Effects of Rehmannia glutinosa polysaccharide b on T-lymphocytes in mice bearing sarcoma 180.

OBJECTIVE

To study immuno-antitumor action mechanism of RGP-b. RGP-b (Rehmannia glutinosa polysaccaride b) is a new component isolated from the herb, had an average molecular mass of 160 kDa and 5 kinds of monosaccharides as acid-splitting products. Its HPLC showed a main sharp peak at 162 kDa.

METHODS

The kinetic effects of RGP-b on IL-2 secretion, cytotoxic T-lymphocyte (CTL) activities and L3T4+, lyt-2+ T-lymphocyte subset in mice bearing S180 were observed.

RESULTS

RGP-b 10 or 20 mg kg-1 ip obviously attenuated the decrease of CTL cytotoxity caused by excessive tumor growth on d 9 after the administration, but only partly ameliorated the descent of IL-2. Its effect on lyt-2+ subset was quite parallel with that on CTL cytotoxity. RGP-b kept the ratio of L3T4+ to lyt-2+ subset lower than that of control.

CONCLUSIONS

Improving the production of lyt-2+ CTL and its cytotoxity were an essential immuno-antitumor mechanisms of RGP-b.