Jian-Hui Xie

Oral administration of patchouli alcohol isolated from Pogostemonis Herba augments protection against influenza viral infection in mice

Seasonal influenza A infection results in considerable morbidity and mortality. The limited efficacy of available therapeutic strategies stresses the need for development and study of new molecules against influenza virus (IFV). Patchouli alcohol (PA), the major chemical constituent of Pogostemonis Herba, was previously found to strongly inhibit influenza H1N1 replication in vitro. In the present study, the in vivo anti-IFV effect of PA was investigated. In a mouse model infected with lethal levels of FM1, oral administration of PA (20 mg/kg to 80 mg/kg) for 7 d post IFV infection significantly increased the survival rate and survival time. For IFV infection at nonlethal levels, the quantity of IFV in the lungs 5 d after infection was significantly reduced after PA (20 mg/kg to 80 mg/kg) administration. Anti-IFV IgA, IgM, and IgG titers in serum on day 6 were significantly higher in the PA-treated group than the IFV-control group. Anti-IFV immune response augmentation was further confirmed by the elevated production of CD3+, CD4+, and CD8+ T cell levels in blood. Furthermore, the levels of inflammatory cytokines, including TNF-alpha, IL-10 and IFN-gamma in serum of mice, were regulated. Lung inflammation was reduced significantly after PA administration, and the effect may be mediated, at least in part, by regulating the lung levels of inflammatory cytokines. Thus, oral administration of PA appears to be able to augment protection against IFV infection in mice via enhancement of host immune responses, and attenuation of systemic and pulmonary inflammatory responses.

Gastroprotective effect and mechanism of patchouli alcohol against ethanol, indomethacin and stress-induced ulcer in rats

Pogostemonis Herba is an important Chinese medicine widely used in the treatment of gastrointestinal dysfunction. Patchouli alcohol (PA), a tricyclic sesquiterpene, is the major active constituent of Pogostemonis Herba. This study aimed to investigate the possible anti-ulcerogenic potential of PA and the underlying mechanism against ethanol, indomethacin and water immersion restraint-induced gastric ulcers in rats. Gross and histological gastric lesions, biochemical and immunological parameters were taken into consideration. The gastric mucus content and the antisecretory activity were analyzed through pylorus ligature model in rats. Results indicated that oral administration with PA significantly reduced the ulcer areas induced by ethanol, indomethacin and water immersion restraint. PA pretreatment significantly promoted gastric prostaglandin E2 (PGE2) and non-protein sulfhydryl group (NP-SH) levels, upregulated the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) mRNA expression, and considerably boosted the gastric blood flow (GBF) and gastric mucus production in comparison with vehicle. In addition, PA modulated the levels of interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α). The levels of glutathione (GSH), catalase (CAT) and malonaldehyde (MDA) were also restored by PA. However, the gastric secretion parameters (pH, volume of gastric juice and pepsin) did not show any significant alteration. These findings suggest that PA exhibited significant gastroprotective effects against gastric ulceration. The underlying mechanisms might involve the stimulation of COX-mediated PGE2, improvement of antioxidant and anti-inflammatory status, preservation of GBF and NP-SH, as well as boost of gastric mucus production.

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.

Insecticidal activity of pogostone against Spodoptera litura and Spodoptera exigua (Lepidoptera: Noctuidae).

BACKGROUND Essential oil of Pogostemon cablin (Blanco) Benth. has been reported to exhibit strong insecticidal activities, but few studies have focused on the insecticidal activity of its main individual constituent, pogostone (PO). The goal of this research was to investigate the insecticidal activity of PO against two harmful noctuid insects, Spodoptera litura (Fabricius) and Spodoptera exigua (Hübner). RESULTS In a no-choice assay, PO exhibited strong antifeedant activity against S. litura and S. exigua. PO showed pronounced larvicidal activities, including oral toxicity (LC50 986.88 mg L(-1) and 545.61 mg L(-1) respectively) and contact toxicity (LC50 1041.42 mg L(-1) and 519.48 mg L(-1) respectively) against these two noctuid insects. Additionally, PO treatment significantly increased the larval and pupal developmental period. Furthermore, PO showed moderate ovicidal activities and influenced the emergence and deformity of the moth. However, PO failed to exert a potent effect on adult development. These tested parameters proved to be dose dependent for both insect species. CONCLUSION PO possesses strong insecticidal activities, especially antifeedant, larvicidal, growth inhibitory and pupicidal activities, against S. litura and S. exigua. PO may partly account for the insecticidal activity of patchouli oil and may be a promising candidate for the control of agricultural insects.

Inhibitory Effect of Hydroxysafflor Yellow A on Mouse Skin Photoaging Induced by Ultraviolet Irradiation

Chronic exposure to ultraviolet (UV) irradiation is believed to be the major cause of skin damage that results in premature aging of the skin, so called photoaging, characterized by increases in skin thickness, formation of wrinkles, and loss of skin elasticity. UV induces damage to skin mainly by oxidative stress and collagen degradation. In this study, we examined the photo-protective effect of hydroxysafflor yellow A (HSYA), a major active chemical component isolated from Carthamus tinctorius L., by topical application on the skin of mice. Exposure of the dorsal depilated skin of mice to UV radiation four times a week for 10 weeks induced epidermal hyperplasia, elastin accumulation, collagen degradation, etc. HSYA at the doses of 50, 100, and 200 μg/mouse was topically applied immediately following each UV exposure. The effects of HSYA were evaluated by a series of tests, including macroscopic and histopathological evaluation of skin, pinch test, and redox homeostasis of skin homogenates. Results showed that the UV-induced skin damage was significantly improved after HSYA treatment, especially at doses of 100 and 200 μg/mouse. This protective effect is possibly related to the anti-oxidative property of HSYA and mediated by promoting endogenous collagen synthesis. This is the first study providing preclinical evidence for the protective effect of HSYA against photoaging.

Gastroprotective effect of andrographolide sodium bisulfite against indomethacin-induced gastric ulceration in rats.

Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of andrographolide has been shown to possess anti-inflammatory, antipyretic and analgesic activities. However, there is no report on the gastroprotective effect of ASB against indomethacin-induced gastric ulcer. Here we investigated the possible anti-ulcerogenic potential of ASB and the underlying mechanism against indomethacin-induced gastric ulcer in rats. The ulcer area, histopathological assessment, contents of gastric mucosal glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), malonaldehyde (MDA) and prostaglandin E2 (PGE2) were examined. In addition, cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) mRNA expression and immunohistochemical evaluation of HSP70, Bcl-2 and Bax proteins were also investigated. Results indicated that ASB pre-treatment significantly reduced the ulcer areas induced by indomethacin compared with the vehicle group. The gastric levels of GSH, CAT and SOD were markedly increased by ASB while the level of MDA was decreased. In addition, ASB pretreatment significantly promoted the gastric PGE2 levels and up-regulated the COX-1 and COX-2 mRNA expression in comparison with the vehicle group. Immunohistochemistry analysis showed obvious up-regulation of HSP70 and Bcl-2 protein expression while suppression of Bax protein in the gastric tissue of ASB-pretreated group. Taken together, these findings indicated that the gastroprotective effect of ASB might be associated with the improvement of antioxidative status, activation of COX-mediated PGE2 synthesis, down-regulation of Bax proteins and up-regulation of Bcl-2 and HSP70 proteins. ASB might have the potential for further development as a promising alternative for antiulcer treatment.

Anti-inflammatory activity of β-patchoulene isolated from patchouli oil in mice.

β-Patchoulene (β-PAE) is a tricyclic sesquiterpene isolated from the oil of Pogostemon cablin (patchouli oil), which has been widely used in traditional Chinese medicine for the treatment of inflammatory diseases. However, as one of the major principle of patchouli oil, the biological activity of β-PAE has not been explored so far. In the present study, the anti-inflammatory activity in vivo, and the underlying mechanism, of β-PAE was investigated on experimental mice models of acute inflammation, i.e. xylene-induced ear edema, acetic acid-induced vascular permeability and carrageenan-induced paw edema. The results showed that β-PAE evoked a significant dose-dependent inhibition of ear edema induced by xylene, paw edema induced by carrageenan and suppressed the increase of vascular permeability elicited by acetic acid. Histopathological analysis indicated that β-PAE could markedly decrease the cellular infiltration in paw tissue. β-PAE was also shown to significantly decrease the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in edema paw. In addition, carrageenan-induced production of some pro-inflammatory cytokines: tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO), were suppressed in a dose-dependent manner in mice subjected to β-PAE pretreatment, and it also significantly down-regulated the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Further analysis revealed that β-PAE also inhibited the translocation of nuclear factor-κB (NF-κB) from the cytoplasm to the nucleus and stabilize the conversion of nuclear factor-κBα (IκBα) level. These results provided additional chemical and pharmacological basis for the traditional application of P. cablin in inflammatory 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

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.