Baicalin Protected Rats Against Parkinson’s Neurodegeneration

A bioactive agent called baicalin prevented neurodegeneration of Parkinson’s disease in rats by protecting against oxidative stress and neuronal death, according to a recent study.

The results, “Neuroprotective effect and mechanism of baicalin on Parkinson’s disease model induced by 6-OHDA,” were published recently in the journal Neuropsychiatric Disease and Treatment.

Although Parkinson’s trigger is unknown, research indicates its causative mechanism involves genetics, malfunction of mitochondria (the cells’ “powerhouses”), and oxidative stress — an imbalance between the production of harmful free radicals and the ability of cells to detoxify them, resulting in cellular damage.

Taken together, these molecular and cellular changes eventually result in the death of dopamine-producing neurons, the nerve cell type that is gradually lost in Parkinson’s disease.

Available treatments only ease disease symptoms, and there are currently no disease-modifying therapies that can delay or prevent Parkinson’s neurodegeneration.

Baicalin, a compound isolated from the Chinese skullcap‘s (Labiatae Scutellaria Linn Scutellaria baicalensis Georgi) dry roots, has been shown to have antibacterial, antiviral, anti-inflammatory, anti-tumor, cardiovascular, and neuroprotective activities.

Importantly, evidence shows that baicalin protects against dopaminergic neuronal damage induced by either rotenone or MPTP, two neurotoxins that are commonly used to replicate Parkinson’s in animal models.

A Chinese team of researchers now investigated the effects of baicalin on a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson’s disease. Like rotenone and MPTP, 6-OHDA induces the death of dopamine-producing neurons and mimics Parkinson’s symptoms.

Baicalin was given in one of three doses: low (50 mg/kg), medium (100 mg/kg), or high (150 mg/kg). Following baicalin continuous administration for eight weeks, scientists assessed animals’ fatigue, motor coordination, voluntary movement, anxiety and exploratory behavior on a weekly basis. Neuronal changes following baicalin treatment also were evaluated.

Baicalin was found to improve rats’ coordination and voluntary movement. The compound also prevented oxidative stress-related neuronal damage and death, and promoted the release of neurotransmitters to regulate dopamine-dependent communication within the rats’ brain by regulating six small metabolic molecules: N-acetyl-aspartate (NAA), aspartate, glutamate, gamma-aminobutyric acid, glycine, and taurine.

“NAA is a hallmark of neuronal changes in the brain, and a decreased level suggests a loss or dysfunction of neurons,” researchers noted. On the other hand, glutamate is mainly involved in signal transmission, and learning and memory formation.

Further analysis revealed rats with Parkinson’s had low levels of N-acetyl-aspartate (NAA) and high levels of glutamate in the striatum (a brain region involved in motor control). After continuous administration of baicalin for two months, NAA and glutamate concentrations in the striatum changed in a dose-dependent manner to almost similar levels of those seen in healthy animals: higher baicalin doses resulted in increased metabolite concentrations.

Importantly, the team believes that both NAA and glutamate levels could be potential diagnostic biomarkers to assess neurodegeneration in the context of Parkinson’s disease.