An In Vitro Study to elucidate the Effects of Artemisia afra, Aspalathus linearis (rooibos) and SeptilinTM on Immune Pathways

Abstract

Objective: Herbal immunomodulatory preparations are increasing in popularity. In vitro, in vivo and clinical trial studies are needed to ensure safety, quality and efficacy of these herbal medicines. SeptilinTM, a proprietary herbal medicinal product has been reported to have immunomodulatory effects. Aspalathus linearis (rooibos) is a commercialised South African (SA) tea recognised for its phytopharmaceutical potential. Artemisia afra is a well known SA herbal medicine used for various inflammatory conditions. This study assessed the effects of Artemisia afra, Aspalathus linearis (rooibos) and SeptilinTM on inflammatory biomarkers using RAW 264.7 cells, a murine macrophage cell line.

Materials and Methods: RAW 264.7 cells and lipopolysaccharide (LPS) activated RAW 264.7 cells were treated with various concentrations of the above mentioned samples after which the culture supernatants were assayed for specific inflammatory biomarkers namely, IL-6 and nitric oxide (NO).

Results: Artemisia afra, Aspalathus linearis (rooibos) and SeptilinTM were shown to be non-cytotoxic on unstimulated RAW 264.7 cells across all concentrations tested (31-1000μg/ml). Addition of Aspalathus linearis (rooibos) to unstimulated RAW 264.7 cells significantly up regulated (P<0.001) NO and IL-6 production at concentrations of 500μg/ml and 1000μg/ml when compared to the control, whilst Septilin^TM and Artemisia afra had no effect. Artemisia afra and Aspalathus linearis (rooibos) were shown to be noncytotoxic on stimulated RAW 264.7 cells across all concentrations tested (31-1000μg/ml). However, SeptilinTM significantly (P<0.001) decreased metabolic activity at the highest concentration tested (1000μg/ml). Addition of Artemisia afra to stimulated RAW 264.7 cells significantly down regulated (P<0.001) NO and IL-6 production when compared to the control. Aspalathus linearis (rooibos) and SeptilinTM samples had no effect on the synthesis of NO and IL-6 in stimulated RAW 264.7 cells when compared to the controls.

Conclusion: Artemisia afra has anti-inflammatory effects while Aspalathus linearis (rooibos) up regulated the immune system. This study also shows that Septilin^TM had no effects on RAW 264.7 cells.

International Journal of Human and Health Sciences Vol. 03 No. 03 July’19. Page: 134-145