Immunomodulatory effect of camellia oil (Camellia oleifera Abel.) on CD19+ B cells enrichment and IL-10 production in BALB/c mice

[Display omitted] •Oleic acid (77.98%) was abundant in camellia oil (Camellia oleifera Abel.).•Camellia oil significantly increased phagocytosis in macrophages.•IL-10 was significantly induced by camellia oil treatment in primary splenocytes.•Camellia oil significantly enriched the CD19+ B cell population in BALB/c mice. Camellia oil (Camellia oleifera Abel.) has anti-inflammatory, antioxidant, and microbiota-modulating abilities, but little is known about the effects of camellia oil on immune cell immunomodulation. This study aimed to evaluate the immunomodulatory ability of camellia oil. Firstly, oleic acid (77.98%) rich and antioxidant characteristics were found in camellia oil. Besides, camellia oil significantly increased phagocytosis in RAW 264.7 macrophages and primary peritoneal macrophages, respectively. Nitric oxide (NO) production was reduced in camellia oil-treated RAW 264.7 cells and BALB/c mice. Additionally, interleukin-10 (IL-10) was significantly induced by camellia oil treatment in primary splenocytes. Interestingly, IL-10-producing splenic macrophages have been demonstrated to promote B cell proliferation. Noteworthily, this study provided compelling evidence that administration of camellia oil significantly enriched the cluster of differentiation 19 positive (CD19+) B cell population in BALB/c mice. In conclusion, the data demonstrated that oleic acid-rich camellia oil may significantly induce the CD19+ humoral immune response.