Anti‐allergic effect of vitamin C through inhibiting degranulation and regulating TH1/TH2 cell polarization

BACKGROUND Food allergy has become a global public health problem. This study aimed to explore the possible anti‐allergic effect of vitamin C (VC). A rat basophilic leukemia (RBL)‐2H3 cell degranulation model was used to assess the effect of VC on degranulation in vitro , and an ovalbumin (OVA)‐induced BALB/c mouse allergy model was used to assess the anti‐allergy effect of VC in vivo . RESULTS In vitro , VC significantly attenuated the release of β‐hexosaminidase, tryptase and histamine, and also reduced cytokine production (interleukins 4 and 6, tumor necrosis factor α) significantly ( P < 0.05), with the inhibitory effect demonstrating a positive correlation with VC dose. In vivo , compared with the OVA group, the levels of serum immunoglobulins E and G 1 of the VC low‐dose (VCL) group (50 mg kg −1 ) and high‐dose (VCH) group (200 mg·kg −1 ) were significantly reduced ( P < 0.05). Furthermore, the plasma histamine level was also significantly decreased ( P < 0.05). Moreover, T H 2 cell polarization in mice of the VCL and VCH groups was significantly inhibited ( P < 0.05), promoting the T H 1/T H 2 cell polarization balance. Additionally, VC treatment enhanced the expression of CD80 ( P < 0.05) in spleen and small intestine tissues, while significantly inhibiting the expression of CD86 ( P < 0.05); notably, high‐dose VC treatment was more effective. CONCLUSION VC exerted an anti‐allergic effect through inhibiting degranulation and regulating T H 1/T H 2 cell polarization balance.