The effect of Catechin of Uncaria Gambir on Amyloid Precursor Protein (APP) Gene Expression and Malondialdehyde (MDA) Level and Cognitive Function amongst The Elderly: An Experimental Study

1) Background: Catechins from Uncaria gambir exhibit antioxidant and neuroprotective properties. Animal studies suggest they reduce oxidative stress and downregulate amyloid precursor protein (APP) gene expression, a contributor to amyloid plaque formation in cognitive decline. However, human studies, particularly in the elderly, remain limited, and molecular mechanisms are not fully understood. Objective: To evaluate the effect of Uncaria gambir catechin supplementation on APP gene expression, malondialdehyde (MDA) levels, and cognitive function in the elderly. 2) Methods: A double-blind randomized controlled trial (RCT) was conducted involving 58 elderly participants (≥60 years) in Padang, West Sumatra, Indonesia, with MoCA-Ina scores of 20–25. Participants were randomly assigned to receive either a daily 224mg Uncaria gambir catechin supplement (n=29) or a placebo (n=29) for 12 weeks. APP gene expression, MDA levels, and cognitive performance (MoCA-Ina) were measured before and after the intervention. 3) Results: After 12 weeks, the intervention group demonstrated a significant decrease in APP gene expression and MDA levels, along with a notable improvement in MoCA-Ina scores compared to the control group. 4) Conclusion: Daily supplementation with 224mg Uncaria gambir catechins over 12 weeks significantly reduced oxidative stress and APP gene expression while improving cognitive function in the elderly. This study addresses prior research gaps by providing clinical evidence in a human elderly population and offers insight into the molecular pathways involved.