The marijuana plant is not listed as a medicinal plant for treating cancer either in Ayurveda or in Traditional Chinese Medicine. It is recognized as a narcotic in both these ancient medicine systems. Pliny the Elder makes mention of the use of cannabis for pain relief. Sushruta Samhita mentions the use of cannabis as an anti-phlegmatic and as a cure for leprosy.
Marijuana was added as a plant with medicinal value to the US Pharmacopeia in 1850. It is listed as a treatment for neuralgia, tetanus, leprosy, dysentery, uterine bleeding, and many other ailments.
The synthetic form of THC (Tetrahydrocannabinol is the bioactive molecule in marijuana) going under the trade name of Marinol was approved for medical use in May 1985 to treat nausea and vomiting caused by chemotherapy.
According to the Indian Central Science and Industrial Research publication, Cannabis plants are used as a tonic, intoxicant, stomachic, anti-spasmodic, analgesic, narcotic, sedative, and anodyne in folk medicine. Seeds and leaves are used to treat cancerous ulcers and tumors.
A US Department of Health and Human Services patent US 6630507 B1 was awarded to Aidan J. Hampson, Julius Axelrod, and Maurizio Grimaldi in October 2003. The abstract citation is reproduced below:
Cannabinoids have been found to have antioxidant properties unrelated to NMDA (N-methyl-D-aspartate) receptor antagonism. This new-found property makes cannabinoids useful in the prophylaxis of a wide variety of oxidation-associated diseases, such as ischemic, age-related, inflammatory, and autoimmune diseases. Cannabinoids are found to have application as neuroprotectants, for example, in limiting neurological damage following ischemic insults, such as stroke and trauma, or in the treatment of neurodegenerative diseases, such as Alzheimer’s disease Parkinson’s disease, and HIV dementia. Nonpsychoactive cannabinoids, such as cannabidiol, are particularly advantageous to use because they avoid toxicity that is encountered with psychoactive cannabinoids at high doses useful in the method of the present invention…