Anti-ageing and attenuating cognitive declines of Dicliptera chinensis extracts and purified compounds in vitro and in scopolamine-induced cognitive dysfunction mice.

Background: The cognitive decline is one of the age-associated physical dysfunctions and also found in Alzheimer's disease (AD). The whole plants of Dicliptera chinensis (L.) Nees (DC) are belonged to edible materials as fresh vegetables, and dried DC powders as tea materials or used as folk medicines for clearing heat and removing toxic substance in Taiwan. However, DC extracts and the active compounds on anti-ageing and attenuating cognitive declines are not clear.

Results: The dried powders of the whole DC plants are extracted with 95% ethanol to get DC-95EE. The DC-95EE is partitioned in sequences to get ethyl acetate fraction, butanol fraction (BuOH fraction), and water faction. Two flavone C-glycosides (vicenin II and schaftoside) are purified from the BuOH fraction. It is found that the pre-treatments of DC-95EE, BuOH fraction, and vicenin II and schaftoside show to elevate cell viabilities, reduce the senescence-associated β-galactosidase (SAβG) activity and intracellular reactive oxygen species (ROS) levels in galactose-treated SH-SY5Y neuronal cell models. The pre-treatments of vicenin II or schaftoside also show to lower ageing-associated p16 and p21 gene expressions and enhance SIRT-1 gene expressions in galactose-treated SH-SY5Y cells. The DC-95EE, vicenin II, and schaftoside show dose-dependent anti-acetylcholinesterase activities. The oral administrations of DC-95EE (200 mg/kg) and purified schaftoside (25 and 50 mg/kg) daily for 7 days ameliorate cognitive declines in scopolamine-induced ICR mice evaluated by Morris water maze. The quantification of vicenin II and schaftoside, respectively, account for 2.53% and 8.17% of DC-95EE by HPLC quantifications, which may be active compounds in the DC-95EE for anti-ageing activities.

Conclusion: The DC-95EE exhibit anti-ageing in neuron cell models and attenuate cognitive declines in mice models, which may be potentials in developing functional foods for anti-ageing purposes and need further investigations.