Abstract
In order to promote gastrointestinal health, significant increases in the prevalence of gastrointestinal disorders should be paralleled by similar surges in therapeutics research. Nutraceutical interventions may play a significant role in patient management. The current study aimed to determine the potential of Aspalathus linearis (rooibos) to prevent gastrointestinal dysregulation resulting from high-dose trace-amine (TA) exposure. Considering the substantial female bias in functional gastrointestinal disorders, and the suggested phytoestrogenicity of rooibos, the study design allowed for a comparison between the effects of an ethanol extract of green rooibos and 17β-estradiol (E2). High levels of ρ-tyramine (TYR) and agmatine (AGM), but not β-phenethylamine (PEA) or tryptamine (TRP), resulted in prostaglandin E2 (PGE2) hypersecretion, increased tight-junction protein (TJP; occludin and ZO-1) secretion and (dissimilarly) disrupted the TJP cellular distribution profile. Modulating benefits of rooibos and E2 were TA-specific. Rooibos pre-treatment generally reduced IL-8 secretion across all TA conditions and prevented PGE2 hypersecretion after exposure to both TYR and AGM, but was only able to normalise TJP levels and the distribution profile in AGM-exposed cells. In contrast, E2 pre-treatment prevented only TYR-associated PGE2 hypersecretion and TJP dysregulation. Together, the data suggest that the antioxidant and anti-inflammatory effects of rooibos, rather than phytoestrogenicity, affect benefits illustrated for rooibos.