The Oncostatic Activity of Serotonin

Abstract

Pukhalskaya et al. (1957) of the Institute of Experimental and Clinical Oncology, Moscow, reported the isolation of an agent from the bark of an Asiatic plant, Hippophae rhamnoides, which inhibited Ehrlich mouse carcinoma. Pukhalskaya (1958) furthermore described that an alcoholic extract of the bark, after elimination of tannic acid, with the total dose of 750 mg/kg/rat resulted in LD₅₀. A total dose of 400 mg/kg/rat of the factor inhibited up to 80–90% of Guerin carcinoma, sarcoma 45 and sarcoma M-1, but no complete regression of the tumors was observed. The oncostatic activity of the factor, called hippophainum, was much less pronounced in regard to mouse hepatoma C₃HA, Ehrlich carcinoma, Passy melanoma and Walker rat carcinoma. Petrova et al. (1959) by further chemical purification of hippophainum were able to increase its biological activity up to LD₅₀ 250 mg/kg. Pukhalskaya et al. (1960) identified the active factor as 5-hydroxytryptamine. They obtained it in the form of a hydrochloride. Daily doses of 10 mg/kg.wt./mouse and 5 mg per kg.wt./rat were found of low toxicity. Larger doses of hippophainum caused renal injury, affecting the blood forming system, however, little if at all. A total dose 60 mg/kg.wt./mouse, given for 12 days, inhibited Ehrlich carcinoma by 42%. The same dose inhibited Guerin carcinoma by 67%. No inhibiting effect was observed on rat lymphosarcoma, nor was the complete inhibition or resorption of any tested tumor recorded. Pukhalskaya (1960), in her review of the pharmacology of hippophainum, which was identified by her as a hydrochloride serotonin, stressed its role in anaphylactic shock and as a vasoconstrictor. Petrova and Menshikov (1961) described in detail the method of producing 5-HT from the bark of Hippophae rhamnoides.