[Studies on dosage-efficacy/toxicity relationship of anti-hypoxia effects and quality standard of Tibetan medicine Brassicea Radix extract].

To evaluate the efficacy and safety associated with anti-hypoxia effect and establish the quality standard for Brassicea Radix extract, the investigations of acute toxicity and subacute toxicity were carried out to preliminarily appraise the toxicity, and the models of normal pressure hypoxia, acute cerebral ischemia and sodium nitrite poisoning in mice were used to evaluate the effect of enhancing anoxia endurance. Then according to the methods described in the Appendix of Chinese Pharmacopoeia (2010 edition), the sulfuric acid-phenol method was applied to determine the content of polysaccharide, and the water, ash and insoluble matter in water inspections were carried out and the control medicinal herb was identified with the samples by qualitative TLC. The results indicated that ① the toxic effects (LD₅₀) of mice was 56.73 g•kg⁻¹ by oral administration of Brassicea Radix extract, while Dm and Dn were respective 86.80 g•kg•d⁻¹ and 35.55 g•kg•d⁻¹;②the determined effective dosage of Brassicea Radix extract which could enhance anoxia endurance was 0.388 g•kg⁻¹•d⁻¹; ③ the methods of TLC and the content of polysaccharide were established. The method of quality control has been recorded in Sichuan Province Standard for Tibetan Medicine, which is reliable, accurate and simple, with good reproducibility. Meanwhile, given the prominent effect on anti-hypoxia and good safety, it provided important basis for clinic safe and effective usage and the development of health products.