Leaves and stem bark from Allophylus africanus P. Beauv.: An approach to anti-inflammatory properties and characterization of their flavonoid profile.

The small tree Allophylus africanus, widespread in the African continent, has long been considered valuable, as noted by the number of reports on their multiple medicinal uses. With this work, we aimed to extend the current, and so far restricted, knowledge on the chemical composition of the plant, particularly as source of flavonoids, as well as to assess its potential anti-inflammatory properties. The chemical characterization of the aqueous extract obtained from the leaves allowed the identification and quantitation of 30 flavones, predominantly apigenin derivatives, but also four luteolin derivatives, while the stem bark extract was solely characterized by apigenin di-C-glycosides and mono-C-glycosides-O-glycosylated. Strong inhibitory effects towards 5-lipoxygenase were observed with the aqueous extracts obtained from the leaves and stem bark, with IC50 values of 41.28 and 107.77 µg mL-1, respectively. Both extracts were also found to reduce NO levels in LPS-challenged RAW 264.7 macrophages, without noticeable cytotoxicity. The flavonoid profile of the plant is disclosed for the first time, allowing the identification of several molecules that may contribute to mitigate the inflammatory response. Jointly, with the current study the anti-inflammatory use of the leaves and stem bark is partially validated.

Toxicity of phenolipids: Protocatechuic acid alkyl esters trigger disruption of mitochondrial membrane potential and caspase activation in macrophages.

Phenolipids are a class of phenolic compounds with a lipidic moiety that have been receiving increasing attention due to their promising biological activities; however data regarding their toxicity and mechanism of action are scarce. A series of 11 phenolipids consisting of alkyl esters derivatives of the natural molecule protocatechuic acid was synthesized and evaluated against a panel of cancer and non-cancer cell lines. The macrophage cell line RAW 264.7, widely used as a tool for screening anti-inflammatory drugs, was more susceptible to the toxicity of these molecules than human cancer cells, reason for which mechanist studies were conducted. The parent molecule was not toxic up to 100µM, however structural modifications by inclusion of carbon side chains resulted in increased toxicity, compounds bearing 8-14 carbons being the most toxic and displaying IC50 in the nanomolar range. Mechanistic studies showed that phenolipids elicit chromatin condensation, loss of cell viability and disruption of mitochondrial membrane potential (ΔΨm), increased reactive oxygen species (ROS) and activation of caspase-9/3, thus pointing to the involvement of mitochondria in the programmed cell death process taking place. This is the first study addressing the toxicity and mechanism of action of protocatechuic acid derivatives, which is relevant in light of the recent interest in these molecules.

Immunohistologic appraisal of infiltating cells in skin biopsies from young patients clinically suspected of having various forms of leprosy

FUNDAMENTOS - Na hanseníase, existem poucas informaçäes imunológicas sobre os tipos celulares nas lesöes iniciais de pacientes jovens. MAERIAL E MÉTODOS - Biópsias da pele obtidas de 28 pacientes jovens näo clinicamente suspeitos de hanseníase foram utilizadas para estudar os fenótipos de superfície produzidos pelas células inflamatórias, demonstrados pela imunohistoquímica usando-se os anticorpos monoclonais LCA;HAM-56;Pan-B;Pan-T;CD4;CD8;Leu7, e os policlonais anti proteína S-100 e anti BCG. Uma análise semiquantitativa das células coradas foi feita. RESULTADOS - Em 24 casos, o diagnóstico histopatológico de Hanseníase pôde ser feito: nove de forma indeterminada (IND); cinco da forma tuberculóide (TT); seis da forma dimorfa tuberculóide (BT) e quatro da forma virchowiana (LL). Todos os casos foram positivos para LCA. No grupo LL as células mais conspícuas foram os macrófagos, seguidos pelos linfócitos T. A subpopulaçäo TCD8 foi mais frequente que TCD4. No grupo BT as células T eram predominantes, com as CD4 discretamente mais frequentes que CD8, seguidas dos macrófagos. No grupo TT as células T também predominavam e dentre estas as CD4 eram as mais conspícuas. Os macrófagos eram as segundas células mais frequentes. O grupo IND foi heterogêneo. As células T foram as mais frequentes com células CD4 e CD8 mostrando mesma frequência que os macrófagos. DISCUSSÄO - Este estudo confirmou que as células T säo as mais frequentes nos grupos TT/BT, existindo maior número destas células nestes casos que no grupo LL, indicando reatividade imunológica consoante com a presença e atividade de células T. Além disso, anticorpos contra subpopulaçöes de células T mostraram nos casos TT/BT mais células CD4 positivas e nos casos LL mais células CD8 positivas proliferaram. As formas IND mostraram gradaçäo na composiçäo dos infiltrados. Nossos resultados demonstram que lesöes cutâneas em pacientes jovens com a forma indeterminada inicial da Hanseníase e com várias formas definidas diferem em relaçäo às células inflamatórias