Effect of patchouli alcohol on acid resistance of Helicobacter pylori

LIAN Dawei; XU Yifei; FU Lijun; REN Wenkang; WEI Wenhui; ZHUANG Huiling; HUANG Ping; CAO Hongying

doi:10.3969/j.issn.1002-266X.2017.34.005

Abstract：Objective To investigate the effect of patchouli alcohol on acid resistance of Helicobater pylori (Hp) and its mechanism.Methods After Hp were cultured in vitro and identified, Hp were divided into 5 groups.The high-, medium-, and low-dose drug groups were added with 20, 10, and 5 mg/L patchouli alcohol;the positive control group was added with urea enzyme inhibitor AHA;the blank control group was added with the same amount of DMSO.Agar dilution method was used to detect the bacterial survival rates in the acidic (pH=1.0) and neutral (pH=7.0) conditions after 0.5 hour.We obtained the Hp urease protein A (UreA) , urease protein B (UreB), and urease protein G (UreG) by E.coli expression system, and mixed up UreA and UreB protein.Then, we took the UreA/UreB protein mixed solution to simulate the Ure maturation process and mixed the UreG protein monomer solution with the nickel ion (Ni2+) solution.The Ure activity was detected by Berthelot method to determine the Ure maturity.The concentration of Ni2+ was measured by atomic absorption spectrometry to determine the ability of UreG carrying Ni2+.Results In the neutral condition, there was no significant difference in the Hp colony forming units among the high-, medium-, and low-dose drug groups, positive control group, and blank control group.Compared with the blank control group, the Hp colony forming units of the high-, medium-, and low-dose drug groups and positive control group decreased in neutral conditions (all P<0.05), and the order was as follows: the high-dose drug group, positive control group < medium-dose drug group < low-dose drug group (all P<0.01).The urease activities of the high-, medium-, low-dose drug groups and the control group were 54.89％±11.47％, 63.99％±9.46％, 83.88％±11.81％, and 101.53％±2.55％;the concentrations of Ni2+ were (0.77±0.24), (0.80±0.22), (1.12±0.35), (1.56±0.42) μmol/L, and the order was as follows: the high-dose drug group, medium-dose drug group < low-dose drug group < control group (all P<0.01).Conclusions Patchouli alcohol can decrease the acid resistance of Hp, which may be associated with blocking the transmission pathway of Ni2+ and Ure''s maturation process and thus inhibiting Ure activity.