Abstract

Background: Long-term treatment of haloperidol, a neuroleptic, induces neurodegeneration specifically in the striatum (caudate and putamen), which plays an important role in the development of orofacial dyskinesia, a putative model of tardive dyskinesia (TD). This study investigated the protective effects of a concomitant treatment of aqueous fruit extract of Sea buckthorn (Hippophae rhamnoides L. spp. Turkestanica) (SBT-FE) (40 mg/kg, orally) plus haloperidol (3.0 mg/kg, ip) administration on an animal model of TD and on striatal neuronal alterations.
Material/Methods: Rats received daily haloperidol (3.0 mg/kg ip) and saline injections for 15 days. Seven-day posttreatment, aqueous SBT-FE (40 mg/kg) was administered daily via a feeding tube. Hypolocomotive effects (home cage activity, exploratory activity, catalepsy, and vacuous chewing movements) were monitored consecutively in each group. On the last day of the experiments, changes in extracellular levels of striatal dopamine (DA), dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA) were determined by HPLC-EC.
Results: Aqueous SBT-FE attenuated haloperidol-induced VCMs after second week of treatment and locomotor activity was greater in rats treated with SBT-FE compared with the controls. The results indicate that DA and HVA levels in the striatum were significantly (P <.01) altered in rats given SBT-FE before injections of haloperidol.
Conclusions: Hippophae rhamnoides fruit extract has a protective role against haloperidol-induced orofacial dyskinesia. Consequently, use of Hippophae rhamnoides as a possible therapeutic agent for the treatment of tardive dyskinesia should be considered.

Keywords: Phytotherapy, Neurons - pathology, Neostriatum - pathology, Movement Disorders - drug therapy, Motor Activity - drug effects, Homovanillic Acid - metabolism, Hippophae - chemistry, Haloperidol - adverse effects, Fruit - chemistry, Exploratory Behavior - drug effects, Dopamine - metabolism, Catalepsy - complications, Animals, Administration, Oral, Plant Extracts - therapeutic use, Protective Agents - therapeutic use, Rats, Rats, Wistar