IACM-Bulletin of October 26, 2008

Germany — Experts unanimously acknowledge the medical value of dronabinol and cannabis

At a 15. October 2008 public hearing of the Health Committee of the German Parliament all participating experts agreed on the proven medical value of dronabinol (THC) and cannabis for a range of illnesses. All medical and legal experts further declared that the current situation was unsatisfactory for patients. Only the representative of the health insurance industry insisted that the medical benefits of a dronabinol therapy remained to be proven and thus health insurance should not be obligated to pay for such treatment.

The public hearing was held in response to similar requests by the parliamentary groups of the Green Party and the "Left", both of whom demanded regulations that would prompt health insurance agencies to pay for treatment with THC more often and terminate criminalization of people who need cannabis for medical reasons but cannot afford to pay for dronabinol. While the German Society of Pain Therapists and the German Society for Addiction Medicine supported these requests, other institutions (German MS Society, German Association of Physicians) opposed the permission of doctor-assisted self-medication with uncertified cannabis medicines. Yet, they did support the therapeutic use of pharmaceutical-grade cannabis products. Representatives of the Association of Cannabis for Medicine (ACM) pointed out that the current system represents a two-class medicine in which the well off can afford to buy dronabinol in pharmacies whereas most patients are forced into illegality if they want to benefit from cannabis products. The current criminalization of patients who engage in self-medication was not justifiable unless true alternatives were provided.

Extensive information on the website of the German Bundestag:

http://www.bundestag.de/aktuell/archiv/2008/22381411_kw42_gesundheit/index.html

Science — According to basic research cannabinoids may restore the blood-brain barrier in HIV infection

According to research by scientists of Beth Israel Deaconess Medical Center, Harvard Medical School, and Northeastern University in Boston, USA, cannabinoids that activate cannabinoid receptors are able to inhibit the transmigration of certain immune cells (monocytes) across the blood-brain barrier (BBB). They also decreased the permeability of endothel cells of small blood vessels (microvascular endothelial cells, HBMEC). Authors noted that for the first time it was demonstrated "that cannabinoid agonists are able to restore the integrity of HBMEC and the BBB following insults by HIV-1 Gp120. These studies may lead to better strategies for treatment modalities targeted to the BBB following HIV-1 infection of the brain based on cannabinoid pharmacotherapies."

It is known that HIV-1 infection has significant effect on the immune system as well as on the nervous system. Breakdown of the blood-brain barrier is frequently observed in patients with HIV-associated dementia. Cellular products and viral proteins secreted by HIV-1 infected cells, such as the HIV-1 Gp120, play important roles in blood-brain barrier impairment and HIV-associated dementia development. Microvascular endothelial cells are a major component of the blood-brain barrier. The researchers used microvascular endothelial cells and certain nerve cells (human astrocytes) as a model system for human blood-brain barrier.

(Source: Lu TS, Avraham HK, Seng S, Tachado SD, Koziel H, Makriyannis A, Avraham S. Cannabinoids Inhibit HIV-1 Gp120-Mediated Insults in Brain Microvascular Endothelial Cells. J Immunol 2008;181(9):6406-16.)

News in brief

USA — Anti-drug campaign

Despite investing one billion US-Dollars (about 780 million Euros) in a massive anti-drug campaign, a controversial new study suggests that it has failed to have a positive effect on drug use by youths. A congressionally mandated study released on 15 October concluded that the National Youth Anti-Drug Media Campaign launched in the late 1990s to encourage young people to stay away from drugs "is unlikely to have had favorable effects on youths." In fact, the study's authors assert that anti-drug ads may have unwittingly delivered the message that other kids were taking drugs. "Those who came to believe that their peers were using marijuana were more likely to initiate use themselves," the authors say. (Source: ABC News of 15 October 2008)

UK — Classification of cannabis

On 13 October the Home Secretary, Jacqui Smith, has confirmed that repeat cannabis offenders will face tougher penalties from 26 January 2009 on. She said, that those caught with cannabis on a first occasion could still get a cannabis warning, but on a second occasion are likely face a fine of 80 British Pounds and arrest if caught for a third time. (Home Office of 13 October 2008, http://drugs.homeoffice.gov.uk)

Science — Cancer of the intestine

Basic research shows that 17-beta-estradiol induced the formation of CB1 receptors in human colon cancer cells. The induction of CB1 receptors was mediated by the estrogen receptor. Authors noted that the "CB1 receptor can be considered an estrogen-responsive gene" in colon cancer cells. "Up-regulation of CB1 expression by 17-beta-estradiol is a further mechanism of estrogens to control colon cancer proliferation." (Source: Notarnicola M, et al. Scand J Gastroenterol 2008;43(1):66-72.)

Science — Neuroprotection

The endocannabinoid 2-arachidonoylglycerol elicited its neuroprotective effects on brain nerve cells by activating receptors, that are also activated by abnormal cannabidiol, on microglial cells. Abnormal CBD is a synthetic cannabinoid, that does not bind to CB1 and CB2 receptors, but to other receptors. (Source: Kreutz S, et al. Glia. 2008 Oct 3. [Electronic publication ahead of print])

Science — Pregnancy

A deficiency of CB1 receptors alters normal progesterone and oestrogen levels and induces preterm birth in mice. Moreover, the inactivation of the CB1 receptor resulted in aberrant corticosterone activities prior to birth, suggesting that CB1 regulates labour by interacting with the hormonal system, which is responsible for the activity of corticosterone. (Source: Wang H, et al. PLoS ONE 2008;3(10):e3320.)

Science — Stroke

In animal studies with rats, in which a stroke was induced by interruption of an artery in the brain, the neuroprotective effects of the endocannabinoids anandamide (AEA) and palmitoylethanolamide(PEA) were investigated. An infarct reduction of up to 35 per cent was observed following injection with PEA and of up to 26 per cent with AEA. Authors noted that "both endocannabinoids may have the potential to treat acute stroke." (Source: Schomacher M, et al. Brain Res. 2008 Sep 18. [Electronic publication ahead of print])