Comparative Study on Anti-Helicobacter pylori Effects of Licorice Roots Collected from Different Regions of Iran

Helicobacter pylori infection is common in gastrointestinal tract and lead to gastritis, peptic ulcer and finally stomach cancer. Many synthetic drugs are used to eradicate the bacteria but there are some problems in treatment due to drug resistance and frequent relapses of infection. Herbal drugs are very important in the case. Glycyrrhiza glabra is used for treatment of H. pylori infection. This plant grows in different regions of Iran, therefore, investigation of anti H. pylori effects of the plant collected from different growing area is important. The aim of this study is determination of MIC of licorice roots collected from different regions of Iran against H. pylori in order to introduce the best growing area of the plant. Roots of the plant were collected from Kerman, Kermanshah, Sirjan, Sarhadd (Fars province), Istahban (Fars province), Ghasredasht (Fars province), Najaf Abad (Isfahan province), Ganjnameh (Hamedan province), Ekbatan (Hamedan province), Mahabad, Khorram Abad and Ardabil and extracted by using ethanol 80%. MIC of each extract was determined against three clinical isolated strains of H. pylori which obtained during endoscopy procedure. The results showed that susceptibilities of three clinical isolated bacteria to the licorice extracts are different. Among the studied extracts, licorice roots collected from Ardabil showed the lowest MIC (at least: 5 ppm) and all strains were almost resistant to the extract from Mahabad. It is concluded that drug resistance is observed in herbals just like synthetic drugs. Moreover, in order to achieve best therapeutic results, before using an herbal preparation for treatment a disorder, growing area of a medicinal herb should be considered.