Cannabidiol May Help Stop Diabetic Retinopathy

Dr. Liou working with cannabinoids
in the lab; © Phil Jones

“In the central nervous system, cannabinoid receptors are responsible for the neutralisation process that should occur after a nerve impulse is finished,” says Dr. Gregory I. Liou, molecular biologist at the Medical College of Georgia. Endogenous cannabinoids could help balance the excitation and inhibition, at least until oxygen gets scarce.

In the face of inadequate oxygen, or ischemia nerve endings start producing even more glutamate, setting in motion an unhealthy chain of events. Pumps that keep the right substances inside or outside of cells start to malfunction. Excess nitric oxide and superoxides are produced. Another irony is the heightened activity increases the retina’s need for oxygen.

In addition, Glial cells which support nerve cells by supplying nutrients and oxygen are closely attuned to their charges. When they sense something is amiss, microglia, one type of glial cells, start eating the dying nerve cells. “This makes the whole thing irreversibly bad,” says Liou. The body starts producing more endogenous cannabinoids to stop the role reversal, then produces an enzyme to destroy the cannabinoids because of concern there are too many of them. “Long before all these blood vessels start growing, the partnership between glial cells and nerve cells starts breaking down,” says Liou.

Test-tube studies by others, as well as Liou’s pilot studies in diabetic animal models show cannabidiol works to interrupt essentially all these destructive points of action: “What we believe cannabidiol does is go in here as an antioxidant to neutralise the toxic superoxides. Number two, it inhibits the self-destructive system and allows the self-produced endogenous cannabinoids to stay there longer by inhibiting the enzyme that destroys them,” Liou concludes.

MEDICA.de; Source: Medical College of Georgia