Lithraea caustic (Litre) Extract Promotes an Antitumor Response Against B16 Melanoma

Abstract

Melanoma immunotherapy, specifically the autotransplant of dendritic cells charged with tumors antigens, has shown promising results in clinical trials. The positive clinical effects of this therapy have been associated to increased Th17 response and delayed-type hypersensitivity (DTH) against to tumor antigens. Some synthetic compounds, such as diphenylcyclopropenone (DPCP), are capable of triggering a DTH response in cutaneous malignancies and also to induce clinically relevant effects against melanoma. In this work, we evaluated Litre extract (LExT), a standardized extract of a Chilean stinging plant, Lithraea caustic (Litre). As Litre plant is known to induce DTH, we used a murine B16 melanoma model to compare the topical and intratumor efficacy of LExT with synthetic DTH inducers (DPCP and 2,4-dinitrochlorobenzene [DNCB]). LExt contained mainly long chain catechols and sesquiterpenes. The intratumor injection of LExT induced a significant delay in tumor growth, similarly topical treatment of an established tumor with 0.1% LExT ointment induced a growth delay and even tumor regression in 15% of treated animals. No significant changes were observed on the T-cell populations associated to LExT treatment, and neither DNCB nor DPCP were capable to induce none of the LExT-induced antitumoral effects. Interestingly, our results indicate that LExT induces an antitumor response against melanoma in a mouse model and could bring a new –and affordable- treatment for melanoma in humans.

Heterocycles from cyclopropenones

“…53,54 Moreover they were used for the treatment of recalcitrant warts, 55 and others showed antitumor activities in the treatment of B16 melanoma. 56,57 2.2. Synthesis of cyclopropenone (1) and its derivatives 2.2.1.…”

Chitosan-Based Delivery of Avian Reovirus Fusogenic Protein p10 Gene: In Vitro and In Vivo Studies towards a New Vaccine against Melanoma

“…Subsequently, they were incubated with a rabbit anti-p10 polyclonal serum (gently donated by Dr. Roy Duncan, Dalhousie University, Nova Scotia) at a dilution of 1 : 500 in 10% goat serum at 4°C overnight with gentle agitation. Cells were washed for 10 min with PBS three times in gentle agitation living cells were used to induce tumor development in C57BL/6J mice by subcutaneous (s.c.) injection into the lumbar region (challenge), as described previously [17]. Once a tumor reached a volume of 2.0 mm 3 , animals were separated into three groups: (i) without treatment, (ii) CH: treated with chitosan, and (iii) NP-ARV: treated with NPs of chitosan+pIRES-ARV.…”