Termiticidal lectins from Myracrodruon urundeuva (Anacardiaceae) cause midgut damage when ingested by Nasutitermes corniger (Isoptera: Termitidae) workers

Myracrodruon urundeuva is a hardwood tree, and its bark, heartwood and leaf contain lectins (MuBL, MuHL and MuLL respectively) with termiticidal activity against Nasutitermes corniger. In this work, the effects of these lectins on the midgut of N. corniger workers were evaluated. The insects were supplied with an artificial diet containing the lectins at their respective LC 50 (previously determined). At 48 h after treatment, the midguts were dissected and fixed for histopathology analyses. Toluidine-blue-stained midguts from lectin-treated workers showed disorganisation, with the presence of debris in the lumen and the absence of brush border. Fluorescence microscopy revealed that the numbers of digestive and proliferating cells were lower in lectin-treated individuals than in the control, and caspase-3 staining confirmed the occurrence of cell apoptosis. Enteroendocrine cells were not seen in the treated individuals. The midguts from treated insects showed greater staining for peroxidase than the control, suggesting that the lectins caused oxidative stress. Staining with wheat germ agglutinin conjugated to FITC revealed that the lectins interfered with the integrity of the peritrophic matrix. This study showed that termiticidal lectins from M. urundeuva cause severe injuries, oxidative stress and cell death in the midgut of N. corniger workers

A plant proteinase inhibitor from Crataeva tapia (CrataBL) attenuates elastase-induced pulmonary inflammatory, remodeling, and mechanical alterations in mice

AbstractChronic obstructive pulmonary disease (COPD) can lead to chronic and obstructive bronchitis and emphysema resulting in decreased bronchial lumen size.This study evaluated the effect of CrataBL, a protein isolated from the bark of Crataeva tapia, on lung mechanics, inflammation, and remodeling after elastase-induced pulmonary alterations in mice.The use of CrataBL led to decreased mechanical alterations, alveolar septum disruption (Lm), number of macrophage and neutrophil cells in the BALF, and TNF-α, MMP-9, MMP-12, TIMP-1, eNOS, and iNOS positive cells in the airways and alveolar walls compared to the animals in the ELA group. Moreover, a reduction in MUC-5-positive cells in the airway walls was observed. In conclusion, CrataBL attenuates changes in lung mechanics, inflammation, extracellular lung remodeling, and oxidative stress responses induced by the administration of elastase and decreased the volume fraction of isoprostane, collagen, and elastic fibers in the airways and alveolar walls compared to the animals in the ELA groups. Therefore, CrataBL is a potential therapeutic tool in the treatment of COPD