Antitumor agent containing Lactobacillus casei YIT 9018

DETAILED DESCRIPTION OF THE INVENTION AND ITS PREFERRED EMBODIMENTS It has been shown that Lactobacillus casei YIT 9018 (Deposit No.
FERM-P 4751) (hereinafter referred to as "LC 9018") has a higher antitumor activity compared to other lactobacilli.
This bacterial strain exhibited antitumor activity against solid and ascites tumor of Sarcoma 180 with intravenous, subcutaneous, oral or intraperitoneal administration in mice.
Furthermore, it showed an antitumor activity against mouse leukemia L1210 or P-388 on which commercial antitumor streptococcal preparation had no effect.
In addition, the toxicity of LC 9018 was significantly lower than those of other lactobacilli and streptococcal antitumor agents.
LC 9018 was cultivated on a broth containing (per 1000 ml of distilled water) Trypticase--10 g Yeast extract--5 g Tryptose--3 g K.
sub.
2 HPO.
sub.
4 --3 g KH.
sub.
2 PO.
sub.
4 --3 g Ammonium citrate--2 g Sodium acetate--1 g Tween 80 --80 g Glucose--20 g Cystein--0.
2 g MgSO.
sub.
4 -7H.
sub.
2 O--0.
5 g FeSO.
sub.
4 -7H.
sub.
2 O--0.
04 g MnSO.
sub.
4 -2H.
sub.
2 O--0.
12 g at 37.
degree.
C.
for 20-40 hr.
After cultivation, the cells were washed with distilled water and lyophilized.
EXPERIMENT 1: ANTITUMOR ACTIVITY OF LC 9018 EXAMPLE (1) Sarcoma 180 (1-2.
times.
10.
sup.
6 cells/mouse) was implanted into ICR male mice subcutaneously on day 0.
A suspension of lactobacilli in saline (0.
25 mg/mouse) was injected intravenously daily on days +1-+5.
Mice were dissected 3 weeks after the tumor implantation and the weight of the tumor was measured.
The inhibition rate was calculated according to the formula: ##EQU1## As shown in Table 1, other lactobacilli had inhibition rates of 40-70% as did the streptococcal preparation.
LC 9018 showed an inhibition rate of more than 80%.
EXAMPLE (2) Sarcoma 180 (1-2.
times.
10.
sup.
6 cells/mouse) was implanted subcutaneously into male ICR mice after being admixed with 1 mg of LC 9018.
The inhibition rate with LC 9018 was 97.
3%, determined as described in Example (1).
EXAMPLE (3) Sarcoma 180 (1-2