

OBJECTIVE: To evaluate the phytochemical and in vitro antioxidant ability of methanolic extract and different fractions of Amaranthus graecizans subsp. silvestris (A. graecizans subsp. silvestris). METHODS: Methanolic extract of A. graecizans subsp. silvestris was obtained by cold maceration and then methanolic extract was subjected to fractionation and different fractions i.e. n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions were obtained. Methanolic extract and all other fractions were subjected to phytochemical investigation by performing different phytochemical group tests like alkaloid, tannins, carbohydrates, lipids, proteins, etc. In vitro antioxidant activity of A. graecizans subsp. silvestris was evaluated by using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), ferric thiocyanate assay, total antioxidant activity by phosphomolybdenum, ferric reducing antioxidant power, total phenolic content and lipid peroxidation methods. RESULTS: Maximum antioxidant activity was shown by n-hexane fraction of the extract by carrying out DPPH (86.44±0.23), ethyl acetate fraction by total antioxidant (0.95±0.06) and ferric reducing antioxidant power (299.45±1.48) methods, while by employing total phenolic contents and inhibition of lipid per oxidation assays, methanolic extract (92.88±4.16) and n-hexane fraction (69.47±0.68) exhibited maximal activity. Ethyl acetate fraction showed the least IC50 values by DPPH assay, hence a more pronounced potential for antioxidant activity. CONCLUSIONS: The results indicate that A. graecizans subsp. silvestris has antioxidant potential and can be utilized as a natural source of antioxidant.

Phytochemical and in vitro antioxidant evaluation of different fractions of Amaranthus graecizans subsp. silvestris (Vill.) Brenan

Objective: To evaluate the phytochemical and in vitro antioxidant ability of methanolic extract and different fractions of Amaranthus graecizans subsp. silvestris (A. graecizans subsp. silvestris). Methods: Methanolic extract of A. graecizans subsp. silvestris was obtained by cold maceration and then methanolic extract was subjected to fractionation and different fractions i.e. n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions were obtained. Methanolic extract and all other fractions were subjected to phytochemical investigation by performing different phytochemical group tests like alkaloid, tannins, carbohydrates, lipids, proteins, etc. In vitro antioxidant activity of A. graecizans subsp. silvestris was evaluated by using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), ferric thiocyanate assay, total antioxidant activity by phosphomolybdenum, ferric reducing antioxidant power, total phenolic content and lipid peroxidation methods. Results: Maximum antioxidant activity was shown by n-hexane fraction of the extract by carrying out DPPH (86.44±0.23), ethyl acetate fraction by total antioxidant (0.95±0.06) and ferric reducing antioxidant power (299.45±1.48) methods, while by employing total phenolic contents and inhibition of lipid per oxidation assays, methanolic extract (92.88±4.16) and n-hexane fraction (69.47±0.68) exhibited maximal activity. Ethyl acetate fraction showed the least IC

Phytochemical and in vitro antioxidant evaluation of different fractions of Amaranthus graecizans subsp. silvestris (Vill.) Brenan

OBJECTIVE@#To evaluate the phytochemical and in vitro antioxidant ability of methanolic extract and different fractions of Amaranthus graecizans subsp. silvestris (A. graecizans subsp. silvestris).@*METHODS@#Methanolic extract of A. graecizans subsp. silvestris was obtained by cold maceration and then methanolic extract was subjected to fractionation and different fractions i.e. n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions were obtained. Methanolic extract and all other fractions were subjected to phytochemical investigation by performing different phytochemical group tests like alkaloid, tannins, carbohydrates, lipids, proteins, etc. In vitro antioxidant activity of A. graecizans subsp. silvestris was evaluated by using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), ferric thiocyanate assay, total antioxidant activity by phosphomolybdenum, ferric reducing antioxidant power, total phenolic content and lipid peroxidation methods.@*RESULTS@#Maximum antioxidant activity was shown by n-hexane fraction of the extract by carrying out DPPH (86.44±0.23), ethyl acetate fraction by total antioxidant (0.95±0.06) and ferric reducing antioxidant power (299.45±1.48) methods, while by employing total phenolic contents and inhibition of lipid per oxidation assays, methanolic extract (92.88±4.16) and n-hexane fraction (69.47±0.68) exhibited maximal activity. Ethyl acetate fraction showed the least IC50 values by DPPH assay, hence a more pronounced potential for antioxidant activity.@*CONCLUSIONS@#The results indicate that A. graecizans subsp. silvestris has antioxidant potential and can be utilized as a natural source of antioxidant.

Protective effects of propofol against ischemia-reperfusion injury in rat brain / 中华麻醉学杂志

Objective To study the protective effects of propofol against ischemia-reperfusion injury in rat brains.Methods Modified Longa modle of focal cerebral ischemia-reperfusion injury was used. 200 healthy male SD rats, weighing 200-300g were anesthetized with intraperitoneal(I.P.) ketamine and propofol. When righting reflx was abolished, external carotid artery was exposed. A nylon thread with rounded end was inserted cranially until anterior cerebral artery was reached. After 3h ischemia nylon thread was withdrawn for reperfusion which lasted 3h. Bloos samples were obtained from orbit. Skull was opened and brain removed. In control group carotid artery was exposed but nylon thread was not inserted cranially. The animals were divided into four groups: (1)ischemia-reperfusion model group: normal saline 10 ml was administered I.P.,(2)operation control group: normal saline was given I.P.at the end of operation,(3)nimodipine group: nimodipine 1 mg?kg -1 was administered I.P. 10 min before ischemia,(4) propofol group: propofol 110 mg?kg -1 was given I.P. 10 min before ischemia. Brain infarction area, cerebral water content, serum lactate dehydrogenase(LDH) and creatine kinase(CK) levels,brain SOD activity and MDA and Ca 2+ levels were measured. Ultrastracture of brain tissue was examined by electron microscopy.Results Propofol 110 mg?kg -1 reduced mortality after brain ischemia/reperfusion injury. Infarction area of brain was significantly smaller in propofol and nimodipine groups than that in group 1. Propofol significantly inhibited the increases in serum LDH and CK levels induced by ischemia/reperfusion, increased SOD activity and decreased MDA content and Ca 2+ level in brain tissue. There was less brain tissue damage in propofol group.Conclusions Propofol 110 mg?kg -1 has protective effect against cerebral ischemia-reperfusion injury in rats.