“Hemp, Cannabis sativa, is a coarse bushy annual plant with palmate leaves and clusters of small green flowers that grows wild in regions of mild or tropical weather and can attain a height of 3 metres. The genus name Cannabis is complemented by sativa (which means useful). Cannabis has indeed been used throughout history for a variety of purposes…

 Cannabis has been utilised for centuries throughout the world to alleviate disease. Its derivatives were named “panacea”, or “cure-all”, and were sold as a legal medicine, mainly for pain…

The discovery of cannabinoid receptors, their endogenous ligands, and the machinery for the synthesis, transport, and degradation of these retrograde messengers, has equipped us with neurochemical tools for novel drug design. Agonist-activated cannabinoid receptors, modulate nociceptive thresholds, inhibit release of pro-inflammatory molecules, and display synergistic effects with other systems that influence analgesia, especially the endogenous opioid system. Cannabinoid receptor agonists have shown therapeutic value against inflammatory and neuropathic pains, conditions that are often refractory to therapy…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430692/