Anti-Allergic Effects of Myrciaria dubia (Camu-Camu) Fruit Extract by Inhibiting Histamine H1 and H4 Receptors and Histidine Decarboxylase in RBL-2H3 Cells

• Published in: Antioxidants 2021-12, Vol.11 (1), p.104
• Main Authors: Do, Nhung Quynh, Zheng, Shengdao, Oh, Sarang, Nguyen, Quynh T N, Fang, Minzhe, Kim, Minseon, Choi, Junhui, Kim, Myeong-Ju, Jeong, Jeehaeng, Yi, Tae-Hoo
• Format: Article
• Language: English
• Subjects: Allergies; anti-allergic effect; Antihistamines; Calcimycin; Calcium ionophores; camu-camu fruit extract; Cell culture; Chromatography; Degranulation; Dermatitis; Enzymes; Ethanol; Exocytosis; Fruits; Histamine; histamine H1 receptor; histamine H4 receptor; Histidine; Histidine decarboxylase; Inflammation; Kinases; KLF4 protein; MAP kinase; Mast cells; Myrciaria dubia; Natural products; NF-AT protein; Oxidants; Oxidative stress; Protein kinase; Proteins; RBL-2H3 cells; Sp1 protein; Transcription factors
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox11010104

Although (camu-camu) has been shown to exert anti-oxidant and anti-inflammatory effects in both in vitro and in vivo studies, its use in allergic responses has not been elucidated. In the present study, the anti-allergic effect of 70% ethanol camu-camu fruit extract was tested on calcium ionophore (A23187)-induced allergies in RBL-2H3 cells. The RBL-2H3 cells were induced with 100 nM A23187 for 6 h, followed by a 1 h camu-camu fruit extract treatment. A23187 sanitization exacerbated mast cell degranulation; however, camu-camu fruit extract decreased the release of histamine and β-hexosaminidase, which are considered as key biomarkers in cell degranulation. Camu-camu fruit extract inhibited cell exocytosis by regulating the calcium/nuclear factor of activated T cell (NFAT) signaling. By downregulating the activation of mitogen-activated protein kinase (MAPK) signaling, camu-camu fruit extract hindered the activation of both histamine H1 and H4 receptors and inhibited histidine decarboxylase (HDC) expression by mediating its transcription factors KLF4/SP1 and GATA2/MITF. In A23187-induced ROS overproduction, camu-camu fruit extract activated nuclear factor erythroid-2-related factor 2 (Nrf2) to protect mast cells against A23187-induced oxidative stress. These findings indicate that camu-camu fruit extract can be developed to act as a mast cell stabilizer and an anti-histamine. This work also "opens the door" to new investigations using natural products to achieve breakthroughs in allergic disorder treatment.