An immunomodulatory polysaccharide-rich substance from the fruit juice of Morinda citrifolia (Noni) with antitumour activity

The fruit juice of Morinda citrifolia (noni) contains a polysaccharide-rich substance (noni-ppt) with antitumour activity in the Lewis lung (LLC) peri toneal carcinomatosis model. Therapeutic administration of noni-ppt signifi cantly enhanced the duration of survival of inbred syngeneic LLC tumour bea ring mice. It did not exert significant cytotoxic effects in an adapted cul ture of LLC cells, LLC1, but could activate peritoneal exudate cells (PEC) to impart profound toxicity when co-cultured with the tumour cells. This su ggested the possibility that noni-ppt may suppress tumour growth through ac tivation of the host immune system, Concomitant treatment with the immunosu ppressive agent, 2-chloroadenosine (C1-Ade) or cyclosporin (cys-A) diminish ed its activity, thereby substantiating an immunomodulatory mechanism. Noni -ppt was also capable of stimulating the release of several mediators from murine effector cells, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-10), IL-10, IL-12 p70, interferon-gamma (IPN-gamma) and nitric oxide (NO), but had no effect on IL-2 and suppressed IL-4 releas e. Improved survival time and curative effects occurred when noni-ppt was c ombined with sub-optimal doses of the standard chemotherapeutic agents, adr iamycin (Adria), cisplatin (CDDP), 5-fluorouracil (5-FU), and vincristine ( VCR), suggesting important clinical applications of noni-ppt as a supplemen tal agent in cancer treatment. Copyright (C) 1999 John Whey & Sons, Ltd.