Chu-Wen Li

Anti-Candida albicans activity and pharmacokinetics of pogostone isolated from Pogostemonis Herba

The present work was designed to evaluate the in vitro and in vivo anti-Candida activity of pogostone (PO), a natural product isolated from Pogostemon cablin (Blanco) Benth. PO showed potent in vitro activity against clinical Candida spp. isolates tested in this study. PO and the reference drug voriconazole (VRC) were equally effective against all the fluconazole-resistant Candida albicans strains, with MIC ranging from 3.1 μg/ml to 50 μg/ml. Besides, PO was fungicidal against all Candida isolates with MFC ranging from 50 μg/ml to 400 μg/ml. By contrast, VRC was fungistatic as it failed to elicit a fungicidal effect against the Candida spp. isolates at the highest tested concentration (400 μg/ml). Furthermore, oral and topical PO administration effectively reduced the fungal load in vagina of vulvovaginal candidiasis mouse models. Topical PO administration (1.0-4.0 mg/kg) demonstrated higher activity against the vulvovaginal candidiasis than VRC (4.0 mg/kg). The pharmacokinetics and safety profile of PO were also investigated. The pharmacokinetics assay revealed that PO was easily absorbed after oral administration in mice, which might account for its in vivo anti-Candida effect. The acute toxicity test showed that the median lethal dose of PO in mice was 355 mg/kg, which was much higher than the daily dose used for the therapeutic experiments. This study demonstrated the potential of PO as a promising candidate for the treatment of Candida infections, particularly for vulvovaginal candidiasis.

Synthesis and antimicrobial evaluation of pogostone and its analogues

Pogostone (PO) is one of the secondary metabolites from Pogostemon cablin (Blanco) Benth. (Lamiaceae), serving as the effective component of the antimicrobial activity. In this study, PO and a series of its analogues were synthesized by the reaction of dehydroacetate and aldehydes in tetrahydrofuran under a nitrogen atmosphere. Their activities against Candida albicans, Gram positive bacteria and Gram negative bacteria were evaluated. The antifungal results demonstrated that PO (MIC ranged from 12 to 97μg/mL against all strains, MFC ranged from 49 to 97μg/mL against all strains) and A3 (MIC ranged from 12 to 49, MFC over 195μg/mL) showed a strong activity against Candida albicans. While A1 (MIC ranged from 49 to 97μg/mL) and A2 (MIC ranged from 24 to 49μg/mL) have only shown effect against Guangzhou clinical isolates, the antibacterial results demonstrated that PO and its analogues showed no effects against the tested bacteria strains. This study suggests that pogostone analogues, with the appropriated structure modification, represented a kind of promising antifungal agents.

Prevention of UV radiation-induced cutaneous photoaging in mice by topical administration of patchouli oil

ETHNOPHARMACOLOGICAL RELEVANCE Pogostemon cablin has been widely used in traditional Chinese medicine for the treatment of many diseases, including skin disorders. In the skin beauty and care prescriptions, Pogostemon cablin is one of the top ten frequently used traditional Chinese medicines. AIM OF THE STUDY The present study was aimed to investigate the protective effects of the essential oil of Pogostemon cablin (patchouli oil, PO) against UV-induced skin photoaging in mice. MATERIALS AND METHODS To ensure the quality of PO, the chemical compositions of PO were identified, and the content of its chemical marker patchouli alcohol was determined, which was around 28.2% (g/g) in PO. During the experiment period, the dorsal depilated skin of mice was treated with PO for two hours prior to UV irradiation. Then the protective effects of PO on UV-induced skin photoaging were determined by macroscopic and histological evaluations, skin elastic test, collagen content determination and biochemical assays of malondiaidehyde (MDA) content, activities of anti-oxidative indicators including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). RESULTS Compared to UV exposure groups, present results showed that topical administration of PO, especially at dose of 6mg/mouse and 9mg/mouse, significantly inhibited the increase in skin wrinkle formation, alleviated the reduction in skin elasticity and increased the collagen content by about 21.9% and 26.3%, respectively. We also found that application of 6-9mg/mouse PO could not only decrease the epidermal thickness by about 32.6%, but also prevent the UV-induced disruption of collagen fibers and elastic fibers. Furthermore, the content of MDA was decreased by almost 26.5% and activities of SOD, GSH-Px and CAT were significantly up-regulated after the treatment of PO. CONCLUSION Results of present study revealed that PO was capable of maintaining skin structural integrity caused by UV irradiation and it was useful in preventing photoaging. These protective effects of PO were possibly due to its anti-oxidative property. Therefore, we suggested that PO should be viewed as a potential therapeutic agent for preventing photoaging.

Pogostone suppresses proinflammatory mediator production and protects against endotoxic shock in mice

ETHNOPHARMACOLOGICAL RELEVANCE Pogostemon cablin (Blanco) Benth is a well-known medicinal herb commonly used in many Asian countries for inflammatory diseases. Pogostone (PO), a natural product isolated from Pogostemon cablin, is known to exert various pharmacological activities. This study aimed to investigate the anti-inflammatory property of PO, to elucidate its mechanism of action, and to evaluate its potential acute toxicity. MATERIALS AND METHODS The in vitro anti-inflammatory activity of PO was assessed using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The protein and mRNA levels of proinflammatory mediators were measured with ELISA and RT-PCR, respectively. Proteins of the NF-κB and MAPK family were determined by Western blot to investigate the underlying molecular mechanisms. The in vivo anti-inflammatory activity of PO was tested using LPS-induced endotoxic shock in mice. In addition, the median lethal dose (LD50) of PO in mice was tested in an acute toxicity test. RESULTS In vitro, PO significantly inhibited the protein and mRNA expression of proinflammatory mediators including TNF-α, IL-6, IL-1β, NO, and PGE2. The action mechanism of the anti-inflammatory activity of PO was partly dependent on inhibition of the activation of NF-κB and the phosphorylation of JNK and p38 MAPK. In vivo, PO was able to significantly reduce the mortality induced by LPS in mice. Furthermore, PO could markedly suppress the production of the proinflammatory mediators in serum, and attenuate liver and lung injury. The action mechanisms of PO during endotoxic shock may be attributed to down-regulation of the mRNA expression of inflammatory mediators in multiple organs via inhibition of the activation of NF-κB and the phosphorylation of p38 MAPK. Moreover, the LD50 of PO in mice was about 163mg/kg with intravenous administration, which was about 8-fold higher than the dose used in the animal experiment. CONCLUSIONS Our findings regarding the anti-inflammatory effect of PO and the underlying molecular mechanisms help justify the use of Pogostemon cablin in Chinese medicine for the treatment of inflammatory diseases. More importantly, the results also render PO a promising anti-inflammatory agent worthy of further development into a pharmaceutical drug for the treatment of septic shock.

LC-MS/MS determination of pogostone in rat plasma and its application in pharmacokinetic studies.

Pogostone is an important constituent of Pogostemon cablin (Blanco) Benth., and possesses various known bioactivities. A rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of pogostone in rat plasma using chrysophanol as internal standard (IS). The analytes were extracted with methanol and separated using a reversed-phase YMC-UltraHT Pro C18 column. Elution was achieved with a mobile phase consisting of methanol-water (75:25, v/v) for 5 min at a flow rate of 400 μL/min. The precursor/product transitions (m/z) under MS/MS detection with negative electrospray ionization (ESI) were 223.0 → 139.0 and 253.1 → 224.9 for pogostone and IS, respectively. The calibration curve was linear over the concentration range 0.05-160 µg/mL (r = 0.9996). The intra- and inter-day accuracy and precision were within ±10%. The validated method was successfully applied to the preclinical pharmacokinetic investigation of pogostone in rats after intravenous (5, 10 and 20 mg/kg) and oral administration (5, 10 and 20 mg/kg). Finally, the oral absolute bioavailability of pogostone in rats was calculated to be 70.39, 78.18 and 83.99% for 5, 10 and 20 mg/kg, respectively.

The Protective Effects of the Supercritical-Carbon Dioxide Fluid Extract of Chrysanthemum indicum against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Modulating Toll-Like Receptor 4 Signaling Pathway

The supercritical-carbon dioxide fluid extract of Chrysanthemum indicum Linné. (CFE) has been demonstrated to be effective in suppressing inflammation. The aim of this study is to investigate the preventive action and underlying mechanisms of CFE on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. ALI was induced by intratracheal instillation of LPS into lung, and dexamethasone was used as a positive control. Results revealed that pretreatment with CFE abated LPS-induced lung histopathologic changes, reduced the wet/dry ratio and proinflammatory cytokines productions (TNF-α, IL-1β, and IL-6), inhibited inflammatory cells migrations and protein leakages, suppressed the levels of MPO and MDA, and upregulated the abilities of antioxidative enzymes (SOD, CAT, and GPx). Furthermore, the pretreatment with CFE downregulated the activations of NF-κB and the expressions of TLR4/MyD88. These results suggested that CFE exerted potential protective effects against LPS-induced ALI in mice and was a potential therapeutic drug for ALI. Its mechanisms were at least partially associated with the modulations of TLR4 signaling pathways.

Anti-Inflammatory Property of the Ethanol Extract of the Root and Rhizome of Pogostemon cablin (Blanco) Benth

The aim of this study was to investigate the anti-inflammatory property of the ethanol extract of the root and rhizome of Pogostemon cablin (ERP). The anti-inflammatory effect was evaluated using four animal models including xylene-induced mouse ear edema, acetic acid-induced mouse vascular permeability, carrageenan-induced mouse pleurisy, and carrageenan-induced mouse hind paw edema. Results indicated that oral administration of ERP (120, 240, and 480 mg/kg) significantly attenuated xylene-induced ear edema, decreased acetic acid-induced capillary permeability, inhibited carrageenan-induced neutrophils recruitment, and reduced carrageenan-induced paw edema, in a dose-dependent manner. Histopathologically, ERP (480 mg/kg) abated inflammatory response of the edema paw. Preliminary mechanism studies demonstrated that ERP decreased the level of MPO and MDA, increased the activities of anti-oxidant enzymes (SOD, GPx, and GRd), attenuated the productions of TNF-α, IL-1β, IL-6, PGE2 and NO, and suppressed the activities of COX-2 and iNOS. This work demonstrates that ERP has considerable anti-inflammatory potential, which provided experimental evidences for the traditional application of the root and rhizome of Pogostemon cablin in inflammatory diseases.

Anti-Inflammatory Effect of Supercritical-Carbon Dioxide Fluid Extract from Flowers and Buds of Chrysanthemum indicum Linnén

The aim of this study was to analyze the chemical composition and investigate the anti-inflammatory property of the supercritical-carbon dioxide extract from flowers and buds of C. indicum (CISCFE). The anti-inflammatory effect was evaluated in four animal models including xylene-induced mouse ear edema, acetic acid-induced mouse vascular permeability, carrageenan-induced mouse hind paw edema, and cotton pellet-induced rat granuloma formation. The results indicated that CISCFE significantly attenuated xylene-induced ear edema, decreased acetic acid-induced capillary permeability, reduced carrageenan-induced paw, and inhibited the cotton pellet-induced granuloma formation in a dose-dependent manner. Histopathologically, CISCFE abated inflammatory response of the edema paw. Preliminary mechanistic studies demonstrated that CISCFE decreased the MDA level via increasing the activities of anti-oxidant enzymes (SOD, GPx, and GRd), attenuated the productions of NF-κB, TNF-α, IL-1β, IL-6, PGE2 and NO, and suppressed the activities of iNOS and COX-2. In phytochemical study, 35 compounds were identified by GC-MS, and 5 compounds (chlorogenic acid, luteolin-7-glucoside, linarin, luteolin and acacetin) were reconfirmed and quantitatively determined by HPLC-PAD. This paper firstly analyzed the chemical composition by combining GC-MS with HPLC-PAD and explored possible mechanisms for the anti-inflammatory effect of CISCFE.

Experimental study on antinociceptive and anti-allergy effects of patchouli oil

Pogostemon cablin (Blanco) Benth. (Lamiaceae), which is named ‘Guang-Huo-Xiang’ in Chinese, has various therapeutic functions to remove dampness, relieve summer-heat and exterior syndrome, stop vomiting, and stimulate appetite. Patchouli oil is the essential oil of Pogostemonis herba. This study is aimed to investigate the antinociceptive and anti-allergy activities of patchouli oil. The antinociceptive activity of patchouli oil (20, 40, and 80 mg/kg) was evaluated using the acetic acid-induced writhing test (NIH mice) and the hot-plate test (NIH mice), and those for anti-allergy activity were tested using Schultz–Dale reaction, the passive cutaneous anaphylaxis (PCA) test, and delayed-type hypersensitivity (DTH) test. All doses of patchouli oil could significantly (p<0.05) extend writhing latent period and moderately decrease writhing frequency. In the hot-plate test, patchouli oil treatment significantly (p<0.01) increased the latency period at all three doses at 30, 60, and 90-minute time intervals compared with the control group. Patchouli oil could remarkably (p<0.01) inhibit the contraction induced by the Schultz–Dale reaction. Moreover, patchouli oil at all doses significantly (p<0.01) inhibited the PCA reaction induced by Sprague–Dawley rat anti-ovalbumin serum and the DTH reaction induced by the 2,4-dinitrochlorobenzene when comparing with those of the control group. The findings suggested that patchouli oil may provide additional evidence for its potential uses as antinociceptive and anti-allergy agents.

A Standardized Traditional Chinese Medicine Preparation Named Yejuhua Capsule Ameliorates Lipopolysaccharide-Induced Acute Lung Injury in Mice via Downregulating Toll-Like Receptor 4/Nuclear Factor-κB

A standardized traditional Chinese medicine preparation named Yejuhua capsule (YJH) has been clinically used in treatments of various acute respiratory system diseases with high efficacy and low toxicity. In this study, we were aiming to evaluate potential effects and to elucidate underlying mechanisms of YJH against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. Moreover, the chemical analysis and chromatographic fingerprint study were performed for quality evaluation and control of this drug. ALI was induced by intratracheal instillation of LPS (5 mg/kg) into the lung in mice and dexamethasone (5 mg/kg, p.o.) was used as a positive control drug. Results demonstrated that pretreatments with YJH (85, 170, and 340 mg/kg, p.o.) effectively abated LPS-induced histopathologic changes, attenuated the vascular permeability enhancement and edema, inhibited inflammatory cells migrations and protein leakages, suppressed the ability of myeloperoxidase, declined proinflammatory cytokines productions, and downregulated activations of nuclear factor-κB (NF-κB) and expressions of toll-like receptor 4 (TLR4). This study demonstrated that YJH exerted potential protective effects against LPS-induced ALI in mice and supported that YJH was a potential therapeutic drug for ALI in clinic. And its mechanisms were at least partially associated with downregulations of TLR4/NF-κB pathways.