RESUMO
ObjectiveTo investigate the effect of microemulsion on the distribution of index components in different phases of Zexietang extract based on high performance liquid chromatography（HPLC） and phase separation process. MethodParticle size meter and transmission electron microscope were used to characterize the colloidal particles in blank microemulsion， aqueous extract of Zexietang and microemulsion extract of Zexietang. The phase separation process was established by high-speed centrifugation and dialysis， and based on this process， the aqueous extract and microemulsion extract of Zexietang were separated into the true solution phase， the colloidal phase and the precipitation phase， respectively. The contents of six components， including atractylenolide Ⅲ， atractylenolide Ⅱ， 23-acetyl alisol C， alisol A， alisol B and alisol B 23-acetate， were determined by HPLC with the mobile phase of water（A）-acetonitrile（B） for gradient elution（0-5 min， 40%-43%B； 5-20 min， 43%-45%B； 20-45 min. 45%-60%B； 45-75 min， 60%-80%B）. The solubility of the index components in water and microemulsion was determined by saturation solubility method. ResultThe colloidal particles in the aqueous extract， microemulsion extract and blank microemulsion were all spherical， and the particle size， polydispersity index（PDI） and Zeta potential of the colloidal particles were in the order of aqueous extract >microemulsion extract >blank microemulsion. The results of phase separation showed that the colloidal phase and the true solution phase could be completely separated by dialysis for 2.5 h， and the phase separation process was tested to be stable and feasible. Compared with the aqueous extract of Zexietang， the use of microemulsion as an extraction solvent could increase the contents of atractylenolide Ⅲ， 23-acetyl alisol C， atractylenolide Ⅱ ， alisol A， alisol B and alisol B 23-acetate by 3.75， 6.82， 35.47， 10.66， 35.41， 27.75-fold， and could increase the extraction efficiencies of the latter five constituents by 2.03， 1.15， 1.70， 6.43， 5.53 times. The solubility test showed that the microemulsion could significantly improve the solubility of atractylenolide Ⅱ， alisol A， alisol B and alisol B 23-acetate， but it had less effect on the solubility of atractylenolide Ⅲ and 23-acetyl alisol C. ConclusionMicroemulsion can improve the extraction efficiency and increase the distribution of the index components in the colloidal phase state of Zexietang to different degrees， providing a reference for the feasibility of microemulsion as an extraction solvent for traditional Chinese medicine.
RESUMO
Zexietang is a Chinese herbal compound prescription with a long history， which consists of Rhizoma alismatis and Atractylodes macrocephala. Zexietang comes from "Synopsis of Golden Chamber"， as "there is a drink under the heart， and its people are bitter and dizzy". Zexietang has the effect of removing water from drinking water and invigorating spleen for diuresis. Modern pharmacological studies have shown that its lipid-lowering and anti-inflammatory effects are very significant. It can be used to treat hyperlipidemia， anti-atherosclerosis and non-alcoholic fatty liver disease. With the continuous development of molecular biology， the research on the pharmacological effects of Zexietang， extracts and their monomers has deepened to the molecular level gradually， and the relevant mechanism of action has also been continuously elucidated. In terms of lipid-lowering effect of Zexietang， the levels of cytokines or receptors such as 3-hydroxy-3-methyl glutaryl coenzyme A reductase （HMGCR）， cholesterol 7α-hydroxylase （CYP7A1）， and liver X receptors （LXR） are affected. It is widely involved in adenosine 5'-monophosphate-activated protein kinase （AMPK） and peroxisome proliferators-activated receptors （PPAR） pathways， while Zexietang's anti-inflammatory effect mainly affects inflammatory factors such as interleukins （IL） and tumor necrosis factors （TNF）， and simultaneously nuclear factor κB （NF-κB）， toll-like receptors （TLR） and other cytokines or receptor-related pathways. In order to promote the further research and clinical application of Zexietang and contribute to the development of modernization of traditional Chinese medicine， the studies of the past 15 years on molecular mechanism of the lipid-lowering and anti-inflammatory effect of Zexietang， Alisma and Atractylodes extract as well as their monomer components were reviewed.
RESUMO
Zexietang is derived from Jingui Yaolue （《金匮要略》）， which is composed of Alismatis Rhizoma and Atractylodis Macrocephalae Rhizoma， and has the effect of inducing diuresis and invigorating the spleen to produce water. Compared with western medicine in the treatment of related diseases， Zexietang can not only improve the curative effect， but also reduce the occurrence of adverse reactions， so as to achieve long-term stable administration. The authors sorted out and analyzed the chemical composition， pharmacological effect and clinical application of Zexietang in recent years. It was found that the main active components of Zexietang were alismol A and B， 23-acetyl-alismol B and C， atractylenolides （atractylenolide Ⅰ， Ⅱ， Ⅲ） and polysaccharides. Pharmacological experiments showed that they had diuretic， hypolipidemic， anti-inflammatory and others. And it can be used in the treatment of hypertension， hyperlipidemia， vertigo， cerebral vascular insufficiency and other diseases combined with other Chinese materia medica， and the curative effect is obvious. By summarizing the research status of Zexietang in recent years， its active components and pharmacological mechanism can be further clarified， which provides the basis for the clinical application of Zexietang and guides the direction of its further research.