Optimization And Activity Evaluation Of Extraction Process Of Antioxidant Components Of Areca Flower

Areca nut is the main cash crop in Hainan Province of China,with the characteristics of large planting areas and high yield.As the main by-product of Areca nut,Areca flowers contain a variety of active substances like alkaloids,polyphenols,flavonoids,and amino acids.However,at present,most Areca flowers are sold as primary processed products such as food ingredients or flower tea.More research on physiological activity and safety could be done to better develop the industry of Areca flowers.Therefore,taking Areca flowers as the research object,using polyphenol content as evaluation index to optimize the extraction process of Areca flowers antioxidant components,the main components,and contents of polyphenols were determined.Besides,in vitro antioxidant experiments and in vivo antioxidant enzyme activity experiments that used Caenorhabditis elegans as a model organism were designed to evaluate the physiological activity of Areca flowers extract.The results are as follows:1.Using polyphenol content as evaluation index,the optimized extraction conditions of Areca flowers antioxidant components by response surface methodology were determined as:the methanol concentration was 46%,the extraction time was 40 min,and the extraction temperature was 77℃.Under these conditions,the content of Areca polyphenols was 4.52±0.055 mg/g.2.The content of Arecoline in Areca flowers extract was the highest.The total polyphenol content and Arecoline content in Areca flowers extract were 27.02±0.43 mg/g and 12.5±0.42 mg/g,respectively.3.The results of chemical antioxidant experiments showed that the Areca flowers extract had potent ability with scavenging ABTS radicals and DPPH radicals.Also,the iron ion reduction ability is good.The free radical scavenging rates of ABTS and DPPH were90.8%and 87.04%,respectively.The iron ion reducing ability of 3 mg/ml Areca flower extract was equivalent to 30μg/ml ascorbic acid solution,which is 0.449 mol/L Fe SO₄equivalent.4.Areca flowers extract with a concentration of more than 200μg/m L showed toxic effects on Caenorhabditis elegans.As the concentration increased,the mortality increased.The activities of SOD,CAT and GSH-PX enzymes were reduced in Caenorhabditis elegans when the concentration of Areca flowers extract was 100μg/m L,400μg/m L and 800μg/m L,respectively.Arecoline in the extract was not the cause of the decrease in enzyme activity.In summary,although Areca flowers extracts showed good antioxidant activity in vitro,when the concentrations were higher than 100μg/m L,the SOD,CAT and GSH-PX enzyme activities in Caenorhabditis elegans were inhibited.This phenomenon is not caused by Arecoline contained in the extracts.The mechanisms need to be further explored.