The invention discloses enzymolysis polypeptide and use thereof in preparation of a
medicine for treating
lung adenocarcinoma. The enzymolysis polypeptide is prepared from cicada by the following steps: cleaning the cicada,
mincing the cicada into
meat paste, adding Protamex compound
protease for enzymolysis, wherein the enzymolysis conditions are as follows: the pH value is 6.8-7.2, the enzymolysis temperature is 42-47 DEG C, and the enzymolysis time is 7-9 hours; after the enzymolysis is finished, heating to inactivate the compound
protease, and cooling to the
room temperature; after the cooling, carrying out
centrifugation at a rotation speed of 8000rpm-10000rpm for 20-30 minutes, extracting supernatant, and carrying out
freeze drying, so as to obtain freeze-dried
powder; dissolving the freeze-dried
powder with
ultrapure water, separating obtained enzymolysis polypeptide by virtue of
ultrafiltration membranes with different molecular weight
cut-offs, and carrying out freeze-
drying on components obtained through
ultrafiltration, so as to obtain enzymolysis polypeptides with different molecular weights. According to the enzymolysis polypeptide, the proliferation of A549 cells of the
lung adenocarcinoma can be restrained, the
apoptosis of the A549 cells can be promoted, the growth of nude mice transplanted tumors of the A549 cells of the
lung adenocarcinoma is remarkably inhibited, and
drug resistance of the A549 cells of the lung adenocarcinoma to the enzymolysis polypeptide is unlikely to be produced; and
toxicology researches prove that the enzymolysis polypeptide has no toxic and side effects.