Efficacy of Bacopa monnieri on memory and vascular functions: A randomised controlled trial

Abstract

Abstract Bacopa monnieri (L.) Wettst. (Brahmi) is a traditional memory enhancer partly by improved cerebral blood flow. Here we sought to link improved cognitive function with better blood flow in randomised double-blinded placebo-controlled trial in an elderly cohort. Normotensive Thais, aged 55-80y having mini-mental state examination (MMSE) scores > 25, no dementia or other psycho/neurological disease, normal lipid profile, and blood biochemistry were recruited. The trial design was a 2 week run-in, 12 week intervention of test product or placebo, and 4 week washout. The intervention was an extract of B. monnieri leaves (eBM) in 40 ml of mulberry juice. The placebo contained mulberry juice and other constituents to match gustatory properties. End-points were a battery of memory functions, carotid blood velocity, post-ischemic microvascular blood flow, markers of vascular inflammation, blood pressure and the blood markers. Response latency was reduced by 14.2 ± 4.9% (p = 0.022 comparing placebo) but only in > 65s. Other memory recall parameters were either unaffected or for ‘accuracy of recall’ was already maximal preventing further improvement. No change was detected in carotid blood velocity while microvascular blood flow marginally increased (by 28.4 ± 8.3%, p = 0.07). This preliminary evidence warrant further studies on selected patients with microvascular cognitive dysfunction using more discriminating protocols.