Aspalathus linearis (Rooibos) and Agmatine May Act Synergistically to Beneficially Modulate Intestinal Tight Junction...

Area of Science:

• Gastroenterology and Nutraceutical Research
• Molecular and Cellular Biology
• Pharmacology

Background:

• Rising gastrointestinal (GI) disorders necessitate novel therapeutic research, with nutraceuticals offering potential patient management strategies.
• Rooibos (Aspalathus linearis) is investigated for its potential GI health benefits, possibly linked to its suggested phytoestrogenic properties.
• Functional GI disorders disproportionately affect females, prompting comparisons with estrogenic compounds.

Purpose of the Study:

• To evaluate the protective potential of green rooibos extract against gastrointestinal dysregulation induced by high-dose trace-amine (TA) exposure.
• To compare the efficacy of rooibos extract with 17β-estradiol (E2) in mitigating TA-induced GI effects.
• To elucidate the mechanisms underlying rooibos's effects, distinguishing between antioxidant/anti-inflammatory actions and phytoestrogenicity.

Main Methods:

• Exposure of cells to high levels of specific trace-amines: ρ-tyramine (TYR), agmatine (AGM), β-phenethylamine (PEA), and tryptamine (TRP).
• Assessment of prostaglandin E2 (PGE2) and interleukin-8 (IL-8) secretion as markers of inflammation.
• Evaluation of tight-junction protein (TJP; occludin and ZO-1) secretion and cellular distribution.
• Pre-treatment with green rooibos ethanol extract or 17β-estradiol (E2) prior to TA exposure.

Main Results:

• High TYR and AGM levels induced PGE2 hypersecretion, increased TJP secretion, and disrupted TJP cellular distribution.
• Rooibos pre-treatment reduced IL-8 secretion across all TAs and prevented PGE2 hypersecretion with TYR and AGM.
• Rooibos normalized TJP levels and distribution only in AGM-exposed cells, while E2 normalized TYR-induced PGE2 hypersecretion and TJP dysregulation.

Conclusions:

• The protective effects of rooibos against TA-induced gastrointestinal dysregulation appear to stem from its antioxidant and anti-inflammatory properties.
• Phytoestrogenicity is unlikely to be the primary mechanism behind rooibos's observed gastrointestinal benefits.
• Rooibos demonstrates TA-specific modulatory benefits, offering a potential nutraceutical approach for managing certain types of gut dysregulation.