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The main way to avoid contact with ticks and consequently tick-borne disease is the use of synthetic repellents. The search of new repellent compounds to increase the possibilities of use in strategies controls are necessary. The present study evaluated the repellent activity of two natural terpenes carvacrol and thymol in each one two different formulation (encapsulated and nonencapsulated with yeast cell wall) against the ticks Amblyomma sculptum and Rhipicephalus sanguineus sensu lato nymphs. Nymphs of A. sculptum and R. sanguineus s.l. of a single generation were used. The vertical filter paper repellency assay were performed with different concentration of both terpenes encapsulated and nonencapsulated in yeast cell wall. The repellent concentration 50% (RC 50 ) were calculated to each compound formulation. Both carvacrol and thymol (encapsulated and nonencapsulated), had a repellent activity against A. sculptum and R. sanguineus s.l nymphs. Amblyomma sculptum was more sensitive to nonencapsulated carvacrol (RC 50 values: 0.0032 to 0.0082 mg/cm 2 after 1 and 15 min) (P < 0.05), while R. sanguineus s.l. was more sensitive to encapsulated carvacrol (RC 50 values: 0.00008 to 0.0035 mg/cm 2 after 1 and 15 min) (P < 0.05). Among tick species, R. sanguineus s.l. was more sensitive for most compounds than A. sculptum (P < 0.05). Although with distinct repellent activities, carvacrol and thymol encapsulated can be a promising alternative to synthetic repellents against A. sculptum and R. sanguineus s.l., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Sedentarism and chronic non-communicable diseases have been a worldwide health problem that is drastically exacerbated by the COVID-19 pandemic social impacts. Home-based exercises are widely encouraged during social isolation to counterbalance the physical inactive impacts. Although, in the context of hypertension, are home-based exercises effective in blood pressure controlling? Our objective is to conduct a systematic review of high-quality controlled trials comparing the possible effects of different types of home-based exercises in hypertensive patients. The literature search was carried out in three scientific databases: Medline, Europe PMC, and Lilacs. Articles were included following three criteria: analyzing the effect of home-based exercise programs on blood pressure in treated and untreated hypertensive patients; exercises must perform at home and on the frequency, intensity, time, and type (FITT) principle, and the articles were published in English. From the qualitative analysis of 27 original trials screened through 451 identified studies, the main results are the following: 1) both endurance, isometric strength, and respiratory home-based exercise programs were efficient to decrease blood pressure in hypertensive patients; 2) differences in methodological approaches regarding FITT components, distinct blood pressure values at baseline and specific underlying mechanisms must be considered as a potential bias of each home-based interventions. In conclusion, endurance, isometric strength, and breathing home-based programs seems to be effective to reduce blood pressure in hypertensive patients. However, further randomized controlled trials and mechanistic studies must be performing to guide evidence-based recommendations of home-based exercises as antihypertensive therapy., (© 2022. The Author(s).)

Aedes aegypti is the main urban vector of dengue virus, chikungunya virus and Zika virus due to its great dispersal capacity and virus susceptibility. A. aegypti feed on plant-derived sugars but females need a blood meal for egg maturation. Haematophagous arthropods need to overcome host haemostasis and local immune reactions in order to take a blood meal. In this context, molecules present in the saliva and/or intestinal contents of these arthropods must contain inhibitors of the complement system (CS). CS salivary and/or intestinal inhibitors are crucial to protect gut cells of haematophagous arthropods against complement attack. The present work aimed to investigate the anti-complement activity of A. aegypti intestinal contents on the alternative, classical and lectin pathways of the human complement system. Here we show that A. aegypti gut contents inhibited the human classical and the lectin pathways but not the alternative pathway. The A. aegypti gut content has a serine protease able to specifically cleave and inactivate human C4, which is a novel mechanism for human complement inactivation in haematophagous arthropods. The gut of female A. aegypti was capable of capturing human serum factor H (a negative complement modulator), unlike males. C3 molecules in recently blood-fed female A. aegypti remain in their original state, being inactivated to iC3b soon after a blood feed. A transmission-blocking vaccine using these complement inhibitory proteins as antigens has the potential to interfere with the insect's survival, reproductive fitness and block their infection by the arboviruses they transmit to humans., Competing Interests: Declaration of competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Anopheline mosquitoes are vectors of malaria parasites. Their saliva contains anti-hemostatic and immune-modulator molecules that favor blood feeding and parasite transmission. In this study, we describe the inhibition of the alternative pathway of the complement system (AP) by Anopheles aquasalis salivary gland extracts (SGE). According to our results, the inhibitor present in SGE acts on the initial step of the AP blocking deposition of C3b on the activation surfaces. Properdin, which is a positive regulatory molecule of the AP, binds to SGE. When SGE was treated with an excess of properdin, it was unable to inhibit the AP. Through SDS-PAGE analysis, A. aquasalis presented a salivary protein with the same molecular weight as recombinant complement inhibitors belonging to the SG7 family described in the saliva of other anopheline species. At least some SG7 proteins bind to properdin and are AP inhibitors. Searching for SG7 proteins in the A. aquasalis genome, we retrieved a salivary protein that shared an 85% identity with albicin, which is the salivary alternative pathway inhibitor from A. albimanus. This A. aquasalis sequence was also very similar (81% ID) to the SG7 protein from A. darlingi, which is also an AP inhibitor. Our results suggest that the salivary complement inhibitor from A. aquasalis is an SG7 protein that can inhibit the AP by binding to properdin and abrogating its stabilizing activity. Albicin, which is the SG7 from A. albimanus, can directly inhibit AP convertase. Given the high similarity of SG7 proteins, the SG7 from A. aquasalis may also directly inhibit AP convertase in the absence of properdin., (Copyright © 2017 Elsevier Ltd. All rights reserved.)