Chapter 14 - Insights of Phyto-Compounds as Antipathogenic Agents: Controlling Strategies for Inhibiting Biofilms and Quorum Sensing in Candida albicans

Abstract

Candida albicans is a dimorphic fungus that causes a variety of complications ranging from mucosal disease to deep-seated mycoses, particularly in immunocompromised individuals. Majority of these infections are associated with its ability to form biofilms. The intense interest in biofilms studies is due to their resistance to the immune system and tolerance to antimicrobials and stresses. Quorum sensing (QS) or cell-to-cell communication in fungi and bacteria contributes greatly to biofilms tolerance to antimicrobials. It is the first among the fungi reported to have a QS system. Farnesol and tyrosol are the two most significant quorum-sensing molecule (QSM) characterized in C. albicans that control growth, morphogenesis, and biofilm formation. To prevent or to cure biofilm infections, the main focus has been set to QS. QS has enabled coevolution of fungi with other cross-kingdom organisms present in their environment and thereby affecting their pathogenicity to the host. In these perspectives of coevolution and coadaptation, many organisms such as commensal bacteria including probiotics, algae, lichens, plants, and animals synthesize some molecules called QS inhibitors (QSI) as a defense mechanism. These molecules are able to hinder the QS mechanism of other pathogens and thereby reducing their virulence and biofilm forming ability. The communication of the individual cells is essential for the formation of biofilms; therefore blocking this process is an important goal for the control of biofilm infections. Many existing antifungal drugs are becoming insufficient to treat Candida infections due to increased drug resistance and its toxicity. Therefore looking for QSI from natural resources is potential approach to explore novel and most effective alternative drug candidate especially from plants as it is being considered as safe and inexpensive. This strategy of high-throughput screening of plant derive compounds could be interesting for its exploitation in pharmaceutical industries for the development of new potential and cost effective antifungal drugs. The scope of this chapter is to bring to light the current studies going on to understand QS mechanisms in C. albicans with clinical interest as how it uniquely controls production of various virulence factors including biofilms in the host. We have described most recent efforts made with phyto-compounds inhibiting QS-associated pathogenisity and biofilms in C. albicans with the aim of designing novel antimicrobial therapeutics.