Gas Chromatography‑Mass Spectrometry Elucidation and Antipsoriatic Activity on Developed Herbal Formulations from Carissa congesta, Catharanthus roseus, Annona squamosa, and Polyalthia longifolia Plant Extracts

Background: Annonaceae and Apocynaceae families are known for their plethora of pharmacotherapeutic potential. Objectives: To evaluate antipsoriatic potential (ultraviolet [UV]‑induced photodermatitis and tail model) and gas chromatography‑mass spectrometry (GC‑MS) studies on developed formulations from the plant extracts. Materials and Methods: Formulations of ethanolic extracts of Carissa congesta and Catharanthus roseus and petroleum ether extracts of Annona squamosa and Polyalthia longifolia were evaluated for antipsoriatic activity (UV‑induced photodermatitis and tail model) at 250 and 500 mg/ kg. GC‑MS studies were done subsequently after 6 months. Formulation batches were tested by different tests, viz., pH, viscosity, spreadability, washability, homogeneity, grittiness, drug content, Sudan red, bleeding, and sensitivity tests. Results: Histopathology studies indicated the absence of Munro’s microabscess, regular elongation of rete ridges, capillary loop dilatation, granular cell layer, and prominent parakeratosis at 500 mg/kg. Formulations of the plant extracts did not reveal toxic components by GC‑MS interpretation. No greasiness was observed during washing. Uniform homogeneity was observed with neither clumps nor large aggregates. The dispersed globules appeared red against colorless water background. Bleeding time was found to be stable during the experimentation. Conclusion: Developed topical plant formulations showed antipsoriatic potential on selected models. The GC‑MS studies confirmed the presence of no drastic changes in the quantity of active constituents assuring its stability.