With the accelerated aging of human society Alzheimer’s disease (AD) has become one of the most threatening diseases in the elderly. However, there is no efficient therapeutic agent to combat AD. Berberine is a natural isoquinoline alkaloid that possesses a wide range of pharmacological effects. In the present paper, we review the multiple activities of berberine, including antioxidant, acetylcholinesterase and butyrylcholinesterase inhibitory, monoamine oxidase inhibitory, amyloid-b peptide level-reducing and cholesterol-lowering activities, which suggest that berberine may act as a promising multipotent agent to combat AD.

The relationship between poor in vivo bioavailability and effective pharmacological activity are not yet fully clarified for many flavonoids. The analysis of flavonoids-induced alterations in the gut microbiota represents a promising approach to provide useful clues to elucidate the mechanism of action. Here, we investigate the effect of myricetin supplementation on high-fat-diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in rats and explore the associations with the gut microbiota through high-throughput analyses. The 12-week myricetin supplementation and fecal microbiota transplantation outcomes suggest that myricetin significantly slows the development of NAFLD. Meanwhile, the anti-NAFLD effects of myricetin are associated with the modulation of the gut microbiota composition. Myricetin reduces hepatic lipid synthesis and inflammation through modulations in fecal butyric-acid-related gut microbiota and protection of the gut barrier function. This study may facilitate the elucidation of the action mechanism of flavonoids with low bioavailability.

Curcumin is a natural product with multiple biological activities and numerous potential therapeutic applications. However, its poor systemic bioavailability fails to explain the potent pharmacological effects and hinders its clinical application. Using experimental and theoretical approaches, we compared curcumin and its degradation products for its biological activities against Alzheimer’s disease (AD), including the superoxide anion radical (O₂^.–)-scavenging activity, Aβ fibrils (fAβ) formation-inhibiting activity, and enzymatic inhibition activity. We showed that compared to the parent compound curcumin, the degradation products mixture possessed higher O₂^.–-scavenging activity and stronger inhibition against fAβ formation. The docking simulations revealed that the bioactive degradation products should make important contribution to the experimentally observed enzymatic inhibition activities of curcumin. Given that curcumin is readily degraded under physiological condition, our findings strongly suggested that the degradation products should make important contribution to the diverse biological activities of curcumin. Our novel findings not only provide novel insights into the complex pharmacology of curcumin due to its poor bioavailability, but also open new avenues for developing therapeutic applications of this natural product.

B vitamins may correlate with Parkinson’s disease (PD) through regulating homocysteine level. However, there is no comprehensive assessment on the associations between PD and B vitamins. The present study was designed to perform a meta-analytic assessment of the associations between folate, vitamin B6, and vitamin B12 and PD, including the status of B vitamins in PD patients compared with controls, and associations of dietary intakes of B vitamins and risk of PD. A literature search using Medline database obtained 10 eligible studies included in the meta-analyses. Stata 12.0 statistical software was used to perform the meta-analysis. Pooled data revealed that there was no obvious difference in folate level between PD patients and healthy controls, and PD patients had lower level of vitamin B12 than controls. Available data suggested that higher dietary intake of vitamin B6 was associated with a decreased risk of PD (odds ratio (OR) = 0.65, 95% confidence intervals (CI) = (0.30, 1.01)), while no significant association was observed for dietary intake of folate and vitamin B12 and risk of PD. PD patients had lower level of vitamin B12 and similar level of folate compared with controls. Dietary intake of vitamin B6 exhibited preventive effect of developing PD based on the available data. As the number of included studies is limited, more studies are needed to confirm the findings and elucidate the underpinning underlying these associations.