In vivo evaluation of the antipsoriatic effect of hydrogel with lavandin essential oil and its main components after topical application

In our study, lavandin oil was hydrodistillated from Lavandula × intermedia (Lamiaceae), and new alginate-based hydrogel formulations containing lavandin oil, linalool, and linalyl acetate were prepared for the first time. Using the gas chromatography (GC) and gas chromatography - mass spectrometry (GC-MS) methods fifty eight components of obtained essential oil were identified. Subsequently, the antipsoriatic activity of the created formulations was investigated by applying an imiquimod-induced mouse model. Alginate-based hydrogels were used as carriers for lavandin oil, linalool, and linalyl acetate. The histopathological examination of imiquimod-induced psoriasis-like mice ear skin stained with H&E (haematoxylin and eosin) was conducted after applying the examined formulations. Additionally, the impact of lavandin oil, linalool, and linalyl acetate on the expression of CD3 (cluster of differentiation 3), CD68 (monoclonal mouse anti-human), and Ki67 (marker of proliferation Ki-67) were studied. Histopathological studies showed that analysed formulations decreased the mice ears’ thickness and the analysed psoriasis symptoms (parakeratosis epidermal thickening, hypertrophy of the spinous layer, inflammatory infiltrates, Munro's microabscesses, Kogoj's micro-pustules, and dermal papillae oedema). The prepared formulations inhibited proliferation of the cells (Ki67 staining method) and expression of CD3 and CD68. The most potent activity against the inflammation in psoriasis was the preparation containing 5% lavandin oil.