Quality of moxa with different leaf-to-moxa ratios based on correlation analysis of thermogravimetric properties, cellulose content, and microscopic characteristics of non-secretory trichomes / 中国中药杂志

ABSTRACT

The quality of moxa is a key factor affecting the efficacy of moxibustion. Traditional moxa grades are evaluated by the leaf-to-moxa ratio, but there is a lack of support from scientific data. Scanning electron microscopy(SEM), Image Pro Plus, Van Soest method, and stimultaneous thermal analysis(TGA/DSC) were used to characterize the scientific implication of the combustion differences between moxa with different leaf-to-moxa ratios(processed by crusher). The results showed that the median lengths from non-secretory trichomes(NSTs) of natural NSTs and moxa with leaf-to-moxa ratios of 3∶1, 5∶1, 10∶1, and 15∶1 were 542.46, 303.24, 291.18, 220.69, and 170.61 μm, respectively. The cellulose content of moxa increased significantly(P<0.05) with the increase in leaf-to-moxa ratio and the combustion parameters(T_i, t_i, D_i, C,-R_p,-R_v, S, D_b, and J_(total)) all showed an increasing trend. The correlation results showed that the burning properties of moxa(T_i,-R_v, t_i, and J_2) were significantly and positively correlated with cellulose content. NSTs with a length of 1-200 μm were significantly and positively correlated with J_2. NSTs with a length of 200-600 μm were significantly and positively correlated with J_1, T_(peak2), T_(peak1), and-R_v, and negatively correlated with J_(total), T_b, and t_b. As the leaf-to-moxa ratio increases, the NSTs in the moxa become shorter and the cellulose content increases, which is more conducive to ignition performance, heat release, and a milder, longer-lasting burn. The "NSTs-cellulose-TGA/DSC" quantitative evaluation method scientifically reveals the scientific connotation of the combustion of moxa with different leaf-to-moxa ratios and provides a scientific basis for the establishment of quality evaluation methods for moxa with different leaf-to-moxa ratios.