番石榴醇提物抗氧化能力及α-葡萄糖苷酶抑制活性研究

Antioxidant capacity and α-glucosidase inhibitory activity of ethanol extracts from guava fruits

【目的】探讨4种番石榴醇提物的抗氧化能力、α-葡萄糖苷酶抑制活性及功能性成分含量,为番石榴功能产品的开发利用提供参考。【方法】以‘宜盆红’、‘帝王’、‘山美白’、‘山美红’等4个品种番石榴果实为试材,测定其醇提物对DPPH·、·OH、ABTS+3种自由基的清除能力,α-葡萄糖苷酶抑制活性及总多酚和总黄酮含量,并探讨功能活性与物质成分含量的相关性。【结果】4种番石榴醇提物中,‘帝王’醇提物对DPPH·、·OH、ABTS+3种自由基的清除能力最强,半清除浓度(IC50)分别为1.25,1.83和1.48mg/mL;‘山美白’次之,IC50分别为1.46,1.94和1.68mg/mL;‘山美红’的IC50分别为1.61,2.58和1.94mg/mL;‘宜盆红’最弱,IC50分别为2.02,3.15和2.28mg/mL。4种番石榴醇提物对α-葡萄糖苷酶的半抑制浓度(IC50)为0.04～0.19mg/mL,均远低于阳性对照阿卡波糖的IC503.13mg/mL。4种番石榴的总多酚和总黄酮含量分别为11.22～20.70mg/g和21.65～50.68mg/g,总多酚含量与DPPH·、ABTS+自由基清除能力均呈显著正相关性(P<0.05),但与·OH自由基清除能力、α-葡萄糖苷酶抑制活性相关性均不显著(P>0.05),总黄酮含量与抗氧化能力、α-葡萄糖苷酶抑制活性均无显著相关关系(P>0.05)。【结论】4种番石榴醇提物中,‘帝王’醇提物抗氧化能力及总多酚、总黄酮含量最高,‘山美红’醇提物α-葡萄糖苷酶抑制活性最强。

【Objective】This study compared the antioxidant capacity,α-glucosidase inhibitory activity,and contents of functional components of ethanol extracts of 4 different guava cultivars to provide reference for future exploitation of guava functional products.【Method】The fresh fruits of 4 guava cultivars including“Yipenhong”,“Diwang”,“Shanmeibai”,and“Shanmeihong”were selected and the scavenging effects of their ethanol extracts on DPPH·,·OH,and ABTS^+free radicals,inhibition onα-glucosidase activity as well as contents of total polyphenols and flavonoids were determined.The correlation between functional activity and active constituents was also explored.【Result】The ethanol extract of“Diwang”fruit showed the highest scavenging ability against DPPH·(IC50 1.25 mg/mL),·OH(IC50 1.83 mg/mL),and ABTS^+(IC50 1.48 mg/mL),followed by“Shanmeibai”(IC50 1.46,1.94 and 1.68 mg/mL)and“Shanmeihong”(IC50 1.61,2.58 and 1.94 mg/mL).The ethanol extract of“Yipenhong”fruit exhibited the lowest antioxidant capacity with IC50 of 2.02,3.15 and 2.28 mg/mL,respectively.The IC50 values ofα-glucosidase inhibitory activity of the 4 ethanol extracts ranged from 0.04 to 0.19 mg/mL,much lower than that of Acarbose(IC50=3.13 mg/mL).The contents of polyphenols and flavonoids of ethanol extracts ranged from 11.22 to 20.70 mg/g and from 21.65 to 50.68 mg/g,respectively.Correlation analysis revealed that the scavenging ability against DPPH·and ABTS^+was highly significantly and positively correlated with polyphenols contents(P<0.05).The scavenging ability against·OH and the inhibitory activity onα-glucosidase were not significantly correlated with polyphenols contents(P>0.05).The antioxidant capacity andα-glucosidase inhibitory activity had no significant correlation with flavonoids(P>0.05).【Conclusion】The ethanol extract of“Diwang”fruit showed the highest antioxidant capacity,as well as polyphenols and flavonoids contents.The ethanol extract of“Shanmeihong”fruit had the highestα-glucosidase inhibitory activity.