[Antitumor effects of alpha-linolenic acid on the human tumor transplanted in nude mice and on the metastasis of Vx-7 tumor in rabbit].

Many epidemiological studies and laboratory experimentations have shown that dietary omega-6 fatty acids stimulate and omega-3 fatty acids suppress tumorigenesis. On the other hand, some reports presented that parenteral administrations of unsaturated free fatty acids such as oleic, linoleic and linolenic acids inhibited the growth of a transplantable syngeneic tumor in mice. In this report, I examined the effect of alpha-linolenic acid on the growth of 17 lines of human tumor transplanted in nude mice and on the metastasis of Vx-7 tumor transplanted in rabbits. When alpha-linolenic acid was emulsified with HCO-60 and subcutaneously injected in the peripheral region of the transplanted tumor, complete cure rates for MKN-1, MKN-28, NOC-S and PL-14 human tumors were 100, 57, 25 and 75% respectively at a dose of 250 mg/kg/day for four days once a day, although it was not effective on GCH-nu and SKG-III. Using other tumor lines, T/C ratios of the transplanted tumor weight on day 31 were 4% for Taneda, 34% for Lx-1, 47% for Li-7, 31% for Sk-14, 49% for Kuronuma and 16% for Sawayama. When alpha-linolenic acid was intermittently injected in the same manner on day 3, 13, 17 and 24, T/C ratios of tumor weight were 24% for ALL, 34% for Taneda, 23% for Lx-1, 50% for Li-7, 47% for Sk-14 and 54% for Kuronuma. Mammary tumor line (Mx-1) did not respond to administrations of alpha-linolenic acid. Rabbit Vx-7 tumor cells transplanted via lympho-duct were trapped in lymphonodi to metastasize to other organs. When alpha-linolenic acid mixed with Lipiodol was injected once via lympho-duct on day 8 after tumor transplantation at a dose of 250 mg/kg, the tumor growth was reduced in lymphonodi poplitei to 14%, and thus highly inhibited the metastasis of tumor cells to lung.