Evaluation of Phenolic Compounds and Neurotrophic/neuroprotective Activity of Cultivar Extracts Derived from Chrysanthemum morifolium Flowers

Petal extracts of the edible flowers of two typical cultivars, Aboukyu and Enmeiraku, of Japanese Chrysanthemum spp. (Chrysanthemum morifolium Ramat. forma esculentum Makino) were analyzed for their bioactive characteristics, including neuroprotective and neurotrophic-like activity in relation to the chemical profile of phenolic components. Phenolic components of petals differed significantly between the Aboukyu and Enmeiraku cultivars. The level of luteolin, an antioxidant polyphenol that possesses neurotrophic and neuroprotective activities, was higher in Enmeiraku than in Aboukyu. Extracts of Enmeiraku protected neuroblastoma SH-SY5Y cell viability against oxidative stress-induced injury in a concentration-dependent manner (12.5 – 100 µg/mL). By contrast, the neuroprotective effect of Aboukyu extracts was biphasic and was weakened at concentrations > 25 µg/mL. Individually, the Aboukyu and Enmeiraku extracts only slightly induced neurite outgrowth; however, in combination with nerve growth factor, the extracts acted synergistically to induce full neurite outgrowth in PC12 cells. Our findings suggest that differences in the neuroprotective effect of Aboukyu and Enmeiraku extracts are attributable to differences in the composition of the constituent phenolic compounds.