Abstract
Background: Zanthoxylum armatum DC. (ZA) is a traditional Asian culinary spice and medicinal compound, which is rich in monoterpenes and hydroxy α-sanshool. Mechanistic interactions with the monoamine, cholinergic and cannabinoid neurotransmission systems, as well as transient receptor potential (TRP) and potassium ion channels, may predispose ZA to modulate human brain function. Objectives: To investigate the effects of a single dose and 56-days supplementation with a lipid extract of ZA on cognitive function, mood and cerebral blood-flow (CBF) parameters in the pre-frontal cortex during cognitive task performance. Design: Double-blind, randomized, parallel groups study with N = 82 healthy males and females between the ages of 30 and 55 years. Assessments were undertaken pre-dose and at 1, 3 and 5 h post-dose on the first (Day 1) and last (Day 56) days of supplementation. Results: A single dose of ZA (Day 1) resulted in acute improvements on a ‘Speed of Attention’ factor and the Rapid Visual Information Processing (RVIP) task, in comparison to placebo. However, following ZA participants were less accurate on the name-to-face recall task. After 56 days of ZA consumption (Day 56), speed was enhanced on a global ‘Speed of Performance’ measure, comprising data from all of the timed tasks in the computerized battery. Participants also completed more correct Serial 3s Subtractions at the 3 h assessment and were less mentally fatigued throughout the day than participants consuming placebo. These effects were complemented on both Day 1 and Day 56 by modulation of CBF parameters, as assessed by Near Infrared Spectroscopy (NIRS). The primary finding here was a reduced hemodynamic response during the RVIP task. Conclusion: ZA improves aspects of cognitive performance, in particular the speed of performing tasks, in healthy humans and results in concomitant reductions in hemodynamic responses in the frontal cortex during task performance. The findings suggest an increase in neural efficiency following ZA.
Highlights
The plant species Zanthoxylum armatum DC. (ZA; known as Nepalese or Timur pepper) is from the Rutaceae or citrus, family and its bark, seeds and fruits have a long history as sources of medicinal treatments
There was a significant difference between groups in terms of self-rated mental fatigue during the Cognitive Demand Battery, with participants in the ZA group rating themselves as more mentally fatigued than placebo [F(1, 79) = 8.10, p = 0.006] during the Day 1 pre-dose assessment
Participants in the ZA group made significantly more false alarms on the Rapid Visual Information Processing (RVIP) task during the Day 1 pre-dose assessment compared to placebo [F(1, 79) = 7.34, p = 0.008]
Summary
The plant species Zanthoxylum armatum DC. (ZA; known as Nepalese or Timur pepper) is from the Rutaceae or citrus, family and its bark, seeds and fruits have a long history as sources of medicinal treatments. Nutrients 2019, 11, 3022 topical treatments for toothache and skin irritation/wounds [1,2,3] It is one of several species of the Zanthoxylum genus generically known as Szechuan pepper; a traditional Chinese and Nepalese culinary spice comprising the fruit pericarp which is typically added to wok and dumpling dishes to provide a characteristic grapefruit-like taste and flavor and a tingling numbness in the mouth. The alkamide group of compounds, which are found in 300+ species from the Zanthoxylum, Acmella (Spilanthes), Anacyclus, Echinacea and Heliopsis genera, typically have insecticidal, larvicidal and antimicrobial properties and act as plant growth factors [4] In mammals, they have anti-inflammatory, immunomodulatory and analgesic properties and may underlie the putative medicinal effects of plants such as Echinacea and ‘maca’ (Lepidium meyeni) [1,4]. These effects were complemented on both Day 1 and Day 56 by modulation of CBF parameters, as assessed by
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
