*1.18.1. Mechanism of action of phytochemicals*

Phytochemicals may inhibit microorganisms, may interfere with some metabolic processes, or may modulate gene expression and signal transduction pathways [46–48]. Among the many uses, phytochemicals may either be used as chemotherapeutic or chemopreventive agents. Chemoprevention refers to the use of agents to inhibit, reverse, or retard tumorigenesis. In this sense chemopreventive phytochemicals are applicable to cancer therapy, and molecular mechanisms may be common to both chemoprevention and cancer therapy [49, 50].

The mechanism of action of phytochemicals in general is attributed to proton-motive force disruption, active transport, cytoplasmic membrane disturbance, electron flow, and cell contents' coagulation [51]. There are different modes of action of phytoconstituents which could be anticancer, anti-inflammatory, antioxidant, anti-ulcer, antidiabetic and may be a multifunctional target.
