Previous research has shown that hibiscus can boost the immune system, control blood pressure, and reduce body weight. Now, a new study highlights how a flavonoid found in hibiscus called gossypetin can help fight Alzheimer’s disease (AD). A study published in Alzheimer’s Research and Therapy showed that gossypetin protects against AD by enhancing microglial Aβ phagocytosis (the removal of dead or dying neurons).
Gossypetin activates an immune response in which microglia scavenge amyloid-beta (Aβ) in the brain and thus minimize cognitive impairments caused by AD. Aβ and Tau protein aggregates form deposits in the brain tissue as AD progresses. Microglia internalize such aggregates (phagocytosis) to protect the brain, but constant exposure to Aβ eventually exhausts the microglia and results in a chronic inflammatory reaction and nerve cell damage, cognitive decline, and memory loss.
The Pohang University of Science and Technology research team observed the mice’s impaired memory and cognition were almost restored to normal functioning after the mice received gossypetin treatments for three months. They also noted a decrease in the various types of Aβ aggregates, which are commonly found in the brain tissue with AD-type dementia.
The researchers then proceeded with single-cell RNA sequencing. The analysis demonstrated that gossypetin prevented gliosis by inhibiting the expression of genes associated with chronic inflammatory reactions. They confirmed that gossypetin facilitated microglia’s Aβ clearance. In addition, gossypetin treatment improved spatial learning and memory by decreasing Aβ deposition in the hippocampus and cortex of 5xFAD. According to Professor Kyong-Tai Kim, “We have confirmed that removing Aβ aggregates deposited in the brain is effective in preventing and treating dementia. Gossypetin from hibiscus will contribute to the development of a safe and affordable drug for patients suffering from AD.” This study provides a basis for further research on the safety and efficacy of gossypetin treatments.
Sources: Alzheimer’s Research and Therapy, Eureka News Alert, Pohang University of Science and Technology
