Biological & pharmaceutical bulletin
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The present study was designed to evaluate central inhibitory effects of the essential oil from Acori graminei Rhizoma (AGR), the dry rhizomes of Acorus gramineus SOLANDER (Araceae) upon fragrance inhalation (aroma therapy). Preinhalation of the oil markedly delayed the appearance of pentylenetetrazole-induced convulsion. Furthermore, inhalation impressively inhibited the activity of gamma-aminobutyric acid (GABA) transaminase, a degrading enzyme for GABA as the inhalation period was lengthened. ⋯ Ten hour inhalation corresponded almost to the effect (145% increase) of oral administration (60 mg/kg). This sedative effect after inhalation or oral administration of AGR essential oil suggests that this oil may act on the CNS via the GABAergic system. The inhibitory activity of preinhalation of the essential oil on lipid peroxidation, to which the anticonvulsive action is attributed, also supported the above results, confirming and amplifying our previous reports on the CNS inhibitory effects of AGR.
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Calprotectin, a complex of two calcium-binding proteins that belong to the S100 protein family, is abundant in the cytosolic fraction of neutrophils. A high level of calprotectin reportedly exists in extracellular fluid during various inflammatory conditions, such as rheumatoid arthritis, cystic fibrosis and abscesses. However, the exact biological role(s) of the factor is now under investigation. ⋯ Therefore, the protein factor may be a new drug target to control inflammatory reactions. We found that a few of the Amaryllidaceae alkaloids effectively inhibited the growth-inhibitory and apoptosis-inducing activities of calprotectin. In this article, we focus on the biological functions of calprotectin in extracellular fluids, focusing on its apoptosis-inducing activity.
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In this study, we examined whether several types of non-opioid agents would inhibit the pain-related responses of melanoma-bearing mice. Orthotopic inoculation with melanoma into the hind paw induced marked tactile allodynia and mechanical hyperalgesia. A peroral injection (p.o.) of gabapentin (100-300 mg/kg) inhibited the allodynia and hyperalgesia, without effects on gross behaviors. ⋯ Subcutaneous injections of baclofen (3 mg/kg) and N(G)-nitro-L-arginine methyl ester (100 mg/kg) were also without effects. Repeated administration of gabapentin (150 mg/kg, p.o.) produced constant inhibitions, suggesting no analgesic tolerance. Gabapentin may be useful for the management of cancer pain.
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The aims of this study were to examine the enhancing effects of aloe-emodin anthrone (AEA) on the colonic membrane permeability of water-soluble and poorly permeable compounds and to clarify the mechanism of the permeation-enhancing activity of AEA. The permeation-enhancing activity of AEA was estimated from changes in the permeability coefficient of 5(6)-carboxyfluorescein (CF) in rat colonic mucosa using a Ussing-type chamber. Various inhibitors were used to investigate the mechanism of action of AEA. ⋯ In conclusion, AEA is a candidate for effective absorption enhancers without damage of the membrane and cytotoxicity. We propose that AEA stimulates mast cells within the colonic mucosa to release histamine, which probably bind to the H(1) receptor. The intracellular PKC route activated by H(1) receptor activation enhances the permeability of water-soluble and poorly permeable drugs via opening of tight junctions in rat colonic membrane.
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Stoichiometric evaluation of the radical scavenging activity of O-substituted derivatives at the C-2 position of ascorbic acid (AA) was conducted. Their reaction with a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), under an acidic condition was assessed by the colorimetric method. 2-O-alpha-D-Glucopyranosyl-L-ascorbic acid (AA-2G) and a series of 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G) had long-term radical scavenging activity against DPPH. ⋯ In contrast, one molecule of AA scavenged two molecules of DPPH radicals, and the reaction ended in the short time (<10 min). The quantity of radicals quenched by AA-2G and 6-Acyl-AA-2G was superior to that of AA in a long-term reaction.