To study the effects of superfine grinding treatment on the composition and efficacy of loquat branches.

After the loquat branches were superfine grinding treated, the contents of total phenols, total flavonoids, polysaccharides, ursolic acid, oleanolic acid in the extracts from loquat branches with different particle sizes were detected by spectrophotometry and high-performance liquid chromatography. The in vitro antioxidant capacity of extracts from superfine loquat branches was evaluated by DPPH, ABTS free radical scavenging assay and FRAP assay. SPF-grade male Kunming mice were randomly divided into blank/model control group, drug group, loquat leaf control group, and low, medium, and high dosage of superfine loquat branches according to their body weights. The expectorant effect of extracts from superfine loquat branches was evaluated by phenol red excretion assay, and the antitussive effect of extracts from superfine loquat branches was evaluated by ammonia-induced cough assay.

The total phenol, total flavonoid and oleanolic acid contents of the three particle size loquat branch groups were higher than those of the branch control group (P<0.05, P<0.01), the total phenol and total flavonoid contents of the 220-mesh and 400-mesh loquat branch groups were higher than those of the leaf control group (P<0.05), and the ursolic acid contents of the 220-mesh and 400-mesh loquat branch groups were higher than those of the branch control group (P<0.01). In the in vitro experiment, the DPPH IC₅₀ and ABTS IC₅₀ of the three particle size loquat branch groups were lower than that of the branch control group (P<0.05), and the FRAP value was higher than that of the branch control group (P<0.05), and the DPPH IC50 and ABTS IC50 of the 200 mesh and 400 mesh loquat branch groups were lower than that of the leaf control group (P<0.05), and the FRAP value was higher than that of the leaf control group (P <0.05). In the phenol red excretion experiment, the phenol red excretion was significantly elevated in mice in the high-dose superfine loquat branch group (P<0.05). In the ammonia-induced cough experiment, both medium-dose and high-dose superfine loquat branches groups prolonged the latency period of coughing and the number of coughs in mice (P<0.05).

Appropriate superfine grinding treatment can increase the content of the efficacy components of loquat branches, enhance their antioxidant effect, and at the same time, they have certain expectorant and antitussive effects.