Guarana (Paullinia cupana) Extract Protects Caenorhabditis elegans Models for Alzheimer Disease and Huntington Disease through Activation of Antioxidant and Protein Degradation Pathways

Figure 9

Hypothetical model of the mode of action of guarana hydroalcoholic extract (GHE) on C. elegans. Abnormal proteins are formed due to oxidation, misfolding, or mutations in specific genes. Cellular protein quality control systems, such as chaperones, proteasomes, and lysosomes, act to repair or degrade the abnormal proteins. These proteins, when not repaired or degraded, can be aggregated into cells, which increase endogenous ROS level, oxidative stress, and cellular damage. Our results indicate that GHE treatment is able to reduce the pathological phenotypes associated with AD and HD in C. elegans through the induction of proteasome and lysosome activity and the expression of chaperone HSP-16.2. GHE treatment also reduces oxidative stress by neutralizing ROS and inducing the expression of an antioxidant enzyme, SOD-3.