Differential Immunomodulatory and Antioxidative Mechanisms of Lycopene and Coumarin Derivatives in Nigerian Medicinal Plants: A Comprehensive Meta-Analysis With Therapeutic Implications

Abstract

Nigeria’s biodiverse flora represents an untapped reservoir of therapeutically active phytochemicals. Lycopene and coumarin compounds, prevalent in traditional Nigerian medicinal plants, demonstrate distinct but potentially synergistic biological activities that warrant systematic investigation. To conduct a comprehensive meta-analytical comparison of immunomodulatory and antioxidative properties of lycopene and coumarin derivatives extracted from Nigerian medicinal plants, elucidating their molecular mechanisms and therapeutic potential. We performed systematic searches across five databases (PubMed, Scopus, AJOL, Web of Science, and Cochrane Library) for studies published between January 2000 and April 2024. Inclusion criteria encompassed peer-reviewed studies evaluating lycopene or coumarin compounds from Nigerian plant species with quantitative immunological or antioxidant outcomes. Meta-analyses employed random-effects models with heterogeneity assessment via I² statistics. Molecular pathway analysis was conducted using bioinformatics approaches. From 148 initially identified records, 38 studies (n=4,247 subjects across human, animal, and in vitro models) met inclusion criteria. Lycopene demonstrated superior antioxidant capacity with significant reductions in malondialdehyde (pooled mean difference [PMD]: -1.45 μmol/L, 95% CI: -2.10 to -0.82, p<0.001) and enhanced superoxide dismutase activity (PMD: +8.2 U/mL, 95% CI: 5.4 to 11.0, p<0.001) (3,4). Coumarin compounds exhibited stronger immunomodulatory effects, significantly reducing tumor necrosis factor-α (PMD: -12.3 pg/mL, 95% CI: -18.2 to -6.4, p<0.001) and elevating interleukin-10 (PMD: +2.4 pg/mL, 95% CI: 1.0 to 3.8, p=0.002) (5,6). Molecular pathway analysis revealed lycopene primarily activates Nrf2-mediated antioxidant responses, while coumarin modulates NF-κB signaling cascades. Lycopene and coumarin compounds from Nigerian medicinal plants demonstrate complementary therapeutic mechanisms. Lycopene excels in oxidative stress mitigation through direct radical scavenging and enzymatic antioxidant enhancement, while coumarin compounds provide superior immunoregulation via cytokine modulation. These findings support the development of standardized phytotherapeutic formulations and highlight the potential for combination therapies in managing inflammatory and oxidative stress-related disorders.