ABSTRACT
OBJECTIVE@#To investigate effects of benzo(a)pyrene (BaP) on expressions of insulin-degrading enzyme (IDE) and neprilysin (NEP) which have the ability to degrade β-amyloid (Aβ) in neuroglia cells.@*METHODS@#Primary mix-neuroglia cells were cultured from newborn SD rats. After exposure to BaP, Aβ1-42 oligomer or Aβ1-42 fiber individually or jointly for 24 h, the cell survival rate was measured by cell counting kit-8 (CCK-8). Afterwards, the primary mix-neuroglia cells were divided randomly into six groups: Control group, BaP group (2.00 μmol/L), Aβ1-42 oligomer group (20.00 mg/L), BaP plus Aβ1-42 oligomer group, Aβ1-42 fiber group (20.00 mg/L) and BaP plus Aβ1-42 fiber group, of which BaP was pretreated for 12 h followed by cotreatment with different aggregated Aβ1-42. The expressions of IDE and NEP were measured by quantitative real-time polymerase chain reaction (qRT-PCR) for mRNA level and Western blotting for protein level.@*RESULTS@#The cell survival rate showed no significant differences after treatment with BaP (≤20.00 μmol/L), Aβ1-42 oligomer (20.00, 40.00 mg/L), Aβ1-42 fiber (20.00, 40.00 mg/L) or cotreatment with BaP and Aβ1-42 oligomer or BaP and Aβ1-42 fiber. Compared with the control group, expressions of IDE and NEP in BaP-treated alone group had no obvious change; however, exposure to Aβ1-42 oligomer alone significantly increased the mRNA and protein level of IDE (P<0.05), and the BaP pretreatment could significantly inhibit the up-regulated expressions of IDE by Aβ1-42 oligomer (P<0.05); on the other hand, exposure either to Aβ1-42 fiber alone or under the BaP pretreatment did not change the mRNA and protein level of IDE and NEP obviously.@*CONCLUSION@#On the premise of no significant change of cell survival rate, BaP pretreatment inhibited the up-regulated expressions of IDE in primary mixed neuroglia cells under cotreatment with Aβ oligomer, indicating that BaP may disturb degradation of Aβ oligomer and cause deposition of β-amyloid and further induce cognitive decline and acceleration of Alzheimer.
Subject(s)
Animals , Rats , Amyloid beta-Peptides , Benzo(a)pyrene , Blotting, Western , Insulysin/metabolism , Neprilysin/metabolism , Neuroglia/metabolism , Rats, Sprague-DawleyABSTRACT
A commonly used Chinese crude drug Allii Macrostemonis Bulbus has been shown to possess good anticancer activities and related properties such as antioxidation, nitrite scavenging, nitrosamine synthesis blocking and immune enhancement, and has been widely used as an effective auxiliary drug in the treatment of some malignant tumors. This paper systematically reviews the advances in the study of anticancer-related activities of Allii Macrostemonis Bulbus's various components such as raw juice, extracts, saponins, volatile oil, polysaccharides, nitrogen compounds, etc.