Brown seaweeds administration generate psychotherapeutic response associated with brain norepinephrine modulation in rats

Abstract

Research in the area of herbal psychopharmacology has increased considerably over the past few decades in search of panacea for neuroprotection. Seaweeds are one of the herbal sources consumed in many Asian countries as medicine due to their remarkable bioprospecting properties and evident health benefits. Keeping in view the bioactive potential of seaweeds, the present study was designed to evaluate the psychotherapeutic potential of Sargassum swartzii and Stoechospermum marginatum, in association with the role of brain norepinephrine (NE) using a rat model. Adult male albino Wistar rats were divided into three groups (n=6) as control rats (CR), S. swartzii extract treated (SSET) and S. marginatum extract treated (SMET). Seaweeds were extracted using methanol and administered orally to rats for four weeks at a dose of 60 mg/kg. Behavioral changes for stimulant activities were assessed by activity cage and open field tests, while anxiety was observed in light-dark exploration test. Followed by scoring behavioral activities, rats were decapitated and brain samples taken out from the cranial cavity were immediately stored at -70°C until estimation of brain NE levels by high performance liquid chromatography-electrochemical detection (HPLC-ECD). Results exhibited an increase in ambulatory and anxiolytic activities by SSET and SMET rats with subsequent increase in brain NE as compared to CR. The increase in NE in SSET and SMET rats could be attributed to the lipolytic activity of seaweeds. However, the exact mechanism underlying the increase in NE needs further investigations. In conclusion, seaweed extracts showed significant psychostimulant and anxiolytic activity by ameliorating brain NE levels and could be studied further for isolation of active ingredients responsible for eliciting such a response. Key words: Brown seaweeds, norepinephrine, psychostimulant activity, anxiety.