Topical Application of a Plant Extract Mixture for Anti Inflammatory Therapy: In Vivo and In Vitro Assessment

Abstract

This study aimed to evaluate the biological efficacy of a compound plant extract prepared from a group of traditionally widely used medicinal and aromatic plants, including saffron (Crocus sativus L.), thyme (Thymus vulgaris L.), clove (Syzygium aromaticum), walnut bark (Juglans regia L.), as well as coarse salt and alum. The extracts of these plants were prepared by hydrolyzing and used in the formulation of a topical cream. The cream was tested on an animal model to evaluate its therapeutic properties, particularly in accelerating wound healing and reducing inflammation and oxidative stress. The methodology was based on three main axes: a field study to investigate popular practices associated with medicinal plants among the population of El Oued Province; physiological experiments to evaluate the cream's effect on wound healing; and laboratory analyses covering hematological, immunological, inflammatory markers, and oxidative stress aspects, in addition to histological studies. The results showed that ZASSC cream has physical properties suitable for skin use (yellow color, pH = 4.93, wet texture, and 100% stability). Animal experiments also demonstrated its high effectiveness in accelerating wound healing, with a healing rate of 79.12% by day 14, outperforming MEBO cream and the base cream. Furthermore, BSA Denaturation Test analyses revealed the extract's ability to inhibit inflammation by 83.89% compared to 60.36% for diclofenac, with a low IC₅₀ value (145.31 µg/mL), reflecting its strong anti-inflammatory activity. Regarding hematological parameters, the extract contributed to a reduction in white blood cell and platelet counts, as well as lower CRP, ESR, and ASL values, reinforcing the hypothesis of its immunoregulatory effect. The extract also demonstrated significant efficacy in reducing MDA levels and increasing antioxidant activity (GSH, SOD, CAT) in the skin and lymphoid tissues (spleen and thymus). Histological analyses confirmed these results through tissue remodeling and regularity of cellular structure in the ZASSC group compared to the other groups. Together, these results highlight the effectiveness of ZASSC cream as a multifunctional natural product, with anti-inflammatory and antioxidant properties, and an effective role in accelerating wound healing and regulating immune balance, making it a promising candidate for dermatological and cosmetic applications.