Inhibitory Effect Of Extracts Research Articles

PREVENTION OF ENZYMATIC BROWNING OF ASIAN PEAR (PYRUS SEROTINA REHD.) BY SOME ANTI-BROWNING AGENTS

Mature fruit of the 'KS 13 ' Asian pear (Pyrus serotina Rehd.) cultivar were harvested from eight-year-old trees grown on European pear seedling rootstocks at Tarbiat Modares University (TMU) research orchard. Water extracts of onion and garlic bulbs were prepared and their effects on polyphenol oxidase activity and browning of Asian pear fruit juice were investigated. The polyphenol oxidase (PPO) of Asian pear was inhibited by onion and garlic extracts, and the inhibitory effect of these extracts on PPO was increased after heating them. The extracts' inhibitory effect increased with increasing heating temperature and time. In addition, results indicated that the inhibitory effect of garlic extract was greater than that of onion extract. The browning of Asian pear juice was retarded by addition of both fresh and heated onion and garlic extracts. The extracts inhibited the PPO activity non-competitively. Therefore, the inhibitory effect of these extracts against juice browning seems to be due to their impact on PPO activity.

The inhibitory effect of extracts of elm and eucalyptus and the synergy between its active ingredients and antibiotics in Staphylococcus aureus and Salmonella typhimurium isolated from food poisoning

The inhibitory effect of extracts of elm and eucalyptus and the synergy between its active ingredients and antibiotics in Staphylococcus aureus and Salmonella typhimurium isolated from food poisoning

Allelopathic properties of knotweed rhizome extracts

Our objective was to determine which rhizome extract from Japanese knotweed, Giant knotweed or Bohemian knotweed has the most significant inhibition effect on the germinated seeds. The seeds of white mustard were incubated with the extracts for two days under laboratory conditions. We monitored differences in number of germinated seeds, length of radicles, hypocotyls and root/shoot ratio between the control and experimental seeds. Inhibitory effect of extracts from dried knotweed rhizomes was confirmed, but without differences among tested plants. A higher allelopathic effect was revealed in the case of extract from aboveground parts.

Inhibitory effect of extracts from Brazilian medicinal plants on the adhesion of Candida albicans to buccal epithelial cells

Plants are known to produce a plethora of secondary metabolites which are recognized as a useful source of new drugs or drug leads. Extracts and fractions of Schinus terebinthifolius Raddi (Anacardiaceae), Piper regnellii C.D.C. (Piperaceae), Rumex acetosa L. (Polygonaceae), and Punica granatum L. (Punicaceae) were assessed for their antifungal activity against eight clinical isolates of C. albicans. They were also evaluated for their effect on the adhesion of these C. albicans isolates to buccal epithelial cells (BECs). The ethyl acetate fraction from the leaves of S. terebinthifolius showed promising activity, inhibiting the growth of three C. albicans isolates at 7.8 μg ml−1 and significantly inhibiting their adhesion to BEC at 15 μg ml−1 . In addition, this fraction did not show cytotoxic activity against murine macrophages. The results show the potential of the plant extracts studied as a source of new antifungal compounds. Further studies are necessary for isolation and characterization of the active compounds of these plants.

Inhibition of Leukotriene Biosynthesis by Secondary Plant Metabolites

Leukotrienes (LTs) are a group of biologically highly potent mediators of inflammation, synthesised in the first metabolic step by 5-lipoxygenase from 20 carbon fatty acids, predominantly arachidonic acid. They include the cysteinyl leukotrienes LTC4, LTD4, LTE4, which cause bronchoconstriction, chemotaxis and enhanced blood vessel-permeability, and therefore play a major role in asthma, and the dihydroxyeicosatetraenoate LTB4, an important mediator for acute and chronic inflammatory ailments. Inhibition of leukotriene biosynthesis therefore is a promising target for combating a number of diseases. Plant secondary metabolites offer a structurally very diverse potential source of new therapeutic leads. The aim of this review is to update the current knowledge of plant compounds with inhibitory effects on leukotriene metabolism, by presenting results published in the last seven years. Substances are presented with their IC50 values together with the activities of the positive controls to enable better comparability. Inhibitory effects of extracts are not discussed. Keywords: Kniphofia foliosa, Clerodane Type Diterpenes, FLAP inhibitors, Atractylodes lancea, Polyprenylated Hydroquinones, Maesanin

The protective effect of Opuntia dillenii Haw fruit against low-density lipoprotein peroxidation and its active compounds

The antioxidant activity and inhibitory effect of extracts from Opuntia dillenii Haw fruit (ODHF) and its active compounds on low-density lipoprotein (LDL) peroxidation were investigated. The results indicated that the antioxidant activity of methanolic extracts of ODHF in Trolox equivalent antioxidant capacity and oxygen-radical absorbance capacity assays were in the order of seed > peel > pulp. The lag time of conjugated diene formation in Cu 2+-induced LDL oxidation was increased by incubation of LDL with various methanolic extracts of ODHF. The methanolic extracts from seed, peel and pulp prolonged the lag time compared to control (154.1 min) to 514.8, 163.9 and 190.2 min, respectively, at a concentration of 10 μg/ml. Among the extracts, seed extracts of ODHF (10 μg/ml) possessed the highest inhibitory effect on the formation of thiobarbituric acid reactive substances and relative electrophoretic mobility. The results also demonstrated that seeds of ODHF contained the highest amounts of polyphenols and flavonoids (212.8 and 144.1 mg/100 g fresh seed, respectively), such as gallic acid, catechin, sinapinic acid, epicatechin, p-coumaric acid, quercetin and ferulic acid, but no betanin, isobetanin and ascorbic acid as determined by HPLC. However, the peel and pulp contained high amounts of betanin, isobetanin and ascorbic acid, but with lower contents of phenolics and flavonoids as compared to the seed. These findings suggest that phenolics and flavonoids may directly contribute to the antioxidant activity of the seeds of ODHF.

The Inhibitory Effect of Extracts from Jordanian Medicinal Plants Against Phytopathogenic Fungi

The Inhibitory Effect of Extracts from Jordanian Medicinal Plants Against Phytopathogenic Fungi

The inhibitory effect of extracts of tea plant and tannins isolated from the growth of E. coli pathogen of isolated intestines from infants with diarrhea Enteropathogenic Escherchia coli (EPEC) in Mosul

The inhibitory effect of extracts of tea plant and tannins isolated from the growth of E. coli pathogen of isolated intestines from infants with diarrhea Enteropathogenic Escherchia coli (EPEC) in Mosul

Inhibitory Effects of Extracts from Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae) on Immediate Type Allergy Induced Compound 48/80 in ICR Mice

The expression of interleukin (IL)-12 (a key role in Th1 differentiation) and IL-18 (a proinflammatory cytokine in enhancing Th1 immune response) mRNA in a macrophage-like cell line, RAW264.7, stimulated with a polysaccharide purified in Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae) (ABSW), were investigated using RT-PCR. We have reported that mRNA expression in IL-18 indicated no drastic changes during stimulation with polysaccharide purified in ABSW for 12 hours, but its level rapidly increased to 5.6-fold at 24 hours as compared with the initial level. The level of IL-12 p40 mRNA expression was different from those of IL-18. After 6 hours of stimulation, its level had not been reached at all, but started to increase at 12 hours and continued to increase by 24 hours. Moreover, polysaccharides from ABSW changed the percentage of splenic Thy 1.2- and L3T4 (CD4)-positive cells in the T cell subsets in ABSW-treated mice. It was presumed from the results that this mushroom possessed the ability to differentiate from naive T cells to T-helper type 1 (Th1) and showed antiallergic activity.To test this hypothesis, in this study, extracts from ABSW (3.6 mg/mL) were dissolved in distilled water and ingested by 8-week-old male ICR mice as drinking water for 14 days. No drastic differences were observed in the body weights of the mice. The cumulative number of scratching behaviors for 30 minutes in saline-treated mice (control) was approximately 2300 after intradermal injection of compound 48/80, which is a pruritogenic agent, whereas those in ABSW decreased to approximately 960. To determine the effects of ABSW on degranulation in mast cell activation, histamine contents in blood were measured. AB SW treatment suppressed histamine release (36% compared to the control). Similarly, suppression of degranulation from must cells also was detected histochemically by toluidine blue staining.The differentiation of naive T cells to the Th1 and Th2 subset of effector cells was regulated by the cytokines to which T cells were exposed at the time of antigenic stimulation. Interferon (INF)-γ and IL-12 promote Th1 development, whereas IL-4 promotes differentiation to Th2. To confirm which ABSW could change the differentiation of naive T cells to Th1 or Th2, contents of INF-γ, IL-12, and IL-4 in the spleen of mice were measured with or without Concanavalin A (Con A; T-cell mitogen). The cytokines did not show any difference without Con A. When splenocytes were incubated with Con A, contents of INF-γ and IL-4 secreted from T cells significantly increased compared with the control, but IL-12, which was produced from macrophages, did not. Moreover, ABSW induced INF-γ more potently than IL-12 in splenocytes incubated with Con A. These results indicate that ABSW possessed immunomodulating properties that might be involved in the development of Th1 cells, culminating in an inhibition of immediate type allergy caused by compound 48/80.

Inhibitory Effects of Extracts from Shochu Distillation Remnants on the Growth of Human Stomach Tumor Cells

Development of a new processing method for the effective use of rice-Shochu distillation remnants is an important subject for the reduction of environmental pollution. In this study, inhibitory effects on the growth of human stomach tumor cells along with the induction of apoptosis were obtained for powder treated with ethanol from freeze-dried supernatant of rice-Shochu distillation remnants in vitro. Futhermore, the powder obtained from rice-Shochu distillation remnants showed no toxicity to normal rats in vivo experiments. These results suggest that rice-Shochu distillation remnants might be effectively used not only as medicine but also as food supplements for health.

Inhibitory Effects of Extracts from Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae) on Immediate Type Allergy Induced Compound 48/80 in ICR Mice

Inhibitory Effects of Extracts from Agaricus brasiliensis S. Wasser et al. (Agaricomycetideae) on Immediate Type Allergy Induced Compound 48/80 in ICR Mice

味噌のがん抑制効果

[in Japanese]

Prevention of enzymatic browning of pear by onion extract

Onion extract was prepared by extracting onion with water, and the effects of the extract on pear polyphenol oxidase and browning of pear were investigated. The polyphenol oxidase of pear was inhibited by onion extract, and the inhibitory effect of onion extract toward pear polyphenol oxidase was increased with the heated extract. The inhibitory effect of the extract was increased with increasing heating temperature and time. The browning of pear juice was retarded by addition of both fresh and heated onion extracts. The onion extract inhibited the pear polyphenol oxidase non-competitively. Therefore, the inhibitory effect of onion extract against pear browning seems to be due to the inhibitory effect of onion extract against pear polyphenol oxidase.

Antimicrobial Activity of Nerium oleander Linn.

The invitro antimicrobial activity of Nerium oleander roots bark and leaf extracts were studied against Bacillus pumilus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Aspergillus niger. The chloroform, ethanol and methanol extracts of Nerium oleander showed high activity against all the tested bacteria. None of the crude extracts of the selected plant exhibited activity against Aspergillus niger. These results were compared with the Zones of inhibition produced by commercially available standard antibiotics. The inhibitory effects of extracts are very close and identical in magnitude and are comparable with the standard antibiotics used.

Inhibitory Effects of Extracts from Peels of Citrus natsudaidai Encapsulated in Hybrid Liposomes on the Growth of Tumor Cells in Vitro

Inhibitory effects of extracts from peels of Citrus natsudaidai (natsumikan) encapsulated in hybrid liposomes (HL) composed of L-alpha-dimyristoylphosphatidylcholine and polyoxyethylene (20) sorbitan monolaurate on the growth of tumor cells were examined. The extracts with lower polar solvents inhibited the growth of B-16 mouse melanoma and human lung carcinoma cells, although the extracts with higher polar solvents showed no antitumor activity. In particular, the inhibitory effects of extracts with lower polar solvents encapsulated in HL were enhanced as compared with those of free extracts. Fluorescence microscopic analysis indicated that the HL including petroleum ether extracts induced apoptosis in B-16 mouse melanoma cells. On the other hand, the viability of normal human fibroblast cells was even less affected by the extracts of natsumikan. These results suggest that hydrophobic antitumor agents should be present in peels of natsumikan.

Inhibitory Effect of Extracts of Brazilian Marine Algae on Human T-Cell Lymphotropic Virus Type 1 (HTLV-1)-Induced Syncytium Formation In Vitro

Extracts from four species of Brazilian marine algae collected from the Rio de Janeiro State coast were screened to determine the inhibitory effect on HTLV-1-induced syncytium formation. Before performing the syncytium inhibition assay the 50% cytotoxic dose (CyD50) of the algal extracts was evaluated. The antiviral test was carried out in HeLa cells co-cultured with HTLV-I infected T-cell line (C91/PL cells) in the presence of marine algal extracts in the concentration inferior to that corresponding to the CyD50. It was observed that co-cultured cells exposed to Ulva fasciata extract showed 60.2% syncytium inhibition at a concentration of 2.5%. At 5% concentration, Sargassum vulgare and Vidalia obtusiloba extracts presented 78.8 and 76% syncytium inhibition, respectively. The best inhibitory activity was observed with Laminaria abyssalis that presented 100% syncytium inhibition at a concentration of 2.5%. This work shows that extracts of marine algae, mainly L. abyssalis extract, are able to inhibit the cell-to-cell contact essential for the spreading of the virus and could be useful to prevent the infection.

Antifungal Activity of Methanolic of Centella asiatica and Andrographis panicuiata

The antifungal activity of methanolic extracts of Centella asiatica and Andrographis panicuiata leaves was observed against fourteen fungi, viz., Alternaría alternata, A. brassicae, A. brassicicola, A. solani, A. tenuissima, Cercospora blumae, Curvularia lunata, C. penniseti, and Drechslern monoceras, D. oryzae, D. turifica, Fusarium albizziae and F udum. Different concentrations of the methanolic extract (1000, 2000, 3000, 5000, 7000, 10000ppm) were used. The effect of mixed leaf extract (1500 ppm of C. asiatica + 1500 ppm of A. panicuiata) and its 1:2 ad 1:4 dilutions were also studied. The individual extracts of both the plants showed significant inhibitory effect on spore germination of all the fungi tested. F udum, F. albizzae, D. oryzae, D. natica, and D. monoceras were particularly sensitive to these extracts. In general, the extract of C. asiatica showed a higher inhibitory effect in all concentrations against all the fungi as compared to A. panicuiata, except for A. brassicae A. solani, D. oryzae, D. penniseti and Curvularia sp. The inhibitory effect of extracts increased when they were used in combination with or without dilutions against A. brassicicola, A. solani A. brassicae, A. alternata, A. tenussima, C. blumae, C. lunata, C. penniseti and Curvularia species. Higher efficacy of active ingredient of these extracts under field condition is envisaged against plant pathogens.

Inhibitory effects of the aqueous extract of Pavetta crassipes leaves on gastrointestinal and uterine smooth muscle preparations isolated from rabbits, guinea pigs and rats

The effects of the aqueous extract of Pavetta crassipes leaves were studied on gastrointestinal and uterine smooth muscle preparations isolated from rabbit jejunum, guinea pig ileum and rat uterus. The extract produced a concentration-dependent inhibition of the spontaneous motility or elevated tone in these preparations. The inhibitory effects of the extract were not affected by pretreatment with propranolol or yohimbine, but were completely blocked by verapamil pretreatment. The results indicate the presence of biologically active substances whose action might be mediated through calcium channels. A preliminary phytochemical screening of the leaf extract of P. crassipes revealed the presence of flavonoids, tannins and anthraquinones as possible candidates for such inhibitory substances.

Inhibitory effects of extracts from the marine alga Caulerpa taxifolia and of toxin from Caulerpa racemosa on multixenobiotic resistance in the marine sponge Geodia cydonium

The invasive growth of the introduced green alga Caulerpa taxifolia, already affecting the richness and diversity of the littoral ecosystems, has become a major ecological problem in the Mediterranean Sea. Previously, we demonstrated that the water pollutant tributyltin induces apoptosis in tissue of the marine sponge Geodia cydonium at concentrations of 3 μM and higher. Here we show that exposure of G. cydonium to low (non-toxic) concentrations of Caulerpa extract or purified caulerpin (10 μg/ml) together with low doses of tributyltin (1 μM; non-toxic), results in a strong apoptotic effect. Evidence is presented that the enhancement of toxicity of tributyltin by Caulerpa extract is at least partially caused by inhibition of the multixenobiotic resistance (MXR) pump by the algal toxin. Caulerpa extract, as well as caulerpin, strongly enhance the accumulation of the test substrate of MXR, rhodamine B, in the gills of the mussel Dreissena polymorpha, used as a model system for testing MXR-inhibiting potential.

P-760 - Inhibitory effect of extract from Martensia fragilis or. lipid peroxidation in rat microsome

P-760 - Inhibitory effect of extract from Martensia fragilis or. lipid peroxidation in rat microsome