In this study, in vitro and in vivo antiinflammatory activities of fruits from Lindera erythrocarpa Makino were evaluated. The ethyl acetate soluble fraction derived from the ethanol extract of L. erythrocarpa fruits inhibited significantly nitric oxide (NO) production in lipopolysaccharide (LPS) induced NO in the murine macrophage cell line (RAW264.7) assay, the EC(50) being 16.35 microg/mL. Four compounds, including lucidone (1), cis/trans-methylludicone (2), methyl linderone (3) and linderone (4) were identified from the active fraction based on the bioactivity-guided fractionation procedure. Of these lucidone possessed the strongest NO inhibitory activity with an EC(50) value of 4.22 microg/mL. Furthermore, results from the protein expression assay demonstrated that lucidone suppressed iNOS and COX-2 protein expression in a dose-dependent manner. Lucidone also provided antiinflammatory activity in the croton oil-induced ear edema assay. When it was applied topically at a dosage of 0.5 and 1 mg per ear, the percent edema reduction in treated mice was 44% and 25%, respectively. The results obtained in this study indicated that lucidone has a good potential to be developed as an antiinflammation agent.

Sugiol is a diterpene which was isolated and purified from alcohol extracts of the bark of Calocedrus formosana Florin (Cupressaceae). Although sugiol has low inhibitory activity against the DPPH radical, it could effectively reduce intracellular reactive oxygen species (ROS) production in lipopolysaccharide (LPS)-stimulated macrophages. The present study investigated the potential anti-inflammatory activity of sugiol, and the relationship between signal transduction and inflammatory cytokines in vitro. A dose of 30 microM of sugiol was effectively inhibitory for proIL-1beta, IL-1beta and TNF-alpha production, suggesting that sugiol is bioactive against inflammation. Moreover, sugiol reveals a capacity for suppressing the activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38) activated by LPS-stimulation in J774A.1 murine macrophages. A low dosage of 10 microM of sugiol completely inhibited ERK1/2 phosphorylation, while 30 microM effectively inhibited JNK1/2 and p38 phosphorylation in LPS-stimulated macrophages. In addition, sugiol significantly inhibited LPS-induced ROS production. Our studies suggest that sugiol's efficacy in inhibiting the inflammatory cytokines of IL-1beta and TNF-alpha could be attributed to a reduction of the ROS that leads to a decrease in the phosphorylation of MAPKs.

The effects of lucidone on tyrosinase and antimelanogenic activity were investigated. Initially, we found that lucidone strongly inhibits the activity of mushroom tyrosinase. The effects of lucidone on tyrosinase were further examined in alpha-MSH-induced B16 melanoma cells. Lucidone significantly inhibits tyrosinase activity and leads to decreased melanin content in cultured B16 melanoma cells. Lucidone also attenuates the expression of tyrosinase and MITF (Microphthalmia-associated Transcription Factor) protein in a concentration-dependent manner, as shown by western blot. Quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) confirmed that lucidone inhibits the expression of tyrosinase mRNA. Accordingly, the effects of lucidone on the ERK signaling pathway were also investigated, but lucidone was not found to play major role in the induction of ERK activation. Our data indicate that the antimelanogenic activity of lucidone is probably due to its inhibition of tyrosinase activity and the suppression of tyrosinase and MITF expression.

The extracts from different tissues of Allium fistulosum L. and Allium sativum L. were investigated to evaluate their antioxidant and antimicrobial capacity. The highest yields of the Allium extracts were prepared from the extraction of 30% ethanol solution. The DPPH scavenging activity was the highest in A. fistulosum L. leaves, which IC 50 is 14.61 μg·mL −1. The highest antioxidant activity using TEAC assay and total phenolic content were observed in A. sativum L. stems and A. fistulosum L. stems, where they are determined to be 15.51 mM and 191.04 mg GAE·g , respectively. The inhibitory activity of various Allium extracts against the test bacteria was greater than that of 10 μg·mL −1 allicin. The results indicated that Allium spp. extracts could be used as a potential source of natural antioxidants and antimicrobial agents.

The goals of this study were to elucidate the temporal and quantitative relationships between caffeine and its major bioactive metabolites in blood and cerebrospinal fluid (CSF) and to characterize the pharmacokinetic-pharmacodynamic relationship for caffeine-induced changes in spontaneous locomotor activity in the horse. We hypothesized that caffeine and its metabolites distribute efficiently into the CSF to antagonize adenosine A1 and A2a receptors and that spontaneous locomotor activity correlates well with caffeine and/or metabolite concentrations in CSF and blood. A microdialysis system was developed to allow simultaneous monitoring of locomotor activity and collection of CSF and blood samples for pharmacokinetic analysis. CSF concentrations of caffeine and its metabolites were evaluated to determine the percentage of central adenosine receptor blockade by the established standard inhibition curves. Caffeine increased the spontaneous locomotor activity for up to 4 h in a dose-dependent manner. After 3 mg/kg caffeine administration, blood caffeine concentration as well as locomotor activity increased sharply to near peak level while CSF caffeine concentrations exhibited a slow rise to a steady-state 75 min later. High correlation coefficient was found between locomotor activity and caffeine concentrations in blood (R(2 )=0.95) and in CSF (R(2) = 0.93). At 3 mg/kg dosage, theophylline was the only detectable caffeine metabolite in the CSF. The concentrations reached in the CSF were sufficient to partially block central adenosine A1 (14% blockade) and A2a (11% blockade) receptors. There were no statistically significant differences between the pharmacokinetics of caffeine in the blood and CSF. This study provides novel evidence that locomotor stimulation in horses is closely correlated with caffeine concentrations in the blood and CSF and, furthermore, is consistent with blockade of central adenosine receptors.