Effects of Citrus Aurantium leaves extract on cytokines levels in peripheral blood mononuclear cells of BALB/C MICE

Abstract

Citrus aurantium L., commonly known as sour orange, has long been used in traditional medicine to treat a wide panel of illnesses. Different parts of the fruit, used in distinct ways, are incorporated in day-to-day life. However, some parts remain not used as often as the others e.g., the leaves. This study is focused on the characterization of bigarade leaves extract from several aspects. The primary goal is to add value to bigarade leaves, transforming them from a neglected byproduct into a valuable resource with a wide range of practical uses. The leaves of Citrus aurantium L. contain a variety of secondary metabolites with notable antibacterial and antioxidant effects. Additionally, it has been shown that phenolic compounds have a significant influence on the regulation of immune cells and the generation of pro- and anti-inflammatory cytokines. However, despite their potential immunomodulatory effects, little is known about the precise effects of Citrus aurantium L. leaves extract on the immune system. Therefore, our primary goal was to assess how Citrus aurantium leaves powder extract affects the levels of several cytokines in peripheral blood mononuclear cells (PBMCs) from BALB/c mice. In our study, we found that Citrus aurantium L. leaves extract has not upregulated the proinflammatory cytokines released by PBMCs. Nonetheless, other anti-inflammatory cytokines were upregulated in a dose-dependent manner. Downregulation of IFN- γ and IL-17 suggests the fact that TH1 and TH17 cells differentiation was reduced. On the other hand, the upregulation of IL-4 and IL-10 in a dose-dependent manner suggests favoring TH2 and Treg cell differentiation. At moderate doses, the leaves extract did not interfere with the proliferation or the viability of PBMCs. Citrus aurantium L. leaves extract has potentially the ability to upregulate anti-inflammatory cytokines with a trend to reduce proinflammatory cytokines mainly at a concentration of 50 μg/ml. This study opens a new horizon in implementing the use of Citrus aurantium leaves extract in clinical applications.