Role of Coptis chinensis in antibiotic susceptibility of carbapenem-resistant Klebsiella pneumoniae.

BACKGROUND: The incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has rapidly increased. This study aimed to assess the effect of Coptis chinensis and its compounds on the minimal inhibitory concentrations (MICs) of eight antibiotics against CRKP. METHODS: Cell cultures were used to investigate the effects of C. chinensis and its compounds on the MICs of eight antibiotics against CRKP. The MICs for antibiotics alone and antibiotics with C. chinensis or compounds were measured and compared. Furthermore, the effects of C. chinensis on cell membrane injury and intracellular adenosine triphosphate (ATP) CRKP concentration were also measured. The Mann-Whitney rank-sum test was used to analyze the differences between means. RESULTS: C. chinensis exhibits a notable MIC bacteriostatic effect at 5 mg/mL on CRKP. A significant MIC reduction against CRKP exists when C. chinensis was added to colistin and colistin-containing two-antibiotic combinations. Moreover, C. chinensis could damage cell membrane integrity and decrease intracellular ATP concentration in CRKP. Thus, C. chinensis exhibits antimicrobial activity superiority with colistin against CRKP. Furthermore, the effects of identified compounds in C. chinensis on the MICs of colistin, four-to eight-, two-to four-, and one-to two-fold reductions were found in ferulic acid, magnoflorine, and jatrorrhizine hydrochloride, respectively. Among these compounds, ferulic acid destroys membrane integrity and decreases intracellular ATP concentration. CONCLUSION: C. chinensis and ferulic acid can potentiate the antimicrobial activity of colistin and may represent a promising component of combination therapy against CRKP infections in a clinical setting.

Bioactivity and potential health benefits of licorice.

Licorice is an herbal plant named for its unique sweet flavor. It is widely used in the food and tobacco industries as a sweetener. Licorice is also used in traditional Chinese medicine (TCM) and complementary medicine. Because the use of licorice has long been a part of TCM, the details of its therapeutic applications have been thoroughly established. In modern science, licorice is of interest because of its broad range of applications. Extracts of and compounds isolated from licorice have been well studied and biologically characterized. In this review, we discuss the nutraceutical and functional activities of licorice as well as those of the extracts of and the isolated compounds from licorice, including agents with anti-inflammatory activity, cell-protective abilities, and chemopreventive effects. The side effects of licorice are also enumerated. A comparison of the activities of licorice described by modern science and TCM is also presented, revealing the correspondence of certain characteristics.

Glycyrrhizic acid and 18ß-glycyrrhetinic acid recover glucocorticoid resistance via PI3K-induced AP1, CRE and NFAT activation.

Glucocorticoids are widely used in the clinical setting as remedies for inflammatory diseases, such as asthma and chronic obstructive pulmonary disease. However, the constant increase in the number of patients suffering from glucocorticoid resistance could present a serious problem for clinicians. In these cases, it may be reasonable to use additional treatments to restore the therapeutic effect of glucocorticoids. Glycyrrhizic acid (GA) and 18ß-glycyrrhetinic acid (18ßGA) are bioactive compounds in licorice that have been used for thousands of years in traditional Chinese medicine to treat coughs. We showed that GA and 18ßGA exhibit potential anti-inflammatory and antioxidant properties. GA and 18ßGA induced dual specificity protein phosphatase 1 (DUSP1) expression, and this effect was unchanged by the addition of RU486, a glucocorticoid receptor antagonist. The stimulation of DUSP1 expression by GA and 18ßGA occurred via both glucocorticoid receptor (GR) and PI3K signaling, and the simultaneous activation of transcription elements, such as AP1 (activator protein 1), CRE (cAMP response element), GRE (glucocorticoid receptor element) and NFAT (nuclear factor of activated T-cells), was confirmed. Furthermore, we designed an in vitro glucocorticoid resistance model to verify the effects of GA and 18ßGA on glucocorticoid resistance that was induced by ROS. The data showed that these two phytochemicals restored glucocorticoid sensitivity by depleting ROS through HO-1 expression. p38 and NO, which are factors that are induced by reactive oxygen species and caused depletion of GR signaling, were inhibited by GA and 18ßGA treatment. This phenomenon was considered to be related to the coordinated modulation of GR and PI3K signaling by GA and 18ßGA, in conjugation with AP1, CRE, GRE and NFAT activation. This study provides a possible strategy for enhancing the efficacy of glucocorticoids and may improve the prognosis of patients with serious inflammatory diseases.

Glycyrrhizic acid and 18ß-glycyrrhetinic acid modulate lipopolysaccharide-induced inflammatory response by suppression of NF-κB through PI3K p110δ and p110γ inhibitions.

The roots and rhizomes of licorice ( Glycyrrhia ) species have been used extensively as natural sweeteners and herbal medicines. The aim of this work was to determine the in vitro anti-inflammatory effects of glycyrrhizic acid (GA) and 18ß-glycyrrhetinic acid (18ßGA) from licorice in a lipopolysaccharide (LPS)-stimulated macrophage model. The results showed that treatment with 25-75 µM GA or 18ßGA did not reduce RAW 264.7 cell viability but did significantly inhibit the production of LPS-induced nitric oxide (NO), prostaglandin E(2) (PGE(2)), and intracellular reactive oxygen species (ROS). Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that GA and 18ßGA significantly reduced the protein and mRNA levels of iNOS and COX-2 in LPS-induced macrophages. Both GA and 18ßGA inhibited the activation of NF-κB and the activities of phosphoinositide-3-kinase (PI3K) p110δ and p110γ isoforms and then reduced the production of LPS-induced tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1ß in a dose-dependent manner. In conclusion, these results indicate that GA and 18ßGA may provide an anti-inflammatory effect by attenuating the generation of excessive NO, PGE(2), and ROS and by suppressing the expression of pro-inflammatory genes through the inhibition of NF-κB and PI3K activity. Thus, the results suggest that GA and 18ßGA might serve as potential agents for the treatment of inflammatory-mediated diseases.

Glycyrrhizic acid and 18beta-glycyrrhetinic acid inhibit inflammation via PI3K/Akt/GSK3beta signaling and glucocorticoid receptor activation.

Many lung-related diseases, such as asthma and chronic obstructive pulmonary disease, are initiated by airway inflammation, and several studies indicate that glycyrrhizic acid (GA) alleviates inflammatory lung disease. We previously showed that GA and 18beta-glycyrrhetinic acid (18betaGA), found in licorice, can act as neuroprotective agents by promoting downstream PI3K/Akt signaling. In this study, we investigate the effects of GA and 18betaGA on inflammation. We show that both GA and 18betaGA reduce inflammatory cytokine production and its resulting anti-inflammation. GA acts via PI3K/Akt/GSK3beta to reduce cytokine production, while 18betaGA leads to the dissociation of a glucocorticoid receptor (GR)-HSP90 complex to block inflammation. Our data suggest that GA and 18betaGA display anti-inflammatory activities but inhibit inflammation via different mechanisms. We propose that GA and 18betaGA may be valuable biological inhibitors of lung inflammation. Interestingly, these data may explain why licorice is frequently used to treat inflammatory disease and it might be a promising nutraceutical for remedying inflammation.

Oleanolic acid and ursolic acid induce apoptosis in HuH7 human hepatocellular carcinoma cells through a mitochondrial-dependent pathway and downregulation of XIAP.

Oleanolic acid (OA) and ursolic acid (UA) are commonly found in plants and herbs and have been reported to possess hepatoprotective, anti-inflammatory and anticancer activities. In the present study, the effects of OA and UA on induction of apoptosis in human hepatocellular carcinoma HuH7 cells and the related mechanisms were investigated. The results demonstrate that OA and UA could inhibit the growth of HuH7 cells with IC(50) values of 100 and 75 microM, respectively. Cell cycle analysis using flow cytometry indicated that the fraction of HuH7 cells in sub-G1 phase progressively increased with increasing concentrations of OA or UA from 20 to 80 microM. Treatment with OA and UA for 8 h induced a dramatic loss of the mitochondria membrane potential and interfered with the ratio of expression levels of pro- and antiapoptotic Bcl-2 family members in HuH7 cells. OA and UA-induced apoptosis involving the release of mitochondria cytochrome c into the cytosol and subsequently induced the activation of caspase-9 and caspase-3, followed by cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, HuH7 cells treated with OA and UA suppressed the activity of NF-kappaB and modulated the mRNA expression of X-linked inhibitor of apoptotic protein (XIAP) as compared with untreated cells. These results demonstrate that OA and UA induce apoptosis in HuH7 cells through a mitochondria-mediated pathway and downregulation of XIAP.

Neuroprotective effects of glycyrrhizic acid and 18beta-glycyrrhetinic acid in PC12 cells via modulation of the PI3K/Akt pathway.

Glycyrrhizic acid (GA) and 18beta-glycyrrhetinic acid (18betaGA) are the bioactive compounds of licorice. The neuroprotective effects of GA and 18betaGA against serum/glucose deprivation and 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in PC12 cells were investigated. The intracellular reactive oxygen species (ROS) content, the activity of the antioxidant enzymes of glutathione peroxidase (GPx) and catalase, the mitochondrial membrane potential (MMP), and the mitochondrial Bax/Bcl-2 ratio were determined. PI3K/Akt pathway signaling was also evaluated to study the possible protective mechanism. The results showed that GA treatment decreased the ROS content by elevating the activities of GPx and catalase, leading to a decreased MMP. GA and 18betaGA also lowered the mitochondrial Bax/Bcl-2 ratio and activated PI3K/Akt signal. The results suggest that GA may protect PC12 cells from ischemic injury via modulation of the intracellular antioxidant system and mitochondria-induced apoptosis. Moreover, GA and 18betaGA may modulate the ratio of the mitochondrial Bcl-2 family and influence PI3K/Akt signaling. These results demonstrate the neuroprotective ability of GA and 18betaGA and suggest that the cytotoxicity of 6-OHDA may influence the mitochondrial Bax/Bcl-2 ratio without altering the expression of Bax. This study also suggests a possible compound for treating neural disease and general neuronal health.

Hsian-tsao (Mesona procumbens Heml.) prevents against rat liver fibrosis induced by CCl(4) via inhibition of hepatic stellate cells activation.

In this study, the protective effect of extract of Hsian-tsao (Mesona procumbens) (EHT) against liver fibrogenesis in carbon tetrachloride (CCl(4))-injured rats was evaluated. The inhibitory effect of oleanolic acid (OA) and ursolic acid (UA), which are the active compounds in EHT, on the activation of hepatic stellate cells (HSC) was also determined. The results showed that EHT at a dosage of 1.2g/kg of b.w. significantly reduced the liver injury induced by CCl(4) in rats. It also decreased the activity of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and the deposition of collagen in the liver. Oral administration of EHT reduced the levels of alpha-smooth muscle actin (alpha-SMA) and the activity of metalloproteinases (MMPs) in rats injured by treatment with CCl(4). In addition, we performed experiments with the rat hepatic stellate cell line HSC-T6 in which we induced the expression of MMP-2 and alpha-SMA with phorbol-12-myristate-13-acetate (PMA). Treating these cells with OA (20microM) or UA (10microM) caused a decrease in the levels of both proteins. Taken together, our data indicate that EHT can efficiently inhibit CCl(4)-induced liver fibrosis in rats. EHT may therefore be a useful functional food for preventing liver fibrosis.