Protective effects of F. homotropicum Ohnishi, F. esculentum Moench, and their hybrid against lipid oxidation induced by hydrophilic free radical generators in low-density lipoprotein of rabbits

Ping Jiang ¹ , Clayton G. Campbell ², YingJie Wang ², Frank Burczynski ¹, and Colin J. Briggs ¹

¹ Faculty of Pharmacy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada ² Kade Research Ltd., Morden, Manitoba, Canada

Ping Jiang, Clayton G. Campbell, YingJie Wang, Frank Burczynski, and Colin J. Briggs. 2005. Protective effects of F. homotropicum Ohnishi, F. esculentum Moench, and their hybrid against lipid oxidation induced by hydrophilic free radical generators in low-density lipoprotein of rabbits. Fagopyum 22: 25-30.

Abstract: Buckwheat is considered to be a major dietary source of rutin, a flavonoid glycoside. Dietary flavonoids have been reported to inhibit low-density lipoprotein oxidation and benefit cardiovascular system. This study was conducted to investigate the rutin content and the antioxidant activities of two parental lines, Fagopyrum homotropicum K970851 and the self-pollinating line T990036 together with their hybrid Q010001.The rutin content of buckwheat seeds were determined using a high-performance liquid chromatographic (HPLC) assay. A free radical-induced low-density lipoproteins (LDL) oxidation model was used in this study. The malondialdehyde (MDA) content, as determined as the thiobarbituric acid reactive substances (TBARS) and conjugated diene formation were utilized to detect the extent of lipid peroxidation. The rutin content of the three buckwheat lines were significantly different, being 263 mg/100 g seeds in K970851, 80 mg/100 g seeds in T990036, and 120 mg/100 g seeds in Q010001. The results obtained from a TBARS test showed that all three buckwheat lines K970851, T990036 and Q010001 significantly decreased MDA production in the LDL. In the conjugated diene assay, the three buckwheat lines produced a greater increase in lag time and a significant reduction in the ea under the oxidative-time curve (AUC) value as compared to the control. Their inhibitory effect on lipid peroxidation decreased in the order: K970851 Q010001 T990036 (P 0.05). The findings in the present study revealed the potential of Fagopyrum homotropicum lines and their crosses for transfer of desirable traits such as functional foods or antioxidants into self-pollinating buckwheat. It specifically demonstrated that Fagopyrum homotropicum may be used as a parent to develop lines for enhanced rutin content.

Key words:BAC library, buckwheat, heterostylous, positional cloning, self-incompatibility