Therapeutic Activity of Pretazettine, a Narcissus Alkaloid, on Spontaneous AKR Leukemia

Abstract

A narcissus alkaloid, pretazettine hydrochloride (PTZ) has been shown to be active against spontaneous AKR leukemia. The long-term treatment with PTZ begining at 5–7 months of age of a group of AKR mice containing 10–20% of advanced leuke-mic mice significantly prolonged the life span of the group. The therapeutic effectiveness of PTZ has been compared with several standard antileukemic drugs. PTZ decreased the AKR virus titer in the circulating blood of mice and its antiviral activity in AKR virus infected NIH/3T3 cells has been confirmed by XC assay.

Effect of Pretazettine and Viva-Natural, a Dietary Seaweed Extract, on Spontaneous AKR Leukemia in Comparison with Standard Drugs

“…Tables I-V include these results. It was confirmed that PTZ prolonged the life span of mice significantly (65 138%) over the controls, as demonstrated in our earlier experiments [3]. Among the standard cytotoxic drugs, VCR was found to be most effective, which demonstrated constantly above 100% prolongation of life span over the controls as shown in tables 1.…”

“…Our present results demonstrated the highest activity by VCR (av erage 114% ILS), followed by PTZ (90%), MTX (71%), 6-TG (60%), and ADR (49%). Our previous results [3] showed activity of PTZ (109% ILS) and CY (139%) but no activity by BCNU. With consideration of many reports mentioned above and our results, activity of PTZ relative to standard drugs seems to be superior to those of ADR, 6-TG, and MTX and in ferior to VCR and CY.…”

“…We previously reported that PTZ was active against spontaneous AKR T cell leukemia in com parison with cyclophosphamide (CY) on prolonging the survival time of AKR mice at 5-7 months of age [3]. We have also reported that an extract of a dietary seaweed, Viva-Natural, showed antileukemic activity in the same system [15].…”

“…a narcissus alkaloid, was therapeu tically active against Rauscher viral leukemia and spontaneous AKR T cell leukemia [1][2][3]. PTZ is in hibitory to the growth of murine retroviruses in cell cultures and in mice [2,3], PTZ is an inhibitor of viral reverse transcriptase [2] and is cytotoxic due to the specific inhibitory action on cellular protein synthesis [2], and therefore PTZ is also effective against nonviral transplantable tumors such as Ehrlich ascites and Lewis lung carcinoma [4.…”

“…a narcissus alkaloid, was therapeu tically active against Rauscher viral leukemia and spontaneous AKR T cell leukemia [1][2][3]. PTZ is in hibitory to the growth of murine retroviruses in cell cultures and in mice [2,3], PTZ is an inhibitor of viral reverse transcriptase [2] and is cytotoxic due to the specific inhibitory action on cellular protein synthesis [2], and therefore PTZ is also effective against nonviral transplantable tumors such as Ehrlich ascites and Lewis lung carcinoma [4. 5], Recently, we have found that an extract of a dietary seaweed Undaria pinnantifida, named Viva-Natural, was therapeutically active against Lewis lung carcinoma probably through the activation of immune systems [6], We have now studied the effect of PTZ and Viva-Natural for their antileukemic activity against AKR spontaneous T cell leukemia in comparison to standard cytotoxic and immunomodulating agents.…”