Preclinical Assessment of <i>Crocus sativus</i> Extract Loaded Nano Emulsion for Scopolamine Induced Cognitive Impairment: A Comprehensive Safety and Efficacy Study

Abstract

Background              
 Crocus sativus is popular herb used to improve and treat the memory, cognition related functions of brain and thereby impose significant role in improve and maintain brain health. The medicinal important part of Crocus sativus is stigma of flower which is rich in apocarotenoids crocin, picrocrocin, safranal and many more volatile compounds. The pharmacological actions such as antioxidant, anti-amyloidogenic, anti-depressant, anti depressant, anti cancer, anti inflammatory etc. properties are attributed due to of presence of caratenoids. However the poor stability, solubility and enzymatic degradation of bioactives of Crocus sativus have substantially limited their therapeutic application. In this study, a saffron nano emulsion of carotenoid rich fraction of Crocus sativus extract was assessed for its safety and efficacy.
 Methodology
 The single dose acute oral toxicity assessment of nanoemulsion was performed as per OECD 420 to determine the lethal dose (LD50). The subacute repeated 28 days oral toxicity was performed to provide the effective dose for the preclinical assessment as per OECD guideline 407 The animals were observed during the entire toxicity experimentation for any toxic signs and changes of hematological, biochemistry parameters. The efficacy study of saffron nano emulsion was evaluated by two behavioral test models- Passive avoidance test and Morris water maze test using scopolamine induced memory impairment.
 Results & Conclusions
 Animals administered 500 mg/kg/day as single dose orally did not cause any signs of toxicity or mortality in rats and results of acute toxicity assessment of saffron nano emulsion has indicated that the NOAEL (No Observed Adverse Effective Level) of saffron nano emulsion was found to be 500 mg/kg. In subacute toxicity study three different dose of 75, 100 & 125 mg/kg/day for 28 days administered orally in animals revealed no significant changes in body weight, hematological, biochemical parameters. The histopathological study has indicated no pathological changes observed in the vital organs of rats treated with the 125 mg/kg/day.
 The efficacy assessment of saffron nano emulsion using two behavioral models have suggested that nano emulsion at the dose of 10 mg/kg/day was significantly reduced the Scopolamine induced memory impairment.