A Comprehensive Systematic Review of Natural Biomedicines for Immune-Mediated and Inflammatory Dermatologic Diseases

Natural biomedicines (NBMs) are frequently used to manage immune-mediated and inflammatory dermatologic diseases (IMIDDs). This systematic review evaluates the efficacy, safety, and clinical relevance of NBMs in IMIDDs, providing an evidence-based analysis to guide dermatologic practice.

Following PRISMA guidelines, a systematic search was conducted in PubMed, Embase, Medline, and Google Scholar for randomized controlled trials (RCTs) investigating NBMs in IMIDDs from 1990 to 2023. Studies were included if they met predefined eligibility criteria: RCT design, relevant IMIDD condition, NBM intervention, and quantitative outcome measures. Risk of bias was assessed using the Jadad scale. Results were synthesized qualitatively due to heterogeneity in study designs and outcome measures.

Of 1364 records screened, 95 RCTs were included, encompassing 5265 participants across 23 countries. Indigo naturalis, fish oil (⍵-3), and aloe vera demonstrated the most consistent efficacy in managing psoriasis, systemic lupus erythematosus (SLE), atopic dermatitis (AD), and lichen planus (LP). Indigo naturalis significantly improved erythema, scaling, and PASI scores in psoriasis patients. Fish oil showed benefits in SLE disease activity indices and AD severity, while aloe vera demonstrated improvements in SCORAD and LP severity criteria. Most NBMs exhibited favorable safety profiles, although adverse event reporting was inconsistent.

While these findings highlight the potential of NBMs in dermatologic care, methodological limitations, including small sample sizes, heterogeneity in study designs, and lack of direct comparisons to conventional therapies, limit definitive conclusions. Additionally, not all natural agents can be easily searched and captured in systematic reviews, which may have restricted the scope of included NBMs. Future research should emphasize high-quality RCTs, standardized outcome measures, and comparative studies against conventional treatments.

The review protocol is registered with Open Science Framework (OSF) ( https://doi.org/10.17605/OSF.IO/UH9XJ ).