Screening Of Antidiarrheal Bioactive Guided Fraction Of Pomegranate Peels And Optimization Of Extraction Process Of Punicalagin

Pomegranate peels are from the dry pericarp of Punica granatum L.which belongs to the Punicaceae family and is a deciduous shrub or small tree.Traditionally,it is used to antidiarrhea and anthelmintic as a herb.Nevertheless,no available data and relevant reports are obtained on antidiarrheal bioactivity guided fraction and main components of the bioactivity guided fraction.Therefore,the present study was aimed at describing the protective ability of pomegranate peels against castor oil-induced diarrhea.The bioactivity guided fraction and its main components were also performed.And the extraction process of the main compound punicalagin was optimized.It has provided a scientific basis for the further development of antidiarrhea research for pomegranate peel resources and laid the foundation for pomegranate peel in the industrial production of drug extraction.The study first verified the antidiarrhea effect of pomegranate peel,and the bioactivity guided fraction of pomegranate peels aqueous extract was performed using different solvents of increasing polarity viz.ethyl acetate,n-butyl alcohol,and residue.The results revealed that only ethyl acetate fraction possessed strong antidiarrheal activity against castor oil-induced diarrhea among all the fractions(p < 0.05).Further,ethyl acetate fraction at 100,200 and 400 mg/kg produced a significant reduction in gastrointestinal transit in charcoal meal tests in mice(p < 0.05).It also significantly inhibited castor oil-induced enteropooling and was dose-related compared to control animals(p < 0.05).Histopathological analysis revealed that the small intestine lesions of mice treated with ethyl acetate fraction were alleviated compared to that of mice treated with castor oil.Based on the HPLC/ESI-MS analysis,the principal chemical compositions in the ethyl acetate fragment were analyzed.The collective results indicated that ethyl acetate fragment was the active fragment of aqueous extract of pomegranate peels.The principal chemical compositions(HHDP-glucose,Gallic acid,Punicalin,Punicalagin,Corilagin and Ellagic acid)played a crucial role in the antidiarrheal effect of the active fragment.On the basis of determining the antidiarrheal main compounds in pomegranate peel,extraction process of punicalagin which is the main component of bioactive fraction was optimized.Based on the single-factor analysis,Taguchi method was employed to obtain the best possible combination of ethanol concentration,extraction temperature,extraction time,liquid-solid ratio,particle diameter and extraction times for maximum punicalagin extraction.Results showed that the ethanol concentration,extraction temperature,extraction time,liquid-solid ratio,particle diameter and extraction times were 10%,80 ?,2 h,40:1 mL/g,0.09 mm,and two experimental runs respectively.Under these optimum conditions,the experimental yield was(492.16±1.91)mg/g.The extraction process obtained by Taguchi method was stable and reasonable,accurate and reliable.It was a feasible method to extract the active compound from pomegranate peels.In this study,the bioactivity guided fraction and its main components of pomegranate peels aqueous extract were performed scientifically and systematically for the first time;and it adopted the Taguchi method to optimize the extraction process of punicalagin with the main component in bioactive fraction.This study provides a scientific basis for the further development of antidiarrhea research on pomegranate peels resources and lays a foundation for pomegranate peels in the industrial production of drug extraction.