Dereplication coupled with in vitro antioxidant assay of two flavonoid glycosides from Diospyros peregrina fruit

Diospyros peregrina is an edible seasonal fruit found in coastal West Bengal, India. The fruits have been reported to possess a significant antioxidant activity. In this study, the aim was to isolate the lead compound responsible for the above-mentioned activity. The aqueous extract of D. peregrina fruit was subjected to dereplication coupled with an in?vitro 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. The n-butanol fraction of the aqueous extract of D. peregrina fruit exhibited significant antioxidant activity (IC(50), 131.10?μg?mL(-1)) as compared with the parent extract (IC(50), 285.15?μg?mL(-1)). The n-butanol fraction was subjected to silica gel column chromatographic separation coupled with a chemo-autographic study of column eluents, employing ethanolic DPPH as a spraying reagent. Two bioactive flavonoid glycosides, namely luteoline-4'-methyl-ether-7-O-glucoside and quercetin-3-O-(glucosyl)-glucoside, were identified to exhibit IC(50) values of 74.04 and 65.78?μg?mL(-1), respectively in the DPPH assay.     

Cytotoxic compounds from the leaves of Gaillardia aristata Pursh. growing in Egypt

Ten compounds, neopulchellin (1), 6α- hydroxyneopulchellin (2), β-sitosterol-3-O-β-D-glucoside (3), apigenin (4), quercitin (5), eupafolin (6), kaempferol-3-methoxy-7-O-α-L-rhamnoside (7), apigenin-7-O-β-D-glucopyranoside (8), α-amyrin (9) and β-sitosterol (10), were isolated from the leaves of Gaillardia aristata by applying bioassay guided fractionation. The cytotoxicity was traced against two human cancer cell lines (breast (MCF7) and colon (HCT116)). The highest cytotoxicity was revealed by compounds 1 and 2 (isolated from chloroform extract); with IC(50) values of 0.43, 0.32?μg?mL(-1) against MCF7 and 0.46, 0.34?μg?mL(-1) against HCT116, respectively. Compounds 9 and 10 (isolated from the n-hexane extract) exhibited lower IC(50) values of 3.05, 2.35?μg?mL(-1) against MCF7 and 3.05, 2.35?μg?mL(-1) against HCT116, respectively, while compounds 4-7 obtained from the ethyl acetate extract revealed the lowest cytotoxicity. Identification of the aforementioned compounds was carried out on the basis of their physico-chemical properties and spectral analysis (UV, EI/MS, 1D and 2D).     

Phytochemical analysis, cytotoxic activity and constituents-activity relationships of the leaves of Cinnamomum iners (Reinw. ex Blume-Lauraceae)

The leaves of Cinnamomum iners (Reinw. ex Blume-Lauraceae) have been refluxed successively with chloroform and alcohol to get chloroform extract and alcoholic extract. Both the extracts have been assayed for cytotoxicity against human colorectal tumour cells. The chloroform extract exhibited significant cytotoxicity with IC(50) 31?μg mL(-1) (p??200?μg mL(-1). The chloroform extract has been further proceeded for chemical analysis by GC-TOFMS and 178 components were identified including acids, amines, amides, aldehydes, alcohols, esters, benzene derivatives, bicyclic compounds, terpenes, hydrocarbons, naphthalene derivatives, furan derivatives, azulenes, etc. Nine components representing 51.73% of the total chloroform extract were detected as major components. Caryophyllene (14.41%) and Eicosanoic acid ethyl ester (12.17%) are the most prominent components of the chloroform extract. β-Caryophyllene (14.41%) as most abundant compound supports potent cytotoxicity as shown by chloroform extract.     

Studies on the potential antioxidant properties of Senecio stabianus Lacaita (Asteraceae) and its inhibitory activity against carbohydrate-hydrolysing enzymes

This study showed for the first time the antioxidant and hypoglycaemic properties of the methanol, n-hexane and ethyl acetate extracts from Senecio stabianus Lacaita, a plant that belongs to the Asteraceae family. The antioxidant activities were carried out using two different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate) (ABTS) test. The ethyl acetate extract showed the highest activity with inhibitory concentration 50% (IC(50)) values of 35.5 and 32.7?μg?mL(-1) on DPPH test and ABTS test, respectively. This activity may be related to a good total phenol and flavonoid content. All extracts were also tested for their potential inhibitory activity of α-amylase and α-glucosidase digestive enzymes. The n-hexane extract exhibited the highest α-amylase inhibition with an IC(50) value of 0.21?mg?mL(-1). Through bioassay-guided fractionation processes seven fractions (A-G) were obtained and tested. Based on the phytochemical analysis, the activity of n-hexane extract may be related to the presence of monoterpenes and sesquiterpenes.     

Antioxidant and structure-activity relationships of five tetraoxygenated xanthones from Swertia minor (Griscb.) Knobl

Antioxidant activity-guided fractionations of chloroform extract of Swertia minor yielded five known tetraoxygenated xanthones (1-5), of which compound 3 was isolated for the first time from plant sources. Compounds 1-5 were identified with the aid of extensive NMR spectroscopic studies. A relationship between the structural features of 1-5 and their antioxidant activity was also determined. Among these bioactive isolates (1-5), compound 4 exhibited strong scavenging effect in DPPH (IC(50)?=?10.31?μg?mL(-1)), FRAP (8536.32?±?34.1?Mmol Fe (II)?g(-1)) and metal chelating (17.2?±?0.88?mg?EDTA?g(-1)) assays. Compound 5 was potently active in secondary antioxidant assay (i.e. binding to metal ions strongly); however, its primary antioxidant capacity was found to be feeble.     

Ethanolic extract of Rubia peregrina L. (Rubiaceae) inhibits haloperidol-induced catalepsy and reserpine-induced orofacial dyskinesia

In the traditional Sardinian system of medicine, Rubia peregrina L. (Rubiaceae) is reported as an aphrodisiac herb. Since the aphrodisiacs may also have antioxidant and dopaminergic activities, the aim of this study was to study the effect of ethanolic extract of aerial parts of R. peregrina for the scavenging of free DPPH radicals and the inhibition of haloperidol-induced catalepsy in mice and reserpine-induced orofacial dyskinesia in rats. The extract exhibited significant antioxidant activity in a free radical DPPH assay with IC(50)?=?55.6?μg?mL(-1), which was very close to IC(50) of ascorbic acid. The extract of R. peregrina (100 and 200?mg?kg(-1) intraperitoneally, i.p.) significantly inhibited haloperidol (1?mg?kg(-1) i.p.) - induced catalepsy in mice (p?相似文献   

A new lignan from Oxytropis myriophylla

The 70% alcohol extract of Oxytropis myriophylla (PALL.) DC. (Leguminosae) exhibited high radical scavenging activity (IC(50) value: 88.0?μg?mL(-1) and 86.7?μg?mL(-1)) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Further chemical investigation led the isolation of one new lignan, namely myriophylloside G (1), together with three known compounds. Their structural elucidations of all the compounds were based on extensive spectroscopic methods, including HRESIMS and 2D NMR experiments (HSQC, HMBC and (1)H-(1)HCOSY) and by comparison with reference values.     

Citrus sinensis leaf aqueous extract green-synthesized silver nanoparticles: Characterization and cytotoxicity,antioxidant, and anti-human lung carcinoma effects

The present work demonstrates the synthesis of Ag nanoparticles (Ag NPs) by using aqueous extract of Citrus sinensis as green reductant and capping agent without any toxic reagent. Physicochemical characteristics of the said nanoparticles were elucidated by field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV-Vids) techniques. The biogenic Ag NPs are uniformly globular. The Ag NPs has been explored biologically in the anticancer and antioxidant assays. In the cellular and molecular part of the recent study, the treated cells with Ag NPs were assessed by MTT assay for 48 h about the cytotoxicity and anti-human lung carcinoma properties on normal (HUVEC) and lung carcinoma cell lines i.e. NCI-H661, HLC-1, NCI-H1563, LC-2/ad, NCI-H1299, and PC-14. The viability of malignant lung cell line reduced dose-dependently in the presence of Ag NPs. The IC50 of Ag NPs were 82, 139, 170, 66, 62, and 50 µg/mL against NCI-H661, HLC-1, NCI-H1563, LC-2/ad, NCI-H1299, and PC-14 cell lines, respectively. In the antioxidant test, the IC50 of Ag NPs and vitamin E against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals were 21 and 15 µg/mL, respectively. After clinical study, Ag NPs containing Citrus sinensis leaf aqueous extract may be used to formulate a new chemotherapeutic drug or supplement to treat the several types of human lung adenocarcinoma.     

Composition of essential oil and antioxidant capacity of Centaurea drabifolia Sm. subsp. detonsa (Bornm.) Wagenitz, endemic to Turkey

In this study, composition of essential oil and antioxidant capacity of Centaurea drabifolia subsp. detonsa were investigated. The antioxidant capacity of the methanolic extract was evaluated by various methods including measuring the total phenolic content, total antioxidant capacity, free radical scavenging activity (DPPH assay), β-carotene/linoleic acid bleaching assay and ferric and cupric ion reducing power assay. The composition of essential oil was identified by using gas chromatography-mass spectrometry. Totally, 41 compounds were described in the essential oil. Germacrene D (44.829%) was determined as the major compound of the essential oil. The total phenolic content, total antioxidant capacity, inhibition rate of oxidation of linoleic acid, IC(50) (in DPPH assay) and EC(50) (in reducing power) value were found to be 40.454?mg?GAE/g, 100.840?mg?AAE/g, 65.639%, 39.584?μg?mL(-1) and 0.603?mg?mL(-1), respectively. The results indicated that the extract of C. drabifolia subsp. detonsa has strong antioxidant properties and this species can be used as a natural antioxidant in food processing and pharmaceutical industries.     

Chemical composition and antioxidant activity of the essential oil and various extracts of Haplophyllum robustum Bge

This study was designed to examine the chemical composition and in vitro antioxidant activity of the essential oil and various extracts of Haplophyllum robustum. GC-MS analysis of the oil resulted in the identification of 30 compounds, representing 99.2% of the oil; 1,8-cineole (38.1%), myrcene (10.7%), α-pinene (8.5%), 4-terpineol (7.0%) and sabinene (6.1%) were the main components. The antioxidant potential of the oil and extracts was evaluated using three separate methods: inhibition of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene-linoleic acid assay and reducing power systems. The essential oil of the plant was able to reduce the stable free radical DPPH with an IC(50) of 72.0?±?1.2?μg?mL(-1) (the IC(50) for ascorbic acid was determined as 5.8?±?0.4?μg?mL(-1)). The essential oil also showed strong reducing power. The level of total phenolics was highest in the essential oil (179.5?±?2.1?μg?mg(-1)).     

Anti-HIV-1 and cytotoxicity of the alkaloids of Erythrina abyssinica Lam. growing in Sudan

Erythrina abyssinica Lam. is an important medicinal plant growing in Sudan; its seeds were investigated for the first time for their alkaloidal constituents and biological activity. The in vitro cytotoxicity of the crude alkaloidal fraction (CAF) against the cell lines HeLa, Hep-G2, HEP-2, HCT116, MCF-7 and HFB4 showed promising activity, with IC?? values of 13.8, 10.1, 8.16, 13.9, 11.4 and 12.2?μg?mL?1, respectively. Doxorubicin (positive control) showed in vitro cytotoxic activity with IC?? values 3.64, 4.57, 4.89, 3.74, 2.97 and 3.96?μg?mL?1, respectively. Bioassay-guided fractionation and isolation of the CAF led to the isolation of five Erythrina alkaloids, identified as erythraline, erysodine, erysotrine, 8-oxoerythraline and 11-methoxyerysodine. These were evaluated for their in vitro cytotoxic activity against Hep-G2 which resulted in IC?? values 17.60, 11.80, 15.80, 3.89 and 11.40?μg?mL?1, respectively. Furthermore, in vitro cytotoxic activity against HEP-2 was evaluated, which resulted in IC?? values 15.90, 19.90, 21.60, 18.50 and 11.50?μg?mL?1, respectively. The CAF caused a reduction in the viability of mock-infected MT-4 cells with a CC?? of 53?μM and a 50% protection of MT-4 cells against HIV-1 induced cytopathogeneticy with a EC?? of >53?μM, compared with EFV as a positive control, which had a CC?? of 45?μM and an EC?? of 0.003?μM. We concluded that the isolated alkaloids were responsible for the carcinogenic actions of the plant extract previously reported in the literature.     

Chemical composition of the essential oil from basil (Ocimum basilicum Linn.) and its in vitro cytotoxicity against HeLa and HEp-2 human cancer cell lines and NIH 3T3 mouse embryonic fibroblasts

This study examines the chemical composition and in?vitro anticancer activity of the essential oil from Ocimum basilicum Linn. (Lamiaceae), cultivated in the Western Ghats of South India. The chemical compositions of basil fresh leaves were identified by GC-MS: 11 components were identified. The major constituents were found to be methyl cinnamate (70.1%), linalool (17.5%), β-elemene (2.6%) and camphor (1.52%). The results revealed that this plant may belong to the methyl cinnamate and linalool chemotype. A methyl thiazol tetrazolium assay was used for in?vitro cytotoxicity screening against the human cervical cancer cell line (HeLa), human laryngeal epithelial carcinoma cell line (HEp-2) and NIH 3T3 mouse embryonic fibroblasts. The IC(50) values obtained were 90.5 and 96.3?μg?mL(-1), respectively, and the results revealed that basil oil has potent cytotoxicity.     

Bioguided isolation of pentacyclic triterpenes from the leaves of Alstonia scholaris (Linn.) R. Br. growing in Egypt

Ethanolic and aqueous extracts of the leaves and flowers of Alstonia scholaris were evaluated for their antioxidant activity by investigating their effect on blood glutathione levels in alloxan-induced diabetic rats. The ethanolic extract of the leaves was the most active; therefore, its cytotoxicity against HepG2 cells was also tested. Promising GI?? values of 1.96, 4.34 and 4.65?μg?mL?1 were observed for the extract, its chloroform and ethyl acetate fractions, respectively. The chloroform active subfraction I (GI???=?2.97?μg?mL?1) yielded betulin (1), betulinic acid (2) and ursolic acid (3) upon purification. Compounds 1-3 were identified using spectroscopic techniques and by comparison with reported data. GLC of unsaponifiable and saponifiable fractions of the hexane extract revealed β-sitosterol (7.37%) and n-tetracosane (54.4%) to be the major sterol and hydrocarbon components, respectively. Linoleic acid (48.89%) was the predominant fatty acid.     

Thai plants from Doi Tung: brine shrimp lethality, antioxidative activity and combination effect with L-ascorbic acid

Methanolic extracts of 18 Thai plants from Doi Tung, the north of Thailand, were examined for brine shrimp lethality and antioxidative activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In brine shrimp lethality, the highly toxic plant extracts were Mitrephora wangii (LC(50) 14.8?μg?mL(-1)) and Hydrocotyle javanica (LC(50) 13.3?μg?mL(-1)). The extracts of Sageretia cordifolia, Ulmus lancaefolia and Acer chiangdaoense exhibited highly antioxidative activities with IC(50) values of 6.7, 8.1 and 9.8?μg?mL(-1), respectively. Moreover, the extracts of S. cordifolia, U. lancaefolia and A. chiangdaoense have shown slightly synergistic effects (combination index; CI?相似文献   

δ-Lactam derivative from thermophilic soil fungus exhibits in vitro anti-allergic activity

From cultures of thermophilic soil fungus Humicola grisea var thermoidea, a δ-lactam derivative (3-(2-(4-hydroxyphenyl)-2-oxoethyl)-5,6-dihydropyridin-2(1H)-one) that displayed anti-allergic activity was isolated, which was predicted by in silico computational chemistry approaches. The in?vitro anti-allergic activity was investigated by β-hexosaminidase release assay in rat basophilic leukaemia RBL-2H3 cells. The δ-lactam derivative exhibited similar anti-allergic activity (IC(50)?=?18.7?±?6.7?μM) in comparison with ketotifen fumarate (IC(50)?=?15.0?±?1.3?μM) and stronger anti-allergic activity than azelastine (IC(50)?=?32.0?μM). Also, the MTT cytotoxicity assay with RBL-2H3 cells showed that δ-lactam does not display cytotoxicity at concentrations lower than 50?μM. This study suggests that the δ-lactam derivative has the potential to be used as a lead compound in the development of anti-allergic drugs for clinical use in humans.     

In vitro toxicity, antiplatelet and acetylcholinesterase inhibition of Buddleja thyrsoides Lam. leaves

Alzheimer's disease (AD) is a neurodegenerative disorder resulting in impaired memory and behaviour of remarkable socio-economic impact. A decrease in cholinergic activity is a key event in the biochemical of AD. Buddleja thyrsoides is a plant widely distributed in Southern parts of South America. In Brazilian traditional medicine, the infusion of its leaves and flowers is used for the treatment of bronchitis and cough. Crude ethanolic (70%) extract and fractions (dichloromethane, ethyl acetate and n-butanolic) were investigated regarding their toxicities in?vitro and antiplatelet action. The enzyme acetylcholinesterase inhibition was evaluated to study the crude extract. The crude extract and fractions were evaluated by means of Brine Shrimp Lethality test and they showed low activities with LC(50) values 1698, 2818, 2187 and 3672?μg?mL(-1) for dichloromethane, ethyl acetate, n-butanolic fractions and crude extract, respectively. Buddleja thyrsoides presented great antiplatelet action. The IC(50) values obtained for crude extract and dichloromethane, ethyl acetate and n-butanolic fractions were 361.29, 354.23, 368.75 and 344.30, respectively, while the IC(50) for the standard AAS was 257.01?μg?mL(-1). The crude extract showed an inhibition of 22.8% of the acetylcholinesterase enzyme in 24?h.     

Photoprotecting action and phytochemical analysis of a multiple radical scavenger lipophilic fraction obtained from the leaf of the seagrass Thalassia testudinum

The apolar fraction F1 of Thalassia testudinum was chemically characterized by gas chromatography-mass spectrometry, which led to the identification of 43 metabolites, all of them reported for the first time in the genus Thalassia. More than 80% of the F1 composition was constituted by aromatic metabolites including the major components 1,1-bis(p-tolyl)ethane (6.0%), 4,4'-diisopropylbiphenyl (4.8%) and a 1,1-bis(p-tolyl)ethane isomer (4.7%). This lipophilic fraction was assayed for its antioxidant effects and skin protective action. In vitro assays showed that F1 strongly scavenged DPPH* (IC(50) 312.0 ± 8.0 μg mL(-1)), hydroxyl (IC(50) 23.8 ± 0.5 μg mL(-1)) and peroxyl radical (IC(50) 6.6 ± 0.3 μg mL(-1) ), as well as superoxide anion (IC(50) 50.0 ± 0.7 μg mL(-1)). Also, F1 markedly inhibited the spontaneous lipid peroxidation (LPO) in brain homogenates (IC(50) 93.0 ± 6.0 μg mL(-1)) and the LPS-stimulated nitrite generation on RAW624.7 macrophages (58.6 ± 3.2%, 400 μg mL(-1)). In agreement with these findings, its topical application at 250 and 500 μg cm(-2) strikingly reduced skin damage on mice exposed to acute UVB radiation by 45% and 70%, respectively and significantly attenuated the LPO developed following the first 48 h after acute exposure to UVB irradiation, as manifested by the decreased malondialdehide level and by the increased of reduced gluthatione content. Our results suggest that F1 may contribute to skin repair by attenuating oxidative stress due to its antioxidant activity.     

Cytotoxic activity of antioxidant constituents from Hypericum triquetrifolium Turra

The Sulforodamine B (SRB) assay was used to test cytotoxicity against four human cancer cell lines and one normal cell line of antioxidant constituents isolated from Hypericum triquetrifolium Turra. Methanolic extract and pure compounds were tested against the large cell lung carcinoma cell line COR-L23, the hepatocellular carcinoma cell line HepG-2, renal cell adenocarcinoma ACHN, the amelanotic melanoma cell line C32 and normal human foetal lung MRC5. The results showed that I3-II8-biapigenin exhibited strong cytotoxic activity (IC50 = 5.73 micro g mL(-1)) showing a certain degree of selectivity against the different cell types.     

Turmerin, the antioxidant protein from turmeric (Curcuma longa) exhibits antihyperglycaemic effects

A wide range of proteinaceous inhibitors are present in plants to protect themselves from hydrolytic enzymes. In this study, turmerin, a water-soluble peptide in turmeric rhizomes, was evaluated for its inhibitory potential against glucosidase and its antioxidant (AO) capacity. Turmerin inhibited α-amylase and α-glucosidase activities with IC?? values 31 and 192?μg?mL?1, respectively. Under the experimental conditions, those values for a standard glucosidase inhibitor, acarbose, were 81 and 296?μg?mL?1, respectively. The AO capacity of turmerin was evaluated using in vitro assay systems. Turmerin showed good DPPH (IC???=?29?μg?mL?1) and superoxide (IC???=?48?μg?mL?1) and moderate ABTS (IC???=?83?μg?mL?1) radical scavenging and Fe(II) chelation (IC???=?101?μg?mL?1) capacities. The inhibitory potential showed by turmerin against enzymes linked to type 2 diabetes, as well as its moderate AO capacity, could rationalise the traditional usage of turmeric rhizome preparations against diabetes.     

Mutagenic effect, antioxidant and anticancer activities of six medicinal plants from Burkina Faso

The antiproliferative activities of six medicinal plant extracts from Burkina Faso were evaluated in order to justify their traditional use for the treatment of cancer. The SOS chromotest method was used in vitro on Escherichia coli PQ37 to evaluate the mutagenic effect of the plant extracts. The DPPH method was used to evaluate the antioxidant activity of each plant. The antiproliferative activity was evaluated by MTS method on normal cells (Vero and MCR5) and cancer cells (KB) in contact with the extracts for 72?h. The results showed that the studied plants are not genotoxic. Lantana ukambensis and Acacia macrostachya induced a very significant antiproliferative effect against cancer cells with 94% and 95%, respectively. They also developed a strong antioxidant activity. The IC?? values were 5.96?±?0.40?μg?mL?1 for L. ukambensis and 4.30?±?0.26?μg?mL?1 for A. macrostachya. These two plants are therefore potential sources for isolating new antioxidant and anticancer molecules.