To study the antitumor activity of alkaloid extracted from Oxytropis ochrocephala and its possible mechanism, we observed the effect of alkaloid on tumor weight and expression of PCNA and p53 in mice bearing H22 hepatocellular carcinoma by means of immunohistochemistry SP method. After treatment with alkaloid from Oxytropis ochrocephala, the results showed that alkaloid administration (25 and 50 mg/kg body weight, p.o.) could inhibit H22 hepatocellular carcinoma growth to various extent, and the rates of inhibition were 48.5% and 57.7% respectively (p<0.01). The antitumor activity of the alkaloid is in a dose dependent manner, with no signs of toxicity to weight, kidney and liver. The sections of tumor showed the number of tumor cell decreased and nucleus appeared putrescence such as nucleus atrophy, disintegrating and dissolving. Meanwhile, the expression of PCNA and mutant p53 protein positive cell numbers in mice bearing H22 hepatocellular carcinoma also suppressed by alkaloid (p<0.05). It suggested that Alkaloid from Oxytropis ochrocephala showed antitumor effect and its possible mechanism might be associated with the expression inhibition of PCNA and mutant p53 protein. Further studies are needed to explore the antitumor activity of the other compounds of Oxytropis ochrocephala and to specify their possible mechanism of action.
2005 by the PHARMACEUTICAL SOCIETY OF JAPAN