Novel serotonin-boosting effect of incense smoke from Kynam agarwood in mice: The involvement of multiple neuroactive pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Stress is a state of feeling that inhibits one from responding properly in the face of a threat. Agarwood smoke has been used in traditional medicine as a sedative anti-anxious, and anti-restless therapy. Its scent emitted from heat induces people to enter a stable state; however, the underlying molecular effect is still unclear. AIM OF THE STUDY: This study analyzed novel biological events and gene expression signatures induced by agarwood incense smoke in mice. MATERIALS AND METHODS: Incense smoke was produced by heating at 150 °C for 30 min in a headspace autosampler oven. We treated mice with exposure to incense smoke from Kynam agarwood for 45 min/day for 7 consecutive days. After a 7-day inhalation period, the potent agarwood smoke affected-indicators in serum were measured, and the RNA profiles of the mouse brains were analyzed by microarray to elucidate the biological events induced by agarwood incense smoke. RESULTS: Chemical profile analysis showed that the major component in the incense smoke of Kynam was 2-(2-phenylethyl) chromone (26.82%). Incense smoke from Kynam induced mice to enter a stable state and increased the levels of serotonin in sera. The emotion-related pathways, including dopaminergic synapse, serotonergic synapse, GABAergic synapse, long-term depression and neuroactive ligand-receptor interaction, were significantly affected by incense smoke. Moreover, the expression of Crhr2 and Chrnd genes, involved with neuroactive ligand-receptor interaction pathway, was upregulated by incense smoke. CONCLUSIONS: By a newly-established incense smoke exposure system, we first identified that anti-anxious and anti-depressant effects of agarwood incense smoke were likely associated with the increase of serotonin levels and multiple neuroactive pathways in mice.

Chemical Profiles of Incense Smoke Ingredients from Agarwood by Headspace Gas Chromatography-Tandem Mass Spectrometry.

Agarwood, the resinous wood in the heartwood of Aquilaria trees, has been used as incense in traditional Chinese medicine for its sedative, aphrodisiac, carminative, and anti-emetic effects. Grading of agarwood is usually based on its physical properties. Therefore, it is important to develop analytic methods for judgment and grading of agarwood. Here, we created a headspace (HS) preheating system that is combined with gas chromatography-mass spectrometry (HS GC-MS) to analyze the chemical constituents in the incense smoke produced by agarwood. Incense smoke generated in the HS preheating system was injected directly to GC-MS for analysis. A total of 40 compounds were identified in the incense smoke produced by Kynam agarwood, the best agarwood in the world. About half of the compounds are aromatics and sesquiterpenes. By analyzing chemical constituents in the incense smoke produced by Vietnamese, Lao, and Cambodian varieties of agarwood, we found that butyl hexadecanoate, butyl octadecanoate, bis(2-ethylhexyl) 1,2-benzenedicarboxylate, and squalene were common in the aforementioned four varieties of agarwoods. 2-(2-Phenylethyl) chromone derivatives were identified only in the incense smoke produced by Kynam agarwood, and were the major ingredient (27.23%) in the same. In conclusion, this is the first study that analyzes chemical profiles of incense smoke produced by agarwood using HS GC-MS. Our data showed that 2-(2-phenylethyl) chromone derivatives could be used to assess quality of agarwoods. Moreover, HS GC/MS may be a useful tool for grading quality of agarwood.

Effect of Tianma Gouteng Decoction with subtractive ingredients and its active constituents on memory acquisition.

Accumulating evidence indicates that the high blood pressure (BP) is a potent risk factor for dementia in the elderly. In line with this theory, we had found the mixture of Chinese herbs (TGD) which were traditionally used to treat hypertension, could enhance the cognitive function. The aim of this study was to decrease the number of herbs used from 11 (TGD) to 4 herbs (TGDS) and further to search the active constituents. After administering a dose of 10 g/kg of TGDS0 to ICR mice, no cholinergic symptoms of lacrimation, salivation, emesis, eyeclosure, increased respiration and fibrillation were observed. All the mice survived without any deaths after 24 hours and 7 days. No changes were observed in control and experimental groups on locomotor activity (no stimulant or sedative effects). It was also revealed that TGDS could prolong the step-through latency at the dose of 1.0 and 2.5 g/kg on passive avoidance tasks in mice. This result was the same as the previous study. The active constituents which enhanced the memory acquisition were discovered in the butanol layer and ethyl acetate layer after the extraction.

Traditional Chinese herbs against hypertension enhance memory acquisition.

Recent findings of a link between high blood pressure (BP) and dementia have given new prospects. The aim of this study is to analyze a mixture of Chinese herbs, Tianma Gouteng Decoction (TGD), which was traditionally used to treat hypertension, and investigate its relation to ameliorating cognitive impairment. We discovered that TGD also had properties involving enhancement of memory acquisition (learning) skills in mice, but not memory consolidation. It was observed that TGD could prolong the step-through latency at doses of 1.0 and 2.5 g/kg on passive avoidance task in mice. TGD could be developed further to treat mice with amnesia, which was induced by scopolamine at the same dose under long-term (8 days) administration.

Establishment of the mimetic aging effect in mice caused by D-galactose.

We successfully established an oxidant damage of mimetic aging model using mice induced by D-galactose, and the mimetic aging model is relative to free radical and the accumulation of waste substances in metabolism. The animals were divided into 3 groups: (1) phosphate-buffered saline (PBS); (2) 1% D-galactose; (3) 5% D-galactose by subcutaneous injection every day. After 45 days, mice treated with D-galactose showed a significant increase in the malondialdehyde (MDA), total antioxidant status (TAS) and a decrease in superoxide dismutase (SOD) in the blood compared with the PBS group. In the brain, the D-galactose treated mice exhibited a higher level MDA and a lower level SOD activity. In the liver, only the 5% D-galactose group indicated a significant increase in MDA. By reference to the oxidative biomarkers in blood, brain and liver, we have confirmed the reliability of the mimetic aging model.