Effectivity of flavonoids on animal model psoriasis – thermographic evaluation

Background and purpose: Psoriasiform lesions are characterized by hyperproliferation and aberrant differentiation of epidermal keratinocytes, accompanied by inflammation, leading to a disrupted skin barrier with an abnormal stratum corneum. Psoriasis is a chronic inflammatory disease whose etiopathogenesis has not yet been fully resolved, and therefore there is no standardized therapeutical approach. This study examined the possible positive effects of propolis and its polyphenolic/flavonoid compounds on animal model psoriasis, induced by the Di-n-Propyl Disulfide iritant (PPD), and the possibility to assess usefulness of thermography in psoriatic lesion regression. Material and methods: We monitored the inflammation process by monitoring the total number of inflammatory cells in peritoneal cavity, macrophage spreading index and thermographic scanning. Thermographic is scanning an effective and simplemethod which reproducibly records thermographic images of the examined area. The tested animals were divided into sixteen groups and locally processed during five days with PPD, water and ethanolic extract (WSDP or EEP) of propolis preparations and flavonoids (Epigallocatechin 3-gallate, Quercetin, Chrisin, Curcumin). Results: The results of thermal imaging showed no statistically significant differences in temperature changes on skin locuses of psoriasis formed lesions among the examined groups. The total number of inflammatory cells in peritoneal cavity and the macrophage spreading index were reduced in psoriatic mice treated with test components. Conclusions: These results demonstrate that topical application of propolis and the flavonoids present in propolis may improve psoriatic-like skin lesions by suppressing functional activity of macrophages and ROS production. Taken toghether, it is suggested that propolis and flavonoids offer some protection against psoriatic complications through their roles as inhibitors of inflammation and as free radical scavengers. Thermal imaging was realistic, and can be applicable in examining the inflammatory process in psoriasis and in evaluating the effectiveness of tested substances