Effect of Sophora flavescens Aiton extract on degranulation of mast cells and contact dermatitis induced by dinitrofluorobenzene in mice

Ethnopharmacological relevance

The dried root of Sophora flavescens Aiton (Sophorae radix, SR) has long been used in traditional medicine for the treatment of fever and swelling in eastern countries.

Materials and methods

The present study investigated the anti-allergic and anti-inflammatory effects of SR using 1-fluoro-2,4-dinitrofluorobenzene (DNFB)-induced contact dermatitis mouse model and in vitro using RBL-2H3 cells.

Results

In mice, the topical application of 10 mg/mL of SR effectively inhibited enlargement of ear thickness and weight induced by repeated painting with DNFB. Topical application of SR also inhibited hyperplasia, edema, spongiosis and infiltration of mononuclear cells in ear tissue. In addition, production levels of interferon-gamma and tumor necrosis factor-alpha were decreased by SR in vivo. Finally, the release of histamine and β-hexosaminidase, and migration were inhibited by treatment with SR.

Conclusions

These data indicate the potential of SR in treating patients with allergic skin diseases and also suggest that related mechanisms are involved in anti-inflammatory action on the Th 1 skewing reaction and inhibition against recruitment and degranulation of mast cells.     

Identification of the toxic constituents in Rhizoma Coptidis

Aim of the study

Rhizoma Coptidis (Huanglian) is a widely used Traditional Chinese Medicine. However, it causes human as well as animal toxicities. In this study, we aimed to ascertain the toxic constituents in Rhizoma Coptidis.

Materials and methods

The acute toxicity of both the total extract and the alkaloid-rich extract of Rhizoma Coptidis were tested in mice. The dose related tissue concentration of the Rhizoma Coptidis alkaloids in mice was determined using high performance liquid chromatography with ultraviolet detection. The influence of phenobarbital sodium [a non-selective hepatic enzyme (P450) inducer] on the acute toxicity of Rhizoma Coptidis as well as the tissue concentration of the alkaloids was investigated. The cytotoxicity of the Rhizoma Coptidis alkaloids was tested in six cell lines using the MTT assay.

Results

The median acute oral lethal dose of the total extract of Rhizoma Coptidis was 2.95 g/kg in mice. The alkaloid-rich extract was much more toxic than the total extract of Rhizoma Coptidis. Four Rhizoma Coptidis alkaloids were detected in brain, heart, and lung tissues of mice that received the oral total extract of Rhizoma Coptidis. Tissue concentration increased nonlinearly with higher doses. Phenobarbital sodium decreased the tissue concentration of every alkaloid as well as the toxicity of Rhizoma Coptidis. All alkaloids, especially berberine, showed dose and time dependent cytotoxicity.

Conclusions

The toxic constituents of Rhizoma Coptidis were the alkaloids, mainly berberine.     

Ligusticum chuanxiong as a potential neuroprotectant for preventing serum deprivation-induced apoptosis in rat pheochromocytoma cells: Functional roles of mitogen-activated protein kinases

Ethnopharmacological relevance

Ligusticum chuanxiong (LC) as a common component in many traditional Chinese medicinal formulas and decoctions has been used to treat different central nervous diseases, suggesting a neuroprotective function.

Aim of the study

To investigate the functional roles of mitogen-activated protein kinases (MAPKs) in mediating the neuroprotection of LC.

Materials and methods

Different extractions of LC were applied with or without MAPK inhibitor to test their protection against serum deprivation-induced apoptosis in rat neuronal-like pheochromocytoma (PC12) cells as revealed by an MTT assay or Hoechst staining. Western blot was used to identify the activations of MAPKs.

Results

The most effective butanol extraction (LC-BuOH) was used in the following experiments. LC-BuOH reversed serum deprivation-induced decreased phosphorylation of extracellular signal-regulated kinase (ERK) and increased phosphorylation of c-Jun NH₂-terminal kinase (JNK) and p38, the family of MAPKs. A PKA inhibitor, blocked the protection of LC-BuOH and partially blocked LC-BuOH-induced alterations in MAPKs, suggesting that the LC-BuOH regulates MAPKs through both PKA-dependent and -independent pathways. Although PD 98059, an inhibitor of MEK which activates ERK, blocked LC-BuOH-induced ERK phosphorylation, it did not block the protection of LC-BuOH.

Conclusions

LC-BuOH mediates protection by suppressing JNK/p38 instead of activating ERK activity.     

Effects of Catalpa ovata stem bark on atopic dermatitis-like skin lesions in NC/Nga mice

Ethnopharmacological relevance

The stem bark of Catalpa ovata has been used as a traditional herbal medicine for the treatment of various inflammatory diseases such as itching and scabies.

Aim of the study

In the present study, we investigated the anti-AD effects of Catalpa ovata stem bark on Dermatophagoides farinae-induced AD in a NC/Nga mouse AD model. We determined dermatitis score, histology, IgE, cytokines, and chemokines related to hypersensitive immune responses in AD. The mechanism of action was also investigated using HaCaT cells.

Materials and methods

We investigated the topical effects of Catalpa ovata stem bark on AD-like skin lesions in NC/Nga mice. Five category-experiments were performed, including assessment of dermatitis score; histological analysis of dorsal skin lesions; quantitative measurement of serum total IgE; quantitative measurement of cytokines (IL-1β, IL-4, IL-5, IL-6, IL-13, TNF-α) from dorsal tissue; and RT-PCR analysis of for TSLP and TARC mRNA expression in HaCaT cells.

Results

The clinical dermatitis score was significantly lower in Catalpa ovata extract (COE) groups than in the control group. Histological analysis showed that COE inhibited hypertrophy and hyperkeratosis of the epidermis, intracellular edema, and reduced the infiltration of inflammatory cells. COE significantly inhibited serum total IgE; Th2 cytokines IL-4, IL-5 and IL-13; pro-inflammatory cytokines IL-1β, IL6 and TNF-α; the Th2 chemokine TARC and the pro-Th2 cytokine TSLP.

Conclusion

These results demonstrate that Catalpa ovata stem bark may be a useful external medicine for treatment of AD. Further investigation is necessary to determine appropriate COE dosage and to evaluate the safety of this medicinal herb.     

Mechanisms of Panax ginseng in preventing rat pheochromocytoma cells from apoptosis

Aims of the study

Although ginseng root possesses dominant central therapeutic effects and has recently undergone investigations for treating different neuronal diseases, most of its mechanisms are still unknown. Therefore, the neuroprotective mechanisms of ginseng were studied.

Materials and methods

The protection afforded by different methanol extracts of Panax ginseng (PG) was tested in a serum deprivation-induced apoptotic model using neuronal-like pheochromocytoma (PC12) cells. An MTT assay, annexin V-FITC staining, and Western blots were, respectively, applied to identify the viability of cells, the apoptotic form of cell death, and the activity of antiapoptotic signaling.

Results

The known antiapoptotic PI3-K/Akt and MEK/ERK pathways in this system were ruled out due to failure of LY 294002 and PD 98059 to block the protection by PG. A protein kinase A (PKA) inhibitor was found to block the protection by PG and PG-induced CREB phosphorylation, suggesting that the PKA/CREB pathway mediates the protective effect of PG. Downregulation of classical and novel PKCs failed to block the protection by PG, while an atypical PKC inhibitor blocked protection by PG.

Conclusions

PKA and atypical PKC are important for the protection afforded by PG in preventing serum deprivation-induced PC12 cell apoptosis.     

The effects of Rhizoma drynariae on interleukin-2 and T-lymphocyte levels in rats after severe head injury

Objective

To investigate the effects of Rhizoma drynariae on the levels of interleukin-2(IL-2) and T-lymphocyte subset in rats with severe head injury (SHI).

Methods

72 Sprague Dawley (SD) rats were randomly divided into 3 groups: control group, model group, and R. drynariae group. The experimental group received intragastrical infusions of with aqueous R. drynariae extract four hours after SHI while the other groups were administered with equivalent volumes of physiological saline. Infusions were administered to the 3 groups once a day for 7 d. IL-2 and T-lymphocyte (CD3, CD4, CD8) levels were measured at 24, 72, and 168 h after initial infusion.

Results

The levels of IL-2 and CD4 T cells reduced obviously after 24 h in the model group (P<0.05), but recovered to the levels of the control group after 72 h, and remained elevated after 168 h. In the R. drynariae group, IL-2 and CD4 levels were did not decrease while the level of CD8 T cells was reduced significantly (P<0.05).

Conclusions

R. drynariae can protect against immune dysfunction or improve immunity in rats with severe head injury (SHI).     

The effect of Dodonaea viscosa var. angustifolia on Candida albicans proteinase and phospholipase production and adherence to oral epithelial cells

Aim of the study

This study investigated effect of a crude extract of Dodonaea viscosa on the proteinase and phospholipase production and adherence to epithelial cells by Candida albicans isolated from HIV positive and HIV negative patients.

Materials and methods

Twenty Candida albicans strains isolated from HIV positive and 20 from HIV negative patients were investigated. The isolates were exposed to subinhibitory concentration of crude plant extract and adherence, proteinase and phospholipase production were assessed. The results were analysed using Student's t-test and a two-way ANOVA.

Results

Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells (p = <0.01) but no significant effect of the plant extract on proteinase and phospholipase production was observed. Results from Candida albicans strains isolated from HIV positive and HIV negative patients were similar.

Conclusions

Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells, which is the initial step of colonization in the infection process. This plant has a therapeutic potential at subinhibitory concentration.     

Pharmacological investigation on the wound healing effects of Radix Rehmanniae in an animal model of diabetic foot ulcer

Ethnopharmacological relevance

Radix Rehmanniae (RR) has a very long history of usage in traditional Chinese medicine and is usually one of the principal herb found in many herbal formulae used in diabetic foot ulcer.

Aim of the study

RR aqueous extract was investigated for its wound healing effects in a diabetic foot ulcer rat model and its detailed mechanism of actions.

Materials and methods

A previously established diabetic foot ulcer rat model was used to assess the effect of RR extract on wound area reduction, tissue regeneration and angiogenesis. Carrageenan-induced inflammation rat model was used for inflammation study; and diabetic control was evaluated using a neonatal streptozotocin-induced diabetic rat model.

Results

In the RR treated group, a trend of reduction of the wound area was observed from days 8 to 18 and a significant difference (as compared with control group) was found on day 8. The ulcer healing effect of RR extract was further supported by better developed scars and epithelialization as well as good formation of capillaries with enhanced VEGF expression. Carrageenan-induced inflammation was also significantly alleviated with RR extract.

Conclusions

Our results demonstrated for the first time that Radix Rehmanniae was effective in promoting diabetic foot ulcer healing in rats through the processes of tissue regeneration, angiogenesis and inflammation control, but not glycemia control. The present study provided scientific basis to support the traditional use of Radix Rehmanniae in diabetic foot ulcer.     

Inhibitory effects of Acorus calamus extracts on mast cell-dependent anaphylactic reactions using mast cell and mouse model

Ethnopharmacological relevance

Acorus calamus Linn. (Araceae) is a traditional herbal plant used for centuries to treat various allergic symptoms including asthma and bronchitis.

Aim of the study

The present study was focused to provide a pharmacological basis for the traditional use of Acorus calamus in allergic symptoms using the mast cell-dependent anaphylactic reactions in in vitro and in vivo models.

Materials and methods

Cell viabilities were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Dinitrophenyl-human serum albumin (DNP-HSA) induced β-hexosaminidase and interleukin (IL)-4 productions in IgE-sensitized rat basophilic leukaemia (RBL-2H3) cells were measured by enzymatic assay and enzyme-linked immunosorbent assay (ELISA). Passive cutaneous anaphylaxis (PCA) reaction mouse model was implemented for in vivo studies.

Results

Hot water (HW), butylene glycol (BG), hexane (HE) and steam distilled (SD) extracts of Acorus calamus showed different cytoxicity levels evaluated in RBL-2H3 cells. Sub-toxic doses of HW extract suppressed the β-hexosaminidase secretion and IL-4 production significantly and dose dependently in DNP-HSA induced IgE-sensitized RBL-2H3 cells compared to other extracts of Acorus calamus. Further, in vivo studies also revealed that the HW extract significantly inhibited the PCA reaction in mouse compared to the normal control group.

Conclusion

HW extract of Acorus calamus most effectively inhibited degranulation and IL-4 secretion in DNP-HSA-stimulated RBL-2H3 cells and also reduced the mast cell-mediated PCA reaction in mouse, providing a therapeutic evidence for its traditional use in ameliorating allergic reactions.     

Immunomodulatory and antitumor activity of triterpenoid fractions from the rhizomes of Astilbe chinensis

Aim of the study

The objectives of this study were to evaluate the in vivo antitumor potential of the triterpenoid fraction from the rhizomes of Astilbe chinensis (Saxifragaceae) (Saxifragaceae) (ATF) and to elucidate its immunological mechanisms by determining its effects on the growth of mouse transplanted tumors and the immune response in naïve and tumor-bearing mice.

Materials and methods

The mice inoculated with mouse tumor cell lines were treated per os with ATF at the doses of 20, 40, 60 mg/kg for 10 days. The effects of ATF on the growth of transplantable tumor, splenocyte proliferation, the activity of natural killer (NK) cells, and production of interleukin-2 (IL-2) from splenocytes in tumor-bearing mice were measured. Meanwhile, the effects of ATF on 2,4-dinitrofluorobenzene (DNFB)-induced delayed type hypersensitivity (DTH) reaction and the sheep red blood cell (SRBC)-induced antibody response in naïve mice were also studied.

Results

ATF could not only significantly inhibit the growth of mice transplantable tumor, but also remarkably increase splenocytes proliferation, NK cells activity, and the level of IL-2 secreted by splenocytes in tumor-bearing mice, promote the DTH reaction and enhance anti-SRBC antibody level in naïve mice, which indicated that the ATF could improve both specific and non-specific cellular and humoral immune response.

Conclusions

The antitumor activity of ATF might be achieved by improving immune response, and ATF could act as antitumor agent with immunomodulatory activity.     

Pharmacokinetics and tissue distribution of resveratrol,emodin and their metabolites after intake of Polygonum cuspidatum in rats

Ethnopharmacological relevance

The rhizome of Polygonum cuspidatum SIEB. et ZUCC. (Polygonaceae, PC), a widely used Chinese medicine, is commonly prescribed for the treatments of amenorrhea, arthralgia, jaundice, abscess, scald and bruises.

Aim of the study

PC contains various polyphenols including stilbenes, anthraquinones and flavonoids. This study investigated the pharmacokinetics and tissue distribution of emodin and resveratrol in PC.

Material and methods

Male Sprague-Dawley rats were orally administered PC (2 and 4 g/kg) and blood samples were withdrawn at the designed time points via cardiopuncture. Moreover, after 7-dose administrations of PC (4 g/kg), brain, liver, lung, kidney and heart were collected. The concentrations of resveratrol and emodin in the plasma and tissues were assayed by HPLC before and after hydrolysis with β-glucuronidase and sulfatase.

Results

The glucuronides/sulfates of emodin and resveratrol were exclusively present in the plasma. In liver, kidney, lung and heart, the glucuronides/sulfates of resveratrol were the major forms. For emodin, its glucuronides/sulfates were the major forms in kidney and lung, whereas considerable concentration of emodin free form was found in liver. Neither free forms nor conjugated metabolites of resveratrol and emodin were detected in brain.

Conclusion

The sulfates/glucuronides of resveratrol and emodin were the major forms in circulation and most assayed organs after oral intake of PC. However, the free form of emodin was predominant in liver.     

Investigation of the absorbed and metabolized components of Danshen from Fuzheng Huayu recipe and study on the anti-hepatic fibrosis effects of these components

Ethnopharmacology

Fuzheng Huayu recipe (FZHY) was formulated on the basis of Chinese medicine theory in treating liver fibrosis. It has a significant efficacy against liver fibrosis caused by chronic hepatitis B, with the action mechanisms of inhibition of hepatic stellate cell activation, protection of hepatocyte oxidative injury and regulations of hepatic matrix remodeling etc.

Aim of the study

To identify the absorbed components and metabolites of Danshen in FZHY in rat serum, and find their active components for anti-liver fibrosis.

Material and methods

A valid high performance liquid chromatography–electrospray ionization ion trap mass spectrometry (HPLC-ESI/MSⁿ) method was established to investigate the absorbed and metabolized compounds of Danshen in FZHY in rat serum after oral administration. Mass spectra were acquired in both negative and positive modes. Otherwise, to evaluate the anti-hepatic fibrosis efficacies of absorbed and metabolized compounds, the LX-2 cell line of hepatic stellate cell (HSC), which was crucial cellular basis of fibrogenesis, was cultured and incubated with absorbed compounds, the cytotoxicity was determined with the cellomics Multiparameter Cytotoxicity Kit 1 by High Content Screening (HCS), the cell proliferation was assayed with EdU-DNA incorporation, and the cell activation was analyzed through α-smooth muscle actin (α–SMA) expression with high content screening technology.

Results

More than 11 compounds and 2 metabolites from Danshen were identified in the serum after oral administration of FZHY by comparing their mass spectra and retention behavior with reference compounds or literature data. Among these compounds, there were no obvious changes in nuclear morphology, membrane permeability with blow 96 μM of six polar compounds treatment in comparison with control cells, respectively. And the salvianolic acid B (6 μM, 48 μM), caffeic acid (6 μM, 48 μM) and rosmarinic acid (48 μM) could obviously inhibit LX-2 cells proliferation, down-regulate α–SMA expression.

Conclusion

The results proved that the established method could be applied to analyze the absorbed into blood compounds of Danshen after oral administration FZHY. These absorbed compounds included 11 compounds and 2 metabolites of Danshen. Among them, the salvianolic acid B, caffeic acid and rosmarinic acid were the effective components of FZHY to anti-hepatic fibrosis effects.     

Study on the correlation between constituents detected in serum from Rhizoma Smilacis Glabrae and the reduction of uric acid levels in hyperuricemia

Ethnopharmacological relevance

Rhizoma Smilacis Glabrae (RSG) has been used in the clinical treatment of gout and hyperuricemia in China for thousands of years. Modern pharmacological studies have shown that RSG exhibits hypouricemic effects because of its significant inhibitory effect on the activity of xanthine oxidase.

Materials and methods

The Rhizoma Smilacis Glabrae extract (RSGE) at 1 mL/100 g oral administration was demonstrated to possess in vivo potent hypouricemic effects in hyperuricemic rats pretreated with oxonic acid potassium salt (200 mg/kg, 2 mL/kg). UPLC–MS was used to identify the constituents absorbed in the serum. In addition, a bivariate correlation analysis between the changes in the relative contents of the constituents from RSGE detected by HPLC and the serum uric acid levels in hyperuricemic rats at different points in time was used to calculate their correlation coefficients.

Results

A total of 14 constituents were observed in the RSGE-treated rat serum, and 11 of these were inferred. An RSGE constituent was considered correlated with the hypouricemic effects if its correlation coefficient was above 0.5. The results suggested that only seven of the constituents absorbed in the serum of the hyperuricemic rats were correlated with hypouricemic effects, namely, palmitic acid, 3′-O-methyltaxifolin glucuronide, 3′-O-methyiastilbin glucuronide, astilbin glucuronide, 5-O-caffeoylshikimic acid glucuronide, resveratrol glucuronide, and dihydrokaempferol.

Conclusion

These findings provide potent evidence for the study on RSG as a pharmacodynamic material basis and for developing RSG as a safe and promising natural drug to prevent hyperuricemia and gout instead of allopurinol.     

Drosera rotundifolia and Drosera tokaiensis suppress the activation of HMC-1 human mast cells

Ethnopharmacological relevance

Several Northern Hemisphere Drosera species have been used in the therapy of respiratory tract infections as the traditional medicine Droserae Herba.

Aim of the study

To determine the anti-inflammatory effects of Drosera species and to investigate a substitute material for Droserae Herba, we examined the effect of extracts of Drosera rotundifolia, Drosera tokaiensis and Drosera spatulata on activated T cell membrane (aTc-m)-induced inflammatory gene expression in HMC-1 human mast cells.

Materials and methods

Drosera rotundifolia, Drosera spatulata and Drosera tokaiensis were collected in Japan. Herbs were extracted with 80% EtOH, and subsequently applied to OASIS HLB column. HMC-1 cells were treated with each Drosera column-adsorbed fraction for 15 min, and subsequently added to aTc-m and incubated for 16 h. Inflammatory gene and protein expressions were determined by DNA microarray, RT-PCR and Western blotting.

Results

Drosera rotundifolia and Drosera tokaiensis fractions, but not the Drosera spatulata fraction, suppressed inflammatory gene expression induced by aTc-m in HMC-1 cells.

Conclusions

Drosera rotundifolia and Drosera tokaiensis suppressed activation of HMC-1 cells induced by aTc-m. Since the Drosera tokaiensis fraction was more effective than the traditionally used Drosera rotundifolia, Drosera tokaiensis is a likely substitute as a source of Droserae Herba.     

Effects of San-Huang-Xie-Xin-tang,a traditional Chinese prescription for clearing away heat and toxin,on the pacemaker activities of interstitial cells of Cajal from the murine small intestine

Ethnopharmacological relevance

San-Huang-Xie-Xin-Tang (SHXXT) is a traditional Chinese medicinal formula composed of Coptidis rhizoma (Coptis chinesis Franch), Scutellariae radix (Scutellaria baicalensis Georgi), and Rhei rhizoma (Rheum officinale Baill) and is widely used in Eastern Asia, especially to ameliorate the symptoms of gastrointestinal (GI) disorders related to gastritis, gastric bleeding, peptic ulcers, and abnormal GI motility

Aim of the study

Interstitial cells of Cajal (ICCs) are pacemaker cells in the GI tract that generate rhythmic oscillations in membrane potentials known as slow waves. Because GI disorders, especially abnormal GI motility, are major lifelong problems, the authors investigated the effects of SHXXT on mouse small intestine ICCs, and sought to identify the receptors and the action mechanisms involved.

Materials and methods

Enzymatic digestions were used to dissociate ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record potentials generated by cultured ICCs.

Results

SHXXT produced membrane depolarization in current-clamp mode, and Y25130 (a 5-HT₃ receptor antagonist) and RS39604 (a 5-HT₄ receptor antagonist) blocked SHXXT-induced membrane depolarizations, whereas SB269970 (a 5-HT₇ receptor antagonist) did not. However, during external Ca²⁺ free conditions or in the presence of thapsigargin, SHXXT did not exhibit membrane depolarization. Furthermore, the application of flufenamic acid (a nonselective cation channel (NSCC) blocker) or DIDS (a chloride channel blocker) abolished pacemaker potential generation and blocked SHXXT-induced membrane depolarizations. In addition, SHXXT-induced membrane depolarizations, which are dependent on G-protein, in ICCs were blocked by PD 98059 (a p42/44 mitogen-activated protein kinase (MAPK) inhibitor), SB203580 (a p38 MAPK inhibitor), and by a c-jun NH2-terminal kinase (JNK) II inhibitor. Regarding the components of SHXXT, Coptidis rhizome and Rhei rhizoma modulated ICC pacemaking activity, whereas Scutellariae radix did not.

Conclusion

SHXXT modulates pacemaker potentials via 5-HT₃ and 5-HT₄ receptor-mediated pathways, external Ca²⁺ influx, and Ca²⁺ release from internal stores. Furthermore, NSCCs and Cl- channels play important roles in the regulation of pacemaking activity in a MAPK dependent manner in ICCs. The regulation of pacemaking activity by SHXXT may be due to the activity of Coptidis rhizome and Rhei rhizome. The study shows SHXXT can modulate the pacemaking activity of ICCs in the GI tract, and thus, suggests SHXXT has potential pharmacological relevance for the treatment of GI motility disorders.     

Inhibitory activity of Dodonaea viscosa var. angustifolia extract against Streptococcus mutans and its biofilm

Ethnopharmacological relevance

The leaves of Dodonaea viscosa var. angustifolia (DVA) are traditionally used for the treatment of fever, colds, oral thrush, toothaches and related problems. Streptococcus mutans is implicated in many oral infections. This study investigated the inhibitory activity of DVA extract against Streptococcus mutans and its biofilm.

Materials and Methods

Crude extract of the leaves was prepared using methanol. The time-kill curve for Streptococcus mutans at different concentrations of methanol extract after 6 and 24 h was determined. Biofilms of Streptococcus mutans were grown in the presence of subinhibitory concentration of extract (0.78 mg/ml) for 30 h and the bacterial counts were obtained after 6, 24 and 30 h. The chemical profile of the crude extract was obtained using gas chromatography-mass spectrometry (GC-MS).

Results

The reduction of Streptococcus mutans was concentration and exposure time dependent. The crude extract killed 48% of S. mutans at a lowest concentration of 0.1 mg/ml and 100% at 25 mg/ml after 6 h. Biofilm formation was reduced by 95, 97 and 99% after 6, 24 and 30 h of exposure to the subinhibitory concentration of crude extract respectively. GC–MS analyses revealed the presence of polyphenols such as catechin or chromene groups, chalcones with trimethoxyphenyl group and tannin with 4-O-β-D-xylopyranoside. At high concentration the crude extract was bactericidal to Streptococcus mutans but subinhibitory concentration significantly reduced the planktonic cells and biofilm formation.

Conclusions

These results suggest that this plant has the potential to be used to control S. mutans and its biofilm which are responsible for oral infections.     

Inhibitory effect of Coptis chinensis on inflammation in LPS-induced endotoxemia

Ethnopharmacological relevance

Rhizoma coptidis (RC) has been used as a remedy for inflammation-related diseases in traditional medicine. Although it is known to have anti-inflammatory activities, its mechanism of action on lipopolysaccharide (LPS)-induced inflammation has not yet been identified in detail.

Aim of the study

This study was designed to assess the beneficial effects of pretreatment with RC in ameliorating LPS-induced liver inflammation.

Materials and methods

Mice were orally administered RC (500, 1000 mg/kg) for three days in a row. 1 h after the last RC administration, the mice were intraperitoneally injected with LPS (35 mg/kg). After treatment, histological alterations and inflammatory factor levels in the liver and proinflammatory cytokines in the serum associated with inflammation were examined.

Results

We found that pretreatment with RC (500 and 1000 mg/kg) exerted a significant protective effect by attenuating liver histopathological changes in endotoxemic mice. The results also demonstrated that RC suppressed secretion of LPS-stimulated pro-inflammatory cytokines, such as interleukin-6 (IL-6). Furthermore, RC inhibited LPS-mediated nuclear factor (NF)-κB activation via the prevention of IκB-α phosphorylation, as well as the phosphorylation of ERK1/2, JNK, and p38 MAPKs. These results were associated with decreases in the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (I-NOS).

Conclusions

The results presented here clearly demonstrate that RC could significantly protect mice against LPS-induced acute liver injury.     

Rhizoma coptidis and berberine-induced activation of murine microglia N9 cells

Aims of the study

To investigate the effect of water extract of Rhizoma coptidis (WEC) and berberine on the activation of murine microglia N9 cells and corresponding mechanism related to mitochondria.

Materials and methods

Phagocytic activity of murine microglia N9 cells was measured by neutral red staining method after the cells were treated with various concentrations of WEC and alkaloids for 24 h. Flow cytometric analysis was performed to determine the level of intracellular ROS, Ca²⁺, and mitochondrial transmembrane potential (Δψ) after 87 μg/ml of WEC and 12.4 μg/ml of berberine treatment. Global changes of gene expression in WEC- and berberine-treated N9 cells were measured using cDNA microarray.

Results

WEC and berberine, but not palmatine and jatrorrhizine, enhanced phagocytic activity of murine N9 cells in a dose-dependent manner. Both of WEC and berberine stimulated free radical generation, enhanced mitochondrial Δψ and induced gene expression of Ndufab1, Cox6a2 and Atp5a1. However, a more significant phagocytic effect was observed for WEC. WEC, but not berberine, increased intracellular Ca²⁺ concentration. The gene expression of Atp5c1 was selectively up-regulated by WEC, while three genes of Uqcrq, Cox8b, and Atp5g2 were induced by berberine.

Conclusions

WEC and berberine activated murine microglia N9 cells by the regulation of mitochondrial function and mitochondria-related signal molecules. The action of WEC is stronger than that of berberine, indicating that the effect of WEC is ascribed partially, but not totally, to berberine.