Long-term Course of Alzheimer Disease in Patients Treated According to the Dutch Dementia Guideline at a Memory Clinic

Targeting autophagy using saponins as a therapeutic and preventive strategy against human diseases

Autophagy is a ubiquitous mechanism for maintaining cellular homeostasis through the degradation of long-lived proteins, insoluble protein aggregates, and superfluous or damaged organelles. Dysfunctional autophagy is observed in a variety of human diseases. With advanced research into the role that autophagy plays in physiological and pathological conditions, targeting autophagy is becoming a novel tactic for disease management. Saponins are naturally occurring glycosides containing triterpenoids or steroidal sapogenins as aglycones, and some saponins are reported to modulate autophagy. Research suggests that saponins may have therapeutic and preventive efficacy against many autophagy-related diseases. Therefore, this review comprehensively summarizes and discusses the reported saponins that exhibit autophagy regulating activities. In addition, the relevant signaling pathways that the mechanisms involved in regulating autophagy and the targeted diseases were also discussed. By regulating autophagy and related pathways, saponins exhibit bioactivities against cancer, neurodegenerative diseases, atherosclerosis and other cardiac diseases, kidney diseases, liver diseases, acute pancreatitis, and osteoporosis. This review provides an overview of the autophagy-regulating activity of saponins, the underlying mechanisms and potential applications for managing various diseases.

Cohort Effects in Progression Rate on Cognitive and Functional Measures in an Alzheimer's Disease Clinical Cohort

BACKGROUND

Accurate prediction of Alzheimer's disease (AD) cognitive and functional outcomes in clinical research requires consistent underlying rates of change over time.

OBJECTIVE

To examine cohort effects in AD progression rate over five years of follow-up using a clinical database of probable AD patients.

METHODS

Baseline characteristics of three cohorts enrolled from 1995-1999, 2000-2004, and 2005-2009 were compared using ANOVA and chi-square tests. Differences in 5-year decline on the Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and Clinical Dementia Rating Scale Sum of Boxes (CDR-SB), the Lawton and Brody Physical Self-maintenance Scale (PSMS), and Activities of Daily Living Scale (ADL) were assessed using longitudinal mixed effects regression, adjusting for age, sex, education, and other relevant clinical characteristics.

RESULTS

Cohorts 1 (n = 287), 2 (n = 257), and 3 (n = 374) did not differ on age, race, APOE genotype, or cognitive and functional measures. Educational attainment increased over time (13.4, 14.1, and 14.5 years, respectively, p < 0.001). Anti-dementia drug use at baseline was less common in Cohort 1 (32.2% versus 65.0%, and 66.8%, p < 0.001). The rate of decline in MMSE and CDR-SB did not differ across cohorts. ADAS-Cog scores for Cohort 2 declined more slowly than Cohort 3 (Btime ×cohort2 = -0.91 ± 0.35, p = 0.009), whereas Cohort 1 did not differ from cohort 3 (reference). Cohorts 1 and 2 differed from Cohort 3 in progression rate on the PSMS, but not the IADL.

CONCLUSIONS

There were no consistent temporal trends in progression rates over time. Longitudinal data over 15-20 years may be confidently pooled for outcomes analysis, but unexplained variability in rate of decline on some measures may occur.