In a study by Lui et al., it was found that low concentrations of garlic oil-led the majority of T-helper cells to respond toward the Th1 type. At high concentrations of garlic oil, T-helper cells were more oriented toward the Th2 type. However, a study from Zamani et. Al demonstrated that in rats, garlic oil oriented T-helper cells more toward the Th2 type by increasing IL-4 production in the spleen blood cells.