Objective To explore the effects of different processing methods on the expectorant and antitussive effects of Zhuli (Bambusae Succus, BS). Methods The chemical composition differences of BS prepared by different processing methods were analyzed by GC-MS technology, and a comprehensive evaluation was conducted using principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) to screen for differential and specific components. The microscopic characteristics of bamboo before and after processing were further compared and analyzed. A chronic obstructive pulmonary disease (COPD) mouse model was established to evaluate the expectorant and antitussive effects of BS prepared by different processing methods. Results This study determined the relative contents of guaiacol and syringol and the overall proportion of phenolic components in BS prepared by three processing methods through GC-MS analysis. In the fire treatment method, the proportions were 4.68%, 2.22%, and 14.93% respectively; in the dry distillation method, they were 5.98%, 6.96%, and 24.77% respectively; in the water boiling method, the overall proportion of phenolic components was 3.65%, and the relative contents of the two components were both below the detection limit. PCA and OPLS-DA indicated that the three processing methods had certain differences in chemical composition and screened out 13 characteristic differential components with distinguishing significance, including 2-methylpheno, creosol, eugenol, 2-methoxy-4-propyl-Phenol, (E)-isoeugenol, vanillin, 2-propenal, 2-methoxy-5-methylphenol, 4-ethylguaiacol, maltol, oleamide, 3, 5-dimethoxy-4-hydroxybenzaldehyde, pyrrole-2-carboxaldehyde. Cluster analysis showed that the components of the fire processing and dry distillation methods were relatively similar, while both were significantly different from the water boiling method. Microscopic structure observation revealed that the bamboo structure corresponding to the BS prepared by the water boiling method was similar to that of fresh bamboo, while the fire processing and dry distillation methods had more significant changes in bamboo structure. Pharmacological experiments showed that BS prepared by the three methods all exhibited varying degrees of cough-suppressing and expectorant effects, among which the dry distillation method significantly prolonged the cough latency period (P < 0.05) and increased phenol red excretion (P < 0.01). Conclusion Compared with the fire processing and water boiling methods, the dry distillation method can more effectively retain active and convert components such as guaiacol and syringol. Mechanism studies indicated that the water boiling method, due to insufficient heating temperature, was unable to thermally decompose lignin to generate phenolic acid components, resulting in significant differences in chemical composition compared to the traditional fire processing and dry distillation methods, leading to distinct quality characteristics among the three approaches. The efficacy experiments showed that all three methods exhibited expectorant and antitussive effects to varying degrees; among them, the dry distillation method had a more significant effect in prolonging the cough latency period and increasing the phenol red excretion volume. By studying the effects of different processing techniques on the quality of BS and its efficacy in relieving cough and expectorating phlegm, this research provides a theoretical basis for its clinical application, the development of new dosage forms, and the scientific connotation of dry distillation processing.

Bambusae Succus  /  dry distillation  /  material basis  /  antitussive, expectorant  /  principal component analysis  /  orthogonal partial least squares-discriminant analysis  /  chronic obstructive pulmonary disease  /  guaiacol  /  syringol  /  phenolic components