Inhibition of lipoxygenases and cyclooxygenase-2 enzymes by extracts isolated from Bacopa monniera (L.) Wettst

AIM OF THE STUDY: Bacopa monniera Linn is described in the Ayurvedic Materia Medica, as a therapeutically useful herb for the treatment of inflammation. In the current study, we investigated the anti-inflammatory activity of methanolic extract of Bacopa monniera (BME). For some experiments EtOAc and bacoside fractions were prepared from BME. The effect of these extracts in modulating key mediators of inflammation was evaluated. MATERIALS AND METHODS: Carrageenan-induced rat paw edema, rat mononuclear cells and human whole blood assay were employed as in vivo and in vitro models. RESULTS: In carrageenan-induced rat paw edema, BME brought about 82% edema inhibition at a dose of 100mg/kg i.p. when compared to indomethacin (INDO) (3mg/kg) that showed 70% edema inhibition. BME also significantly inhibited 5-lipoxygenase (5-LOX), 15-LOX and cyclooxygenase-2 (COX-2) activities in rat monocytes in vivo. Among the fractions tested in vitro, EtOAc fraction possessed significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) value of 30 microg/ml compared to butylated hydroxyl toluene (IC(50) = 13 microg/ml). This fraction also exerted significant hydroxyl radical scavenging activity with IC(50) value of 25 microg/ml in comparison with quercetin (IC(50) = 5 microg/ml). Inhibitory effects of EtOAc and bacoside fractions on LOX and COX activities in Ca-A23187 stimulated rat mononuclear cells were also assessed. 5-LOX IC(50) values were 25 microg/ml for EtOAc, 68 microg/ml for bacosides and 2 microg/ml for nordihydroguaiaretic acid (NDGA) where as COX-2 IC(50) values were 1.32 microg/ml for EtOAc, 1.19 microg/ml for bacoside fraction and 0.23 microg/ml for indomethacin. EtOAc and bacoside fractions also brought about significant decrease in TNF-alpha release ex vivo. CONCLUSION: Bacopa monniera possesses anti-inflammatory activity through inhibition of COX and LOX and downregulation of TNF-alpha.     

Anti-inflammatory and analgesic properties of the stem bark extracts of Erythrophleum suaveolens (Caesalpiniaceae), Guillemin & Perrottet

The MeOH stem bark extract of Erythrophleum suaveolens dissolved in water and shaken up with ethylacetate (EtOAc) and fractionated on a polyamide column with methanol as eluent produced five principal fractions. These fractions were designated as fraction A (74.8 mg yield and rich in alkaloids), fraction B (36.6 mg), fraction C (7.8 mg yield, monomeric procyanidin), fraction D (26.6 mg yield, rich in monomeric and oligomeric procyanidin), and fraction E (18.1 mg yield, rich in polymeric procyanidin). The original MeOH extract administered (100 mg/kg po) produced about 47% inhibition of carrageenin-induced paw oedema 1 h after administration. Fraction D, obtained from the ethylacetate extract and rich in procyanidins produced over 33% inhibition of carrageenan-induced paw oedema while a dose of 19.2 microg/ml produced 100% inhibitory effect on 5-lipoxygenase. A dose of 100 mg/kg of the MeOH extract also produced over 30% reduction of the sensitivity to pain while 50 mg/kg of fraction D rich in procyanidins produced over 45% analgesic effects. These results were judged significant compared to those obtained with indomethacin and acetylsalicylic acid. These findings suggest that extracts of the bark of Erythrophleum suaveolens possess potent anti-inflammatory and analgesic property and that the procyanidins lead to the observable pharmacological effects.     

Evaluation of the anti-inflammatory and anti-proliferation tumoral cells activities of Antrodia camphorata, Cordyceps sinensis, and Cinnamomum osmophloeum bark extracts

The extracts of chloroform (1) and methanol (2) from Antrodia camphorata (AC), and chloroform (3) and n-butanol (4) fractions of methanol extract from Cordyceps sinensis (CS), and hexane (5), ethyl acetate (6), and methanol (7) from Cinnamomum osmophloeum bark (CO) were evaluated for their anti-inflammatory as well as tumor-cell growth inhibitory activities in vitro. All the tested extracts dose dependently inhibited the enhanced production of inflammatory mediators such as nitric oxide (NO) through reducing inducible NO synthase expression, and cytokines (tumor necrosis factor (TNF)-alpha and interleukin (IL)-12 in LPS/IFN-gamma activated murine peritoneal macrophages. In addition, extracts 1 from AC, and 5 and 6 from CO significantly arrest the mitogen-stimulated spleen cells in G0/G1 stage. On the other hand, all these extracts were also evaluated for their tumor-cell proliferation activities in different type of cancer cell lines such as Jurkat, HepG2, PC 3, Colon 205, and MCF 7 as well as normal PBMCs. Compared to untreated controls, the extracts 1, 2, and 4-7 were most active and inhibited Jurkat cells with IC50 value of 22, 40, 18, 4, 5, and 45 microg/ml, respectively. In addition, the extracts 5, 6, and 7 from CO showed potent growth inhibition of HepG2 and PC 3 with IC50 values of 35, 80, 55 microg/ml; and 42, 125, and 50 microg/ml, respectively. Similarly, the extracts 1 and 5 inhibited the growth of Colon 205 and MCF 7 cells with IC50 values of 65, 33; and 95 and 30 microg/ml, respectively. Interestingly, none of the tested extract has shown cytotoxicity towards normal PBMCs up to the concentration range studies (0-150 microg/ml). Taken together, these data suggest that the anti-inflammatory and anti-cancer properties of AC, CS, and CO might result from the growth inhibition of NO, TNF-alpha and IL-12, and tumor cells proliferation, respectively.     

Anti-inflammatory and analgesic properties of the stem bark extract of Mitragyna ciliata (Rubiaceae) Aubrév. & Pellegr

Mitragyna ciliata is widely used in traditional medicine for the treatment of inflammation, hypertension, headache, rheumatism, gonorrhoea and broncho-pulmonary diseases. In the present study, the anti-inflammatory and analgesic properties of the stem bark extract of M. ciliata were investigated. The stem bark of this plant was extracted over Soxhlet with hexane followed by another extraction with methanol. The resulting methanol extract was used for the pharmacological test. Anti-inflammatory activity was evaluated on the basis of the inhibitory effect of the extract on 5-lipoxygenase, and carrageenin-induced hind paw oedema in the rat. The methanol extract, at a dose of 19.2 microg/ml, exhibited no inhibition on 5-lipoxygenase. However, this extract administered per os (50 mg/kg) produced about 70% inhibition of carrageenin-induced paw oedema 1 h after administration. This inhibition was maintained to about 50% 2 h after administration. The dose of 50 mg/kg of MeOH extract significantly decreased sensitivity to pain from 78.75 to 107.5 g These findings suggest that extracts of the bark of M. ciliata, possess potent anti-inflammatory and analgesic effects. Chemical analysis of the extract showed the presence of alkaloids and kaempferol derivative which may be responsible for the anti-inflammatory properties.     

Effect of chronic treatment with Enicostemma littorale in non-insulin-dependent diabetic (NIDDM) rats

In the present study, we have attempted to elucidate the active components for rheumatoidal arthritis using chloroform (CHCl(3)), ethylacetate (EtOAc) and n-butanol (BuOH) fractions of the methanol extract (MeOH) of Kalopanax pictus. Kalopanaxsaponin-A and -I (KPS-A and -I, hederagenin monodesmoside) were isolated from EtOAc fraction and kalopanaxsaponin-B, -H and -K (KPS-B, -H and -K, hederagenin bisdesmosides) obtained from BuOH fraction, respectively. MeOH extract, EtOAc fraction (250, 500 mg/kg, p.o.) and KPS-A and -I (5, 10, 20 mg/kg, i.p.) exhibited significant antinociceptive effects, which were determined by acetic acid-induced writhing test and hot plate test. On Freund's complete adjuvant reagent-induced rheumatoidal arthritis in rats, the administration of EtOAc fraction and KPS-A and -I inhibited edema, agglutination, vascular permeability and trypsin inhibitor. In addition, LD(50) of the MeOH extract was shown to be 4.033 mg/kg. These results suggest that anti-rheumatoidal effects of KPS-A and -I contribute to the inhibition of kinin formation by suppression of trypsin inhibitor activity.     

Supercritical carbon dioxide extract exhibits enhanced antioxidant and anti-inflammatory activities of Physalis peruviana

Physalis peruviana L. (PP) is a medicinal herb widely used in folk medicine. In this study, supercritical carbon dioxide (SFE-CO2) method was employed to obtain three different PP extracts, namely SCEPP-0, SCEPP-4 and SCEPP-5. The total flavonoid and phenol concentrations, as well as antioxidant and anti-inflammatory activities of these extracts were analyzed and compared with aqueous and ethanolic PP extracts. Among all the extracts tested, SCEPP-5 demonstrated the highest total flavonoid (234.63+/-9.61 mg/g) and phenol (90.80+/-2.21 mg/g) contents. At concentrations 0.1-30 microg/ml, SCEPP-5 also demonstrated the strongest superoxide anion scavenging activity and xanthine oxidase inhibitory effect. At 30 microg/ml, SCEPP-5 significantly prevented lipopolysaccharide (LPS; 1 microg/ml)-induced cell cytotoxicity in murine macrophage (Raw 264.7) cells. At 10-50 microg/ml, it also significantly inhibited LPS-induced NO release and PGE2 formation in a dose-dependent pattern. SCEPP-5 at 30 microg/ml remarkably blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Taken together, these results suggest that SCEPP-5, an extract of SFE-CO2, displayed the strongest antioxidant and anti-inflammatory activities as compared to other extracts. Its protection against LPS-induced inflammation could be through the inhibition of iNOS and COX-2 expression.     

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX-2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells

The inhibitors of prostaglandin biosynthesis and nitric oxide production have been considered as potential anti-inflammatory and cancer chemopreventive agents. In this study, we evaluated approximately 170 methanol extracts of natural products including Korean herbal medicines for the inhibition of prostaglandin E(2) production (for COX-2 inhibitors) and nitric oxide formation (for iNOS inhibitors) in lipopolysaccharide (LPS)-induced mouse macrophages RAW264.7 cells. As a result, several extracts such as Aristolochia debilis, Cinnamomum cassia, Cinnamomum loureirii, Curcuma zedoaria, Eugenia caryophyllata, Pterocarpus santalius, Rehmania glutinosa and Tribulus terrestris showed potent inhibition of COX-2 activity (>80% inhibition at the test concentration of 10 micro g/ml). In addition, the extracts of A. debilis, Caesalpinia sappan, Curcuma longa, C. zedoaria, Daphne genkwa and Morus alba were also considered as potential inhibitors of iNOS activity (>70% inhibition at the test concentration of 10 micro g/ml). These active extracts mediating COX-2 and iNOS inhibitory activities are warranted for further elucidation of active principles for development of new cancer chemopreventive and/or anti-inflammatory agents.     

Inhibitory effect of the Korean herbal medicine, Dae-Jo-Whan, on platelet-activating factor-induced platelet aggregation

The anti-thrombic properties of the Korean herbal medicine, Dae-Jo-Hwan (DJW) were investigated. Water extracts, a 70% methanol (MeOH) extract and an ethyl acetate (EtOAc) soluble fraction (III) from DJW inhibited platelet-activating factor (PAF)-induced platelet aggregation in vitro and in vivo assays. The extracts of DJW and eleven herbs from which it is derived, except for Panax ginseng Meyer, Angelica sinensis (OLIV.) DIELS and Schisandra chinensis Baill., inhibited AA-induced blood platelet aggregation to various extents. The effects observed with total DJW was synergistic over-additive rather that additive since the sum of single contributions was lower than the effect of the total extract. Fraction III was specially protected against the lethality of PAF, while verapamil did not afford any protection. Exogenously applied arachidonic acid (AA) (100 microM) led to a 89% platelet aggregation, the release of 14 pmol of ATP, and the formation of either 225 pg of thromboxane A2 (TXA2) or 45 pg of prostaglandin E2 (PGE2), each parameter being related to 10(6) platelets. An application of DJW 5 min before AA, dose-dependently diminished aggregation, ATP-re lease, and the synthesis of TXA2 and PGE2, with IC(50) values of 70, 87, 65 and 72 microg/ml, respectively. The similarity of the IC(50) values suggests the inhibition of cyclooxygenase (COX) by DJW as the primary target, thus suppressing the generation of TXA2, which induces platelet aggregation and the exocytosis of ATP by its binding on TXA2-receptors. These results indicate that DJW shows anti-thrombotic action on human platelets and inhibits the action of PAF in vivo by an antagonistic effect on PAF. Therefore, it may be useful in treating disorders caused by PAF.     

Anti-inflammatory effects of an ethanolic extract from Clematis mandshurica Rupr

Clematis mandshurica Rupr (Ranunculaceae) roots are used in traditional Korean medicine to treat inflammation-related diseases. Therefore, we undertook to investigate their inhibitory effect on inflammation under non-cytotoxic conditions. The ethanolic extract of Clematis mandshurica at 100 microg/ml was found to significantly block the production of the pro-inflammatory mediators, nitric oxide (NO) and prostaglandin E(2) (PGE(2)), in lipopolysaccharide (LPS)/interferon(IFN)-gamma-stimulated mouse peritoneal macrophages, by up to 77% and 59%, respectively. In addition, it significantly inhibited cell proliferation and cytokine production (interleukin (IL)-2 and IFN-gamma) in splenocytes stimulated with Con A (concanavalin A; 5 microg/ml). Furthermore, when splenocytes from extract fed mice (200 mg/kg for 2 weeks) were activated with Con A, cell proliferation and the production of IL-2 and IFN-gamma were significantly inhibited. In addition, the extract reduced in vivo inflammation in oxazolone-induced delayed type hypersensitivity (DTH) model mice. Taken together, these data suggest that Clematis mandshurica is able to ameliorate inflammatory disease by exerting an anti-inflammatory effect in cases of proinflammatory and cell-mediated inflammation.     

In vitro screening of some Strychnos species for antiplasmodial activity

The antiplasmodial activity of crude extracts of 19 species of Strychnos (Loganiaceae) was assessed in vitro against a chloroquine-susceptible strain of Plasmodium falciparum. For each species, ethyl acetate (EtOAc) extracts were analysed and, for the most active species, methanolic (MeOH) extracts were also tested. Among them, Strychnos variabilis De Wild. seemed to be very promising (inhibitory concentration 50% (IC50) < 5 microg/ml) whereas two other species, Strychnos gossweileri Exell and Strychnos mellodora S. Moore, could be interesting (IC50 < 15 microg/ml) in further antimalarial studies.     

Metabolite profiling and chemopreventive bioactivity of plant extracts from Bidens pilosa

Bidens pilosa has been used as a folk medicine in various medications and as a popular ingredient in herb teas. Chemopreventive activities of crude and fractionated plant extracts of Bidens pilosa were evaluated in this study. Ethyl acetate and butanolic fractions, partitioned from the total crude extract of Bidens pilosa, exhibited significant scavenging free radical activity (IC(50) values approximately = with 14-17 microg/mL) comparable to that of alpha-tocopherol. Strong effects on the inhibition of LPS-mediated nitric oxide production in RAW 264.7 cells were also observed for the EA and BuOH fractions. Detectable cytotoxicity on RAW 264.7 cells, however, was observed for the EA fraction at a dose >100 microg/ml. The metabolite profile and major constituents of the BuOH fraction were studied and characterized using various spectroscopic analyses. A new compound, heptanyl 2-O-beta-xylofuranosyl-(1-->6)-beta-glucopyranoside (1), and eight phenolic compounds, namely quercetin 3-O-rabinobioside (2), quercetin 3-O-rutinoside (3), chlorogenic acid (4), 3,4-di-O-caffeoylquinic acid (5), 3,5-di-O-caffeoylquinic acid (6), 4,5-di-O-caffeoylquinic acid (7), jacein (8), centaurein (9) were for the first time isolated from Bidens pilosa. Compounds 2-7 are the major antioxidative constituents in the Bidens pilosa extract.     

Anti-Helicobacter pylori activity of Aristolochia paucinervis Pomel extracts

The anti-Helicobacter pylori effect of the extracts and the fractions obtained from Aristolochia paucinervis rhizome and leaves were studied against a reference strain of H. pylori by using the agar dilution method. Only the methanol extracts and the hexane fractions of either the rhizome or the leaves exhibited an inhibitory activity at a concentration of < or =128 microg/ml. The leaf hexane fraction APLH demonstrated a higher inhibitory activity (MIC: 4 microg/ml) than the rhizome hexane fraction APRH (MIC: 16 microg/ml), the leaf methanol extract APLM (MIC: 32 microg/ml) and the rhizome methanol extract APRM (MIC: 128 microg/ml). This inhibitory activity was confirmed for the active extracts and fractions against clinical isolates of H. pylori (n = 20) for which MIC50) and MIC90 were determined.     

Bioactivity studies on Cassia alata Linn. leaf extracts

The hexane, chloroform and ethyl acetate extracts of the leaves of Cussia alata Linn. were tested for their antimutagenic, antifungal, analgesic, antiinflammatory and hypoglycaemic activities. At a dosage of 5 mg/20 g mouse, the hexane extract was analgesic as it reduced the number of squirms induced by acetic acid by 59.5%. Both the hexane and EtOAc extracts exhibited antiinflammatory activity at a dosage of 5 mg/20 g mouse with a 65.5% and 68.2% decrease in carrageenan-induced inflammation, respectively. The chloroform extract was antimutagenic, at a dosage of 2 mg/20 g mouse, with a 65.8% inhibition in the mutagenicity of tetracycline. It was also the most active against Trichophyton mentagrophytes, at a concentration of 50 mg/mL but it had no activity against Candida albicans. The hexane and EtOAc extracts showed some activity against both organisms, with the EtOAc extract being more active against C. albicans. The EtOAc extract was hypoglycaemic. At a dosage of 5 mg/20 g mouse, it decreased the blood sugar level of mice by 58.3%. Pharmacological studies showed that all extracts caused an immediate decrease in motor activity, enophthalmus, hyperemia, micturition and diarrhoea. At a dosage of 150 mg/20 g mouse, the EtOAc extract caused paralysis, screen grip loss and enophthalmus accompanied by drooping and closure of the eyelids.     

Anti-inflammatory activity of arctigenin from Forsythiae Fructus

Oleaceae Forsythiae Fructus has been used for anti-inflammatory, diuretics, antidote, and antibacterials in traditional herbal medicine. Our previous screening of medicinal plants showed that methanol (MeOH) extract of Forsythiae Fructus had significant anti-inflammatory activity, but the active ingredients remain unclear. For isolation of active ingredient of MeOH extract of Forsythiae Fructus, it was partitioned with n-hexane and ethylacetate (EtOAc), and arctigenin was isolated from EtOAc fraction by column chromatography with anti-inflammatory activity-guided separation. Its activity was evaluated in the animal models of inflammation including myeloperoxidase (MPO) and eosinophil peroxidase (EPO) activities in the edematous tissues homogenate, and silica-induced reactive oxygen species (ROS) production in the RAW 264.7 cell line. It was shown that arctigenin (100 mg/kg) had significantly decreased not only carrageenan-induced paw edema 3 and 4h after injection of carrageenan, arachidonic acid (AA)-induced ear edema at a painting dose of 0.1-1.0mg/ear, and acetic acid-induced writhing response and acetic acid-induced capillary permeability accentuation at an oral dose of 25-100, and 100 mg/kg, respectively, but also MPO and EPO activities at a painting dose of 0.1-1.0mg/ear in the AA-induced edematous tissues homogenate as indicators of neutrophils and eosinophils recruitment into the inflamed tissue. Further, arctigenin (0.1-10 microM) also significantly inhibited the intracellular ROS production by silica. These results indicate that arctigenin is a bioactive agent of Forsythiae Fructus having significant anti-inflammatory action by inhibition of the exudation, and leukocytes recruitment into the inflamed tissues. The pharmacologic mechanism of action of arctigenin may be due to the inhibition of release/production of inflammatory mediators such as AA metabolites and free radicals.     

Salviae miltiorrhizae radix increases dopamine release of rat and pheochromocytoma PC12 cells

The Radix of Salvia miltiorrhiza Bunge (Labiatae) (SMR), an eminent herb, is often included as an ingredient in various herbal remedies recommended for vascular circulation therapies. The present study investigated the effect of SMR on dopaminergic neurotransmission. Various extracts prepared from the stems of SMR were tested for cytotoxic activity on pheochromocytoma PC12 cells using the XTT assay method. The ethanol extract (IC50 > 100 microg/mL), water extract (IC50 > 100 microg/mL) and chloroform (IC50 = 90 microg/mL) fraction exhibited weak cytotoxic activity. However, the butanol (IC50 = 80 microg/mL) and ethyl acetate (EtOAc; IC50 = 70 microg/mL) fractions exhibited strong cytotoxic activity. Also, the extracts and fractions were investigated for dopamine release effects. The EtOAc fraction showed a stronger stimulatory effect on dopamine release activity than the other fractions. The effect of the crude EtOAc fraction (50 microg/mL) of SMR on K+ (20 mm)-stimulated dopamine (DA) release from rat striatal slices was compared with amphetamine (10(-4) m) using high-performance liquid chromatography with electrochemical detection to measure endogenous DA. The EtOAc fraction significantly increased K+ -stimulated DA release (p < 0.001) from rat striatal slices when compared with K+ -stimulated alone. The EtOAc fraction potentiated the effect of amphetamine on K+ -stimulated DA release (p < 0.001) when compared with amphetamine alone. To examine whether in vitro the EtOAc fraction treatment induces DA release in PC12 cells, the role of protein kinases was investigated in the induction of the EtOAc fraction-mediated events by using inhibitors of protein kinase C (PKC), mitogen activated protein kinase (MAP kinase) or protein kinase A (PKA). The PKC inhibitors chelerythrine (50 nm and 100 nm) and Ro31-8220 (100 nm) and the MAP kinase kinase inhibitor, PD98059 (20 microm), inhibited the ability of the EtOAc fraction of SMR to elicit the EtOAc fraction-stimulated DA release. The PKC activator, 12-O-tetradecanoyl phorbol 13-acetate (TPA, 100 nm) mimicked the ability of the EtOAc fraction of SMR to elicit DA release. In contrast, a selective PKA inhibitor, 50 microm Rp-8-Br-cAMP, blocked the development of EtOAc fraction-stimulated DA release. It was demonstrated that the EtOAc fraction of SMR stimulated DA release. Therefore the mechanism by which the EtOAc fraction of SMR induced the enhancement in EtOAc fraction-stimulated DA release is apparent.     

Antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component, 1,2,3,4,6-penta-O-galloyl-beta-D-glucose

The antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component was investigated under in vitro and cellular oxidative stress models. The MeOH extract, and n-hexane, EtOAc, BuOH and H(2)O fractions from geranium showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effects and protective potential from oxidative damage by the radical generator, 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in renal epithelial LLC-PK(1) cells. In particular, the EtOAc fraction exerted the strongest antioxidative potential in not only the in vitro but also in the cellular system. It suggests that the antioxidative activity of geranium is attributed mainly to components from the EtOAc fraction. Furthermore, the active component, 1,2,3,4,6-penta-O-galloyl-beta-d-glucose (PGG), was identified from the EtOAc fraction by the bioassay-linked fractionation method. It displayed a potent antioxidant effect against the DPPH radical, showing an IC(50) value of 1.14 microg/mL. Moreover, the compound recovered the cell viability declined by AAPH treatment significantly and dose-dependently, implying a protective role against cellular oxidative damage. The present study suggests that geranium has an excellent antioxidative potential and that PGG from geranium is considered to be the active component with an antioxidative effect.     

Effects of oral administration of Gardeniae fructus extract and intravenous injection of crocetin on lipopolysaccharide- and prostaglandin E2-induced elevation of aqueous flare in pigmented rabbits

The purpose of this study was to evaluate the effects of extracts of Coptidis rhizoma, Phellodendri cortex and Gardeniae fructus, which are medicinal herbs in Orengedoku-to (Huanglin-Jie-Du-Tang in Chinese), and crocetin (a major component of Gardeniae fructus) on experimental elevation of aqueous flare in pigmented rabbits. To produce aqueous flare elevation, 0.5 microg/kg lipopolysaccharide (LPS) was injected into the ear vein, or prostaglandin E2 (PGE2) 25 microg/ml, was applied to the cornea by means of a glass cylinder. Animals were pretreated by oral administration of 150 g/day of food containing 0.15% (w/w) extract powder of Coptidis rhizoma, 0.10% (w/w) extract powder of Phellodendri cortex or 0.15% (w/w) extract powder of Gardeniae fructus for 4 days, or by intravenous injection of crocetin, 0.3, 3, 30 or 300 microg/kg, 30 minutes before aqueous flare elevation. Aqueous flare was measured with a laser flare-cell meter. Aqueous flare intensity was expressed as the area under the curve (AUC) in arbitrary units. The AUC of LPS- and PGE2-induced aqueous flare elevation was 4685 and 1386 arbitrary units, respectively. Pretreatment by oral administration of 0.15% (w/w) extract of Coptidis rhizoma or 0.10% (w/w) extract of Phellodendri cortex did not inhibit LPS-induced aqueous flare elevation. Pretreatment by oral administration of 0.15% extract of Gardeniae fructus suppressed LPS-induced aqueous flare elevation (AUC: 1411 arbitrary units). Pretreatment by intravenous injection of 3, 30 or 300 microg/kg of crocetin-inhibited LPS-induced aqueous flare elevation in a dose-dependent manner. Pretreatment with 3 or 30 microg/kg of crocetin did not inhibit PGE2-induced aqueous flare elevation, but 300 microg/kg of crocetin inhibited PGE2-induced aqueous flare elevation (AUC: 918 arbitrary units).     

Screening of several Indonesian medicinal plants for their inhibitory effect on histamine release from RBL-2H3 cells

Twelve alcoholic extracts and 12 hexane extracts of plant materials selected on the basis of medicinal folklore for asthma treatment in Indonesia were studied for their activity in inhibiting histamine release from RBL-2H3 cells (rat basophilic leukemia cell line), a tumor analog of mast cells. The results of screening indicated that five alcoholic extracts (Plantago major leaves, Eucalyptus globulus leaves and fruit, Cinnamomum massoiae cortex, Vitex trifolia leaves) and two hexane extracts (Eucalyptus globulus leaves, Vitex trifolia leaves) inhibited IgE-dependent histamine release from RBL-2H3 cells. The inhibitory effects were found to be more than 80% for extract concentrations of 0.5 mg/ml. The results indicate that the extracts contain active compounds that inhibit mast-cell degranulation, and provide insight into the development of new drugs for treating asthma and/or allergic disease.