Cydonia oblonga Mill. (Rosaceae)

Abstract

A fruit of the family of apples and pears. The fruit is regarded in Unani medicine as refrigerant, astringent, diuretic, heart-, brain-, stomach and liver-tonic; its syrup is used for heart weakness, hot palpitations, bilious diarrhea and to soothe heat of stomach and liver. It has been mentioned by Avicenna in Canon of Medicine for the treatment of abnormal uterine bleeding, and in Iran, various parts of quince are used as traditional remedies for cough, bronchitis, nausea, fever, diarrhea, cystitis, constipation, hemorrhoids, hypertension and diabetes, and dried quince has been used as a tea for centuries. In traditional Uyghur medicine, quince is used to treat or prevent cardiovascular diseases. The leaves are consumed as food and used as a folk remedy for the treatment of diabetes in Turkey. Quince varieties vary in their phenolic contents and some with higher contents may be used to promote their positive effect on health. A study on fruits from seven different locations in Portugal found the phenolic contents and total free amino acids (most abundant amino acids were glycine, aspartic acid, and asparagines) to be highest in the peel. Phenolics identified in peel were caffeoylquinic acids and several flavonol glycosides: kaempferol glycoside, quercetin 3-galactoside, rutin, kaempferol 3-glucoside, kaempferol 3-rutinoside and several unidentified compounds; and the pulp contains mainly caffeoylquinic acids and a small amount of rutin, a quercetin glycoside, and aspartic acid, asparagine, and hydroxyproline as the major amino acids. Quince leaves have very high total phenolic contents with 5-O-caffeoylquinic acid as the major phenolic compound, followed by quercetin 3-O-rutinoside; they also have higher relative contents of kaempferol derivatives than fruits. Aqueous fruit extract showed hypolipidemic, hepatoprotective, and renoprotective effects in diabetic rats as it significantly decreased serum TGs, TC, and LDL-C levels and increased the HDL-C. Oral administration of leaf ethanol extract to diabetic rats lowered blood glucose levels by 34%, and significantly reduced TBARS levels only in heart tissue. In a double-blind, RCT, quince syrup was effective in symptomatic relief of GERD in children and Iranian adolescents.