Synergistic Effects of Selenium, Selenoproteins, Selenocysteine and Procyanidin A2 Based on Immune Response and...

Proanthocyanidin A₂ (PA₂) is a class of bioactive small-molecule natural polyphenols, while selenocysteine (Sec) represents an essential functional selenium-containing amino acid in humans and has emerged as a cutting-edge research hotspot in the field of natural bioactive factors. This review systematically summarizes the natural resource distribution and biological signaling pathways of PA₂, as well as the in vivo metabolic profiles of Sec. It further elaborates on the core physiological and pathological processes co-regulated by PA₂ and Sec, including oxidative stress homeostasis, inflammatory immune responses, and metabolic reprogramming. Malignant tumors, severe diseases triggered by disrupted organismal homeostasis, serve as the primary research model for exploring the synergistic regulatory effects of PA₂ combined with Sec. Accumulating evidence has validated the independent anti-tumor efficacy of PA₂ and Sec in respective research domains; nevertheless, studies investigating their synergistic bioactivities remain scarce. Starting from the natural resource distribution of PA₂ and the respective core biological functions of the two agents, this work systematically dissects their individual roles in modulating oxidative stress, inflammatory responses, tumor malignant proliferation and apoptosis, and proposes putative synergistic regulatory mechanisms with hypothetical mechanistic validation. The findings are expected to provide theoretical references and innovative research strategies for developing combinatorial interventions of natural polyphenols and selenocysteine against tumors and related disorders, as well as for constructing antioxidant damage defense systems.