Tatiane Aranha da Penha-Silva

By Renata Mondêgo de Oliveira, Solange de Araújo Melo, Tatiane Aranha da Penha-Silva, Fernando Almeida-Souza and Ana Lucia Abreu-Silva

Leishmaniasis remains as one of the most important neglected diseases in the world and, after all these years, its treatment is still a problem, mainly because of the side effects caused by the first- and second-line drugs and the indiscriminate treatment, which leads to increasing cases of parasite resistance. The search for alternative therapies for the treatment of leishmaniasis is extremely important. In this context, the use of natural products arises as a promising alternative, combining the empirical knowledge disseminated in the population with researches that aim to scientifically prove the therapeutic effects of plants. Based on this, the use of medicinal plants is considered a desirable and accessible tool in the treatment of these diseases and considered by pharmacognosy as a valuable source for the development of new drugs and as adjuvant for conventional therapies.

Part of the book: Leishmaniases as Re-emerging Diseases

By Sandra Alves de Araújo, Tatiane Aranha da Penha-Silva, Jaqueline Diniz Pinho, Marcelo de Souza Andrade and Ana Lucia Abreu-Silva

Leishmaniasis is an infectious and parasitic disease of great importance in public health. Numerous studies indicate that biochemical and molecular mechanisms are factors that contribute to the emergence of antileishmanial drug resistance. Currently, miRNAs have been identified as targets for the invasion of pathogens to control the immune response and imply resistance to treatments. Considering the alarming growth in drug resistance, new possibilities for controlling leishmaniasis have been emerging. Natural compounds originating from medicinal plants are being increasingly explored as promising antileishmanial alternatives. The chapter aims to provide a brief review on mechanisms of action associated with traditional agents used to treat leishmaniasis, focusing mainly on molecular bases associated with the resistance of Leishmania spp. to current drugs and identifying the possible miRNAs involved in this process. In addition, we seek to describe some of the promising plant molecules that can be used as potential antileishmanial agents and their possible mechanisms of action.

Part of the book: Leishmaniasis

By Allana Barros Freitas, Sandra Alves Araújo, Fernando Almeida-Souza and Tatiane Aranha da Penha-Silva

Feline leishmaniasis has a nonspecific clinical condition, like the clinical signs presented by dogs, including anorexia, lymphadenomegaly, dermatitis, emaciation, hyperthermia and atrophy of the temporal muscle. Cats have been identified as an alternative reservoir; however, felines are increasingly sought after as companion animals, further exposing man. Diagnosis in these animals is still considered a challenge, since most cats are asymptomatic. Although infected cats are less often sick than dogs, likely due to natural feline resistance, clinical illness has been linked to immunosuppressive coinfections with feline immunodeficiency virus and feline leukemia virus. The feline immune response to Leishmania infection has been poorly investigated. In cats, the same drugs prescribed for dogs are used in the treatment, namely pentavalent antimonials, allopurinol and miltefosine. Felines play an important role in the epidemiology of leishmaniasis, acting mainly as alternative reservoirs and accelerating the spread of the disease. Thus, there is a need for standardization of diagnostic and treatment methods, including thorough clinical evaluation. It is important to alert to the definition of public policies and to awaken feline owners, as well as the population in general, about care and prevention.

Part of the book: Leishmania Parasites