In-vitro Assessment of PHELA and its Components in Modulating the Innate Immune Response against SARS-CoV-2

Severe acute respiratory syndrome coronavirus (SARS-CoV) 2 induces severe illness, often characterized by an excessive release of proinflammatory cytokines, leading to a cytokine storm associated with disease severity. Traditional medicinal plants have been proposed as promising, cost-effective treatments for SARS-CoV-2. PHELA, a traditional medicine prepared from the extracts of four South African plants, has been proposed for use as an immune booster. This study evaluates the ability of PHELA and its constituents to regulate cytokine release and influence viral replication in SARS-CoV-2 Omicron-infected mammalian cells. Cells were treated with plant extracts before or after viral infection, measuring cytokine levels (IL-1β, IL-2Rα, IL-6, TNF-α, IFN-γ) and viral load at various intervals. No significant difference in viral load was observed between infected cells treated with plant extracts and untreated infected cells. However, PHELA-treated cells showed a delay in viral load increase. Infected cells treated with PHELA exhibited significantly lower levels of IL-1β, IL-2Rα, and TNF-α compared to untreated infected cells at 48 and 72 hours post-infection. Post-treatment was more effective in reducing proinflammatory cytokine production than pre-treatment, highlighting the potential of PHELA and its constituents in modulating cytokine responses during SARS-CoV-2 infection.