Indole alkaloids comprise a large and complex class of natural products found in a variety of marine sources. Infectious diseases remain a major threat to public health, and in the absence of long-term protective vaccines, the control of these infectious diseases is based on a small number of chemotherapeutic agents. Furthermore, the emerging resistance against these drugs makes it urgently necessary to discover and develop new, safe and, effective anti-infective agents. In this regard, the aim of this review is to highlight indole alkaloids from marine sources which have been shown to demonstrate activity against infectious diseases.

Erythrina mulungu Mart. ex Benth., Fabaceae, popularly known as mulungu, is used for the treatment of insomnia and disorders of the central nervous system. This study examined the antinociceptive effects of the hydroalcoholic extracts (HAE), the ethyl acetate and chloroformic fractions from E. mulungu in four experimental models of nociception using laboratory mice. The extracts and fractions were administered orally to mice at doses of 100 mg/kg. Inhibition of abdominal contractions were observed for all the extracts and fractions tested, as compared to controls. All extracts and fractions from E. mulungu reduced the nociception activity produced by formalin in the 2 nd phase. In the hot plate test no significant effect was observed for any extract or fraction. In the peritonitis test induced by Zymosan, all of the tested extracts and the chloroformic fraction, except for the ethyl acetate phase, reduced cell migration of the peritoneal cavity. We concluded that E. mulungu shows antinociceptive effects, which are independent of the opioid system.