Phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit: a comparative study

ObjectiveTo conduct a comparative analysis of the phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit.MethodsThe dried methanolic extracts of mesocarp and epicarp of the fruit and their hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions were subjected to antioxidant assays including ferric reducing antioxidant potential, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, reducing power capacity, 2,2-diphenyl-1-picrylhydrazyl, lipid peroxidation inhibitory and phosphomolybdate assays. Total phenolic and flavonoid contents were also determined.ResultsEthyl acetate fractions of epicarp and mesocarp had considerable amounts of phenolics (243.50 and 109.50 μg/mL of gallic acid equivalents, respectively). 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of ethyl acetate fractions of both the plant parts showed higher activity than vitamin C with IC₅₀ (0.75 and 3.91 mg, respectively). In phosphormolybdate assay, the hexane fractions of both the parts showed highest activity [1.16 and 2.99 μg/mL of ascorbic acid equivalents (AAE) for epicarp and mesocarp, respectively], mesocarp being much potent than epicarp. The n-butanolic fraction of mesocarp also showed much higher activity (1.13 μg/mL AAE) than that of epicarp (0.74 μg/mL AAE), while the chloroform and ethyl acetate fractions of epicarp were also considerably potent. In ferric reducing antioxidant potential assay, the chloroform fractions of both the fruit parts were most active. The hexane fractions of both the parts showed highest activity in reducing power assay, epicarp being more potent than mesocarp. In 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay, the antioxidant activities of ethyl acetate and chloroform fractions of both the parts were comparable to gallic acid and vitamin C. In lipid peroxidation inhibitory assay, all the samples were moderate to good activity sustainable over the period of 72 h, indicating the presence of both slow and fast releasing antioxidants.ConclusionsThe findings of the study suggest that epicarp is a better source of antioxidants than the mesocarp, and the ethyl acetate fractions of both the parts contain higher contents of antioxidants.     

Bioprospecting medicinal plants for antioxidant components

ObjectiveTo evaluate antioxidant activities of seven medicinal plant species and their fractions, and to identify their phenolic compounds.MethodsTwo extractions were processed and further fractionated by column chromatography to evaluate the concentration that inhibit 50% of 2,2′-azinobis (3-ethylbenzothiazoline-6-suslfonic acid, 1,1-diphenyl-2-picryl-hydrazyl radicals, and their ferric reducing antioxidant power. The identification of the fractions of phenolic compounds was done by ultra performance liquid chromatography.ResultsThe aqueous-acetone extracts of Feretia apodanthera and Ozoroa insignis exhibited the highest antioxidant potentials comparable to those of the standard quercetin. Their subsequently silica gel column fractionation showed three most active fractions from which the major constituents quercetin, myricetin, kampferol, rutin and isoquercetin were identified.ConclusionsThese plant species have potent antioxidant profiles and polyphenol compounds that may help to manage with radical related disease and aging.     

In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam.

ObjectiveTo elucidate the antioxidant activity and total phenolic content (TPC) of ethyl acetate extracts of endophytic fungi isolated from Eugenia jambolana by three different antioxidant assays.MethodsTwenty one different endophytic fungal extracts were screened for presence of various phytochemicals, TPC and in vitro antioxidant activity. TPC was tested by Folin-Ciocalteau reagent based assay. DPPH free radical scavenging, hydrogen peroxide scavenging and reducing power assays were used to evaluate the antioxidant activity.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all 21 endophytes. A significant positive correlation was found between antioxidant activity and TPC in fungal extracts. There is 36% endophytic extracts having high phenolic content exhibited potent antioxidant activity. Chaetomium sp., Aspergillus sp., Aspergillus peyronelii and Aspergillus niger strain showed the highest antioxidant activity ranging from 50% to 80% having 58 mg/g to 60 mg/g GAE total phenolics. Ascorbic acid used as a standard showed 90% reducing potential.ConclusionsThe results reveal that metabolites produced by endophytic fungi isolated from Eugenia jambolana can be a potential source of novel natural antioxidant compounds.     

Assessment of the antioxidant potential of Pergularia daemia (Forsk.) extract in vitro and in vivo experiments on hamster buccal pouch carcinogenesis

ObjectiveThe aim of the present study was to investigate the in vitro antioxidant assays and in vivo non enzymatic antioxidant potential of aerial parts of Pergularia daemia methanolic extract (PDME) on 7, 12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis.MethodsThe plant extract was tested for their total phenol and flavonoid content and radical scavenging effect such as 2, 2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^?₊) radical decolorization assay, DPPH (2, 2-diphenyl, 2-picryl hydrazyl) radical scavenging, nitric oxide radical scavenging, reducing power assays.ResultsAccording to IC₅₀values obtained, PDME contains more powerful antioxidant compounds than gallic acid. The level of plasma vitamin C and the levels of Vitamin E and GSH in the plasma and erythrocyte lysate were decreased while the buccal tissue levels of vitamin E and GSH were increased in DMBA induced animals. Pretreatment with P.daemia (200 mg/kg bw) to DMBA induced animals significantly (P < 0.05) increased the levels of plasma and erythrocyte vitamin C, vitamin E and GSH where as the levels of vitamin E and GSH in the buccal tissue were increased compared to DMBA alone induced animals.ConclusionsThe PDME exhibited strong antioxidant activity in free radical scavenging assays and hamster buccal pouch carcinogenesis.     

In vitro screening for acetylcholinesterase inhibition and antioxidant activity of medicinal plants from southern Africa

ObjectiveTo determine the acetylcholinesterase inhibitory (AChEI) and antioxidant activity of the ethyl acetate and methanol extracts of 12 traditional medicinal plants used in the treatment of neurological disorders.MethodsAChEI activity was determined spectrophotometrically using the Ellman's colorimetric method. Antioxidant activity was carried out by determining the ability of the extracts to scavenge 2,2-diphenyl-1-picryl hydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. The levels of total phenols, flavonoids and flavonols were determined quantitatively using spectrophotometric methods.ResultsAChEI was observed to be dose-dependent. Lannea schweinfurthii (L. schweinfurthii) (Engl.) Engl. and Scadoxus puniceus (S. puniceus) (L.) Friis &; I. Nordal. root extracts showed the lowest IC₅₀ value of 0.000 3 mg/mL for the ethyl acetate extracts while Zanthoxylum davyi (Z. davyi) (I. Verd.) P.G. Watermann had the lowest IC₅₀ value of 0.01 mg/mL for the methanol extracts in the AChEI assay. The roots of Piper capense (P. capense) L.f., L. schweinfurthii, Ziziphus mucronata (Z. mucronata) Willd., Z. davyi and Crinum bulbispermum (C. bulbispermum) (Burm.f.) Milne-Redh. &; Schweick. showed noteworthy radical scavenging activity and good AChEI activity.ConclusionsFive plants show good antioxidant and AChEI activity. These findings support the traditional use of the plants for treating neurological disorders especially where a cholinesterase mechanism and reactive oxygen species (ROS) are involved.     

Phytopharmacological approach of free radical scavenging and anti-oxidative potential of eugenol and Ocimum gratissimum Linn.

ObjectiveTo evaluate phytopharmacologically eugenol and two extract products of Ocimum gratissimum Linn. (O. gratissimum) (Labiaceae) on free radical scavenging and antioxidant activity.MethodsAqueous and methanol extract of fresh aerial part of O. gratissimum were prepared and eugenol (1-allyl-4-hydroxy-3-methoxybenzene) was isolated from fresh leaves and characterized by high performance liquid chromatography, fourier transform infrared spectroscopy, 1 h nuclear magnetic resonance. To establish the antioxidant potentiality of aqueous extract, methanol extract and eugenol, 1, 1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, nitric oxide scavenging activity, antioxidant activity by ferric thiocyanate and reducing power were measured in chemical system in vitro.ResultsSignificant (P<0.05) concentration-dependent free radical scavenging activity, antioxidant activity, and reducing power was observed by O. gratissimum products. Moreover, eugenol is more potent than the two extract products of O. gratissimum, but lower than potent antioxidant ascorbic acid.ConclusionsHence, O. gratissimum presents a potentially valuable source of natural antioxidant and bioactive material.     

In vitro evaluation of free radical scavenging activity of Codariocalyx motorius root extract

ObjectiveTo determine the phenolic content in Codariocalyx motorius root extract and to evaluate its antioxidant properties using various in vitro assay systems.MethodsThe antioxidant activity was evaluated based on scavenging of 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radicals, superoxide anions, nitric oxide, hydrogen peroxide, peroxynitrite, reducing power and by inhibition of lipid peroxidation which was estimated in terms of thiobarbituric acid reactive substances.ResultsThe root extract of the Codariocalyx motorius (C. motorius) exhibited potent total antioxidant activity that increased with increasing amount of extract concentration, which was compared with standard drug such as quercetin, butylated hydroxytoluene, tocopherol at different concentrations. The different concentrations of the extracts showed inhibition on lipid peroxidation. In addition, the extracts had effective reducing power, free radical scavenging, super oxide anion scavenging, nitric oxide scavenging, lipid peroxidation, and total phenolic content depending on concentration. High correlation between total phenolic contents and scavenging potential of different reactive oxygen species (r²=0.831–0.978) indicated the polyphenols as the main antioxidants.ConclusionsCodariocalyx motorius (C. motorius) root possess the highly active antioxidant substance which can be used for the treatment of oxidative stress-related diseases.     

Pharmacological properties and related constituents of stem bark of Pterocarpus erinaceus Poir. (Fabaceae)

ObjectiveTo screen methanol and dichloromethane extracts of stem bark of Pterocarpus erinaceus for anti-inflammatory, analgesic, in vitro antioxidant activities and phytochemical analysis.MethodsAnti-inflammatory activity was determined by using carrageenan induced-edema of mice paw and croton oil-induced edema of mice ear; analgesic effect was evaluated using acetic acid-induced writhing. Phytochemical screening of extracts was performed by thin layer chromatography. The chromatographic fractionation led to the isolation of main active components as friedelin, lupeol and epicathechin. The structures were established by TLC and nuclear magnetic resonance studies.ResultsBoth methanol and dichloromethane extracts, friedelin, lupeol and epicatechin showed a significant anti-inflammatory effect using croton oil induced-ear edema. Furthermore, the action of dichloromethane extract was more important. At the doses of 100 and 200 mg/kg, the methanol extract was able to reduce the carrageenan induced-hind paw edema, while at the doses of 100, 200 and 400 mg/kg, it showed an important analgesic effect against writhing induced by acetic acid injection of 38.8%, 68.0% and 74.3%, respectively. Antioxidative properties of methanol extract and its dichloromethane and ethyl acetate fractions were assessed by using the 1,1-diphenyl-2-picrylhydrazyl method. The methanol extract showed the stronger radical scavenging activity than dichloromethane and ethyl acetate fractions, with an antiradical power of 5, 3.5 and 2 respectively. The main components isolated from these extracts as friedelin, lupeol and epicathechin were responsible of these activities.ConclusionsThe results suggest that the stem bark extracts of Pterocarpus erinaceus possessed important anti-inflammatory, analgesic activities and strong antioxidant properties, therefore, they could be used as natural potential ingredients for pharma ceutical industry.     

Anticancer and antioxidant activities of methanol extracts and fractions of some Cameroonian medicinal plants

ObjectiveTo obtain a scientific basis of the use of plant-derived preparations by many rural people in Cameroon, for their primary health care needs in the treatment of diseases such as cancer.MethodsThe antiproliferative effect of 11 plants methanol crude extracts on four cancer cells using sulforhodamine-B assay and their antioxidant activities using 1-diphenyl-2-picrylhydrazyl radical and nitric oxide radical scavenging ability were investigated. The Ekebergia senegalensis (E. senegalensis) and Protea elliotii (P. elliotii) extracts were selected based on their antioxidant and anticancer activities, and partition in hexane, dichloromethane, ethyl acetate, butanol and methanol was done. Each fraction was submitted to antioxidant and anticancer activities, and the effect of the dichloromethane fraction (the most antiproliferative fraction) on NCI-H460 cell cycle was determined by flow cytometry.ResultsThe most antiproliferative substances were found for the extracts from E. senegalensis, P. elliotii, Terminalia macroptera and Vitellaria paradoxa. Whereas the most antioxidant substances were found for the extracts from Cissus populnea, E. senegalensis, P. elliotii, Terminalia macroptera, Vitellaria paradoxa, and Gardenia aqualla. Dichloromethane fraction of P. elliotii was found to be highly antiproliferative to NCI-H460 cancer cells and showed S phase arrest cell cycle progression. Ethyl acetate n-butanol and methanol fractions showed quite strong antioxidant activity for both E. senegalensis and P. elliotii, as compared to that of gallic acid.ConclusionsOverall, the antiproliferative and antioxidant activities of some of the extracts lend some support to their use in the traditional medicine of Adamawa Region, Cameroon to treat cancer.     

In vitro bioactivity and phytochemical screening of Suaeda maritima (Dumort): a mangrove associate from Bhitarkanika, India

ObjectiveTo investigate the in vitro antioxidant and antimicrobial activities along with phytochemical screening of organic and aqueous extracts of leaf and stem of Suaeda maritima (Dumort), a mangrove associate from Bhitarkanika of Odisha, India.MethodsAntioxidant activity of the crude extracts was evaluated in terms of total antioxidant capacity, total phenol content, ascorbic acid content, DPPH radical scavenging, metal chelating, nitric oxide scavenging, and reducing power etc. The antimicrobial activity of the plant was determined by agar well diffusion method along with MIC and MBC carried out by microdilution techniques against 10 gram positive and gram negative human pathogenic bacteria. The qualitative and quantative phytochemical screening were carried out by standard biochemical assays.ResultsOut of the seven antioxidant bioassays, both the leaf and stem extracts were found to posses strong antioxidant properties of 70 % to 92 % for phenol, total antioxidant capacity, DPPH free radical scavenging activity and fairly good ascorbic acid content, metal chelating (1.33 %-22.55 %), reducing power (0.01-0.12) and nitric oxide scavenging (0.84 %-66.99 %) activities. Out of the four extracts evaluated for antimicrobial activity, two leaf extracts such as acetone and ethanol showed promising activity against four pathogenic bacteria and one stem methanol extracts against one pathogenic bacteria when compared with amoxcycillin as standard. The MIC and MBC values of the antimicrobial extracts ranged between 2.5 to 5.0 mg/mL. Screening of phytochemicals showed presence of carbohydrates, protein, tannins, alkaloids and flavonoids in comparatively higher amount than other phytochemicals tested.ConclusionsThe present study reveals the presence of potential antioxidants and antimicrobial properties in the plant extract which could be exploited for pharmaceutical application.     

Antioxidant and anti–glycation activities correlates with phenolic composition of tropical medicinal herbs

ObjectiveTo determine the contribution of total phenolic content (TPC) in glycation inhibitory activity of common tropical medicinal food and spices with potential antioxidative properties.MethodsIn vitro glucose-bovine serum albumin (BSA) assay was used. Ethanolic extracts of ten common household condiments/herbs (Allium sativum, Zingiber officinale, Thymus vulgaris, Petroselinum crispum, Murraya koenigii Spreng, Mentha piperita L., Curcuma longa L., Allium cepa L., Allium fistulosum and Coriandrum sativum L.) were evaluated for antioxidative activity by 2,2-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) and the TPC, flavonoid and tannins content were determined.ResultsFindings showed good correlation between TPC/DPPH (r = 0.8), TPC/FRAP (r = 0.8), TPC/anti–glycation (r = 0.9), DPPH/anti–glycation (r = 0.6), FRAP/anti–glycation (r = 0.9), Flavonoid/anti–glycation (r = 0.7) and Tannins/anti–glycation (r = 0.8) and relatively fair correlation for TPC/Flavonoids (r = 0.5) and TPC/Tannins (r = 0.5). Results imply that these plants are potential sources of natural antioxidants which have free radical scavenging activity and might be used for reducing oxidative stress.ConclusionsThe positive glycation inhibitory and antioxidative activities of these tropical herbs suggest a possible role in targeting ageing, diabetic complications and oxidative stress related diseases.     

Antioxidant capacity and total phenolic contents in hydrophilic extracts of selected Bangladeshi medicinal plants

ObjectiveTo evaluate hydrophilic extracts from edible portions of fifteen plants for total phenolic content (TPC) and anti-oxidant capacity (AC) as an effort to find possible sources for future novel antioxidants.MethodsFolin-Ciocalteau and DPPH radical scavenging assays were employed to determine TPC and AC, respectively.ResultsAmong the assayed plants, TPC (mean±SD), expressed as gallic acid equivalent, varied from 0.04±0.01 (Amaranthus spinosus) to 6.01±0.04 (Zanthoxylum rhetsa) mg gallic acid equivalent/g fresh weight. AC (mean±SD), expressed as trolox equivalent, ranged from 0.14±0.00 (Alternanthera philoxeroides) to 7.54±0.00 (Zanthoxylum rhetsa) μmol trolox equivalent/g fresh weight. A significant and positive linear relationship (R²=0.99) was observed between TPC and AC of Zanthoxylum rhetsa, Oxalis corymbosa, and Alternanthera sessilis.ConclusionsThe results of the present study implies that the analyzed plants possess varying degree of antioxidant capacity and, therefore, the antioxidant potency of these underused plants may be utilized to prevent oxidative damage and oxidative stress related disorders.     

Evaluation of in vitro antioxidant and apoptotic activities of Cyperus rotundus

Objective:To evaluate in vitro antioxidant and apoptotic activities of Crperus rotundas(C.rotundus).Methods:The phytochemical study and the antioxidant activities of both methanol and aqueous extracts from C.rotundus aerial part were determined.In addition,these extracts were also investigated for their cytotoxic and apoptotic activities.The major compound of the methanol extract was isolated.Both metlianol and aqueous extracts(300,150,and 50μg/mL)were evaluated for their antioxidant activity by the xanthine/xanthine oxidase assay system.However,16,8,and 4 mg/mL of each extract were tested to investigate their OH.formation scavenging potential.Aqueous extract(800,400.and 200μg/mL)and melhunol extract(350,175,and 88μg/mL)were tested against lipid peroxidation,induced by 75μM H_2O_2,The cytotoxicity(by MTT assay)and cell DNA fragmentation of both extracts were evaluated Inwards K562 and L1210 cell lines.The major compound was obtained from the butanol fraction of methanol extract and its structure was determined by KMN spectroscopic analysis.Results:The methanol and aqueous extracts showed respectively,88%and 19%inhibition of xanthine oxidase activity.Vet.the same extracts inhibited lipid peroxidation by 61.5%and 42.0%.respectively.Roth extracts inhibited OH.formation by 27.1%and 25.3%,respectively.Only methanol cxtract induced DNA degradation.Orientin was determined as the major compound isolated from the butanol fraction of metlianol extract.Conclusions:It appears that C.rotundus extracts exhibit a potential use as a natural antioxidant and an apoptosis inducer.     

Evaluation of phytochemical constituents and antioxidant activities of successive solvent extracts of leaves of Indigofera caerulea Roxb using various in vitro antioxidant assay systems

ObjectiveTo evaluate the phytochemical constituents and antioxidant activities of successive solvent extracts of Indigofera caerulea Roxb using various in vitro antioxidant assay systems.MethodsTotal phenol and antioxidant activity of different solvent extracts of Indigofera caerulea Roxb leaves were investigated. Extraction was done sequentially in soxhlet apparatus using various solvents (Petroleum ether, Ethyl acetate and Methanol). Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl free radical scavenging assay, hydroxyl radical scavenging assay, superoxide anion radical scavenging assay and Total ion reducing power assay. Total phenol and flavonoid contents were also measured.ResultsMethanolic extract had more total phenol content and more antioxidant activities, confirming to the hypothesis that phenol content and antioxidant activity has a direct correlation.ConclusionsAll the results of the in vitro antioxidant assays revealed that the methanolic extract of Indigofera caerulea Roxb leaves had notable antioxidant and free radical scavenging activity. The results obtained appeared to confirm the antioxidant and free radical scavenging potential of Indigofera caerulea Roxb.     

Free radical scavenging property and antiproliferative activity of Rhodiola imbricata Edgew extracts in HT-29 human colon cancer cells

ObjectiveTo investigate the in vitro antioxidant and antiproliferative activity of rhizome extracts of Rhodiola imbricata (R. imbricata) in HT-29 human colon cancer cell line.MethodsThe successively extracted rhizome of R. imbricata using various solvents was analyzed for their total phenolics, tannins and flavonoid contents. In vitro antioxidant activity was evaluated by employing different assays, including DPPH, ABTS radical scavenging assays, FRAP, phosphomolybdenum reduction assay, superoxide anion, hydroxyl radical scavenging activities and metal chelating ability.ResultsAcetone and methanol extracts recorded higher phenolic content and showed comparable antioxidant activity with standard reference. Additionally, they also inhibited the proliferation of HT-29 cells upon treatment at higher concentration (200 μg/mL) (acetone and methanol, 84% and 84%, respectively). On examination acetone extract exhibited antiproliferative activity in a concentration dependent manner whereas, methanol extract showed both dose dependent and time dependent inhibitory activity.ConclusionsThe results obtained justify the traditional usage of R. imbricata from their promising antioxidant activity.     

Phytochemical analysis, hepatoprotective and antioxidant activity of Alchornea cordifolia methanol leaf extract on carbon tetrachloride-induced hepatic damage in rats

ObjectiveTo investigate the hepatoprotective and antioxidant activities of Alchornea cordifolia (A. cordifolia) leaf extract.MethodsVarious solvent fractions of the methanol extract of the leaf of the plant A. cordifolia Mull. Arg (Fam: Euphorbiaceae) were evaluated for hepatoprotective activity by carbon tetrachloride-induced liver damage in rats. The degree of protection was measured by using biochemical parameters such as serum glutamate oxalate transaminase (SGOT/AST), serum glutamate pyruvate transaminase (SGPT/ALT), alkaline phosphatase (ALP) and total bilirubin. The in vitro antioxidant activity of the extract was also evaluated by the 1, 1-diphenyl- 2-picrylhydrazyl (DPPH) free radical scavenging assay. The extract was subjected to preliminary phytochemical screening.ResultsThe ethyl acetate and chloroform fractions, at a dose of 300 mg/kg, produced significant (P<0.05) hepatoprotection by decreasing the activities of the serum enzymes and bilirubin while there were marked scavenging of the DPPH free radicals by the fractions. The effects were comparable to those of the standard drugs used for the respective experiments, silymarin and ascorbic acid. Alkaloids, flavonoids, saponins and tannins were detected in the phytochemical screening.ConclusionFrom this study, it was concluded that the plant of A. cordifolia possesses hepatoprotective as well as antioxidant activities and these activities reside mainly in the ethyl acetate and acetone fractions of methanol leaf extract.     

Estimation of total phenolic content,cytotoxicity and in–vitro antioxidant activity of stem bark of Moringa oleifera

ObjectiveTo assess the phytochemical constituents, total phenolic content, cytotoxicity and in-vitro antioxidant activity of stem bark extracts of Moringa oleifera (M. oleifera) (Moringaceae).MethodsBrine shrimp lethality (BSL) bioassay was used to investigate the cytotoxic effects. DPPH and nitric oxide radical scavenging activity was used to demonstrate antioxidant activity.ResultsPhytochemical analysis revealed the presence of tannins, flavonoids, steroids and alkaloids. The LC₅₀ values were obtained for extracts as 850 μg/mL for petroleum ether extract, 800 μg/mL for chloroform extract and 900 μg/mL for methanol extract. The total phenolic content of the methanolic extract was 50.72% w/w, equivalent to gallic acid. Petroleum ether, chloroform and methanolic extracts of M. oleifera and standard ascorbic acid were found to be scavenger of DPPH radical with an IC₅₀ of 124.75, 112.08, 54.34 and 13.86 μg/mL, respectively. Methanolic extract was found to be good scavenger of DPPH radical. Petroleum ether, chloroform, ethyl acetate soluble fraction of methanolic extracts of M. oleifera and ascorbic acid were found to be scavenger of nitric oxide radical with an IC₅₀ of 93.32, 65.12, 54.83 and 12.59 μg/mL, respectively. Ethyl acetate soluble fraction was found to be good scavenger of nitric oxide radical.ConclusionsIt can be concluded that the crude extracts of M. oleifera is a potential source of natural antioxidants, and this justifies its uses in folkloric medicines.     

In vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

ObjectiveTo detect the in vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.MethodsThe dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane, ethyl acetate, chloroform, butanol and aqueous methanol. The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane, ethyl acetate, chloroform, butanol and aqueous ethanol were determined by Folin - Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity using α, α-diphenyl- β-picrylhydrazyl (DPPH) method.ResultsThe total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract (386.22 mg/g) followed by ethyl acetate (190.89 mg/g), chloroform (175.89 mg/g), hexane (173.44 mg/g), and butanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil. The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract > ethyl acetate extract >chloroform> butanol > hexane extract also the antioxidant activity was not detected in essential oil.ConclusionsThe findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract. Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.     

Effects of Different Chenopodium formosanum Parts on Antioxidant Capacity and Optimal Extraction Analysis by Taguchi Method

Chenopodium formosanum (CF), rich in nutrients and antioxidants, is a native plant in Taiwan. During the harvest, the seeds are collected, while the roots, stems, and leaves remain on the field as agricultural waste. In this study, di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) radical scavenging ability and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability experiments of seeds, leaves, stems, and roots were designed using the Taguchi method (TM) under three conditions: Ethanol concentration (0–100%), temperature (25–65 °C), and extraction time (30–150 min). The result demonstrates that seeds and leaves have higher radical scavenging ability than stems and roots. Many studies focused on CF seeds. Therefore, this study selected CF leaves and optimized DPPH, ABTS, total phenol content (TPC), total flavonoid content (TFC), and reducing power (RP) through TM, showing that the predicted value of the leaf is close to the actual value. The optimized results of CF leaves were DPPH 85.22%, ABTS 46.51%, TPC 116.54 µg GAE/mL, TFC 143.46 µg QE/mL, and RP 23.29 µg VCE (vitamin C equivalent)/mL. The DPPH and ABTS of CF leaves were second only to the results of CF seeds. It can be seen that CF leaves have the potential as a source of antioxidants and help in waste reduction.     

Anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica

ObjectiveTo evaluate the anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.MethodsIn vitro DPPH radical scavenging activity and lipoxygenase (LOX) inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively. Methanolic extract (MEMI), successive water extract (SWMI) and ethyl acetate fraction (EMEMI), n-butanol fraction (BMEMI) and water soluble fraction (WMEMI) of methanolic extract were evaluated along with respective reference standards.ResultsIn in vitro DPPH radical scavenging activity, the MEMI, EMEMI and BMEMI have offered significant antioxidant activity with IC₅₀ values of 13.37, 3.55 and 14.19 μg/mL respectively. Gallic acid, a reference standard showed significant antioxidant activity with IC₅₀ value of 1.88 and found to be more potent compared to all the extracts and fractions. In in vitro LOX inhibition assay, the MEMI, EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC₅₀ values of 96.71, 63.21 and 107.44 μg/mL respectively. While, reference drug Indomethacin also offered significant inhibition against LOX enzyme activity with IC₅₀ of 57.75. Furthermore, MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.ConclusionsThese findings suggest that the MEMI and EMEMI possess potent anti-oxidant and anti-inflammatory activities in in vitro conditions.