Pharmaceutical composition for promoting neurogenesis and method for promoting neurogenesis and inhibiting senescence of brain neurons

A method for inhibiting senescence of brain neurons of a subject, the method comprising:

• administering an effective amount of a Gastrodia elata extract to the subject to increase amounts of antioxidant enzymes in the subject's brain and blood, wherein the Gastrodia elata extract comprises:
• >50 wt % of parishin compounds;
• >25 wt % of gastrodin;
• gastrodigenin;
• 0.5-4 wt % of N6-(4-hydroxybenzyl) adenosine;
• and
• 4-hydroxybenzaldehyde;
• and
• wherein the antioxidant enzymes comprise catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glucose-6-phosphate dehydrogenase (G6PD);
• and
• wherein the Gastrodia elata extract is prepared by the steps of:
• extracting pieces of Gastrodia elata tubers with a 70% aqueous ethanol solution at 50° C. overnight to obtain an extract solution;
• concentrating and drying the extract solution to obtain a crude extract;
• eluting the crude extract through a macro-porous resin column with 50% ethanol to obtain the Gastrodia elata extract.