Objective:To investigate the phenolic compounds composition and the inhibitory activity of Mangifera indica(M.indica) and Mucuna urens(M.urens) seeds extracts against some key enzymes(-amylase,-glucosidasc and aldose ...Objective:To investigate the phenolic compounds composition and the inhibitory activity of Mangifera indica(M.indica) and Mucuna urens(M.urens) seeds extracts against some key enzymes(-amylase,-glucosidasc and aldose reductase) implicated in the pathology and complications of type 2 diabetes in vitro.Methods:Reverse phase chromatographic quantification of the major flavonoids and phenolic acids in the seeds extracts was carried out using high performance liquid chromatography coupled with diode array detection.The inhibitory activities of the seeds extracts against-amylase and-glucosidase were estimated using soluble starch and p-nitrophenylglucopyranosidc as their respective substrates.Inhibition of aldose reductase activity by the extracts was assayed using partially purified lens homogenate of normal male rat as source of enzyme;inhibition of Fe^(2+)-induced lipid peroxidation by extracts was tested in rat pancreas homogenate.Results:The chromatography result revealed that extracts of both seeds had appreciable levels of some major flavonoids and phenolic acids of pharmacological importance,including gallic acid,chlorogenic acid,caffeic acid,ellagic acid,catechin,rutin,quercitrin.quercetin and kaempferol.Extracts of both seeds effectively inhibited-amylase,-glucosidase and aldose reductase activities in a dose-dependent manner,having inhibitory preference for these enzymes in the order of aldose reductase>-glucosidase>-amylase.With lower half-maximal inhibitory concentrations(IC50)against-amylase,-glucosidase,and aldose reductase,M.indica had stronger inhibitory potency against these enzymes than M.urens.Extracts of both seeds also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern,with M.indica being more potent than M.urens.Conclusions:The results obtained provide support for a possible use of M.indica and M.urens seeds in managing hyperglycemia and preventing the complications associated with it in type 2diabetes.展开更多
The phenolics composition and inhibitory activity of Tetrapleura tetraptera fruit extract on xanthine oxidase(XO)and Fe2+-induced lipid peroxidation in the kidney,liver and lungs tissues of rats were evaluated in vitr...The phenolics composition and inhibitory activity of Tetrapleura tetraptera fruit extract on xanthine oxidase(XO)and Fe2+-induced lipid peroxidation in the kidney,liver and lungs tissues of rats were evaluated in vitro.Phenolics(flavonoids and phenolic acids)were quantified using reverse-phase high performance liquid chromatrography coupled with diode array detection(HPLC-DAD).The XO and Fe2+-induced lipid peroxidation inhibitory abilities of the extract were evaluated using spectrophotometric methods.The extract contained some flavonoids and phenolic acids,including catechin,epicatechin,rutin,quercetin,luteolin,apigenin;gallic,chlorogenic,caffeic and ellagic acids that are beneficial to health.The extract inhibited XO in the kidney,liver and lungs tissues in a dose-dependent manner.The half-maximal inhibitory concentrations(IC50)of the extract on XO from the tissues varied significantly(P<0.05),and were in the order of liver>kidney>lungs.The extract also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern,having IC50 in the order of liver>lungs>kidney.T.tetraptera fruit extract could be a promising nutraceutical for preventing and managing hyperuricaemia and the associated disease conditions,due to its ability to inhibit XO;this bioactivity is attributable to combined effect of its flavonoids and phenolic acids.展开更多
Objective:To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit(SAG)and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential(△...Objective:To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit(SAG)and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential(△Ψ_m)isolated from rat liver.Methods:Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl(DPPH),reducing power,iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats.Also,the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined.Identification and quantification of bioactive polyphenolics was done by HPLC-DAD.Results:SAG exhibited potent and concentration dependent free radical-scavenging activity(IC_(50)/DPPH=275.03±7.8μg/mL).Reductive and iron chelation abilities also increase with increase in SAG concentration.SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault.SAG protected against Ca^(2+)(110μmol/L)-induced mitochondrial swelling and maintained the△Ψ_m.HPLC analysis revealed the presence of gallic acid[(17.54±0.04)mg/g],chlorogenic acid(21.90±0.02 mg/g),caffeic acid(16.64±0.01 mg/g).rutin[(14.71±0.03)mg/g]and quercetin[(7.39±0.05)mg/g].Conclusions:These effects could be attributed to the bioactive polyphenolic compounds present in the extract.Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.展开更多
The effects of ethylacetate extract of red onion(Allium cepa)tunic(ACTE)on some hemodynamic and biochemical parameters were evaluated in normotensive albino rats.Blood pressure parameters were determined in anaestheti...The effects of ethylacetate extract of red onion(Allium cepa)tunic(ACTE)on some hemodynamic and biochemical parameters were evaluated in normotensive albino rats.Blood pressure parameters were determined in anaesthetized rats orally administered ACTE(10-,20-,or 40 mg/kg)or ramipril(1 mg/kg)once daily for 14 days.Respectively,10-,20-,or 40 mg/kg ACTE produced significant(P<0.01),dose-dependent fall in systolic blood pressure,SBP(21%,27%,33%),diastolic blood pressure,DBP(6%,10%,16%),pulse pressure,PP(42%,49%,56%),mean arterial blood pressure,MAPB(13%,18%,23%)and heart rate,HR(4%,5%,7%).The highest effective dose(40 mg/kg)compared well with ramipril(1 mg/kg)with regards to SBP(41%),DBP(19%),PP(70%),MABP(29%)and HR(10%).Similar trends(decreases)were recorded for 40 mg/kg ACTE and ramipril,respectively,as regards the activities of serum enzymes:creatine kinase(60%and 65%),ALT(18%and 14%)and ALP(28%and 16%).HPLC fingerprints of the flavonoid-rich ACTE revealed that flavonols:quercetin,quercitrin,isoquercitrin,rutin and kaempferol are the active flavonoids.The results demonstrate the hypotensive effect of A.cepa tunic flavonoids initiating further investigation of their individual or synergistic contribution(s)to the observed effects.展开更多
This study sought to investigate the possible mechanisms for the use of phenolic extracts from grapefruit peels in the management/prevention of cardiovascular complications.The effects of the phenolic extracts on key ...This study sought to investigate the possible mechanisms for the use of phenolic extracts from grapefruit peels in the management/prevention of cardiovascular complications.The effects of the phenolic extracts on key enzymes relevant to cardiovascular diseases[3-hydroxy-methyl-3-glutaryl coenzyme A reductase(HMG-CoA reductase)and angiotensin-I converting enzyme(ACE)],cellular antioxidant activity in human endothelial cells(EA.Hy 926)and radicals[1,1-diphenyl-2 picrylhydrazyl(DPPH)and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS)]scavenging abilities were investigated.The phenolic contents of the extracts were investigated using HPLC–DAD.There was no significant(P>0.05)difference in the HMG-CoA reductase inhibitory ability of the two extracts,while the bound phenolic extracts had a stronger ACE inhibitory ability than the soluble free phenolics.The extracts also showed intracellular antioxidant activity in human endothelial(EA.Hy 926)cells.Furthermore,the bound phenolics had significantly higher radicals(DPPH*and ABTS*)scavenging abilities than the free phenolics.The HPLC analysis revealed the presence of flavonoids(quercetin and kaempferol),phenolics acids(resveratrol,gallic acid,ellagic acid and caffeic acid)and tannin(catechin).The cellular antioxidative properties and inhibition of enzymes relevant to the management of cardiovascular complications showed that grapefruit peels could be used as nutraceuticals for the management of such conditions.展开更多
Flaxseed (Linum usitatissimum L.) is composed mainly of bioactive components such as polyphenols, polyunsaturated fatty acids, fiber and lignans. Flaxseed can be found in different presentation forms (grain or flour) ...Flaxseed (Linum usitatissimum L.) is composed mainly of bioactive components such as polyphenols, polyunsaturated fatty acids, fiber and lignans. Flaxseed can be found in different presentation forms (grain or flour) and varieties (brown or golden);however, questions have arisen as to whether the presentation form and/or variety may influence the health effects. The objective of this study was to evaluate the effects on blood pressure, anthropometric and oxidative parameters in healthy human volunteers. All subjects received 40 gram aliquots of flaxseed and were instructed to consume them in their entirety mixed with water in the morning for a period of 14 days. Oxidative parameters showed significant reductions (p < 0.05) in oxidative damage to lipids and proteins via dietary intervention with golden flaxseed grains. There were no significant differences in anthropometric parameters, blood pressure, DNA damage and micronuclei frequency after 14-day supplementation. This research indicates that golden flaxseed grains can be a valuable adjunct for disease prevention and protecting the organism against oxidative damage.展开更多
Gastric ulcers affect many people around the world and their development is a result of the imbalance between aggressive and protective factors in the gastric mucosa.Scutia buxifolia,commonly known as coronilha,has at...Gastric ulcers affect many people around the world and their development is a result of the imbalance between aggressive and protective factors in the gastric mucosa.Scutia buxifolia,commonly known as coronilha,has attracted the interest of the scientific community due to its pharmacological properties and its potential therapeutic applications.In this study,the preventive effects of the crude extract of Scutia buxifolia(ceSb)against gastric ulcer induced by 70%ethanol were evaluated in male Wistar rats.In addition,the composition of ceSb was clarified by high-performance liquid chromato-graphy(HPLC).S.buxifolia extract(100,200 and 400 mg/kg body weight)attenuated oxidative and histopathological features induced by ethanol.Moreover,all evaluated doses of ceSb caused significant(P<0.001 and P<0.0001)and dose-dependent increase in sulfhydryl groups(NPSH)levels,catalase(CAT)and superoxide dismutase(SOD)activities.Furthermore,the administration of ceSb reversed the increase in lipid peroxidation produced by ethanol.The protective effect of the extract could be attributed to antioxidant compounds present in the ceSb,such as flavonoids and phenolic acids,which were quantified by HPLC.Thus,an antioxidant effect of the extract leads to a protection on gastric tissue.These results indicate that S.buxifolia could have a beneficial role against ethanol toxicity by preventing oxidative stress and gastric tissue injury.展开更多
文摘Objective:To investigate the phenolic compounds composition and the inhibitory activity of Mangifera indica(M.indica) and Mucuna urens(M.urens) seeds extracts against some key enzymes(-amylase,-glucosidasc and aldose reductase) implicated in the pathology and complications of type 2 diabetes in vitro.Methods:Reverse phase chromatographic quantification of the major flavonoids and phenolic acids in the seeds extracts was carried out using high performance liquid chromatography coupled with diode array detection.The inhibitory activities of the seeds extracts against-amylase and-glucosidase were estimated using soluble starch and p-nitrophenylglucopyranosidc as their respective substrates.Inhibition of aldose reductase activity by the extracts was assayed using partially purified lens homogenate of normal male rat as source of enzyme;inhibition of Fe^(2+)-induced lipid peroxidation by extracts was tested in rat pancreas homogenate.Results:The chromatography result revealed that extracts of both seeds had appreciable levels of some major flavonoids and phenolic acids of pharmacological importance,including gallic acid,chlorogenic acid,caffeic acid,ellagic acid,catechin,rutin,quercitrin.quercetin and kaempferol.Extracts of both seeds effectively inhibited-amylase,-glucosidase and aldose reductase activities in a dose-dependent manner,having inhibitory preference for these enzymes in the order of aldose reductase>-glucosidase>-amylase.With lower half-maximal inhibitory concentrations(IC50)against-amylase,-glucosidase,and aldose reductase,M.indica had stronger inhibitory potency against these enzymes than M.urens.Extracts of both seeds also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern,with M.indica being more potent than M.urens.Conclusions:The results obtained provide support for a possible use of M.indica and M.urens seeds in managing hyperglycemia and preventing the complications associated with it in type 2diabetes.
文摘The phenolics composition and inhibitory activity of Tetrapleura tetraptera fruit extract on xanthine oxidase(XO)and Fe2+-induced lipid peroxidation in the kidney,liver and lungs tissues of rats were evaluated in vitro.Phenolics(flavonoids and phenolic acids)were quantified using reverse-phase high performance liquid chromatrography coupled with diode array detection(HPLC-DAD).The XO and Fe2+-induced lipid peroxidation inhibitory abilities of the extract were evaluated using spectrophotometric methods.The extract contained some flavonoids and phenolic acids,including catechin,epicatechin,rutin,quercetin,luteolin,apigenin;gallic,chlorogenic,caffeic and ellagic acids that are beneficial to health.The extract inhibited XO in the kidney,liver and lungs tissues in a dose-dependent manner.The half-maximal inhibitory concentrations(IC50)of the extract on XO from the tissues varied significantly(P<0.05),and were in the order of liver>kidney>lungs.The extract also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern,having IC50 in the order of liver>lungs>kidney.T.tetraptera fruit extract could be a promising nutraceutical for preventing and managing hyperuricaemia and the associated disease conditions,due to its ability to inhibit XO;this bioactivity is attributable to combined effect of its flavonoids and phenolic acids.
基金Educational Trust Fund,Nigeria with grant number ETF/ES/AST&D/AAU/AKUNGBA/1:2011
文摘Objective:To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit(SAG)and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential(△Ψ_m)isolated from rat liver.Methods:Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl(DPPH),reducing power,iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats.Also,the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined.Identification and quantification of bioactive polyphenolics was done by HPLC-DAD.Results:SAG exhibited potent and concentration dependent free radical-scavenging activity(IC_(50)/DPPH=275.03±7.8μg/mL).Reductive and iron chelation abilities also increase with increase in SAG concentration.SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault.SAG protected against Ca^(2+)(110μmol/L)-induced mitochondrial swelling and maintained the△Ψ_m.HPLC analysis revealed the presence of gallic acid[(17.54±0.04)mg/g],chlorogenic acid(21.90±0.02 mg/g),caffeic acid(16.64±0.01 mg/g).rutin[(14.71±0.03)mg/g]and quercetin[(7.39±0.05)mg/g].Conclusions:These effects could be attributed to the bioactive polyphenolic compounds present in the extract.Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.
文摘The effects of ethylacetate extract of red onion(Allium cepa)tunic(ACTE)on some hemodynamic and biochemical parameters were evaluated in normotensive albino rats.Blood pressure parameters were determined in anaesthetized rats orally administered ACTE(10-,20-,or 40 mg/kg)or ramipril(1 mg/kg)once daily for 14 days.Respectively,10-,20-,or 40 mg/kg ACTE produced significant(P<0.01),dose-dependent fall in systolic blood pressure,SBP(21%,27%,33%),diastolic blood pressure,DBP(6%,10%,16%),pulse pressure,PP(42%,49%,56%),mean arterial blood pressure,MAPB(13%,18%,23%)and heart rate,HR(4%,5%,7%).The highest effective dose(40 mg/kg)compared well with ramipril(1 mg/kg)with regards to SBP(41%),DBP(19%),PP(70%),MABP(29%)and HR(10%).Similar trends(decreases)were recorded for 40 mg/kg ACTE and ramipril,respectively,as regards the activities of serum enzymes:creatine kinase(60%and 65%),ALT(18%and 14%)and ALP(28%and 16%).HPLC fingerprints of the flavonoid-rich ACTE revealed that flavonols:quercetin,quercitrin,isoquercitrin,rutin and kaempferol are the active flavonoids.The results demonstrate the hypotensive effect of A.cepa tunic flavonoids initiating further investigation of their individual or synergistic contribution(s)to the observed effects.
文摘This study sought to investigate the possible mechanisms for the use of phenolic extracts from grapefruit peels in the management/prevention of cardiovascular complications.The effects of the phenolic extracts on key enzymes relevant to cardiovascular diseases[3-hydroxy-methyl-3-glutaryl coenzyme A reductase(HMG-CoA reductase)and angiotensin-I converting enzyme(ACE)],cellular antioxidant activity in human endothelial cells(EA.Hy 926)and radicals[1,1-diphenyl-2 picrylhydrazyl(DPPH)and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS)]scavenging abilities were investigated.The phenolic contents of the extracts were investigated using HPLC–DAD.There was no significant(P>0.05)difference in the HMG-CoA reductase inhibitory ability of the two extracts,while the bound phenolic extracts had a stronger ACE inhibitory ability than the soluble free phenolics.The extracts also showed intracellular antioxidant activity in human endothelial(EA.Hy 926)cells.Furthermore,the bound phenolics had significantly higher radicals(DPPH*and ABTS*)scavenging abilities than the free phenolics.The HPLC analysis revealed the presence of flavonoids(quercetin and kaempferol),phenolics acids(resveratrol,gallic acid,ellagic acid and caffeic acid)and tannin(catechin).The cellular antioxidative properties and inhibition of enzymes relevant to the management of cardiovascular complications showed that grapefruit peels could be used as nutraceuticals for the management of such conditions.
文摘Flaxseed (Linum usitatissimum L.) is composed mainly of bioactive components such as polyphenols, polyunsaturated fatty acids, fiber and lignans. Flaxseed can be found in different presentation forms (grain or flour) and varieties (brown or golden);however, questions have arisen as to whether the presentation form and/or variety may influence the health effects. The objective of this study was to evaluate the effects on blood pressure, anthropometric and oxidative parameters in healthy human volunteers. All subjects received 40 gram aliquots of flaxseed and were instructed to consume them in their entirety mixed with water in the morning for a period of 14 days. Oxidative parameters showed significant reductions (p < 0.05) in oxidative damage to lipids and proteins via dietary intervention with golden flaxseed grains. There were no significant differences in anthropometric parameters, blood pressure, DNA damage and micronuclei frequency after 14-day supplementation. This research indicates that golden flaxseed grains can be a valuable adjunct for disease prevention and protecting the organism against oxidative damage.
文摘Gastric ulcers affect many people around the world and their development is a result of the imbalance between aggressive and protective factors in the gastric mucosa.Scutia buxifolia,commonly known as coronilha,has attracted the interest of the scientific community due to its pharmacological properties and its potential therapeutic applications.In this study,the preventive effects of the crude extract of Scutia buxifolia(ceSb)against gastric ulcer induced by 70%ethanol were evaluated in male Wistar rats.In addition,the composition of ceSb was clarified by high-performance liquid chromato-graphy(HPLC).S.buxifolia extract(100,200 and 400 mg/kg body weight)attenuated oxidative and histopathological features induced by ethanol.Moreover,all evaluated doses of ceSb caused significant(P<0.001 and P<0.0001)and dose-dependent increase in sulfhydryl groups(NPSH)levels,catalase(CAT)and superoxide dismutase(SOD)activities.Furthermore,the administration of ceSb reversed the increase in lipid peroxidation produced by ethanol.The protective effect of the extract could be attributed to antioxidant compounds present in the ceSb,such as flavonoids and phenolic acids,which were quantified by HPLC.Thus,an antioxidant effect of the extract leads to a protection on gastric tissue.These results indicate that S.buxifolia could have a beneficial role against ethanol toxicity by preventing oxidative stress and gastric tissue injury.
