Background: Matricaria chamomilla L. is advantageous due to its anti-inflammatory properties. The present study aimed to assess the efficacy of treating peripheral blood mononuclear cells (PBMCs) of COVID-19 patients with chamomile aqueous and ethanolic extracts on regulating interleukin-6 (IL-6) production.
Materials and Methods: PBMCs obtained from three COVID-19 volunteers were exposed to different concentrations (200, 300, 400, and 500 μg/mL) of ethanolic extract and (400, 500, 600, and 700 μg/mL) of aqueous extract, as well as 1 μg/mL prednisolone (positive control). The chemical content of the extracts was analyzed using high-performance liquid chromatography (HPLC). The production level of IL-6 was quantified using ELISA.
Results: The aqueous extract contained 0.26 and 0.11 mg/g of apigenin and quercetin, respectively, while the ethanolic extract contained 1.32 and 3.22 mg/g of apigenin and quercetin, respectively. Our data revealed that the ethanolic extract (all concentrations, including 200, 300, 400, and 500 μg/mL), aqueous extract (concentrations of 500, 600, and 700 μg/mL), and prednisolone (1 μg/mL) significantly lowered IL-6 production in PBMCs of COVID-19 patients (P<0.05). In terms of viability, 400 μg/mL of aqueous extract, 200 μg/mL and 300 μg/mL of ethanolic extracts, and 1 μg/mL of prednisolone had no significant effect on cell viability (P>0.05).
Conclusion: Given these results, the therapeutic potential of chamomile in hyper-inflammatory contexts can be related to its anti-inflammatory properties; however, its safety seems dose-dependent. Additional investigations are required to examine this herb’s potential as a complementary treatment for inflammatory diseases.