Preparation and in vivo Distribution of Essential Oil from Alpinia zerumbet Fructus Encapsulated Nanoemulsions / 中国实验方剂学杂志

ObjectiveTo prepare oral nanoemulsions encapsulating essential oil from Alpinia zerumbet fructus（EOFAZ） and to investigate its pro-absorption effect in vitro and distribution in vivo. MethodThe proteoglycan conjugate polysaccharides of vinegar-processed Bupleuri Radix-bovine serum albumin（VBCP-BSA） was prepared by Maillard reaction of VBCP and BSA. Taking VBCP-BSA as emulsifier， vitamin B12（VB12） as absorption enhancer， and medium chain triglycerides mixed with EOFAZ as oil phase， the nanoemulsions loaded with EOFAZ was prepared by high energy emulsification method. The particle size， particle size distribution， surface Zeta potential， EOFAZ content and appearance and morphology of the nanoemulsions were characterized， and fluorescein tracer method was used to investigate the absorption effect of fluorescein-labeled EOFAZ nanoemulsions in vitro and their distribution in vivo. ResultVBCP-BSA was formed by Maillard reaction for 48 h with high grafting rate. Using VBCP-BSA as emulsifier， the homogeneous pink nanoemulsions was prepared and denoted as EOFAZ@VBCP-BSA/VB12. The particle size of the nanoemulsions was less than 100 nm and the particle size distribution was uniform. The surface of the nanoemulsions was a weak negative charge， and the shape was spherical. The encapsulation rate of the nanoemulsions for EOFAZ was greater than 80%， which had a good absorption effect in vitro and could enhance liver accumulation after oral administration. ConclusionThe designed proteoglycan nanoemulsions can effectively load EOFAZ， promote oral absorption and enhance liver distribution， which can provide experimental basis for the development of oral EOFAZ liver protection preparations.

Fabrication of a protein-dextran conjugates formed oral nanoemulsion and its application to deliver the essential oil from Alpinia zerumbet Fructus.

The injury of vascular endothelial cells caused by high glucose (HG) is one of the driving factors of vascular complications of diabetes. Oral administration is the most common route of administration for the treatment of diabetes and its vascular complications. Essential oil extracts from Chinese medicine possess potential therapeutic effects on vascular endothelial injury. However, low solubility and volatility of essential oils generally result in poor oral absorption. Development of nanocarriers for essential oils is a promising strategy to overcome the physiological barriers of oral absorption. In this study, a nanoemulsion composed of bovine serum albumin (BSA)-dextran sulfate (DS) conjugate and sodium deoxycholate (SD) was constructed. The nanoemulsions were verified with promoted oral absorption and prolonged circulation time. After the primary evaluation of the nanoemulsion, essential oil from Alpinia zerumbet Fructus (EOFAZ)-loaded nanoemulsion (denoted as EOFAZ@BD5/S) was prepared and characterized. Compared to the free EOFAZ, EOFAZ@BD5/S increased the protective effects on HG-induced HUVEC injury in vitro and ameliorative effects on the vascular endothelium disorder and tunica media fibroelastosis in a T2DM mouse model. Collectively, this study provides a nanoemulsion for the oral delivery of essential oils, which holds strong promise in the treatment of diabetes-induced vascular endothelial injury.

Inhibitory Effect of Essential Oil from Fructus Alpinia zerumbet on Endothelial-to-mesenchymal Transition Induced by High Glucose via Nrf2/Notch1 Signaling Pathway / 中国实验方剂学杂志

Objective:To investigate the inhibitory effect and the possible mechanism of essential oil from fructus Alpinia zerumbet （EOFAZ） on endothelial-to-mesenchymal transition （EndMT） induced by high glucose （HG）. Method:Human umbilical vein endothelial cells （HUVECs） was cultured in vitro to analyze the pharmacodynamic effects of EOFAZ on EndMT and oxidative stress damage induced by HG. The experiment was set the blank group， HG group （35 mmol·L-1）， EOFAZ low dose group （1 μg·L-1） and EOFAZ high dose group （4 μg·L-1）. After EOFAZ intervention for 2 h， HG was added to incubate for 72 h in order to establish EndMT cell model. Western blot was used to detect the protein expression of vimentin and platelet endothelial cell adhesion molecule （CD31）. Angiogenesis experiment was used to detect the ability of cell migration ability in order to analyze the effect of EOFAZ on EndMT. The changes of reactive oxygen species （ROS） levels were detected by 2'，7'-dichlorodihydrofluorescein diacetate （DCFH-DA） fluorescence probe and the contents of malondialdehyde （MDA）， superoxide dismutase （SOD） and catalase （CAT） in cells were detected by the kit method to analyze the effect of EOFAZ on oxidative stress. Western blot was used to detect the protein expression levels of nuclear transcription factor E2 related factor 2 （Nrf2） and Notch1. The overexpression of Nrf2 was achieved by adenovirus （AD） transfection and the mechanism of EOFAZ inhibiting EndMT was further analyzed. The experiment was set the blank group， HG group （35 mmol·L-1）， AD-Nrf2 group， EOFAZ group （4 μg·L-1）， AD-Nrf2+EOFAZ group （4 μg·L-1）. The cells were infected with recombinant adenovirus overexpression plasmid of Nrf2 gene for 6 h， then replaced with normal medium for 24 h. After EOFAZ intervention for 2 h， HG was added to co-incubate for 72 h to induce EndMT. Western blot was used to detect the protein expressions of Nrf2， CD31， vimentin， Notch1 and Snail. Result:Compared with the HG group， after treatment with EOFAZ， the protein expression of CD31 was significantly up-regulated （P<0.05）， the protein expression of vimentin was significantly down-regulated （P<0.01）， the ability of cell migration was decreased （P<0.01）， and the contents of ROS and MDA were decreased （P<0.05， P<0.01）， the levels of CAT and SOD were increased （P<0.01）. In addition， EOFAZ could significantly up-regulate the protein expression of antioxidant signal Nrf2 （P<0.01） and down-regulate the protein expression of Notch1 （P<0.01）. High expression of Nrf2 was achieved by stable AD transfection into HUVECs. The results of Western blot showed that， compared with the HG group， the protein expression levels of Nrf2 and CD31 in each treatment group were significantly increased （P<0.01）， while the protein expression levels of vimentin， Notch1 and Snail were down-regulated （P<0.01）. At the same time， compared with the AD-Nrf2 group， the AD-Nrf2+EOFAZ group could further up-regulate the protein expressions of Nrf2 and CD31 （P<0.05， P<0.01）， while decrease the protein expression levels of vimentin， Notch1 and Snail （P<0.01）. Conclusion:EOFAZ ameliorates oxidative stress injury of vascular endothelial cells induced by HG and inhibits EndMT， which is related to Nrf2/Notch1 signaling pathway.