Phase Preparation of Xiao-chai-hu Decoction and its Pharmacodynamics of Acute Liver Injury

BACKGROUND: Self-emulsifying nano-phase of traditional Chinese medicine are a research hotspot. Xiao-Chai-Hu decoction is a commonly used compound decoction in clinical practice, which is of great research significance. The aim of this study was to isolate and characterize the self-emulsifying nano-phase and other phases of Xiao-Chai-Hu decoction, and to study the effects of each phase on acute liver injury. METHODS: The liquid medicine was prepared employing centrifugation followed by dialysis. Single- factor investigation methodology was utilized to optimize the preparation parameters for both phases. Characterization of the formulated phase involved analyses such as surface morphology assessment, measurement of nanoparticle size and Zeta potential using an analyzer, observation of the Tyndall effect, conducting diffusion and dilution tests, examination under a microscope, and structural visualization via transmission electron microscopy (TEM). Furthermore, an acute liver injury model was established in rats through intraperitoneal injection of D-Galactosamine (D-Gal- N). To assess hepatic function and oxidative stress status, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content in liver tissue were quantified. The liver coefficients for each group were calculated as an additional parameter. For histopathological evaluation, liver tissue sections from the experimental group were stained with Hematoxylin and Eosin (H&E) and examined microscopically under light conditions. These revisions aim to enhance clarity, correct minor grammatical errors (such as capitalization of "HE" to "H&E"), and ensure a smoother flow of information without altering the scientific content of your original text. RESULTS: Successful establishment and separation of four distinct phases were achieved, including the self-emulsifying nano-phase, precipitation phase, suspension phase, and true solution phase. The self-emulsifying nano-phase was characterized as spherical particles with an average diameter of approximately 100 nm. Pharmacodynamic assessments revealed that both Xiao-Chai-Hu decoction and its self-emulsifying nano-phase significantly reduced liver coefficients and alanine aminotransferase (ALT) levels compared to controls (P<0.05). However, no statistically significant differences were observed in regards to aspartate aminotransferase (AST) concentrations, malondialdehyde (MDA) content, or superoxide dismutase (SOD) activity between the treatment groups and control (P>0.05). These findings indicate that both Xiao-Chai-Hu decoction and its self-emulsifying nano-formulation ameliorated D-GalN-induced acute liver injury, albeit without statistically distinguishable efficacy between them (P>0.05). CONCLUSION: The presence of a self-emulsifying nano-phase within Xiao-Chai-Hu decoction is confirmed, and this nano-phase emerges as a therapeutically efficacious component in mitigating acute liver injury.