Polygonum tinctorium leaf extract ameliorates high-fat diet-induced intestinal epithelial damage in mice.

Dietary fat strongly influences the intestinal mucosal barrier, which protects against invading pathogenic bacteria. A high-fat diet (HFD) compromises the integrity of epithelial tight junctions (TJs) and reduces mucin production, leading to intestinal barrier disruption and metabolic endotoxemia. It has been shown that the active constituents of indigo plants can protect against intestinal inflammation; however, their protective role in HFD-induced intestinal epithelial damage remains unknown. The present study aimed to investigate the effects of Polygonum tinctorium leaf extract (indigo Ex) on HFD-induced intestinal damage in mice. Male C57BL6/J mice were fed a HFD and injected intraperitoneally with either indigo Ex or phosphate-buffered saline (PBS) for 4 weeks. The expression levels of TJ proteins, zonula occludens-1 and Claudin-1, were analyzed by immunofluorescence staining and western blotting. The colon mRNA expression levels of tumor necrosis factor-α, interleukin (IL)-12p40, IL-10 and IL-22 were measured by reverse transcription-quantitative PCR. The results revealed that indigo Ex administration attenuated the HFD-induced shortening of the colon. Colon crypt length was shown to be significantly greater in the indigo Ex-treated group mice compared with that in the PBS-treated group mice. Moreover, indigo Ex administration increased the number of goblet cells, and ameliorated the redistribution of TJ proteins. Notably, indigo Ex significantly increased the colon mRNA expression levels of IL-10. Indigo Ex displayed little effect on the gut microbial composition of HFD-fed mice. Taken together, these results suggested that indigo Ex may protect against HFD-induced epithelial damage. The leaves of indigo plants contain promising natural therapeutic compounds that could be used to treat obesity-associated intestinal damage and metabolic inflammation.

Polygonum tinctorium leaves suppress sodium dextran sulfate-induced colitis through interleukin-10-related pathway.

Indigo naturalis, a herbal medicine purified from indigo-containing plants, such as Strobilanthes cusia, Isatis tinctoria, and Polygonum tinctorium, has been reported to be useful in the treatment of ulcerative colitis by activating the aryl hydrocarbon receptor. However, the aryl hydrocarbon receptor pathway causes crucial side effects, such as pulmonary arterial hypertension. Although P. tinctorium is one of the plant derivatives of indigo naturalis, it is not identical to it. To date, the pure leaves of P. tinctorium have not been reported to ameliorate ulcerative colitis. Therefore, we investigated the effect of pure P. tinctorium leaves, which are consumed in some regions, on experimental colitis induced in mice using sodium dextran sulfate. We found that P. tinctorium leaves ameliorated weight loss (P < 0.01) and pathological inflammatory changes in the colon (P < 0.05), enhanced mRNA expression of interleukin-10 (P < 0.05), and decreased expression of tumor necrosis factor-in colonic tissues (P < 0.05), as determined using quantitative real-time reverse transcription polymerase chain reaction. The intraperitoneal administration of an aryl hydrocarbon receptor antagonist did not antagonize the inhibition of mucosal destruction, whereas an anti-interleukin-10 receptor antibody did. These results suggest that P. tinctorium ameliorate sodium dextran sulfate-induced intestinal inflammation via interleukin-10-related pathway, independent of the aryl hydrocarbon receptor pathway. P. tinctorium leaves have the potential to be a new, safe treatment for ulcerative colitis.

A new hexenoic acid glycoside with cytotoxic activity from the leaves of Psychotria luzoniensis.

A new hexenoic acid glycoside (1) together with known compounds, flavonol glycosides (2-4), iridoid glycoside (5), megastigmane glycoside (6), and amino acid (7) were isolated from the leaves of P. luzoniensis by resin column chromatography and preparative HPLC. Their structures were determined based on spectroscopic analysis, including HRFABMS and NMR (1H and 13C, 1H-1H COSY, HMQC, and HMBC) data. All compounds tested for cytotoxicity were active (IC50 < 50 µM) with IC50 values ranging from 1.97 to 32.85 µM against human colon adenocarcinoma cell line, compared to etoposide (IC50 1.19 µM).

Indirubin promotes adipocyte differentiation and reduces lipid accumulation in 3T3­L1 cells via peroxisome proliferator­activated receptor γ activation.

The peroxisome proliferator­activated receptor Î³ (PPARγ) plays an important role in insulin sensitivity and adipocyte differentiation. It is known as ligand­receptor that improves insulin sensitivity in type 2 diabetes mellitus. Several kinds of indigo plant have been already used to treat diabetes in oriental traditional medicine, but its mechanism has not been clarified yet. To investigate the effect of indirubin, which is a component of Polygonum tinctorium on the cell differentiation and adipprocess in 3T3­L1 cells, 3T3­L1 cells were cultured to determine the effect of cell differentiation and glucose uptake with indirubin. As a result, Indirubin compound enhanced adipocyte differentiation in 3T3­L1 cells similar to rosiglitazone. This effect was terminated by cotreatment with GW9662, a PPARγ antagonist. In mature 3T3­L1 adipocytes, the lipid droplet size and accumulation were reduced by this compound. The basal and insulin­stimulated glucose uptakes were also significantly increased. In addition, indirubin treatment significantly enhanced estrogen level by 1.64­fold with mature adipocytes which can be attributed to its aromatase activity. Conclutionaly, this finding suggested that indirubin is a potential anti­diabetic compound for type 2 diabetes mellitus by promoting adipocyte differentiation and glucose uptake via PPARγ.

Astragalus root induces ovarian ß­oxidation and suppresses estrogen­dependent uterine proliferation.

Continuous estrogen stimulation in the uterus has been known to cause excess proliferation of the functional layer of endometrium, resulting in endometrial hyperplasia and leading to infertility. Estrogens can modulate other nuclear receptor signaling pathways, such as peroxisome proliferator­activated receptors (PPARs). Astragalus root (AsR) has exhibited strong PPARα agonistic activity. Female Imprinting Control Region mice were fed a powder diet that included 5% AsR hot water extract or 0.1% bezafibrate as a positive control for 56 days to investigate AsR effects on the reproductive tract, ovary and uterus. AsR resulted in upregulation of the expression of uterine and ovarian PPARα mRNA by 2.5­fold, and 1.5­fold, respectively, compared with controls. AsR significantly increased ovarian expression levels of mitochondrial 2,4­dienoyl­CoA reductase (mDECR), an auxiliary enzyme involved in ß­oxidation. AsR­fed mice also exhibited a significant increase in blood estradiol levels and tended to have higher ovary weight. AsR resulted in significantly decreased uterine weight and mDECR expression levels. It has been reported that a PPARα agonist suppresses the development of estrogen­dependent endometrial hyperplasia. These findings raise the possibility that AsR suppresses estrogen­dependent endometrial hyperplasia and ovarian dysfunction leading to infertility.

Antioxidant Flavonols and Phenolic Compounds from Atraphaxis frutescens and Their Inhibitory Activities against Insect Phenoloxidase and Mushroom Tyrosinase.

Chemical investigation of the aerial parts of Atraphaxis frutescens resulted in the isolation of five 7-methoxyflavonols with pyrogallol B-ring moieties (1-5), a fisetinidol glucoside (13), and a benzyl glycoside (18), together with 26 known compounds including flavonoids, phenylpropanoid amides, anthraquinone glycosides, lignans, and a benzyl derivative. The principal chemical structural feature of the isolated compounds was either a pyrogallol or catechol B-ring moiety, and they showed potent 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. To assess the effects of these antioxidants on biological enzymes, their inhibitory effects against an insect phenoloxidase and a mushroom tyrosinase were evaluated. This study indicated that insect phenoloxidase was inhibited by phenylpropanoid amides and that mushroom tyrosinase was inhibited by the characteristic 7-methoxyflavonol 3-O-rhamnopyranosides.

Boiogito Increases the Metabolism of Fatty Acids in Proximal Tubular Cells through Peroxisome Proliferators-Activated Receptor (PPAR) α Agonistic Activity.

The promotion of fatty acid metabolism, to which peroxisome proliferators-activated receptor (PPAR) α contributes, has been suggested to participate in maintaining the function of renal proximal tubular epithelial cells (PTECs). The loading of fatty acids to PTECs could result in cell inflammation and cell death. A "Kampo" medicine, Boiogito (BO), is used to treat overweight women exhibiting chronic fatigue and edema in the lower extremities or knees. BO improves renal function by reducing the portion of fatty acids, thereby preventing damage to PTECs. In this study, BO and Astragalus Root (AsR), a constituent crude drug of BO, were administered orally to intravenously bovine serum albumin (BSA)-administered mice to evaluate the PPARα-cAMP responsive element binding protein (CREB) binding protein (CBP) complex binding activity and/or mRNA expression of PPARα, as quantified by enzyme-linked immunosorbent assay (ELISA) and/or polymerase chain reaction (PCR). Increases in PPARα-CBP complex binding activity and the expression of PPARα mRNA were observed not only in BO-administered mice but also in AsR-administered mice, accompanied by a decrease in the amount of renal fatty acid.

Resveratrol improves hippocampal atrophy in chronic fatigue mice by enhancing neurogenesis and inhibiting apoptosis of granular cells.

Neuroimaging evidence showed structural and/or functional abnormalities existing in the central nervous system, especially the hippocampus, in chronic fatigue syndrome (CFS) patients. However, its pathophysiologic mechanisms are unclear in part due to the lack of an applicable animal model. We established a chronic fatigue murine model by six repeated injections of Brucella abortus antigen to mice, which was manifested as reduced daily running activity and hippocampal atrophy. Thereafter, resveratrol, a polyphenolic activator of sirtuin 1, was used for treatment in this model. Daily running activity was increased by more than 20%, and the hippocampus was enlarged after 4-week resveratrol therapy. Furthermore, resveratrol inhibited neuronal apoptosis and expression of hippocampal acetylated p53 in the fatigue mice. Resveratrol also improved neurogenesis and expression of brain-derived neurotrophic factor mRNA in the hippocampus. We concluded that repeated injection of B. abortus antigen could induce hypoactivity and hippocampal atrophy in mice. Resveratrol may be effective for improving fatigue symptoms and enlarging the atrophic hippocampus by repressing apoptosis and promoting neurogenesis.

Hochu-ekki-to combined with interferon-gamma moderately enhances daily activity of chronic fatigue syndrome mice by increasing NK cell activity, but not neuroprotection.

The purpose of this study was to evaluate the beneficial effect of Hochu-ekki-to (TJ-41) combined with interferon-gamma (IFN gamma) on daily activity, immunological and neurological alternation in a mouse model of chronic fatigue syndrome (CFS). CFS was induced by 6 times of repeated injection of Brucella abortus antigen every 2 weeks. Both single TJ-41 and TJ-41 combined with IFN gamma increased running activity and thymus weight of CFS mice, while thicker thymic cortex together with elevation of natural killer cell activity was only found in the combined treatment group. No significant improvement was observed in the atrophic brain and decreased expression level of brain-derived neurotrophic factor and Bcl-2 mRNA in hippocampus in both treatment groups. Our results suggest that TJ-41 combined with IFN gamma might have a protective effect on the marked reduction in the activity in a model of CFS via normalization of host immune responses, but not neuroprotection.

Oral Administration of Ren-Shen-Yang-Rong-Tang 'Ninjin'yoeito' Protects Against Hematotoxicity and Induces Immature Erythroid Progenitor Cells in 5-Fluorouracil-induced Anemia.

The purpose of this study was to investigate the efficacy of four different Japanese and Chinese herbal prescriptions, Ren-Shen-Yang-Rong-Tang (Ninjin'yoeito, NYT), Chai-Hu-Gui-Zhi-Gan-Jiang-Tang (Saikokeishikankyoto, SKKT), Si-Jun-Zi-Tang (Shikunshito, SKT) and Si-Wu-Tang (Shimotsuto, SMT), which are traditionally used for anemia and fatigue, against hematotoxicity in mice treated with 5-fluorouracil (5-FU). NYT 1-100 mg kg(-1) day(-1) injected orally for 7 consecutive days before and after 5-FU injection significantly suppressed reductions in red blood cell, white blood cell and platelet counts in peripheral blood, and accelerated their recovery. Administration of SKKT also produced a slight but significant improvement in 5-FU-induced erythrocytopenia, whereas SMT and SKT could not prevent anemia. Oral injection of NYT also inhibited 5-FU-induced decreases in peripheral reticulocyte and bone marrow cell counts on day 10, and markedly hastened their recovery on day 20, in a dose-dependent manner. Erythroid progenitor colonies, such as colony forming units-erythroid and burst forming units-erythroid, formed by marrow cells from mice treated with 5-FU were significantly increased by oral administration of NYT. These findings suggest that NYT has the potential to protect against hematotoxicity, and also has hematopoietic activity, through stimulation of immature erythroid progenitor cell differentiation.

Anti-hepatitis C virus effect of citrus unshiu peel and its active ingredient nobiletin.

We investigated the effects of water and ethyl acetate extracts of Citrus unshiu peel (Aurantii Nobilis pericarpium) on hepatitis C virus (HCV) absorption in MOLT-4 cells (a human lymphoblastoid leukemia cell line). By reverse transcription polymerase chain reaction (RT-PCR), we showed that both the ethyl acetate layer of Citrus unshiu peel extract and fraction 7 decreased HCV absorption in MOLT-4 cells. Furthermore, we demonstrated that 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) is the active ingredient that markedly inhibited HCV infection in MOLT-4 cells.

Nonopioid receptor-mediated effects of U-50,488H on [Ca(2+)]i and extracellular dopamine in PC12 cells.

The present studies were carried out to determine the effects of a kappa-opioid receptor agonist on cytosolic Ca(2+) concentration, [Ca(2+)](i), and extracellular dopamine in undifferentiated PC12 cells. The kappa-opioid receptor agonist U-50,488H caused concentration-dependent increases in [Ca(2+)](i) and extracellular dopamine. Neither effect was blocked by the selective kappa-opioid receptor antagonist nor-binaltorphimine. Increases in extracellular dopamine content and [Ca(2+)](i) caused by U-50,488H were correlated positively in the presence of extracellular Ca(2+); however, reduction of extracellular Ca(2+) abolished the increase in [Ca(2+)](i), but not that in dopamine. The latter observation suggests that stimulation of exocytotic release is not the primary mechanism involved in the increase in extracellular dopamine caused by U-50,488H. Effects on dopamine synthesis or catabolism also seem unlikely because the enhancement of extracellular dopamine occurred rapidly, and the amount of a major metabolite of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), was not affected. In any event, neither the increase in [Ca(2+)](i) nor the increase in extracellular dopamine caused by U-50,488H is mediated by the kappa-opioid receptor.

The interaction of morphine and gamma-aminobutyric acid (GABA)ergic systems in anxiolytic behavior: using mu-opioid receptor knockout mice.

We investigated the interaction of morphine and gamma-aminobutyric acid (GABA)ergic systems in anxiolytic action using mu-opioid receptor knockout and wild-type female mice. An elevated plus-maze test was used to assess anxiolytic behavior. The anxiolytic activities were monitored after experimental animals were pretreated with morphine [15 mg/kg, subcutaneous (s.c.)] and 3 h later received a single dose of muscimol (0.5 mg/kg, s.c.). In another experiment, mice received a single dose of opioid antagonist, naloxone [1.0 mg/kg, intraperitoneal (i.p.)], or GABA(A) receptor antagonist, (+)bicucullin (2.0 mg/kg, i.p.), 2.5 h after the morphine and 30 min before the muscimol injection. Control mice received vehicle only. The results show that morphine enhanced muscimol-induced staying time in open arms by 160% in wild-type mice. Moreover, the effect of morphine in the wild type was inhibited by the pretreatment of either naloxone or (+)bicucullin. Autoradiographic analysis indicated that morphine-administration raised [(3)H]muscimol binding by around 25% of the basal level in posterior thalamic, mediodorsal thalamic, and amygdaloid areas, but not in the hippocampal area in wild-type mice. In contrast, morphine administration did not alter the [(3)H]muscimol binding in mu-opioid receptor knockout mice. The present results reveal that mu-opioid receptor may play a role in the modification of anxiolytic behavior regulated by GABAergic neurotransmission.