Treatment with a herbal preparation called Tongtian oral liquid, long used in traditional Chinese medicine, helped prevent nervous system damage and normalize movement in a zebrafish model of Parkinson’s disease.
Scientists in China reported these findings in the study, “Neuroprotective effects of Tongtian oral fluid, a traditional Chinese medicine in the zebrafish model induced by Parkinson’s disease,” Posted in Biomedicine & Pharmacotherapy.
Tongtian oral liquid, also called Tongtian Koufuye or TTKFY, is believed to have antioxidant and neuroprotective effects. It contains 11 herbal constituents including tea, licorice, mint, and chrysanthemum.
In a first series of experiments, the researchers treated zebrafish larvae with varying doses of TTKFY. At low doses, herbal medicine was well tolerated by fish. But doses of 8 ml/L caused developmental malformations, and higher doses (16 or 32 ml/L) were lethal to developing fish.
The team then tested TTKFY in a zebrafish model, with Parkinson’s disease induced by exposing the fish to a toxic chemical called MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) . Fish given MPTP had significantly smaller dopamine (dopamine-producing) neurons, which is consistent with Parkinson’s disease, which is caused by the death and dysfunction of these nerve cells. The fish also had Parkinson-like motor abnormalities, such as slower swimming speed.
“MPTP-induced parkinsonism is a well-accepted model and currently the most appropriate to study [Parkinson’s]“, wrote the researchers.
Treatment with TTKFY, at doses of 2 or 4 ml/L, made it possible to relaunch the growth of dopamine-producing neurons and also to improve fish locomotion (swimming speed and distance).
“These results suggest that MPTP-induced locomotor aberration can be rescued by higher doses of TTKFY in zebrafish larvae,” the researchers wrote. However, they added that even with the TTKFY treatment, motor behavior in the fish model of Parkinson’s disease “did not reach the … level” of healthy zebrafish included as a control group.
Further analyzes indicated that treatment with TTKFY reduced oxidative stress – a type of cellular damage caused by highly reactive oxygen-containing molecules and characteristic of Parkinson’s disease – caused by MPTP. The herbal combination also normalized changes in the expression of several dopamine-related genes that were dysregulated by MPTP. (Gene expression is the process by which the information in a gene is synthesized to create a protein.)
“All of these results collectively provide ample evidence regarding the neuroprotective ability of TTKFY in MPTP-induced neurotoxicity in the zebrafish model of [Parkinson’s]“, concluded the scientists.
“Further studies are needed to manifest the exact mechanism of action of TTKFY on neuroprotection in experimental MPTP-induced parkinsonism in the zebrafish model,” they added.