Phytochemical Profile and Molecular Mechanisms of Syzygium polyanthum Leaf Extract as an Anti-Inflammatory and Antioxidant Agent in Gastritis: A Scoping Review

Abstract

Gastritis is a prevalent gastrointestinal disorder characterized by gastric mucosal inflammation and oxidative stress that can progress to ulceration and other severe complications. Although Syzygium polyanthum (Indonesian bay leaf) has been widely reported to possess anti-inflammatory and antioxidant properties, its phytochemical profile and molecular mechanisms in gastritis have not been comprehensively synthesized. This scoping review aimed to map the available evidence regarding the bioactive compounds, molecular targets, inflammatory and oxidative stress biomarkers, and gastroprotective mechanisms of S. polyanthum. The review followed the Arksey and O'Malley framework, Joanna Briggs Institute methodology, and PRISMA-ScR guidelines. Literature published between 2016 and 2026 was systematically searched in PubMed, Scopus, and ScienceDirect. Because direct evidence in gastritis remains limited, the synthesis integrated phytochemical studies with anti-inflammatory, antioxidant, and gastritis-related molecular evidence. The findings identified flavonoids, phenolic compounds, tannins, terpenoids, essential oils, alkaloids, saponins, and phytosterols as the major bioactive constituents, with flavonoids and phenolics emerging as the principal contributors to biological activity. These compounds consistently inhibited inflammatory signaling by suppressing the TLR4/MyD88/TRAF6/NF-κB pathway, resulting in reduced TNF-α, IL-1β, IL-6, COX-2, and iNOS expression, while attenuating oxidative stress through decreased reactive oxygen species and malondialdehyde levels and enhanced endogenous antioxidant defenses, including SOD, CAT, GSH, GPx, and total antioxidant capacity. Several phytochemicals were also associated with improved gastric mucosal protection through regulation of PGE₂, TFF3, EGFR, and mucus production.