The authors wish to acknowledge financial support from the project “AquaValor—Centro
de Valorização e Transferência de Tecnologia da Água” (NORTE-01-0246-FEDER-000053), supported
by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020
Partnership Agreement, through the European Regional Development Fund (ERDF). The authors
are also grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support
through national funds FCT/MCTES to CIMO (UIDB/00690/2020); and L. Barros is grateful for her
contract through the institutional scientific employment program-contract.
The use of natural products to promote health is as old as human civilization. In recent
years, the perception of natural products derived from plants as abundant sources of biologically
active compounds has driven their exploitation towards the search for new chemical products that
can lead to further pharmaceutical formulations. Candida fungi, being opportunistic pathogens,
increase their virulence by acquiring resistance to conventional antimicrobials, triggering diseases,
especially in immunosuppressed hosts. They are also pointed to as the main pathogens responsible
for most fungal infections of the oral cavity. This increased resistance to conventional synthetic
antimicrobials has driven the search for new molecules present in plant extracts, which have been
widely explored as alternative agents in the prevention and treatment of infections. This review aims
to provide a critical view and scope of the in vitro antimicrobial and antibiofilm activity of several
medicinal plants, revealing species with inhibition/reduction effects on the biofilm formed by Candida
spp. in the oral cavity. The most promising plant extracts in fighting oral biofilm, given their high
capacity to reduce it to low concentrations were the essential oils extracted from Allium sativum L.,
Cinnamomum zeylanicum Blume. and Cymbopogon citratus (DC) Stapf.
