Antitumor Effect of Inula viscosa Extracts on DMBA-Induced Skin Carcinoma Are Mediated by Proteasome Inhibition

The aim of this work is to evaluate the antitumor effect mediated by the proteasome inhibitors of Inula viscosa extracts on skin carcinogenesis. Female Swiss albino mice were divided into five groups depending on the combination of skin cancer-inducing 7,12-dimethylbenz(a)anthracene (DMBA) and extract of Inula viscosa treatments. Histology of the affected skin and measurement of proteasome activity were performed to demonstrate the effect of Inula viscosa on mice. The identification of the molecules responsible for this inhibitory activity was carried out through the docking studies. The results showed that Inula viscosa extracts inhibit the development of papilloma in mice. Therefore, the best chemopreventive action of Inula viscosa was observed on mice in which extract treatment was performed before and after the induction of skin carcinogenesis. It was revealed that the ingestion of extracts Inula viscosa delays the formation of skin papillomas in animals and simultaneously decreases the size and number of papillomas, which is also reflected on the skin histology of the mice treated. Structure–activity relationship information obtained from component of Inula viscosa particularly tomentosin, inuviscolide, and isocosticacid demonstrated that distinct bonding modes in β1, β2, and β5 subunits determine its selectivity and potent inhibition for β5 subunit.

Secondary syphilis presenting as erythema multiforme in a HIV-positive homosexual man: a case report and literature review

Early syphilis can rarely cause erythema multiforme-type eruptions as well as triggering erythema multiforme (EM). EM-like lesions in secondary syphilis are characterized by clinical features of EM and laboratory tests consistent with secondary syphilis and the skin histology shows predominantly a plasma cell infiltrate with the presence of treponemes. When EM is triggered by early syphilis, the skin histology shows mixed inflammatory cells usually in the absence of treponemes in the skin lesion. There may also be mixed histology with the presence of treponemes in the absence of a plasma cell infiltrate and vice versa. We describe a case of secondary syphilis presenting as EM with bullae and histology showing EM features without a plasma cell infiltrate but positive for Treponema pallidum by immunohistochemical staining. The patient was also coinfected with cytomegalovirus, human immunodeficiency virus, and anal warts. The EM eruptions resolved with treatment for secondary syphilis with benzathine penicillin G.