Influence of puerarin, paeoniflorin, and menthol on structure and barrier function of tight junctions in MDCK and MDCK-MDR1 Cells

Enhancing the stability, BBB permeability and neuroprotective activity of verbascoside in vitro using lipid nanocapsules in combination with menthol

Verbascoside (VER) shows promising neuroprotective activity. However, the instability and low permeability in crossing the blood-brain barrier (BBB) greatly hinder its application. In the present study, verbascoside was encapsulated into lipid nanocapsules (LNC) by reverse micelle (RM) to increase its stability. Besides, we used VER-RM-LNC combined with an envoy drug, menthol, to improve its BBB permeability and neuroprotective activity. VER-RM-LNC was prepared by the phase inversion temperature method, resulting in an encapsulation efficiency of nearly 85 %. The formulated VER-RM-LNC was stable for 6 months at 4 °C. VER encapsulated into LNC possessed enhanced stability and a reduced release profile. Menthol increased the cellular uptake and the permeability of VER-RM-LNC in the BBB model in vitro. In addition, the improved neuroprotective activity of VER through incubation with menthol and VER-RM-LNC was verified in the neurotoxic human brain microvascular endothelial cells model induced by Aβ_25-35.

Effect and molecular mechanism research of Astragalus membranaceus on inhibiting intestinal absorption of six alkaloids of Aconitum carmichaelii in spleen deficiency rats

Objective

To investigate the effect and the mechanism of Astragalus membranaceus (Huangqi in Chinese, HQ) extract on the intestinal absorption of six alkaloids of Aconitum carmichaelii (Fuzi in Chinese, FZ) in rats with spleen deficiency and provide novel insights into the application of HQ on modulating intestinal barrier.

Methods

Four-week-old male Sprague-Dawley rats were fed with Xiaochengqi Decoction to induce the spleen deficiency model for 40 d. Single-pass intestinal perfusion model were used to study the effects of HQ extract on the absorption of alkaloids. Protein expression and mRNA levels of MRP2 and BCRP and tight junction proteins (TJ, including Claudin-1, Occludin and ZO-1) were measured using Western blot and real-time PCR, respectively. The location and expression of TJ protein was also investigated by the immunofluorescence method.

Results

Compared with the normal group, the protein expression of MRP2, BCRP and TJ proteins in the model group were significantly down-regulated. After oral administration of HQ, the alkaloid absorption in intestinal villi was inhibited, MRP2, BCRP and TJ proteins were up-regulated, the green fluorescence staining of Claudin-1, Occludin, and ZO-1 was enhanced, and a thick layer of mucus was deposited on the surface of the epithelium of the intestinal cavity.

Conclusion

HQ as an intestinal barrier modulator improves the physiological changes of the intestinal environment of spleen deficiency to reduce the absorption of toxic components, leading to a decrease in the absorption of drug-like molecules.

Traditional Chinese herbal medicine Astragalus Radix and its effects on intestinal absorption of aconite alkaloids in rats

Objective

Methods

Results

Conclusion

Dietary Puerarin Supplementation Alleviates Oxidative Stress in the Small Intestines of Diquat-Challenged Piglets

Simple Summary

The oxidant stress which piglets suffer from during the weaning period has caused huge losses to the pig farm industry. It is important for scientists to find an effective way to alleviate the oxidant stress in weaned piglets. This study was designed to test the hypothesis that dietary puerarin supplementation alleviates oxidative stress in the small intestine of diquat-challenged piglets. Interestingly, dietary puerarin supplementation improved intestinal morphology, cell proliferation, barrier function, and increased Nrf2 and its downstream enzymes in diquat-challenged piglets, which shows that puerarin has potent protective effects against diquat-induced oxidative stress. These findings will be very beneficial to the pig industry, especially to the development of antibiotic-free diets, new anti-inflammatory drugs and the application of puerarin in piglets.

Abstract

This study was conducted to demonstrate that dietary puerarin supplementation alleviates oxidative stress in the small intestine of diquat-challenged piglets. The results showed that puerarin administration markedly alleviated diquat-induced intestinal injury, which was indicated by the improvement of intestinal morphology, cell proliferation and barrier function. One of the potential mechanisms responsible for this was the decrease in oxidative stress, as evidenced by the increase in activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in the small intestine. Puerarin increased the protein expression levels of NF-E2-related factor 2 (Nrf2) and its downstream enzymes, including heme oxygenase 1 (HO-1), glutamate–cysteine ligase catalytic and its modifier subunit (GCLc and GCLm) in the jejunal mucosa of diquat-induced piglets. Puerarin administration improved intestinal morphology, cell proliferation, and barrier function, and increased Nrf2 and its downstream enzymes. These findings indicate that the dietary supplementation of puerarin attenuates the oxidative stress involving Nrf2 signaling pathways in diquat-challenged piglets.

Natural Brain Penetration Enhancer-Modified Albumin Nanoparticles for Glioma Targeting Delivery

The unsatisfactory therapeutic outcome for glioma is mainly due to the poor blood-brain barrier (BBB) permeability and inefficient accumulation in the glioma area of chemotherapeutic agents. The existing drug delivery strategies can increase drug transport to the brain but are restricted by side effects and/or poor delivery efficiency. In this study, potent brain penetration enhancers were screened from the active components of aromatic resuscitation drugs used in traditional Chinese medicine. A novel glioma-targeting system based on enhancer-modified albumin nanoparticles was developed to safely and efficiently deliver drugs to the glioma regions in the brain. The nanoparticles improved the transport of nanoparticles across brain capillary endothelial cell (BCEC) monolayer by increasing endocytosis in endothelial cells and causing BBB disruption. In vivo imaging studies demonstrated that the systems could enter the brain and subsequently accumulate in glioma cells with a much higher targeting efficiency than that of transferrin-modified albumin nanoparticles. Of note, the nanoparticles could be captured and penetrate through endothelial cells fenestrae in pineal gland, which is suggestive of an effective way to deliver a nanosystem to the brain by bypassing the BBB. The nanoparticles showed good biocompatibility and negligible cytotoxicity. The results reveal an efficient and safe strategy for brain drug delivery in glioma therapy.