Leishmaniasis, Chagas disease (CD), and Human African Trypanosomiasis (HAT) are neglected tropical diseases in humans caused by intracellular parasites from the class Kinetoplastida. Leishmaniasis is one infectious disease that exhibits sex-bias not explained solely by behavioral or cultural differences. However, HAT and CD have less well documented and understood sex-related differences, either due to a lack of differences or insufficient research and reporting.

This paper reviews the rate of disease and disease severity among male and females infected with CD, HAT, and leishmaniasis. We further review the specific immune response to each pathogen and potential sex-based mechanisms which could impact immune responses and disease outcomes.

These mechanisms include sex hormone modulation of the immune response, sex-related genetic differences, and socio-cultural factors impacting risky behaviors in men and women. The mechanistic differences in immune response among sexes and pathogens provide important insights and identification of areas for further research.

This information can aid in future development of inclusive, targeted, safe, and effective treatments and control measures for these neglected diseases and other infectious diseases.

The global incidences of leishmaniasis are increasing due to changing environmental conditions and growing poverty. Leishmaniasis, caused by the Leishmania parasite, presents itself in six different clinical forms, the cutaneous and the visceral diseases being the most prevalent. While the cutaneous form causes disfigurement, the visceral form could be fatal if not treated. With no available vaccines combined with serious side effects of current medications and emerging drug resistance, it is crucial to discover new drugs whether as novel compounds or as repurposed existing pharmaceuticals. In the realm of drug development, mitochondria are recognized as important pharmacological targets due to their critical role in energy control, which, when disrupted, leads to irreversible cell damage. Certain plant-based compounds able to target the parasite mitochondrion, have been studied for their potential anti-leishmanial effects.

These compounds have shown promising effects in eliminating the Leishmania parasite. Artemisinin and chloroquine, two anti-malarial drugs that target mitochondria, exert strong anti-leishmanial effectiveness in both in vitro cultures and in vivo animal models. Quinolones, coumarins and quercetin are other compounds with leishmanicidal properties, which disrupt mitochondrial activity to effectively eliminate parasites in animal models of the disease and could be considered as potential drugs.

Therefore, plant-based compounds hold promise as potential candidates for anti-leishmanial drug development.

The development of oxidative stress depends on the deregulation of the fine balance between the proportion of reactive oxygen species (ROS) generation and the activity of antioxidants. As oxidative stress is deleterious for Leishmania sp., their host cell generates ROS as one of the foremost defence strategies. The parasites have also raised a variety of counteracting tricks in order to conquer this challenge. Upon infection, the host’s own antioxidant system is activated by the parasite to neutralise the oxidative stress-mediated protection. In addition to using the host’s antioxidant mechanisms, some genes within the parasite also make them more tolerant against oxidative stress. Therefore, the present review focuses on some major regulators intimately related to the equilibrium between oxidation and antioxidation following infection with Leishmania sp., which may be helpful in developing a comprehensive knowledge of this specific wing of infection biology associated with oxidative stress.

Reactive oxygen species (ROS) play a dual role in leishmaniasis by contributing to both host defence and parasite survival mechanisms. In the host, ROS promote parasite clearance through induction of apoptosis, activation of pro-inflammatory signalling pathways (e.g., MAPK, JNK), inflammasome assembly, and M1 macrophage polarisation. Conversely, Leishmania species have evolved multiple strategies to neutralize ROS, including the upregulation of host antioxidant enzymes like HO-1, inhibition of ROS-producing pathways, and expression of parasite-derived antioxidants such as SOD, GPx, and trypanothione reductase. The parasite alsoadapts through gene regulation and metabolic changes to counter oxidative stress. Importantly, ROS have emerged as key targets for antileishmanial therapies, with various drugs and natural compounds shown to induce ROS-mediated parasite death, highlighting their potential in future therapeutic development.

In summary, the survival of Leishmania hinges on its ability to counteract host-induced oxidative stress. Targeting its antioxidant defences and enhancing host ROS production can disrupt this balance, leading to parasite death. Exploring ROS-related signalling offers a promising path for developing effective therapies against leishmaniasis.

Dengue is one of the neglected tropical diseases endemic to tropical and subtropical regions worldwide. Due to its substantial disease burden, this arthropod-borne viral disease is a significant public health concern. Infection involving any one of the five distinct serotypes causes a wide range of disease manifestations, from self-limiting to mild to life-threatening outcomes.

The current review comprehensively provides an overview of dengue virus-mediated immunopathogenesis with special emphasis on innate immune cells, their pathogen recognition sensors and their association with pathogenesis. Additionally we have also briefly discussed recent advancements in vaccine studies and the development of therapeutics over the last decade.

The immunological response to dengue virus involves an amalgamation of a variety of innate cells and inflammatory mediators, resulting in the favouring or dampening of the antiviral response. Viral components activating innate cells through pattern recognition receptors, such as Toll-like receptors, retinoic-acid-inducible gene I and melanoma differentiation-associated gene 5, are vital in eliciting a downstream signalling cascade, which culminates in the secretion of inflammatory proteins.

Understanding the specific mechanisms involved in the acute phase of infection is indispensable for detecting differential biomarkers against flavivirus infections as well as designing more efficient therapeutic agents and vaccines.