Screening Of A High-quality Cordyceps Militaris Strain MF27 With Anti-cancer Activity On HepG2 Cells

This study aimed to screen out a high-quality Cordyceps militaris strain with anti-cancer activity on HepG2 cells.First,22 strains were collected from different sources,and the strains were identified of distinctness by ITS sequence and antagonistic experiments.Then,comparing the color changing ability,mycelial growth rate,mycelium biomass,fruit body yield and cordycepin content to preliminary screening of strains,and comparing the anti-cancer activity on HepG2 cells of mycelium ethanol extract by MTT method to further screen a high-quality Cordyceps militaris strain.Finally,further compare high-quality Cordyceps militaris strain with other cordycipitoid fungal on HepG2 cell inhibition activity,which provided theoretical basis for the popularization and application of high quality strains.The main research contents and results are as follows:(1)According to the ITS sequence homology comparison and phylogenetic tree analysis,it was confirmed that the 22 strains collected were all Cordyceps militaris,but the tested strains had almost the same developmental status on the phylogenetic tree,showing the genetic relationship very close,it is impossible to distinguish the "allogeneic"phenomenon.(2)Differentiating the tested strains with the ITS sequence mapping split network and antagonistic assays.The results showed that 22 strains of Cordyceps militaris had some differences in their ITS sequences,and there were antagonistic reactions among the strains,indicating there was a genetic difference between Cordyceps militaris strains,and there was no"allogeneic" phenomenon among strains.(3)By comparing the strains’ ability of color changing,mycelial growth rate,biomass and fruiting body yield,it was found that the strains of MF27 performed well,and the yield of biomass and fruit body was higher than other strains.The average biomass was 1.273±0.185 g/100mL,the average fruit body yield was 45.638± 11.354 g/bottle,and the biological efficiency was as high as 97.1%.(4)Compare the fermented mycelial cordycepin content of the tested strains and the activity of ethanol extract against HepG2 cells,and found that MF27 not only has a higher mycelial cordycepin content(1.53±0.47 mg/g)than other strains,but also strong in anti-HepG2 cell activity,IC50 is 48.06 μg/mL.(5)By comparing 22 strains of Cordyceps militaris,MF27 was found to be a high-quality strain with high anti-hepatoma activity.This study further compared the anti-HepG2 activity of MF27 and other cordycipitoid fungal strains.The results showed that the MF27 strain of Cordyceps militaris ethanol extract mycelial compared to Isaria cicadae strains(MF11,MF12,MF13),Isaria tenuipes strains(MF7,MF9,MF14),Beauveria bassiana strains(MF10),Paecilomyces hepialid(Jinshuibao capsule)and Hirsutella sinensis(Bailing capsule),had lower IC50 and higher activity in inhibiting HepG2 cells.In this study,a high-quality Cordyceps militaris strain MF27 were screened.which not only for higher fruiting body yield,cordycepin content,and anti-HepG2 cell activity than other tested Cordyceps militaris strains,but also more resistant to HepG2 cells than Hirsutella sinensis(Bailing capsule)and some other cordycipitoid fungal strains,or it can be used as a potential substitute for Cordyceps sinensis with good development and application value.