CANNABIS INGREDIENT COULD FIGHT CANCER, CLAIM RESEARCHERS

CANNABIS could provide an unlikely new weapon in the fight against
cancer, new research suggested yesterday.

Scientists have discovered the chemical in the drug which gets users
'high' combats cancer-causing viruses. Experiments show the active
cannabis ingredient tetrahydrocannibol (THC) can prevent the
activation and replication of gamma herpes viruses.

Two of these viruses, Kaposis Sarcoma Associated Herpes virus and
Epstein- Barr virus, predispose infected individuals to the cancers
Kaposis sarcoma, Burkitt's lymphoma and Hodgkin's disease.

Gamma herpes viruses are different from the herpes simplex viruses
responsible for cold sores and genital herpes.

Kaposis sarcoma is especially prevalent among Aids sufferers and is
now the most common form of cancer in Africa.

Once infected, it is almost impossible to get rid of the viruses as
they lie dormant for long periods within white blood cells.

The dormant viruses can reactivate, replicating themselves and
bursting out of the cells to spread between individuals and cause illness.

Scientists at the University of South Florida in the United States
found reactivation was prevented if infected cells were grown in the
presence of THC.

Cells infected with a mouse gamma herpes virus normally died when the
virus reactivated. But they survived when cultured with the
cannabinoid compound.

Writing in the online journal BMC Medicine, the scientists showed that
THC acted specifically on gamma herpes viruses. It was unable to
prevent the reactivation of the cold sore virus herpes simplex-1.

Team leader Dr Peter Medveczky and his fellow researchers wrote: "We
believe that studies on cannabinoids and herpes viruses are important
to continue because there are obvious benefits. Better understanding
may lead to the development of specific non-psychoactive drugs
that may inhibit reactivation of cancer-causing herpes viruses."

Dr Medveczky pointed out that THC could also suppress the immune
system and patients infected with these viruses often had weakened
immune systems already.

Whether or not the beneficial effects of THC outweighed this hazard
was yet to be tested in mice.

"We have not evaluated the effect of THC in an animal model yet.
Therefore, our findings do not recommend that people take pot to
prevent or treat cancers associated with gamma herpes viruses." he
said.

Dr Medveczky believes THC targets a viral gene shared by gamma herpes
viruses called ORF50.

By preventing activation of this gene, the compound is thought to
block viral replication.