Jullyana de Souza Siqueira Quintans

By Raimundo Gonçalves de Oliveira Júnior, Christiane Adrielly Alves Ferraz, Mariana Gama e Silva, Érica Martins de Lavor, Larissa Araújo Rolim, Julianeli Tolentino de Lima, Audrey Fleury, Laurent Picot, Jullyana de Souza Siqueira Quintans, Lucindo José Quintans Júnior and Jackson Roberto Guedes da Silva Almeida

Melanoma, which is the most malignant skin cancer type, has got one of the fastest increasing incidence rates of all cancer types in the world. When belatedly diagnosed, melanoma is extremely invasive and metastatic. Although there are effective drugs used to treat melanoma, some cell lines have proven resistant to chemotherapy. In this context, several research groups on natural products have investigated the anticancer effect of new natural molecules in the treatment of melanoma. Flavonoids have shown to play an important role in chemoprevention and inhibition of the proliferation, migration, and invasion of melanoma cells. In this chapter, we present a systematic review performed through a literature search over a period of 20 years, using specialized databases. Analysis of all selected manuscripts demonstrated that at least 97 flavonoids have already been investigated for the treatment of melanoma using in vitro or in vivo models. Most of the bioactive flavonoids belong to the classes of flavones (38.0%), flavonols (17.5%), or isoflavonoids (17.5%). Apigenin, diosmin, fisetin, luteolin, and quercetin were considered as the most studied flavonoids for melanoma treatment. In general, flavonoids have shown to be a promising source of molecules with great potential for the treatment of melanoma.

Part of the book: Natural Products and Cancer Drug Discovery

By Renan Guedes Brito, Priscila Laise Santos, Marlange Almeida Oliveira, Lícia Tairiny Santos Pina, Angelo Roberto Antoniolli, Jackson Roberto Guedes da Silva Almeida, Laurent Picot, Gokhan Zengin, Jullyana Souza Siqueira Quintans and Lucindo José Quintans Júnior

Fibromyalgia (FM) is the second most common rheumatologic disorder, affecting 5% of the world population, and has a serious effect on the quality of life of patients, as well as an economic impact through lost workdays. This pain syndrome is a common cause of chronic widespread pain and is characterized by reduced pressure pain thresholds with hyperalgesia and allodynia, nonrestorative sleep, fatigue, cognitive dysfunction, and mood disturbances. The pharmacological treatment strategies for FM include the use of antidepressants, calcium channel modulators, muscle relaxants, and analgesics but have shown limited efficacy and therapeutic adherence. Thus, researchers have been seeking potential substances (new chemical entities or through drug repositioning) that could be used for FM treatment. In this context, natural products (NPs) have been shown to be promising pharmacological tools due to the variety of their pharmacological activity and the number of molecular sites available as possible active targets. Recent clinical and preclinical studies have been conducted to verify the possible applicability of NPs such as essential oils (EOs), plants extracts, terpenes, sapogenins, and alkaloids in the treatment of FM. The results have shown that natural products have an analgesic effect in different animal models of FM, probably by activation of inhibitory descending pathways, such as the periaqueductal gray and rostroventromedial medulla. Natural products and their secondary metabolites could therefore be a promising source for FM management. However, translational studies that seek to validate the preclinical studies are scarce, incipient, and lacking an approach focused on the traditional pharmaceutical market.

Part of the book: Discussions of Unusual Topics in Fibromyalgia