OBJECTIVE: To explore the effects of Eriodictyol to the growth, apoptosis and oxidative stress of Burkitt lymphoma (BL) cells and phosphorylation of protein kinase B (AKT) in children. METHODS: The effects of Eriodictyol (0, 1.25, 2.5, 5, 10, 20, 40, 80, 160, 320 μmol/L) to viability of BL cell line DG-75 cells were detected by CCK-8. The effects of Eriodictyol (0, 10, 20, 40 μmol/L) to the proliferation activity of DG-75, apoptosis rate, levels of apoptosis-related proteins, oxidative stress indexes ［superoxide dismutase (SOD), malondialdehyde (MDA)］, mitochondrial membrane potential (MMP) and phosphorylation level of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycinm (mTOR) were detected by clony formation assay and Wester blot. RESULTS: When the treatment concentration of Eriodictyol was 20 μmol/L, the proliferation activity of the cells was decreased (P<0.05). The concentrations at 10, 20, 40 μmol/L were selected for subsequent experiments. Compared with 0 μmol/L Eriodictyol, the proliferation activity of DG-75, SOD activity, MMP, phosphorylation levels of PI3K, AKT and mTOR in 20 and 40 μmol/L Eriodictyol treatment groups were significantly decreased (P<0.05), while cells apoptosis rate, Cleaved-Caspase-3/Caspase-3, Bax/Bcl-2 and MDA level were significantly increased (P<0.05). CONCLUSION Eriodictyol may promote the mitochondrial apoptosis pathway by inhibiting the abnormal activation of PI3K/AKT/mTOR to reduce the proliferation activity of DG-75, and inhibit oxidative stress response to increase the apoptosis rate and play anti-tumor roles.
Apoptosis ; Flavanones ; Phosphatidylinositol 3-Kinases/metabolism* ; Signal Transduction

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.
COVID-19 ; Cohort Studies ; Contact Tracing ; Humans ; Incidence ; Prospective Studies