ShenJiaoLingCao decoction ameliorates cyclophosphamide-induced splenic injury and immunosuppression via the inhibition of MEK/ERK signaling pathway activity and modulation of amino acid metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: ShenJiaoLingCao Decoction (SJLCD) is derived from the classic Chinese medicine prescription, which consists of ten kinds of herbs. In China, SJLCD has been used as an immunomodulator in clinical practice for more than ten years. However, no relevant studies have been done to clarify the pharmacodynamic underpinnings of its regulation of the body's immune system and its related processes.

AIM OF THE STUDY: This study aims to assess the immunomodulatory effects of SJLCD.

MATERIALS AND METHODS: Ultra performance liquid chromatography-quadrupole-orbitrap mass spectrometry (UPLC-Q-Orbitrap MS) was utilized to characterize the chemical constituents in SJLCD and establish its fingerprint profile. Predicting potential bioactive compounds in SJLCD for immunomodulatory effects and elucidating their mechanisms of action using artificial intelligence technology. Experiments at the animal level were carried out to verify the accuracy of the predictions. Firstly, an immunocompromised model was constructed by intraperitoneal injection of 80 mg/kg of cyclophosphamide (CTX) into rats for 3 consecutive days, and SJLCD was administered by oral administration for 14 days. The immunomodulatory effect of SJLCD on immune organs was verified by evaluating the immune organ index and histopathological examinations using hematoxylin and eosin (H&E) staining. The effect of SJLCD on relevant immune cells was examined by measuring erythrocytes, leukocytes and lymphocytes. The effect of SJLCD on relevant immune molecules was assessed by detecting the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), matrix metalloproteinase-9 (MMP9), cluster of differentiation 3 (CD3), cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8). Western blot was used to verify and analyze the possible immunomodulatory mechanisms of SJLCD. Finally, serum untargeted metabolomics was used to detect the differential metabolites of SJLCD in immunocompromised rats.

RESULTS: In this study, a total of 91 compounds were identified in the SJLCD, and the results showed a high degree of similarity (S1-S11 > 0.935) among the 11 samples in positive ion mode. Artificial intelligence computer techniques predicted that quercetin, kaempferol, and fumarine in SJLCD bound better to core targets, especially MAPK1. On animal-level validation, it was found that from an immune organ perspective, SJLCD ameliorated CTX-induced thymus and spleen damage. From an immune cell perspective, SJLCD significantly increased peripheral erythrocyte, leukocyte and lymphocyte counts in immunocompromised rats. From the immune molecular level, SJLCD down-regulated the levels of TNF-α, IL-6, IL-1β, MMP9, CD8 and up-regulated the level of CD3 and CD4 which normalize its secretion. Mechanistically, SJLCD regulates immunity possibly through the MEK/ERK signaling pathway and by affecting amino acid metabolism.

CONCLUSION: In the present study, we found that SJLCD has satisfactory immunomodulatory activity, which may be achieved by affecting the MEK/ERK signaling pathway and amino acid metabolism of the body.