Optimization of Allium sativum Solvent Extraction for the Inhibition of in Vitro Growth of Helicobacter Pylori

Abstract

Helicobacter pylori (Hp) is the bacterium responsible for serious gastric diseases such as ulcers and cancer. The work described here involved the study of the inhibitory power of Allium sativum extracts against the in vitro growth of Hp (Hp ivg). We used purple garlic of the "Las Pedroñeras" variety for this study. The effects of two different extraction methods (Soxhlet, stirred tank extractor) and four solvents with different characteristics (water, acetone, ethanol, and hexane) were investigated in terms of the efficiency of the extraction process. Satisfactory results were obtained in most cases in the activity tests, indicating that different extracts gave rise to good inhibitory activity against Hp ivg. The extracts that showed the highest bacteriostatic activities were selected to evaluate the influence of the most important operation variables on the extraction yield: stirring speed, operation time, garlic conditioning, and garlic storage time. The best results were obtained using ethanol and acetone as solvents in a stirred tank. The inhibitory powers of these extracts were compared to those shown by some commercial antibiotics used in the medical treatment of Hp infections. The results of this study show that garlic extracts produce levels of inhibition similar to those of the commercial materials. These extracts were also tested against other common bacteria, and equally satisfactory results were obtained. The research described here represents an important starting point in the fight against and/or prevention of peptic ulcers, as well as other pathologies associated with Hp infections such us gastric cancer. The extracted material can be used by direct application and involves a simple and economical extraction procedure that avoids isolation or purification techniques.

Utilização do óleo de alho e da amoxilina, metronidazol e omeprazol no controle de Helicobacter spp. em cães

“…Efeitos sinérgicos do extrato de alho com omeprazol in vitro sugerem que o seu uso, com o inibidor da bomba de prótons, pode ser indicado com sucesso (Cellini et al, 1996;O'Gara et al, 2000).…”

“…A terapia com alho resultou em redução da densidade de bactérias espiraladas no estômago de cães, diferente do que foi constatado por Ohta et al (1999), Sivam (2001) e Canizares et al (2002), em estudos experimentais realizados in vitro.…”

“…Estudos realizados por Canizares et al (2002), nos quais foram comparadas as capacidades inibitórias do extrato de alho e de alguns antibióticos usados no tratamento de infecções por H. pylori, sugeriram que o extrato de alho possui graus de inibição in vitro similar ao desses antibióticos.…”

“…implicada como determinante etiológico de úlceras pépticas, sobretudo as duodenais (Canizares et al, 2002). Helicobacter spp.…”

“…Dessa forma, vários tratamentos alternativos têm sido propostos, tais como a utilização de óleo de alho, cuja atividade anti-H. pylori foi demonstrada por meio de estudos in vitro. (Cellini et al, 1996;Sivam et al, 1997;Canizares et al, 2004).…”