Acute and sub-acute oral toxicity studies of the aqueous extract from radix, radix with cortex and cortex of Psammosilene tunicoides in mice and rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Psammosilene tunicoides is one of the important ingredients of a famous Chinese traditional medicine formulation "Yunnan Baiyao". Also, this plant is commonly used as an anodyne and hemostatic agent in southwest China. Currently, little toxicological information is available on its safety following prolonged use. AIM OF THE STUDY: In this study, we sought to evaluate the toxicity of the three different parts of Psammosilene tunicoides: Psammosilenes Radix (PR), Psammosilenes Radix with Cortex (PRC) and Psammosilenes Cortex (PC) by acute and sub-acute toxicity studies. MATERIALS AND METHODS: In the acute toxicity study, mice were orally administrated with different doses of PR, PRC and PC. General behavior and mortality were observed up to 14 days. In sub-acute toxicity study, these aqueous extracts were given orally as a single administration to rats at doses of 0.3, 0.6 and 1.2g/kg/day, respectively, for 28 days. General behavior, body weight, biochemical, hematological, organ coefficients and pathological morphology parameters were detected. RESULTS: In acute study, single oral administration of the aqueous extract of PR, PRC and PC caused dose-dependent general behavior adverse effects and mortality. The LD50 values of PR, PRC and PC were 4.64g/kg, 4.85g/kg and 6.40g/kg, respectively. In sub-acute study, the administration of the extract of PR, PRC and PC during 28 days at all doses reduced spontaneous activities with both genders. Occasional nasal secretion with blood at high doses (1.2g/kg) of PR, PRC and PC were observed. Daily single oral administration provoked varying degrees of growth retardation in female rats. The relative heart and spleen weight in the female rats were reduced after the administration. On the hematological and biochemical analyses, the administration of the extract of PR, PRC and PC during 28 days mainly caused variation of indexes in female rats. Histopathological analysis has shown vascular congestion in heart, thickened alveolar wall and emphysema in lung, and vascular congestion in kidney of rats after sub-acute oral administrations. CONCLUSIONS: As shown in the results, Psammosilene tunicoides has a toxic potential in acute and sub-acute oral administrations. However, there is no direct relationship between toxicity and the cortex. Daily oral administration of three different parts from Psammosilene tunicoides (PR, PRC and PC) may cause damages to heart, lung and kidney in rats. Thus these extracts should be used with caution.

[Advanced in studies on anxiolytic effects of natural flavonoids].

Anxiety is one of the most common diseases endangering human health. Its pathogenesis is complex, the studies on the mechanisms of anxiety disorder are concentrated on neurotransmitter, neuroendocrine, immunologic system. Flavonoids are a kind of compounds which possess a variety of physiological activity, used in plenty of diseases. In recent years, researches of natural flavonoids on anti-anxiety were increasing, but contents were incomplete. It was just involved several neurotransmitters in research area. This paper is based on different anxiolytic effect mechanisms and structure-activity relationships of natural flavonoids, summarizing the researches of domestic and foreign, which can serve as a reference for further studies on anxiolytic effects of natural flavonoids.