Crude Plant Extracts and Their Anti-Inflammatory Potential in Oral Inflammatory Cell Models: A Systematic Review of In Vitro Studies.

Plants are a rich source of bioactive compounds with broad pharmaceutical potential, particularly for their anti-inflammatory properties. Oral inflammation underlies many local and systemic diseases, yet conventional anti-inflammatory drugs have adverse effects. Crude plant extracts offer promising, safer alternatives. This systematic review synthesizes evidence on the anti-inflammatory activity of whole plant extracts in vitro oral models of inflammation. It also highlights methodological considerations for improved reproducibility. PubMed searches following PRISMA guidelines identified studies using oral or periodontal cells stimulated with relevant inflammatory triggers and treated with crude plant extracts. Extracts from Camellia sinensis, Salvia officinalis, Paeonia x suffruticosa, Houttuynia cordata, Theobroma cacao, and others consistently reduced pro-inflammatory cytokines such as IL-6, IL-8, IL-1β, and TNF-α, with no reported cytotoxicity at the effective concentrations. Variations in model design, extract characterization, and stimulation protocols were noted. Overall, this review demonstrates that crude plant extracts effectively modulate oral inflammatory responses in vitro. Findings suggest a possible non-cytotoxic anti-inflammatory activity that requires further investigation and underscore the need for methodological standardization to advance clinical translation.