In vivo and molecular docking studies of Micromeria imbricata var. imbricata extract reveal alleviation of the DSS-induced IBD phenotype via interaction with key inflammatory mediators.

ETHNOPHARMACOLOGICAL RELEVANCE: Satureja punctata (Benth.) R.Br. ex Briq. Currently named Micromeria imbricata var. imbricata, is a flowering, an erect, perennial herb that grows 10-100 cm in height and is traditionally used in herbal medicine. The aerial parts are commonly applied to treat stomach pain, manage headaches, stop menstruation, address liver disease, and enhance milk quality. The traditional healers use both fresh and dried leaves to treat gastrointestinal ailments characterized by abdominal irritation and acute stomach disorder, typically through oral administration. However, the therapeutic potential of M. imbricata for IBD has not yet been thoroughly investigated. Neither the molecular mechanism nor the phytochemical mechanism of action has been deciphered.

AIM OF THE STUDY: This study investigated the mechanism by which Micromeria imbricata var. imbricata (M. imbricata) ameliorates a Dextran sulfate sodium (DSS) induced murine IBD phenotype.

MATERIALS AND METHODS: The M. imbricata leaf sample was initially extracted with methanol and subsequently fractionated using hexane, dichloromethane, ethyl acetate, and methanol. Both the crude extract and its fractions were evaluated for potential therapeutic properties in a DSS induced murine model of IBD. Bioactive constituents were assessed for antioxidant activity, total phenol, and flavonoid content. Functional groups were assessed via FT-IR analysis, while GC-MS provided compound characterization. Finally, molecular binding affinities were analyzed by using Autodock Vina integrated in PyRx against selected proinflammatory cytokines.

RESULTS: The methanol crude extract and its fractions were found to mitigate body weight loss and protected against colonic injury, preserving the overall colon architecture, including the integrity of villi. Analysis of the methanol extract revealed significantly elevated levels of the phenolic and flavonoid compounds (51.14 ± 0.81 mg QE/g and 56.65 ± 0.65 mg GAE/g P= 0.001). Antioxidant assays demonstrated notable free radical scavenging activity, with the methanol fraction showing 68.61 ± 3.37% inhibition in the DPPH test and 66.66 ± 2.18% in the ABTS assay. FT-IR analysis confirmed the presence of diverse functional groups, including alkanes, fatty acids, phenols, and alcohols. GC-MS profiling identified 39 compounds in Dichloromethene fraction (DCMF) and 29 compounds in the methanol fraction (MF). Molecular docking studies revealed binding affinities ranging from -3.4 to -8.1 kcal/mol against key pro-inflammatory cytokines, including IL-1β, IL-6, IL-17, COX-2, iNOS, and TNF-α.

CONCLUSION: The methanol extract and its fractions demonstrated substantial therapeutic and antioxidant potential by alleviating body weight loss and protecting colonic tissue integrity, including villi preservation. Elevated phenolic and flavonoid compounds, coupled with free radical scavenging activity, highlighted their capacity to counter oxidative stress. FT-IR and GC-MS analyses confirmed the presence of a wide array of bioactive constituents. Their biological significance was further affirmed by the molecular docking results, which demonstrated favorable binding affinity against major pro-inflammatory cytokines, thereby inhibiting their pro-inflammatory activities as revealed by reduced IBD phenotypes.