Colon-targeted delivery of polyphenols: construction principles, targeting mechanisms and evaluation methods.

Polyphenols have received considerable attention for their promotive effects on colonic health. However, polyphenols are mostly sensitive to harsh gastrointestinal environments, thus, must be protected. It is necessary to design and develop a colon-targeted delivery system to improve the stability, colon-targeting and bioavailability of polyphenols. This paper mainly introduces research on colon-targeted controlled release of polyphenols. The physiological features affecting the dissolution, release and absorption of polyphenol-loaded delivery systems in the colon are first discussed. Simultaneously, the types of colon-targeted carriers with different release mechanisms are described, and colon-targeting assessment models that have been studied so far and their advantages and limitations are summarized. Based on the current research on polyphenols colon-targeting, outlook and reflections are proposed, with the goal of inspiring strategic development of new colon-targeted therapeutics to ensure that the polyphenols reach the colon with complete bioactivity.

Positron Emission Tomography Imaging of Synaptic Dysfunction in Parkinson's Disease.

Parkinson's disease (PD) is one of the most common neurodegenerative diseases with a complex pathogenesis. Aggregations formed by abnormal deposition of alpha-synuclein (αSyn) lead to synapse dysfunction of the dopamine and non-dopamine systems. The loss of dopaminergic neurons and concomitant alterations in non-dopaminergic function in PD constitute its primary pathological manifestation. Positron emission tomography (PET), as a representative molecular imaging technique, enables the non-invasive visualization, characterization, and quantification of biological processes at cellular and molecular levels. Imaging synaptic function with PET would provide insights into the mechanisms underlying PD and facilitate the optimization of clinical management. In this review, we focus on the synaptic dysfunction associated with the αSyn pathology of PD, summarize various related targets and radiopharmaceuticals, and discuss applications and perspectives of PET imaging of synaptic dysfunction in PD.

Comparative study on alleviating effect of kiwi berry (Actinidia arguta) polysaccharide and polyphenol extracts on constipated mice.

Kiwi berry (Actinidia arguta) is beneficial for relieving constipation, but the mechanism of easing constipation is still unknown. The alleviating effects of kiwi berry polysaccharide and polyphenol extracts on loperamide induced constipation were studied. Administration with polysaccharide extract of kiwi berry in loperamide-induced constipation mice distinctly decreased the body weight gain by 124.0%, the number and the water content of feces was decreased by 152.4% and 107.0% respectively, gastrointestinal (GI) transit rate was decreased by 39.5% and the time to the first dark stool was largen by 56.2% as compared with those in the loperamide group, respectively. The levels of excitability neurotransmitters were increased, and the inhibitory neurotransmitter was decreased in the kiwi berry extracts groups compared with the loperamide group. The levels of aquaporins were decreased to ameliorate constipation. Moreover, kiwi berry extracts can protect colon smooth muscle cells from apoptosis and help to restore colon health. Interstitial cells of Cajal (ICC) and animal experiments suggested that kiwi berry extracts can up-regulate the expression levels of stem cell factors (SCF)/c-kit protein. Kiwi berry can remodel the structure of microbial communities. All findings suggest that kiwi berry polysaccharide and polyphenol especially its polysaccharide extract, can effectively alleviate constipation induced by loperamide. Kiwi berry is a promising food supplement that can be used to relieve constipation.