Anti-hypoxia effects of the ethanol extract of Oxytropis ochrocephala

Oxytropis ochrocephala is one of the most extensively used herbs in traditional Tibetan folk medicine to clear heat through detumescence, strengthen the body, and improve immune system. However, research studies examining its medicinal value are limited. By conducting experiments using animal models (mice) in airtight space at ambient and reduced pressure, as well as sodium nitrite exposure, the anti-hypoxia effects of the ethanol extract of O. ochrocephala (EEOO) were investigated in the present study.

EEOO was administered to three groups of mice for 7 days; 1.5 g/kg for the high-dosage group (EHD), 1.0 g/kg for the medium-dosage group (EMD) and 0.5 g/kg for the low-dosage group (ELD). Hypoxia was induced in mice by placing the animals in an airtight space at reduced pressure, and sodium nitrite poisoning was conducted for 1 hour after the last intragastric administration. The levels of glutathione peroxidase enzyme (GSH-Px), superoxide dismutase (SOD) and malondialdehyde (MDA) in the myocardium and cerebral tissues were determined by the colorimetric method. Protein expression of BAX and BCL-2 was detected by ELISA. A high lethal dose (LD₅₀) of 3, 000 mg/kg was obtained in acute toxicity. Mice in the blank control group survived longer than those in the EHD group under hypoxic conditions. All biochemical criteria were significantly enhanced (P< 0.05). EEOO increased the tolerance of mice to hypoxia, which is indicative of its anti-hypoxia effects. The major components are 5, 7-Dihydroxy- 4′-methoxy-hydroxy-2-phenyl, 5, 7-Dihydroxy- 4′-methoxy-2-phenyl-4-benzopyrone-3-O-β-galactopyranoside.