Anti-psoriatic effects of tetrahydrocurcumin lipidic nanoparticles in IMQ induced psoriatic plaque: A research report

Abstract

Present investigation was designed to evaluate the efficacy of lipidic nanoparticles (LNs) of tetrahydrocurcumin (THC) embedded into an ointment base in an animal model of psoriasis. Latter is characterized by infiltration of inflammatory cells into epidermis with excessive skin vascularisation, thus causing hyperproliferation. THC, a metabolite of curcumin is colorless, non-staining, non-irritating, and stable at physiological pH with excellent anti-inflammatory activity. THC-LNs prepared using patented modified microemulsification method showed a particle size of 106.1 ± 0.56 nm (polydispersity index: 0.290) and zeta potential of −4.35 mV. Drug loading of THC was 97.26% ± 2.57 in LNs while drug assay was 99.35% ± 0.25% in ointment. THC-LNs were incorporated into an ointment base post concentration to enhance its spreadability and its occlusive properties. Significantly higher drug release (2 times) and permeation (2.5 times) were observed in dermatokinetic studies with THC-LNs loaded into ointment as compared to free drug in an ointment base. CLSM study demonstrated penetrability of THC-LNs with higher fluorescence intensity in deeper layers of skin and short-term toxicity of THC-LNs ointment confirmed the normal status of all cellular components and supportive glands. Pharmacodynamic evaluation for assessing effectiveness of LNs ointment against imiquimod (IMQ) induced psoriatic model evidently showed superior bioactivity of THC post incorporation of nanoparticles into the ointment. This was confirmed via biochemical and histopathological evaluation. To the best of our knowledge this is the first paper reporting the usefulness of THC nanoparticles in psoriasis. Thus, the novel THC-LNs ointment would be a safe and effective alternative over the existing therapies for psoriasis in addition to presenting de-pigmenting properties for the treatment of psoriasis.