Ji-Yan Su

Anti-inflammatory activity of patchouli alcohol isolated from Pogostemonis Herba in animal models

Pogostemonis Herba has long been used in traditional Chinese medicine for the treatment of inflammatory disorders. Patchouli alcohol (PA), a tricyclic sesquiterpene isolated from Pogostemonis Herba, is known to possess a variety of pharmacological activities. The present study aimed to investigate the in vivo anti-inflammatory effect of PA using two common inflammatory animal models i.e., xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. The degree of edema in both inflammatory animals, as well as the protein and mRNA expression of some inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), prostaglandin E₂ (PGE₂) and nitric oxide (NO) in the hind paw of carrageenan-treated rats were measured. Results showed that PA (10-40 mg/kg) significantly inhibited the ear edema induced by xylene in mice and the paw edema induced by carrageenan in rats. In addition, treatment with PA (10-40 mg/kg) also dose-dependently decreased the production of TNF-α, IL-1β, PGE₂ and NO in the hind paw of carrageenan-treated rats. Furthermore, PA treatment also suppressed the mRNA expression of TNF-α, IL-1β, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the hind paw of carrageenan-treated rats. These results suggest that PA possesses potent anti-inflammatory activity, which may be mediated, at least in part, by down-regulating the mRNA expression of a panel of inflammatory mediators including TNF-α, IL-1β, iNOS and COX-2.

Effect of a derived herbal recipe from an ancient Chinese formula, Danggui Buxue Tang, on ovariectomized rats

ETHNOPHARMACOLOGICAL RELEVANCE Radix Astragali (root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao, RA), Radix Angelicae sinensis (root of Angelica sinensis (Oliv.) Diels, RAS) and Folium Epimedii (leaves of Epimedium brevicomum Maxim., FE) are three of the extensively applied herbal remedies among traditional Chinese medicines for gynecological disorders and osteoporosis. A derivative herbal recipe-RRF, composed of the three medicines with a weight ratio of 5:1:5, is derived from a famous Chinese herbal formula-Danggui Buxue Tang (DBT). RRF has shown noteworthy protective effect in ovariectomized rats, which might represent a promising candidate for the treatment of perimenopausal disorders. The aim of this study was to investigate the herbal recipe RRF for its efficacy on perimenopausal disorders and the underlying mechanisms via ovariectomy (OVX) models. MATERIALS AND METHODS An experimental model of OVX female rats was applied. Vehicle (Sham and OVX group), RRF (564, 282 and 141 mg/kg/d) and conjugated equine estrogens (CEE, 0.1mg/kg/d, reference drug) were all administrated orally once daily for 16 weeks post operation. After the treatment, radioimmunoassay for estradiol (E(2)), lutenizing hormone (LH), follicle stimulating hormone (FSH) and β-endorphin (β--EP), neurotransmitter determination by high-performance liquid chromatography with electrochemical detector (HPLC-ECD) for norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT) and 5-HIAA (5-hydroxyindoleacetic acid), bone mineral density (BMD) assay as well as lipid peroxidation assessment, were carried out to probe into the effectiveness of RRF. RESULTS (1) RRF treatment enhanced E(2) synthese while diminished the elevated serum FSH and LH levels; in terms of neurotransmitter, β-EP syntheses rallied whereas the hypothalamic NE, DA and 5-HT release experienced varying mitigation in OVX female rats. (2) Repeated administration of RRF was able to attenuate osteoporosis by elevating the BMD levels of total body, and arrest the bone trabeculae degradation. (3) RRF exposure decreased serum levels of constituent MDA and increased endogenous SOD activity. CONCLUSIONS Results of the current studies revealed that RRF was capable of acting at multiple targets which presumably underlay its potential protective effect in OVX rats mimicking symptoms as observed in perimenopausal women. Hence, RRF might represent a promising candidate in the treatment of perimenopausal disorders in midlife women.

Experimental study on anti-inflammatory activity of a TCM recipe consisting of the supercritical fluid CO2 extract of Chrysanthemum indicum, Patchouli Oil and Zedoary Turmeric Oil in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE Chrysanthemum indicum (Compositae) Linné, Pogostemon cablin (Blanco) Benth and Curcuma wenyujin (Zingiberaceae) Y. H. Chen et C. Ling are three of the extensively used herbal remedies among traditional Chinese medicines for the purpose of anti-inflammation. A traditional Chinese medicine (TCM) recipe named CPZ consisting extracts of the above three herbs, has shown noteworthy anti-influenza activity, which is closely related to its anti-inflammatory feature. AIM OF THIS STUDY To investigated the anti-inflammtory activity of CPZ in vivo for a further exploration of the recipes anti-inflammatory properties. MATERIALS AND METHODS The anti-inflammatory property of CPZ on acute inflammation was evaluated by inflammatory models of dimethylbenzene (DMB)-induced ear vasodilatation and acetic acid-induced capillary permeability enhancement in mice, as well as the carrageenan-induced paw edema rat model, in which inflammation-related cytokine including prostaglandin E(2) (PGE(2)), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) in the edematous paw tissue were determined by enzyme linked immunosorbent assay (ELISA). Moreover, effect of CPZ on chronic inflammation was observed through granuloma formation in rats subjected to cotton pellet implantation. RESULTS CPZ (340, 170, and 85 mg/kg for mice, p.o.) not only decreased the DMB-induced ear vasodilatation but also attenuated capillary permeability under acetic acid challenge in mice. And the significant inhibition on carrageenan-induced paw edema was observed. Further more, the ELISA results showed that CPZ (170, 85, and 42.5 mg/kg for rats, p.o.) could up-regulate the level of IL-1β in the edema paw tissue of rats significantly while down-regulate that of PGE(2), but no apparent effect on TNF-α or NO was observed in the test. Besides, CPZ had a certain degree of restraining effect on the cotton pellet-induced granuloma formation in rats and the highest dose of 170 mg/kg even showed a significant suppression on it. CONCLUSION The above results indicated that CPZ possessed a potent anti-inflammatory activity, which is indicated to be closely associated with its regulation on IL-1β and PGE(2) thereby mediating the inflammatory response acting at an appropriate level.

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.

Fingerprinting and simultaneous determination of alkaloids in Picrasma quassioides from different locations by high performance liquid chromatography with photodiode array detection

A simple and sensitive method was developed and validated for profiling and simultaneous quantitation of seven alkaloids (6-hydroxy-β-carboline-1-carboxylic acid, β-carboline-1-carboxylic acid, β-carboline-1-propanoic acid, 3-methylcanthin-5,6-dione, 5-hydroxy-4-methoxycanthin-6-one, 1-methoxycarbony-β-carboline, and 4,5-dimethoxycanthin-6-one) in Picrasma quassioide grown in different locations by high-performance liquid chromatography with photodiode array detection. The analysis was conducted on a Phenomenex Gemini C(18) column at 35°C with mobile phase of 25 mM aqueous ammonium acetate (pH 4.0, adjusted by glacial acetate acid) and acetonitrile. A common fingerprint chromatograph under 254 nm consisting of 27 peaks was constructed for the evaluation of the similarities among 31 P. quassioide samples. Samples from Guangdong and Guangxi Provinces were found to be within group linkage and showed significant difference from that of Jiangxi Province origin by using principal component analysis and hierarchical clustering analysis. In addition, the seven alkaloids were identified by electrospray ionization mass spectrometry and comparing with reference standards and literature data. All of them were determined simultaneously using the established HPLC method. This rapid and effective analytical method could be employed for quality assessment of P. quassioide, as well as pharmaceutical products containing this herbal material.

Immunosuppressive activity of pogostone on T cells: Blocking proliferation via S phase arrest.

Pogostone (PO) is one of the major chemical constituents of the essential oil of Pogostemon cablin (Blanco) Benth. In the present study, the effect of PO on T cell responsiveness was investigated to explore its potential in immunosuppression by a Concanavalin A (ConA)-stimulation model using splenocytes isolated from C57BL/6 mice. Cytotoxicity by PO on normal splenocytes was evaluated by MTS assays. Characteristics of apoptosis, proliferation, and cell cycle were analyzed by flow cytometry. Related expressions of cyclins and cyclin-dependent kinases (CDKs) were also determined by flow cytometry. Inflammatory cytokine profiling was performed emplying cytometric beads assays (CBA). Moreover, the T cell-mediated delayed Type hepersensity (DTH) model was applied to evaluate the immunosuppressive activity of PO. Neither viability reduction in normal splenocytes nor apoptosis in ConA-stimulated splenocytes was observed under PO treatments. Meanwhile, PO remarkably reduced the total population of ConA-stimulated T cell, blocked T cell proliferation induced by Con A, and inhibited the production of IFN-γ and IL-10. This blockade of stimulated T cell proliferation by PO was likely attributed to down-regulation of cyclin E, cyclin B and CDK1 and the subsequent S-phase arrest. Additionally, PO could inhibit the DTH reaction by alleviating ear swelling and inflammatory infiltrations in the DNCB-challenged ear. Taken together, PO exhibited an immunosuppressive property by directly blocking T cell proliferation as well as altering inflammatory cytokine profile, suggesting that PO may have clinical implications for treating autoimmune diseases and other immune-based disorders.

Inactivation of jack bean urease by scutellarin: Elucidation of inhibitory efficacy, kinetics and mechanism

In the present study, the inactivation effect of scutellarin (SL) on jack bean urease was investigated to elucidate the inhibitory potency, kinetics and mechanism of inhibition. It was revealed that SL acted as a concentration- and time-dependent inactivator of urease characteristic of slow-binding inhibition with an IC50 of 1.35±0.15 mM. The rapid formation of the initial SL-urease complex with an inhibition constant of Ki=5.37×10(-2) mM was followed by a slow isomerization into the final complex with the overall inhibition constant of Ki*=3.49×10(-3) mM. High effectiveness of thiol protectors, such as L-cysteine (L-cys), 2-mercaptoethanol (2-ME) and dithiothreitol (DTT) significantly slowed down the rate of inactivation, indicating the strategic role of the active site sulfhydryl group in the blocking process. While the insignificant protection by boric acid and fluoride from the inactivation further confirmed that the active site cysteine should be obligatory for urease inhibition, which was also rationalized by the molecular docking study. The inhibition of SL on urease proved to be reversible since SL-blocked urease could be reactivated by DTT application and multidilution. The results obtained indicated that urease inactivation resulted from the reaction between SL and the sulfhydryl group.

Selective antibacterial activity of patchouli alcohol against Helicobacter Pylori based on inhibition of urease

The aim of this study is to evaluate the antibacterial activity and urease inhibitory effects of patchouli alcohol (PA), the bioactive ingredient isolated from Pogostemonis Herba, which has been widely used for the treatment of gastrointestinal disorders. The activities of PA against selected bacteria and fungi were determined by agar dilution method. It was demonstrated that PA exhibited selective antibacterial activity against Helicobacter pylori, without influencing the major normal gastrointestinal bacteria. Noticeably, the antibacterial activity of PA was superior to that of amoxicillin, with minimal inhibition concentration value of 78 µg/mL. On the other hand, PA inhibited ureases from H. pylori and jack bean in concentration‐dependent fashion with IC50 values of 2.67 ± 0.79 mM and 2.99 ± 0.41 mM, respectively. Lineweaver‐Burk plots indicated that the type of inhibition was non‐competitive against H. pylori urease whereas uncompetitive against jack bean urease. Reactivation of PA‐inactivated urease assay showed DL‐dithiothreitol, the thiol reagent, synergistically inactivated urease with PA instead of enzymatic activity recovery. In conclusion, the selective H. pylori antibacterial activity along with urease inhibitory potential of PA could make it a possible drug candidate for the treatment of H. pylori infection. Copyright

Kinetics and Mechanism Study of Competitive Inhibition of Jack-Bean Urease by Baicalin

Baicalin (BA) is the principal component of Radix Scutellariae responsible for its pharmacological activity. In this study, kinetics and mechanism of inhibition by BA against jack-bean urease were investigated for its therapeutic potential. It was revealed that the IC50 of BA against jack-bean urease was 2.74 ± 0.51 mM, which was proved to be a competitive and concentration-dependent inhibition with slow-binding progress curves. The rapid formation of initial BA-urease complex with an inhibition constant of K i = 3.89 × 10−3 mM was followed by a slow isomerization into the final complex with an overall inhibition constant of K i* = 1.47 × 10−4 mM. High effectiveness of thiol protectors against BA inhibition indicated that the strategic role of the active-site sulfhydryl group of the urease was involved in the blocking process. Moreover, the inhibition of BA was proved to be reversible due to the fact that urease could be reactivated by dithiothreitol but not reactant dilution. Molecular docking assay suggested that BA made contacts with the important activating sulfhydryl group Cys-592 residues and restricted the mobility of the active-site flap. Taken together, it could be deduced that BA was a competitive inhibitor targeting thiol groups of urease in a slow-binding manner both reversibly and concentration-dependently, serving as a promising urease inhibitor for treatments on urease-related diseases.

Protective effects of apigenin against 1-methyl-4-phenylpyridinium ion‑induced neurotoxicity in PC12 cells

Parkinsons disease is recognized as the second most common neurodegenerative disorder after Alzheimers disease, characterized by the loss of dopominergic neurons in the substantia nigra pars compacta and can be experimentally mimicked by the use of the neurotoxin, 1‑methyl‑4‑phenylpyridinium ion (MPP(+)), in in vitro models. In this study, we investigated the potential protective effects of apigenin (AP), galangin and genkwanin, naturally occurring plant flavonoids, on the MPP(+)‑induced cytotoxicity in cultured rat adrenal pheochromocytoma cells (PC12 cells). The PC12 cells were pre-treated with various concentrations of the test compounds for 4 h, followed by the challenge with 1,000 µM MPP(+) for 48 h. We found that only pre-treatment with AP (3, 6 and 12 µM) before injury significantly increased cell viability, decreased the release of lactate dehydrogenase, reduced the level of intracellular reactive oxygen species and elevated mitochondrial membrane potential in the MPP(+)‑treated PC12 cells. In addition, AP markedly suppressed the increased rate of apoptosis and the reduced Bcl‑2/Bax ratio induced by MPP(+) in the PC12 cells. Taken together, the findings of this study demonstrate that AP exerts neuroprotective effects against MPP(+)‑induced neurotoxicity in PC12 cells, at least in part, through the inhibition of oxidative damage and the suppression of apoptosis through the mitochondrial pathway.