Background
This study aimed to explore the mechanism of Bacillus Calmette-Guerin polysaccharide and nucleic acid injection (BCG-PSN) targeting the transient receptor potential vanilloid subtype 1 (TRPV1) pathway for atopic dermatitis (AD) in mice.
Conclusions
Intramuscular BCG-PSN can target the TRPV1 pathway, inhibit inflammation, and improve the symptoms of AD mice.
Methods
Experiment 1: a total of 30 Kunming (KM) mice were randomized into blank control, model, BCG-PSN low-dose (25 g/kg), BCG-PSN medium-dose (75 g/kg), BCG-PSN high-dose (225 g/kg), and positive drug (hydrocortisone 25 mg/kg) control groups. The AD model mice were established by induction with 2,4-Dinitrochlorobenzene (DNCB). After treatment in groups, the symptom score and scratching frequency in skin lesions were observed. The levels of immunoglobulin E (IgE), interleukin (IL)-4, IL-31, and IL-13 in serum were detected, as well as the levels of tumor necrosis factor-α (TNF-α), TRPV1, and nuclear factor (NF)-κB p65 in skin lesions in each group. Experiment 2: the optimal dose of BCG-PSN in Experiment 1 was adopted. A total of 20 KM mice were randomized into blank control, model, BCG-PSN, and BCG-PSN + PAC (PAC-14028) groups. The symptom score and scratching frequency in skin lesions were observed. The levels of IgE, IL-4, IL-31, and IL-13 in serum were detected, as well as the levels of TNF-α and TRPV1 in skin lesions in each group.
Results
In Experiment 1, compared with the blank control group, the ear tissues of mice in model groups developed AD, with increased symptom score, scratching frequency, levels of IgE, IL-4, IL-31, and IL-13 in serum and levels of TNF-α, TRPV1, and NF-κB p65 in skin lesions. Compared with the model group, BCG-PSN low-dose, BCG-PSN medium-dose, BCG-PSN high-dose, and positive drug control groups had reduced AD symptoms, decreased symptom score, and decreased scratching frequency, with declined expression of each inflammatory substance, including the greatest decrease in the medium-dose group. In Experiment 2, after BCG-PSN was combined with PAC, the inflammation indexes decreased compared with those in the model group, and increased compared with those in the BCG-PSN group. Conclusions: Intramuscular BCG-PSN can target the TRPV1 pathway, inhibit inflammation, and improve the symptoms of AD mice.