The effects of a standardized Acanthopanax koreanum extract on stress-induced behavioral alterations in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots and stem bark of Acanthopanax koreanum Nakai (Araliaceae), a well-known herbal medicine in Jeju Island, Korea, has been used as a tonic agent in treating stress-related states. Despite its popular application, the anti-anxiety or anti-depressive action of Acanthopanax koreanum is not yet known. AIM OF THE STUDY: This study aimed to determine the effects of Acanthopanax koreanum on stress-induced behavioral alterations such as anxiety and depression. MATERIALS AND METHODS: Mice in the acute stress group were exposed to immobilization stress for 2h followed by electric foot shocks (0.5 mA in 1 s duration with a 10 s inter-shock interval) for 2 min, while sub-chronically stressed mice were exposed to these stresses for 2 weeks, once per day. 70% ethanolic extract of Acanthopanax koreanum (EEAK) (25, 50, 100, or 200 mg/kg) was administered once or sub-chronically (for 2 weeks) 1h prior to stress induction. Anxiety- or depression-like behavioral changes were evaluated using the elevated plus-maze (EPM) test and the forced swimming test (FST) a day after the final stress induction. Corticosterone levels and spleen weight were measured after conducting all the behavioral assays. The numbers of BrdU- or DCX-immunopositive cells in the hippocampal region of sub-chronically stressed mice were measured 2 days after EEAK treatment. RESULTS: The percentage of time spent in the open arms was decreased in both the acutely and chronically stressed mice. In the FST, the immobility time was increased by only chronic stress, but not by acute stress. Acute or sub-chronic administration of EEAK significantly prevented the anxiety- or depression-like behavioral changes caused by stress. EEAK also attenuated stress-induced decrease and increase of spleen weight and corticosterone levels, respectively. Furthermore, the sub-chronic administration of EEAK (100 or 200 mg/kg, for 2 weeks) increased the number of BrdU-, doublecortin-, and neuropeptide Y-positive cells in the hippocampal region of the sub-chronically stressed mice. CONCLUSION: EEAK attenuated the behavioral and biochemical changes in acute or sub-chronic stressed mice. These results suggest the therapeutic potential of Acanthopanax koreanum for the treatment of stress-related neuropsychiatric disorders including anxiety disorders or major depressive disorder.

Matrix metalloproteinase-1 inhibitory activity of Kaempferia pandurata Roxb.

Matrix metalloproteinase (MMP)-1 is a superfamily of zinc-dependent endopeptidases that are capable of degrading all components of the extracellular matrix. Kaempferia pandurata extract (0.01-0.5 microg/mL) significantly reduced the expression of MMP-1 and induced the expression of type 1 procollagen at the protein and mRNA levels in a dose-dependent manner. Ultraviolet (UV)-induced MMP-1 initiates cleavage of fibrillar collagen. Once cleaved by MMP-1, collagen can be further degraded by elevated levels of MMP-3 and MMP-9. It was found that increased MMP-1 expression due to UV irradiation was mediated by activation of mitogen-activated protein kinases such as extracellular-regulated kinase (ERK), Jun N-terminal kinase (JNK), and p38 kinase. Treatment of K. pandurata extract in the range of 0.01-0.5 microg/mL inhibited the UV-induced phosphorylations of ERK, JNK, and p38, respectively. Moreover, inhibition of phosphorylated ERK, JNK, and p38 by K. pandurata extract resulted in decreased c-Fos expression and c-Jun phosphorylation induced by UV light. The results strongly suggest that K. pandurata is potentially useful for the prevention and treatment of skin aging.

The effect of xanthorrhizol on the expression of matrix metalloproteinase-1 and type-I procollagen in ultraviolet-irradiated human skin fibroblasts.

Matrix metalloproteinases (MMPs) are key regulators of the skin photoaging process that is set in motion by exposure to ultraviolet (UV) irradiation. This skin damage results from UV-induced generation of reactive oxygen species, which are associated with upregulation of MMPs and decreased collagen synthesis. We investigated the effects of xanthorrhizol, isolated from Curcuma xanthorrhiza, on the expression of MMP-1 and type-I procollagen in UV-irradiated human skin fibroblasts. Fibroblasts cultured in the presence or absence of purified xanthorrhizol or C. xanthorrhiza extract were irradiated with UV (20 mJ/cm(2)), and MMP-1 and type-I procollagen levels were measured using Western blot analysis. Xanthorrhizol (0.001-0.1 microM) and C. xanthorrhiza extract (0.01-0.5 microg/mL) induced a significant, dose-dependent decrease in the expression of MMP-1 protein, and increased the expression of type-1 procollagen. At a concentration of 0.1 microM, xanthorrhizol nearly completely abrogated MMP-1 expression. The MMP-1-suppressing and type-1 procollagen-inducing effects of xanthorrhizol treatment were greater than those of epigallocatechin 3-O-gallate (EGCG), which is known to be a natural anti-aging agent. These results suggest that xanthorrhizol is a potential candidate for the prevention and treatment of skin aging.

Antibacterial activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. against foodborne pathogens.

Xanthorrhizol, isolated from the ethanol extract of Curcuma xanthorrhiza Roxb., is a sesquiterpene compound with a molecular weight of 218. The aim of this study was to investigate the antibacterial activity of xanthorrhizol against foodborne pathogens. The antibacterial activity of xanthorrhizol was measured in terms of the MIC and the MBC. MICs and MBCs of xanthorrhizol against Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium, and Vibrio parahaemolyticus were 8, 16, 8, 8, 16, 8 microg/ml and 16, 32, 16, 16, 16, 16 microg/ml, respectively. The bactericidal study, as determined by the viable cell count method, revealed that xanthorrhizol treatment at 4 x MIC reduced viable cells by at least 6 to 8 log for all six foodborne pathogens in 4 h. Xanthorrhizol maintained its antibacterial activity after thermal treatments (121 degrees C, 15 min) under various pH ranges (pH 3.0, 7.0, and 11.0). These results strongly suggest that xanthorrhizol, conferring strong antibacterial activity with thermal and pH stability, can be effectively used as a natural preservative to prevent the growth of foodborne pathogens.

Inhibitory effect of panduratin A on UV-induced activation of mitogen-activated protein kinases (MAPKs) in dermal fibroblast cells.

Exposure of the skin to ultraviolet (UV) induces photoaging associated with up-regulated matrix metalloproteinases (MMPs) activities and decreased collagen synthesis. We previously reported that panduratin A, a chalcone compound isolated from KAEMPFERIA PANDURATA Roxb ., decreased MMP-1 expression in UV-irradiated human skin fibroblasts. Here, we have investigated the effect of panduratin A on UV-induced activation of mitogen-activated protein kinases (MAPKs) signaling modules such as extracellular-regulated protein kinase (ERK), Jun-N-terminal kinase (JNK) and p38 kinase. Treatment with panduratin A in the range of 0.001 - 0.1 microM significantly inhibited UV-induced ERK, JNK and p38 activation. Moreover, inhibition of ERK, JNK and p38 by panduratin A resulted in decreased c-Fos expression and c-Jun phosphorylation induced by UV, which led to inhibition of activator protein-1 (AP-1) DNA binding activity. Panduratin A showed stronger activity than epigallocatechin 3- O-gallate (EGCG) known as a natural anti-aging agent. The results suggest that panduratin A can down-regulate UV-induced MMP-1 expression by inhibiting the MAPKs pathways and AP-1 activation. AP-1:activator protein-1 EGCG:epigallocatechin 3- O-gallate ERK:extracellular-regulated protein kinase JNK:c-Jun N-terminal kinase MAPK:mitogen-activated protein kinase MMP:matrix metalloproteinase UV:ultraviolet.

Screening of Thai medicinal plants for anticandidal activity.

Medicinal plants are often used in the treatment of various ailments. In this study, 23 of Thai medicinal plants were screened for their anticandidal activity against six pathogenic Candida species: C. albicans, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis and C. tropicalis. The methanol extract of Hibiscus sabdariffa L. fruit, Trigonostemon reidioides (Kurz) Craib root, Usnea siamensis Vain whole plant, Boesenbergia rotunda (L.) Mansf. rhizome, and Albizia myriophylla Benth. stem showed anticandidal activity against one or more species of Candida. Among them, A. myriophylla Benth. showed broad anticandidal activity. The susceptibility tests of A. myriophylla Benth. extract, in terms of minimal inhibitory concentrations (MIC) and minimal fungicidal concentration (MFC), were performed by the broth microdilution techniques as described by the Clinical Laboratory Standard Institute. MICs of A. myriophylla Benth. extract to all Candida species was ranged 100-500 mug ml(-1). The killing activity of A. myriophylla Benth. extract was fast acting against all Candida tested; the reduction in the number of CFU ml(-1) was >3 log(10) units (99.9%) in 2 h. This study indicates that A. myriophylla Benth. extract has considerable anticandidal activity, deserving further investigation for clinical applications for the treatment of candidiasis.

The effects of panduratin A isolated from Kaempferia pandurata on the expression of matrix metalloproteinase-1 and type-1 procollagen in human skin fibroblasts.

Exposure of ultraviolet (UV) light on the skin induces photoaging associated with up-regulated matrix metalloproteinase (MMP) activities and decreased collagen synthesis. We investigated the effects of panduratin A isolated from Kaempferia pandurata Roxb. on the expression of matrix metalloproteinase-1 (MMP-1) and type-1 procollagen in UV-irradiated human skin fibroblasts. Cultured human fibroblasts were irradiated with UV (20 mJ/cm (2)) and panduratin A was added into the medium of the fibroblast culture. The expressions of MMP-1 and type-1 procollagen levels were measured using Western blot analysis and RT-RCR. Panduratin A in the range of 0.001 - 0.1 microM significantly reduced the expression of MMP-1 and induced the expression of type-1 procollagen at the protein and mRNA gene levels. Panduratin A showed stronger activity than epigallocatechin 3- O-gallate (EGCG) known as a natural anti-aging agent. The results suggest that panduratin A can be a potential candidate for the prevention and treatment of skin aging brought about by UV.

Depigmentation of melanocytes by isopanduratin A and 4-hydroxypanduratin A isolated from Kaempferia pandurata ROXB.

This study was carried out to investigate the in vitro effects of isopanduratin A and 4-hydroxypanduratin A isolated from Kaempferia pandurata ROXB. on melanin biosynthesis and tyrosinase activity. Two chalcone compounds, isopanduratin A and 4-hydroxypanduratin A, were isolated from the ethyl acetate fraction of ethanol extract as the active principles. Compared with phenylthiourea (IC(50)=34.3 microM) as a positive control, the depigmentation IC(50) values for isopanduratin A and 4-hydroxypanduratin A were 10.6 microM and 23.2 microM, respectively. The compounds also significantly inhibited the activity of tyrosinase, the enzyme that converts DOPA (3,4-dihydroxyphenylalanine) to dopachrome in the biosynthetic process of melanin. The IC(50) values of isopanduratin A and 4-hydroxypanduratin A for tyrosinase were 10.5 microM and >30 microM, respectively, while that of phenylthiourea was 47.6 microM. The tyrosinase protein level was also significantly decreased by isopanduratin A and 4-hydroxypanduratin A. The results indicate that isopanduratin A and 4-hydroxypanduratin A isolated from K. pandurata ROXB. are promising compounds that could be useful for treating hyperpigmentation as skin-whitening agents.

Immunostimulating activity of crude polysaccharide extract isolated from Curcuma xanthorrhiza Roxb.

Curcuma xanthorrhiza Roxb., commonly known as Javanese turmeric, has been reported to possess a variety of biological activities, including anti-inflammatory effects, anticarcinogenic effects, wound healing effects, and serum cholesterol-lowering effects. CPE, crude polysaccharide extract isolated from the rhizome of C. xanthorrhiza using 0.1 N NaOH, consisted of arabinose (18.69%), galactose (14.0%), glucose (50.67%), mannose (12.97%), rhamnose (2.73%), and xylose (0.94%), with an average molecular weight of 33,000 Da. In the present study, we investigated the effect of CPE on nitric oxide (NO), hydrogen peroxide (H2O2), tumor necrosis factor-alpha (TNF-alpha), and prostaglandin E2 (PGE2) production in RAW 264.7 cells. The uptake of fluorescein-labeled Escherichia coli was measured to determine whether CPE stimulates the phagocytic activity of RAW 264.7 cells. CPE significantly increased the phagocytosis of macrophages and the release of NO, H2O2, TNF-alpha, and PGE2 in a dose-dependent manner, and showed a similar activity to lipopolysaccharide (LPS). To study the mechanisms of CPE, we examined induction of iNOS and COX-2. NO and PGE2 were produced as a result of stimulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) respectively. Both modulations of iNOS and COX-2 expression by CPE were evaluated by Western immunoblotting and RT-PCR. Since transcription of these enzymes is under the control of nuclear factor-kappa B (NF-kappaB), we assessed the phosphorylation of inhibitor kappaBalpha (IkappaBalpha) through Western immunoblotting. CPE clearly induced phosphorylation of IkappaBalpha, suggesting a role as an NF-kappaB activator. Taking all this together, we conclude that CPE isolated from Curcuma xanthorrhiza stimulates the immune functions of macrophages, which is mediated in part by specific activation of NF-kappaB.

Anticariogenic activity of some tropical medicinal plants against Streptococcus mutans.

The methanol extracts of five tropical plants, Baeckea frutescens, Glycyrrhiza glabra, Kaempferia pandurata, Physalis angulata and Quercus infectoria, exhibited potent antibacterial activity against the cariogenic bacterium Streptococcus mutans. In particular, G. glabra, K. pandurata and P. angulata conferred fast killing bactericidal effect against S. mutans in 2 min at 50 microg/ml of extract concentration.