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1.

Objectives

Our interest continues in discovering phytocomplexes from medicinal plants with phototoxic activity against human melanoma cells; thus the aim of the present study was to assess antioxidant, anti‐inflammatory and phototoxic activity of Hypericum perforatum L. subsp. perforatum, and relate these properties to the plant's chemical composition.

Materials and methods

Components of H. perforatum subsp. perforatum were extracted by hydroalcoholic solution and chemical profiles of preparations (HyTE‐3) performed by HPTLC. Linoleic acid peroxidation and DPPH tests were used to assess antioxidant activity, while MTT assay allowed evaluation of anti‐proliferative activity with respect to A375 human melanoma cells after irradiation with UVA dose, 1.8 J/cm2. Inhibition of nitric oxide production of macrophages was also investigated.

Results

HyTE‐3 indicated better antioxidant activity with β‐carotene bleaching test in comparison to DPPH assay (IC50 = 0.89 μg/ml); significant phototoxicity in A375 cells at 78 μg/ml concentration resulted in cell destruction of 50%. HyTE‐3 caused significant dose‐related inhibition of nitric oxide production in murine monocytic macrophage cell line RAW 264.7 with IC50 value of 342 μg/ml.

Conclusions

The H. perforatum subsp. perforatum‐derived product was able to suppress proliferation of human malignant melanoma A375 cells; extract together with UVA irradiation enhanced phototoxicity. This biological activity of antioxidant effects was combined with inhibition of nitric oxide production.
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2.
The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.  相似文献   

3.
Cross metathesis (CM) of 9-butenylpurines with 4-butenyloxycoumarin in the presence of Grubbs 2nd generation catalyst under MW irradiation resulted to conjugated compounds containing homo-N-nucleosides and coumarins. Analogous derivatives received by the CM reaction of 9-butenyl-6-piperidinylpurine with 6- or 7-butenyloxycoumarins, allyloxycoumarins or coumarinyl acrylate. These compounds were tested in vitro for their antioxidant activity and they present significant scavenging activity. The presence of a pentenyloxy moiety, the attachment position on coumarin ring as well as a purine homo-N-nucleoside group are considered as important structural features.  相似文献   

4.
Recent studies suggest that olive leaf is a significant source of bioactive phenolic compounds comparable to olive oil and fruits. Identifying appropriate extraction methods is thus an important step to increase the yield of such bioactive components from olive leaf, which is otherwise agricultural waste. The present study evaluates phenolic contents and compositions of olive leaf extracted by several solvent methods and to further establish their antioxidant activities using various radical scavenging systems. Total flavonoid and phenolic contents were significantly higher in the 80% ethanol extract, butanol, and ethylacetate fractions than hexane, chloroform and water fractions (p < 0.05). Oleuropein was identified as a major phenolic compound with considerable contents in these major three fractions and the extract that correlated with their higher antioxidant and radical scavenging. These results indicate that olive leaf contains significant amounts of oleuropein and phenolics, important factors for antioxidant capacity, which can be substantially modified by different extraction methods.  相似文献   

5.
The hydroalcoholic extract (MIT) of Micromeria imbricata (Forssk.) growing in Saudi Arabia in addition to the chloroform (MIC) and n-butanol (MIB) fractions were investigated for the first time using UPLC-ESI-MS/MS. The analysis revealed the tentative identification of fifty-eight compounds including three organic acids, twenty-five phenolic compounds, three coumarins, two anthocyanins, twenty-one flavonoids, three terpenes, and one miscellaneous. Moreover, the therapeutic potential of M. imbricata (MIT) and its fractions (MIC and MIB) were determined by in vitro evaluation of their cytotoxic, antioxidant, and anti-obesity characteristics. The MIT extract showed the highest phenolic (125.23 ± 0.87 mg gallic acid equivalent/100 gm extract) and flavonoid (112.24 ± 2.45 mg quercetin equivalent/100 gm extract) contents followed by n-butanol and chloroform fractions. The MIT extract revealed a potent cytotoxic activity against HepG-2 (Hepatocellular carcinoma) and MCF-7 (Breast carcinoma) with IC50 28.5 ± 2.0 and 35.2 ± 1.2 µg/mL, respectively. Additionally, the tested hydroalcoholic extract exhibited a significant DPPH scavenging activity with SC50 28.4 ± 1.2 µg/mL and a remarkable lipase inhibitory activity with IC50 54.2 ± 1.2 µg/mL. In conclusion, the current study presents the first insights into the phytochemical constituents and pharmacological properties of M. imbricata extract and its chloroform and n-butanol fractions. The results revealed that M. imbricata hydroalcoholic extract might be a prolific source of bioactive constituents with potent antioxidant, cytotoxic and anti-obesity potential. It might be a natural alternative therapy and nutritional strategy for obesity treatment.  相似文献   

6.
Aims: The aim of the study is to isolate and characterize a melanin pigment from a new strain of Aspergillus bridgeri isolated from rhizosphere soil of Eucalyptus tree and to investigate its antioxidant activity. Methods and Results: The extracellular pigment was alkali soluble, acid‐resistant and insoluble in organic solvents and water. The pigment was precipitated on treatment with FeCl3, ammoniacal AgNO3 and potassium ferricyanide and was bleached in the presence of oxidants and reductants. It was confirmed as melanin based on the Fourier transform infrared and electron paramagnetic resonance spectroscopy techniques apart from chemical analysis. Inhibition of melanin production by inhibitors like tricyclazole, 6‐hydroxyflavanone, 4‐hydroxy‐7‐methoxy‐3‐phenyl‐coumarin, 7‐hydroxy‐4‐phenyl‐coumarin and 7‐hydroxy‐3,4,8‐trimethylcoumarin confirmed that melanin produced by A. bridgeri is synthesized by 1,8‐dihydroxynaphthalene (DHN)‐melanin pathway. The melanin showed good free radical scavenging activity by DPPH method with an EC50 of 54·12 μg ml?1. Conclusions: The results of the study indicate that the melanin produced by the newly isolated A. bridgeri strain is a member of DHN melanin family and exhibited significant free radical scavenging activity. Significance and Impact of the Study: This is the first report on characterization of DHN melanin produced by a novel strain of A. bridgeri and may find potential application as a natural antioxidant in the cosmetic and pharmaceutical industries.  相似文献   

7.
《Phytomedicine》2014,21(3):240-246
BackgroundCoumarins, also known as benzopyrones, are plant-derived products with several pharmacological properties, including antioxidant and anti-inflammatory activities. Based on the wide distribution of coumarin derivatives in plant-based foods and beverages in the human diet, our objective was to evaluate both the antioxidant and intestinal anti-inflammatory activities of six coumarin derivatives of plant origin (scopoletin, scoparone, fraxetin, 4-methyl-umbeliferone, esculin and daphnetin) to verify if potential intestinal anti-inflammatory activity was related to antioxidant properties.MethodsIntestinal inflammation was induced by intracolonic instillation of TNBS in rats. The animals were treated with coumarins by oral route. The animals were killed 48 h after colitis induction. The colonic segments were obtained after laparotomy and macroscopic and biochemical parameters (determination of glutathione level and myeloperoxidase and alkaline phosphatase activities) were evaluated. The antioxidant properties of these coumarins were examined by lipid peroxidation and DPPH assays.ResultsTreatment with esculin, scoparone and daphnetin produced the best protective effects. All coumarin derivatives showed antioxidant activity in the DPPH assay, while daphnetin and fraxetin also showed antioxidant activity by inhibiting lipid peroxidation. Coumarins, except 4-methyl-umbeliferone, also showed antioxidant activity through the counteraction of glutathione levels or through the inhibition of myeloperoxidase activity.DiscussionThe intestinal anti-inflammatory activity of coumarin derivatives were related to their antioxidant properties, suggesting that consumption of coumarins and/or foods rich in coumarin derivatives, particularly daphnetin, esculin and scoparone, could prevent intestinal inflammatory disease.  相似文献   

8.
This work was conceptualized with the goal to investigate the phytochemical, free radical scavenging and antifungal profile of Cuscuta campestrisYunck . seeds. Total phenolics, amino acid and carbohydrate contents were evaluated in ethanolic, acetone and chloroform extract. Effective antioxidant activity was evaluated throughout seven antioxidant methods. The antifungal activity was assessed against eight fungal strains and Candida albicans. The results showed total phenol, flavonoid, flavonols and phenolic acids contents in amount of 1.51 – 6.35 mg GAE/mL, 78 – 425 μg RU/mL, 1.04 – 2.98 mg QU/g and 12.01 – 30.58 μg CAE/mL, respectively. The total amino acids and carbohydrates content ranged from 8.29 to 185.45 μg Gly/mL and from 0.05 to 0.12 μg Glu/mL. The ethanolic extract showed the best antioxidant activity in phosphomolybdenum, DPPH free radical scavenging, ferric reducing power and lipid peroxidation assays. The best activity in ferrous ion chelating and H2O2 assays had the acetone extract, whereas the best hydroxyl radical scavenging activity was observed with the chloroform extract. The ethanolic extract at a concentration of 6 mg/mL proved to be the most effective antimycotic, since it inhibited the growth of all tested fungi except Penicillium verrucosum. The obtained results indicate that Ccampestris seeds could be attributed to a potential source of natural antioxidants in food and pharmaceutical products.  相似文献   

9.
为了研究菜籽饼提取物对黑色素合成的抑制作用,为菜籽饼提取物作为美白化妆品的天然添加剂提供实验依据。采用ABTS法、DPPH法检测菜籽饼提取物清除自由基的能力,测定A-375黑色素细胞中酪氨酸酶活性和黑色素含量,并利用各自的试剂盒检测A-375细胞中抗氧化相关因子(MDA, SOD, GSH)。研究结果表明:菜籽饼提取物具有清除DPPH和ABTS的能力,对DPPH和ABTS的半数抑制率分别为304μg/mL和305.8μg/mL。菜籽饼提取物具有显著的抑制A-375黑色素的作用,药物作用48 h后,其IC50为113.3μg/m L,同时能够显著的降低黑色素的含量和酪氨酸酶的活性。与空白对照组(17.66 mol/ng)相比,菜籽饼提取物能显著降低A-375细胞内MDA含量,其抑制率为9.21 mol/ng,且能够显著提高SOD的含量,当浓度为125μg/m L时,SOD的含量较空白对照组提高了36.54 U/mL,与此同时,菜籽饼提取物亦能增加GSH的含量,当浓度为62.5μg/mL时,细胞中GSH的含量为6.43 mol/ng,其含量显著高于空白对照组。因此,菜籽饼提取物在降低黑色素含量、抑制酪氨酸酶活性的同时,也能够通过显著的抗氧化能力和清除自由基的能力,抑制A-375细胞中黑色素的生成。  相似文献   

10.
Plant galls are widely distributed, and their extracts are used in traditional medicine worldwide. Traditional remedies containing extracts of plant galls in China, India and some African countries have effective in the treatment of various pathologies. To open a new promising procedure for screening bioactive compounds from plant galls, standardized plant materials were generated in vitro and used for phytochemical and biological investigations. Methanol aqueous chloroform and hexane extracts of Nicotiana tabacum leafy galls induced by Rhodococcus fascians were used to evaluate phenolic and flavonoid contents, and to investigate antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging and ferric reducing antioxidant/power assays and anti‐inflammatory activity by the lipoxygenase inhibition assay. Infection by R. fascians modifies significantly the phytochemical profile of N. tabacum as well as its biological properties. The total polyphenolic content was increased (120–307%), and that of flavonoids was reduced (20–42.5%). Consequently, antioxidant and anti‐inflammatory activities of non‐infected tobacco extracts are significantly modified compared to plants treated with leafy gall extracts. This shows that infection by R. fascians favoured the production of anti‐inflammatory and antioxidant compounds in N. tabacum. The study indicates the benefit of plant galls used in traditional medicines against various pathologies.  相似文献   

11.
The antioxidant activity of the extract ofErigeron annuus was assessed by means of two differentin vitro tests: bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test) and the scavenging of authentic peroxynitrite in company with peroxynitrite generation from 3-morpholinosydnonimine (SIN-1). In both tests, the 85% aq. MeOH andn-BuOH soluble fractions of the crude extract showed a significant scavenging effect on peroxynitrite and DPPH radical in comparison to L-ascorbic acid. And bioassay-guided fractionation of then-BuOH soluble fraction led to the isolation of three compounds: Apigenin (1), quercetin-3-O-glucoside (2), and caffeic acid (3). The structures of the isolated compounds were elucidated on the basis of their spectroscopic data and their antioxidant activities were measured by determining their capacity to scavenge peroxynitrite and the DPPH radical.  相似文献   

12.
The essential oil obtained from hydrodistillation of flowering aerial parts of Athanasia brownii (Asteraceae) was studied for its chemical composition by GC/FID and GC/MS, and for biological activity, namely, antioxidant, antimicrobial, and chemopreventive potential, by DPPH (=2,2‐diphenyl‐1‐picrylhydrazyl), ABTS (=2,2′‐azinobis[3‐ethylbenzothioline‐6‐sulfonic acid), and FRAP (=ferric reducing antioxidant power), disk diffusion test, and MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay, respectively. The oil was characterized by a high content of oxygenated sesquiterpenes (71.2%), with selin‐11‐en‐4α‐ol (24.6%), caryophyllene oxide (8.7%), humulene epoxide II (5.1%), and (E)‐nerolidol (4.9%) as the predominant compounds. The oil showed a moderate activity against streptococci as well as radical‐scavenging potential, while the inhibitory effects against human cancer cells examined such as A375 (malignant melanoma) and HCT 116 (colon carcinoma) were significant, with IC50 values of 19.85 and 29.53 μg/ml, respectively.  相似文献   

13.
Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot . The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL?g?1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH ? and ? OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ? OH. In term of ? OH scavenging activity, the IC50 value of NKA‐9 purification was 0.335 mg mL?1, equivalent to 35.23 % of VC. The IC50 values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL?1, equivalent to 60.99 % and 87.07 % of VC. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage.  相似文献   

14.
Some plant‐derived bioactive compounds produced by fungal endophytes have been proven to have antimicrobial and antioxidant activities. In this study, endophytic fungi were isolated from 20 orchid samples collected in northern Thailand from 12 genera of orchids. In total, 97 isolates were isolated from the leaves (44.3%), stems (40.2%) and flowers (15.5%) of the orchid samples. The antifungal activity was investigated of the endophytic isolates against the plant pathogenic fungi. The results showed that 13 endophytic isolates provided antifungal activities against Fusarium sp., Colletotrichum sp. and Curvularia sp. The endophyte CK F05‐5, which was isolated from the flower part of Dendrobium lindleyi, was chosen for further testing because it the highest level of antifungal activity against Fusarium sp. The isolate CK F05‐5 was identified as Fusarium oxysporum on the basis of its ITS sequences of 5.8 s rRNA, and phytochemical analysis revealed the presence of coumarins. The ethyl acetate extract of CK F05‐5 was examined for its total phenolic content and antioxidant activity using Folin–Ciocalteu's reagent and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay, respectively. The phenolic content was 160.51 mg of GAE/g of extract, and the free radical scavenging activity was 89.61 µg/ml at the half maximal inhibitory concentration (IC50). The antimutagenic potential of the ethyl acetate extract of CK F05‐5 against Trp‐P‐1 mutagenic substances was determined using the Ames test which revealed that the extract of CK F05‐5 at 10 mg/plate had the highest antimutagenic activity against Trp‐P‐1 (51.2%) and 39.6% for strains TA98 and TA100, respectively. The active compounds present in the acetate extract of CK F05‐5 were examined using GC‐MS analysis, which displayed the presence of gibepyrone A, pyrrolo [1, 2‐a] pyrazine‐1, 4‐dione, hexahydro‐3‐(2‐methylpropyl) and indoleacetic acid as major components. Based on the results, this endophytic fungus contains various bioactive components that have various biological activities. This useful information could help in producing potentially valuable and novel pharmaceutical products.  相似文献   

15.
This study was carried out to evaluate the utilization probability of the fibrous root part (FRP) of Bletilla striata, which was usually discarded and harvesting pseudobulb part (PSP). The chemical composition, total phenolic content, DPPH radical scavenging activity, Ferric-reducing antioxidant power and tyrosinase inhibition activity were compared between FRP and PSP. Antioxidant and pro-oxidant effect as well as antitumor effect of the extract of FRP and PSP were analyzed by in vitro cell system as well. Thin layer chromatography and high performance liquid chromatography analysis indicated that the chemical compositions in the two parts were similar, but the content in FRP was much higher than PSP. Meanwhile, the FRP extracts showed higher phenolic content, stronger DPPH scavenging activity, Ferric-reducing antioxidant capacity and tyrosinase inhibition activity. Sub-fraction analysis revealed that the distribution characteristic of phenolic components and other active constituents in FRP and PSP were consistent, and mainly deposited in chloroform and acetoacetate fractions. Especially, the chloroform sub-fraction (sch) of FRP showed extraordinary DPPH scavenging activity and tyrosinase inhibition activity, with IC50 0.848 mg/L and 4.3 mg/L, respectively. Besides, tyrosinase inhibition activity was even stronger than the positive compound arbutin (31.8 mg/L). Moreover, In vitro cell system analysis confirmed that FRP extract exerts comparable activity with PSP, especially, the sub-fraction sch of FRP showed better antioxidant activity at low dosage and stronger per-oxidant activity at high dosage, and both sch of FRP and PSP can dose-dependent induce HepG2 cells apoptosis, which implied tumor therapeutic effect. Considering that an additional 0.3 kg FRP would be obtained when producing 1.0 kg PSP, our work demonstrated that FRP is very potential to be used together with PSP.  相似文献   

16.
In continuous research for bioactive compounds obtained from plants to use for weed control in sustainable agriculture, the aerial parts of Cachrys pungens Jan (Umbelliferae) were extracted with methanol and then fractionated using hexane, chloroform (CHCl3) and ethyl acetate (AcOEt). The potential phytotoxicity of total methanolic extract and each fraction was assayed in vitro on seed germination and root elongation of lettuce (Lactuca sativa L.) and the most active fractions were assayed on three of the most common weeds (Lolium perenne, Amaranthus retroflexus, Echinochloa crus-galli). Non linear regression that allowed to obtain the ED50 index for both physiological processes was applied. The fraction bioassays indicated the following hierarchy of phytotoxicity for both processes: CHCl3 ≥ AcOEt > hexane. Moreover, in the present work was chemically characterized for the first time (through HPTLC) the polar fraction of this species pointing out the high presence of flavonoids and phenolic acids. In particular six of them have been chemically characterized and quantified (naringin, quercetin, catechin, caffeic acid, ferulic acid and gallic acid). These results make C. pungens Jan a potential source of natural compounds employable for an eco-friendly agriculture.  相似文献   

17.
The crude methanolic extract of Andrachne cordifolia Muell. (Euphorbiaceae) and its various fractions in different solvent systems (chloroform, ethyl acetate and n- butanol) were screened for antibacterial and antifungal activities. Crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities against the tested pathogens. Highest antibacterial activity was displayed by both chloroform and ethyl acetate fractions (100%) followed by the crude extract (68%) against Salmonella typhi. Similarly, crude extract and its subsequent fractions showed mild to excellent activities in antifungal bioassay with maximum (76%) antifungal activity against Microsporum canis by the chloroform fraction followed by the crude extract (65%).  相似文献   

18.
Two monoterpene coumarins, designated ferulagol A and B, as well as three known monoterpene coumarins and three sesquiterpene lactones were isolated from the chloroform extract of the roots of Ferula ferulago. The structures of ferulagol A and B were determined to be 7-[(E)-3'-hydroxy-3',7'-dimethyl-4',6'-octadienyloxy]coumarin and 7-[(3'Z,5'E)-7'-hydroxy-3',7'-dimethyl-3',5'-octadienyloxy]coumarin, respectively.  相似文献   

19.
20.
Objectives: Poor therapeutic results have been reported for treatment of malignant melanoma; therefore in this study we have investigated inhibitory capacity of ethyl acetate, chloroform (Chl) and methanol extracts from Moricandia arvensis on mouse melanoma (B16‐F0) and human keratinocyte (HaCaT) cell proliferation. Influence of Chl extract on percentage distribution in cell cycle phases and melanogenesis was also studied. Material and methods: Cell viability was determined at various periods using the MTT assay, and flow cytometry was used to analyse effects of Chl extract on progression through the cell cycle and apoptosis. In addition, amounts of melanin and tyrosinase were measured spectrophotometrically at 475 nm. Results: Chl extract exhibited significant anti‐proliferative activity after incubation with the two types of tumour skin cells. Morphological changes in B16‐F0 cells, accompanied by increase of tyrosinase activity, and of melanin synthesis were observed, which are markers of differentiation of malignant melanoma cells. Furthermore, cell cycle analysis revealed that B16‐F0 cells treated with Chl extract were arrested predominantly in G1 phase. Conclusion: Chl extract had the ability to reverse malignant melanoma cells from proliferative to differentiated state, thus providing a new perspective in developing novel strategies for prevention and treatment of malignant melanoma, possibly through consumption of the extract in an appropriate cancer prevention diet. Moreover, there is scope for the extract being introduced into cosmetic products as a natural tanning agent.  相似文献   

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