Planta medica
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The phenolic glucoside gastrodin (Gas) is a main component extracted from the rhizome of Gastrodia elata, a Chinese herbal medicine, which has long been used for treating dizziness, epilepsy, stroke and dementia. In this study, we investigated the neuroprotective effects of Gas on cerebral ischemic injury in rats caused by transient middle cerebral arterial occlusion (MCAO), oxygen/glucose deprivation (OGD) and glutamate-induced injury in cultured rat hippocampal neurons. Additionally, the effects of Gas on the extracellular glutamate level and changes in intracellular Ca (2+) and the generation of nitric oxide (NO) were examined in cultured hippocampal neurons subjected to OGD in vitro. ⋯ Gas treatment (15 microg/mL, 30 microg/mL) also significantly inhibited OGD- and glutamate-induced neuronal cell death and reduced the extracellular glutamate level following OGD. Moreover, Gas treatment significantly inhibited the OGD-induced Ca (2+) and NO increases. In conclusion, the present study indicates that Gas has a neuroprotective action.
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Hyperglycaemia in diabetes mellitus results in oxidative stress and pro-inflammatory changes which contribute to vascular complications including endothelial dysfunction and peripheral neuropathy. The aim of this study was to examine whether treatment with the dominant ingredient of clove oil, eugenol, which has antioxidant and anti-inflammatory properties, could improve diabetic vascular and nerve function in streptozotocin-induced diabetic rats. Intervention treatment was given for 2 weeks following 6 weeks of untreated diabetes. ⋯ For renal artery rings, maximum endothelium-dependent relaxation to acetylcholine was 51% reduced by diabetes; eugenol corrected this deficit by 60%, with improvements in both nitric oxide and endothelium-derived hyperpolarising factor (EDHF)-mediated vasorelaxation components. Diabetes increased renal artery sensitivity to phenylephrine-mediated contraction, however, this was unaffected by eugenol treatment. Thus, aspects of both vascular and neural complications in experimental diabetes are improved by eugenol, which could have potential therapeutic implications for diabetic neuropathy and vasculopathy.
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This study assessed the anti-inflammatory effect of the extracts and purified lignans obtained from Phyllanthus amarus. Given orally, the hexane extract (HE), the lignan-rich fraction (LRF), or the lignans phyltetralin, nirtetralin, niranthin, but not hypophyllanthin or phyllanthin, inhibited carrageenan (Cg)-induced paw oedema and neutrophil influx. ⋯ Finally, nirtetralin or phyltetralin caused inhibition of paw oedema induced by PAF or ET-1. These results show that the HE, the LRF and the lignans niranthin, phyltetralin and nirtetralin exhibited marked anti-inflammatory properties and suggest that these lignans seem to be the main active principles responsible for the anti-inflammatory properties reported for the HE of P. amarus.
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We have recently reported that red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng (Panax ginseng C. A. Meyer), shows immunomodulatory and antitumor activities, mainly mediated by the nitric oxide (NO) production of macrophages. ⋯ Flow cytometric analysis of splenocytes in mice treated with paclitaxel showed a significant increase of CD11b+ cells. Additionally, a synergistic effect of RGAP and paclitaxel was found to effect an increased tumoricidal activity of macrophages. The above results suggest that clinical trials of RGAP as an adjuvant in cancer chemotherapy of paclitaxel are highly feasible.
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The roots of Angelica keiskei Koizumi (Umbelliferae) have traditionally been used as a health food considered to have diuretic, laxative, analeptic and lactagogue effects. Recently, it has been thought that the roots and herbs of A. keiskei have preventive effects against coronary heart disease, hypertension and cancer. It has been reported that chalcone derivatives, such as xanthoangelol and 4-hydroxyderricin, are isolated as main components from this root. ⋯ In addition, 4-hydroxyderricin (50 mg/kg x 2/day) inhibited the reduction of the numbers of lymphocytes, CD4+, CD8+ and natural killer (NK)-T cells in the spleen of tumor-removed mice. Doxorubicin reduced the numbers of lymphocytes, CD4+, CD8+ and NK cells compared to those in LLC-removed mice. These results suggest that the antitumor and antimetastatic activities of 4-hydroxyderricin may be modulated by the immune system and the inhibition of angiogenesis.