Herbal medicine for mild cognitive impairment: Neuroimaging perspectives

Table 1 Representative neuroimaging studies investigating herbal medicine interventions in mild cognitive impairment

Neuroimaging modality	Herbal intervention	Study type	Study design	Population/model	Main neuroimaging findings	Association with cognitive or clinical outcomes
sMRI	Ginkgo biloba extract EGb, 761®	Clinical (human)	Longitudinal, observational/RCT-derived imaging analyses	Patients with MCI	Slower hippocampal and medial temporal lobe atrophy compared with controls	Structural preservation associated with stabilization of cognitive performance
sMRI	Kami Guibi-tang	Clinical (human)	Ongoing phase III RCT (protocol)	Patients with MCI	Planned assessment of medial temporal lobe and hippocampal volume	Cognitive outcomes to be correlated with volumetric changes
fMRI (rs-fMRI/task-based)	Multi-component herbal formulation	Clinical (human)	Cross-sectional intervention study	Healthy older adults	Modulation of default mode network and executive control network connectivity	Altered functional connectivity patterns suggest improved network efficiency
PET (18F-FDG)	Danggui Shaoyao San	Preclinical (animal)	Experimental, longitudinal	AD mouse model	Increased hippocampal glucose metabolism; reduced Aβ and tau burden	Improved metabolic activity correlated with cognitive performance
PET (18F-FDG)	PM012 (standardized herbal formula)	Preclinical (animal)	Experimental	3xTg-AD mice	Enhanced whole-brain glucose uptake; increased neurogenesis	Metabolic improvement associated with cognitive improvement
PET (18F-FDG)	Fuzhisan	Preclinical (animal)	Experimental	Aged rats	Enhanced temporoparietal glucose metabolism; increased cholinergic markers	Indirect association with learning and memory improvement
DTI	Epimedium flavonoids	Preclinical (animal)	Experimental	Chronic cerebral hypoperfusion rat model	Increased fractional anisotropy; improved white matter microstructure	White matter integrity associated with improved cognition
DTI (connectomics)	Dengzhan Shengmai	Clinical (human)	RCT	Patients with vascular cognitive impairment	Improved thalamo-hippocampal connectivity; increased global network efficiency	White matter changes predicted cognitive improvement
DTI + ASL	NeuroAiD II (MLC901)	Clinical (human)	Multicenter RCT (ongoing)	Patients with vascular cognitive impairment no dementia	Evaluation of white matter integrity and cerebral perfusion	Clinical–imaging associations under investigation

MCI: Mild cognitive impairment; AD: Alzheimer’s disease; sMRI: Structural magnetic resonance imaging; fMRI: Functional magnetic resonance imaging; rs-fMRI: Resting-state functional magnetic resonance imaging; PET: Positron emission tomography; ¹⁸F-FDG: Fluorine-18 fluorodeoxyglucose; DTI: Diffusion tensor imaging; ASL: Arterial spin labeling; Aβ: Beta-amyloid; RCT: Randomized controlled trial.