Since its discovery in 1984, the beta amyloid peptide has treaded the boards of neurosciences as the star molecule in Alzheimer’s disease pathogenesis. In the last decade, however, this vision has been challenged by evidence-based medicine showing the almost complete failure of clinical trials that experimented anti-amyloid therapies with great hopes. Moreover, data have accumulated which clearly indicate that this small peptide plays a key role in the physiological processes of memory formation. In the present review, we will discuss the different aspects of the amyloid cascade hypothesis, highlighting its pros and cons, and we will analyse the results of the therapeutic approaches attempted to date that should change the direction of Alzheimer’s disease research in the future.

Objective: To investigate if Helicobacter pylori (HP) eradication could make an effective and long-lasting improvement in the pharmacokinetic and clinical response to l-dopa in patients with Parkinson disease (PD) and motor fluctuations. Methods: In a group of 34 HP-infected, motor-fluctuating patients with PD, the short-term (1-week) and long-term (3-month) beneficial effect of HP eradication (n = 17) was investigated in a double-blind fashion in comparison with a generic antioxidant treatment (n = 17), by means of pharmacokinetic, clinical, and gastrointestinal assessments. Results were compared with placebo treatment. Results: Differently from the antioxidant-treated patients, the HP-eradicated patients showed a significant increase of l-dopa absorption, which was coupled with a significant improvement of clinical disability and with a prolonged “on-time” duration, whereas gastritis/duodenitis scores significantly decreased in line with a better l-dopa pharmacokinetics. Conclusions: These data demonstrate a reversible Helicobacter pylori (HP)–induced interference with l-dopa clinical response related to the impaired drug absorption, probably due to active gastroduodenitis. Therefore, the authors suggest that HP eradication may improve the clinical status of infected patients with Parkinson disease and motor fluctuations by modifying l-dopa pharmacokinetics.

BACKGROUND AND PURPOSE Strategies designed to enhance cerebral cAMP have been proposed as symptomatic treatments to counteract cognitive deficits. However, pharmacological therapies aimed at reducing PDE4, the main class of cAMP catabolizing enzymes in the brain, produce severe emetic side effects. We have recently synthesized a 3-cyclopentyloxy-4-methoxybenzaldehyde derivative, structurally related to rolipram, and endowed with selective PDE4D inhibitory activity. The aim of the present study was to investigate the effect of the new drug, namely GEBR-7b, on memory performance, nausea, hippocampal cAMP and amyloid-β (Aβ) levels. EXPERIMENTAL APPROACH To measure memory performance, we performed object recognition tests on rats and mice treated with GEBR-7b or rolipram. The emetic potential of the drug, again compared with rolipram, was evaluated in rats using the taste reactivity test and in mice using the xylazine/ketamine anaesthesia test. Extracellular hippocampal cAMP was evaluated by intracerebral microdialysis in freely moving rats. Levels of soluble Aβ peptides were measured in hippocampal tissues and cultured N2a cells by elisa. KEY RESULTS GEBR-7b increased hippocampal cAMP, did not influence Aβ levels and improved spatial, as well as object memory performance in the object recognition tests. The effect of GEBR-7b on memory was 3 to 10 times more potent than that of rolipram, and its effective doses had no effect on surrogate measures of emesis in rodents. CONCLUSION AND IMPLICATIONS Our results demonstrate that GEBR-7b enhances memory functions at doses that do not cause emesis-like behaviour in rodents, thus offering a promising pharmacological perspective for the treatment of memory impairment.