By Tito Drago
MADRID, Feb 29 2000 (IPS)

A research team in Spain has found that tetrahydrocannibinol (THC), the active ingredient in marijuana, is effective in curing brain cancer in laboratory rats, reported the scientific journal Nature-Medicina.

Manuel Contreras, director of the team conducting the research at Madrid’s Complutense University, explained during his presentation before the press that there is no evidence that smoking marijuana or hashish can have the same effects as medically administered THC.

Cancer of the brain, or glioblastoma, is the most invasive and life-threatening. The team used rats with advanced cancer development in its experiments. Some received THC, while the control group, which was not given the substance, died days later.

Of the rats treated with THC, a third were completely cured, another third showed tumour reduction and prolonged lives, while there were no curative results evident in the remaining third, which, like the control group, also died within a short time.

THC affected the cancerous cells in the brain, leaving normal cells alone, implying that it may also be effective in fighting other types of cancer.

The researchers believe that within one or two years, clinical trials could begin on human patients suffering brain cancer, with the hope – but no certainty – that THC will prove effective for them as well.

Another team of Spanish scientists recently announced the success of their tests, also using laboratory rats, in curing quadraplaegic or paraplaegic paralysis.

This research group, led by Almudena Ramón-Cueto at the Molecular Biology Centre of Valencia, found that 40 percent of paraplaegic rats (paralysis of the hind legs) subjected to the treatment were later able to walk and move about normally.

Ramón-Cueto’s team received funding from the owners of a footwear company who have a family member affected by a spinal cord injury.

The results of a year and a half of work were published by the journal Neuron. Of the 21 paralytic rats treated, nine completely recovered mobility and sensation in their limbs.

The success is due to the transplant of each rat’s own axon cells, or nerve terminals, that transmit information from the brain through the spinal cord and vice-versa.

Ramón-Cueto explained that when the spinal cord is damaged, the immediate result is the loss of sensation and motor function, affecting the lower part of the body (paraplaegic) or both the lower and upper body (quadraplaegic), because axons are incapable of regeneration.

But at the Institute of Biomedicine, scientists discovered that in another part of the body, the olfactory bulb, axons are able to regenerate thanks to what are known as olfactory ensheathing glia cells.

Once they made that discovery, the researchers tried transplanting cells from th bulb to the spinal cord, using rats, an animal whose spinal cord function is similar to that of humans.

Following the transplant, the rodents were put throught tests in which they had to climb a grating at four levels of difficulty. The rats had the incentive of reaching a chocolate cream placed at the top of the lattice.

The researchers put the rats through the tests seven months after the transplant. The nine treated rats recovered sensation and mobility of their limbs and were able to climb the grating when placed at a 45 degree incline. Seven were able to climb at a 60 degree angle, six at 75 degrees, and two made it all the way up a vertical grating.

Physical examinations of the animals proved that the tissue damaged by cancer had repaired itself, which was evident even without the aid of a microscope as it had regenerated three centimetre portions.

According to the scientists, the next step is to experiment with primates. If these animals show positive results, it is almost certain that this type of treatment would also work well for humans. Primate research is to begin immediately in Valencia and at the Autonomous University of Madrid.

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