Have any preclinical (laboratory or animal) studies been conducted using Cannabis or cannabinoids?

Preclinical studies of cannabinoids have investigated the following activities:

Antitumor activity

• Studies in mice and rats have shown that cannabinoids may inhibit tumor growth by causing cell death, blocking cell growth, and blocking the development of blood vessels needed by tumors to grow. Laboratory and animal studies have shown that cannabinoids may be able to kill cancer cells while protecting normal cells.
  
  
• A study in mice showed that cannabinoids may protect against inflammation of the colon and may have potential in reducing the risk of colon cancer, and possibly in its treatment.
  
  
• A laboratory study of delta-9-THC in hepatocellular carcinoma (liver cancer) cells showed that it damaged or killed the cancer cells. The same study of delta-9-THC in mouse models of liver cancer showed that it had antitumor effects. Delta-9-THC has been shown to cause these effects by acting on molecules that may also be found in non-small cell lung cancer cells and breast cancer cells.
  
  
• A laboratory study of cannabidiol in estrogen receptor positive and estrogen receptor negative breast cancer cells showed that it caused cancer cell death while having little effect on normal breast cells.

Cannabis Science, Inc. (OTCBB:CBIS), a pioneering US biotech company developing pharmaceutical cannabis products, is pleased to report a government released update on cancer treatments using medical cannabis (marijuana), updated March 17, 2011, summarizing how the treatment of cancer with cannabinoids goes beyond the simple treatment of symptoms and side effects by exhibiting possible direct antitumor activities.

Robert Melamede, Ph.D., Cannabis Science's CEO stated, "… cannabinoids have profound cancer-killing and anti-metastatic properties. There is strong scientific support, demonstrated in tissue culture and animal studies, of the potent cancer killing properties of cannabinoids for such deadly cancers as glioma, lung cancer, breast and prostate cancer, leukemias and lymphomas, and as well as skin cancers.

Currently the federal government prohibitionist position on cannabis is hindering the medical community by delaying vitally important clinical cannabis research. I was quite elated when I recently saw that the NCI posted on their webpage "In the practice of integrative oncology, the health care provider may recommend medicinal Cannabis not only for symptom management but also for its possible direct antitumor effect." I foolishly thought that finally there would be official recognition of the modern peer reviewed science that shows the cancer killing properties of cannabinoids. Sadly, this statement was removed, without comment, within hours of its posting."

Dr. Melamede goes on to say "Clinical trials are desperately needed. Cannabis Science is actively working on arrangements that will allow us to perform the necessary clinical trials to verify, or not, the numerous anecdotal reports demonstrating what appears to be cancer cures. These observations are occurring with greater frequency since numerous states have legalized the medical use of cannabis.