Two new iridoids and triterpenoid analogues from the leaves of Viburnum chingii and their anti-acetylcholinesterase activity

Two undescribed split-ring iridoids (1-2) with six known triterpenes (3-8) and one steride (9) were isolated from the Viburnum chingii. Compound 2 possessed an unprecedented split-ring iridoid skeleton formed by electrocyclic reaction and split ring. The structures and absolute configurations of the new iridoids were established by NMR, HRESIMS, and ECD calculations. All the isolated compounds were tested for AChE inhibitory activity. Biologically, 1, 2, 3, 4, and 7 displayed significant AChE effects compared to the positive control donepezil, and have also been subjected to molecular docking studies.

Prediction models for assessing long-term outcome in Alzheimer's disease: a review

In Alzheimer's disease (AD), placebo-controlled long-term studies of cholinesterase inhibitors (ChEIs) are not permitted for ethical reasons. Therefore, in these studies, patients' outcomes on cognitive and functional assessment scales must be compared with mathematical models or historical data from untreated cohorts. PubMed and previously published long-term extensions of clinical trials and naturalistic studies of ChEIs were examined to identify empirical statistical models and other approaches, such as use of data from historical cohorts or extrapolated changes from extension studies, that were used to draw comparisons between ChEI-treated and untreated patients. The models and methods were described. It is essential to be aware of the limitations of comparisons made with these approaches. Prediction models based on ChEI-treated patients can be used in the studies of new treatments when those treatments are added to ChEIs. More sophisticated models that also accommodate patient-specific characteristics should be developed for comparisons in future long-term AD studies.

Donepezil in Alzheimer's disease: what to expect after 3 years of treatment in a routine clinical setting

BACKGROUND/AIMS

Clinical short-term trails have shown positive effects of donepezil treatment in patients with Alzheimer's disease. The outcome of continuous long-term treatment in the routine clinical settings remains to be investigated.

METHODS

The Swedish Alzheimer Treatment Study (SATS) is a descriptive, prospective, longitudinal, multicentre study. Four hundred and thirty-five outpatients with the clinical diagnosis of Alzheimer's disease, received treatment with donepezil. Patients were assessed with Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), global rating (CIBIC) and Instrumental Activities of Daily Living (IADL) at baseline and every 6 months for a total period of 3 years.

RESULTS

The mean MMSE change from baseline was positive for more than 6 months and in subgroups of patients for 12 months. After 3 years of treatment the mean change from baseline in MMSE-score was 3.8 points (95% CI, 3.0-4.7) and the ADAS-cog rise was 8.2 points (95% CI, 6.4-10.1). This is better than expected in untreated historical cohorts, and better than the ADAS-cog rise calculated by the Stern equation (15.6 points; 95% CI, 14.5-16.6). After 3 years with 38% of the patients remaining, 30% of the them were unchanged or improved in the global assessment.

CONCLUSION

Three-year donepezil treatment showed a positive global and cognitive outcome in the routine clinical setting.

Years of severe and isolated amnesia can precede the development of dementia in early-onset Alzheimer's disease

A young patient with a severe and isolated memory disorder, meeting the criteria for MCI, was followed for a period of 8 years. His overall functional level remained stable with a CDR-score at 0.5 until the last year when it dropped to 1.0. Neuropsychological testing showed severe memory deficits but otherwise normal cognitive functions. Only minimal progression was measured; however, the last testing showed impaired abstraction and executive functioning as well as discrete problems generating names of objects and people. Neuroimaging, with MRI and SPECT, was consistent with a progressive degenerative disorder, and cerebrospinal fluid levels of beta-amyloid 1-42, tau protein, and phosphorylated tau protein were characteristic of Alzheimer's disease (AD). We argue that this is a case of prodromal AD, which illustrates an extreme version of the normal course with respect to slow progression of the disease and severity of amnesia early in the course.