A new study found that full-spectrum CBD-rich oil reduced brain inflammation and oxidative stress while restoring key neurochemical markers in a rat model of maple syrup urine disease (MSUD), a rare inherited metabolic disorder that can cause severe neurological damage.
The research, published September 3 in the journal Metabolic Brain Disease, was conducted by researchers from several Brazilian institutions, led by a team at Universidade do Extremo Sul Catarinense. The authors said it is the first study to examine a cannabis-related product in an experimental model of MSUD.
MSUD prevents the body from properly breaking down the branched-chain amino acids leucine, isoleucine and valine, causing them to accumulate and potentially damage the central nervous system. Researchers tested whether a full-spectrum CBD-rich oil could counter some of the behavioral and neurochemical effects associated with that buildup.
The study involved 108 male Wistar rats divided into six groups, including healthy controls, animals given CBD-rich oil alone and animals exposed to elevated branched-chain amino acids with or without CBD treatment. The oil was administered daily for 21 days at doses containing 3.5 or 7.5 milligrams of CBD per kilogram of body weight. The hemp-derived formulation also contained small amounts of THC, CBG, CBN, CBDV and CBC.
Both CBD doses reversed abnormalities in two enzymes involved in the brain’s cholinergic system. Animals in the MSUD model had reduced choline acetyltransferase activity and increased acetylcholinesterase activity, while treatment with the CBD-rich oil restored both measures.
CBD treatment also produced substantial anti-inflammatory effects. Both doses reduced elevated interleukin-1β levels and lowered tumor necrosis factor-alpha compared with untreated MSUD-model animals, while the 3.5 mg/kg dose reversed an increase in interleukin-6.
Similar effects were observed for oxidative stress. The MSUD model increased measures of reactive species and lipid damage, and both CBD doses reversed those increases. The higher dose also restored reduced catalase activity, an antioxidant defense mechanism.
Behavioral effects were more limited and depended on dose. The 3.5 mg/kg treatment improved short-term recognition memory in animals exposed to branched-chain amino acids, but neither dose fully restored long-term memory. The researchers found no significant effects on locomotor or exploratory behavior.
The authors concluded that the full-spectrum CBD-rich oil produced significant neurochemical benefits, including reductions in inflammation and oxidative stress, while producing partial and dose-dependent improvements in recognition memory.
