**5.13. Vegetable fruits**

Tomatoes (*Lycopersicon esculentum)* and tomato-based products are a source of important nu‐ trients and contain numerous phytochemicals, such as carotenoids, that may influence health (carotenoids such as phytofluene, phytoene, neurosporene, γ-carotene, and ζ-caro‐ tene) [133,134]. Tomatoes are also a source of a vast array of flavonols (e.g., quercetin and kaempferol), phytosterols, and phenylpropanoids [135]. Lycopene is the most important car‐ otenoid present in tomatoes and tomato products, and their dietary intake has been linked to a decreased risk of chronic illnesses such as cancer and cardiovascular disease [136,137]. Studies performed on human recombinant CYP1 showed that lycopene inhibits CYP1A1 and CYP1B1. Lycopene has also been shown to slightly reduce the induction of ethoxyresor‐ ufin-*O*-deethylase activity by 20% by DMBA in MCF-7 cells [138]. It appears to inhibit bioac‐ tivation enzymes and induce detoxifying enzymes. It has been suggested that lycopene might have a potential advantage over other phytochemicals by facilitating the elimination of genotoxic chemicals and their metabolites [138]. Recent *in vitro* evidence suggests that high dose lycopene supplementation increases hepatic cytochrome P4502E1 protein and in‐ flammation in alcohol-fed rats [139].

Carrots (*Daucus carrota)* are widely consumed as food. The active components of carrots, which include beta-carotene and panaxynol have been studied by many researchers [140-142]. Carrots induce phenolsulfotransferase activity [123] and decrease CYP1A2 activity [122]. It has been reported that a carrot diet increased the activity of ethoxycoumarin O-dee‐ thylase ECD activity in a mouse model [143].

Avocado (*Persea americana*) is a good source of bioactive compounds such as monounsatu‐ rated fatty acids and sterols [144]. Growing evidence on the health benefits of avocadoes have led to increased consumption and research on potential health benefits [145, 146]. Phy‐ tochemicals extracted from avocado can selectively induce several biological functions [147,148]. Two papers published in the 1990's reported avocados interact with warfarin, stat‐ ing that the fruit inhibited the effect of warfarin. They, however, did not establish the cause of such inhibition [149, 150].

Red pepper (*Capsicum annuum* L.) is used as a spice that enhances the palatability of food and drugs such as the counterirritant present in stomach medicines across many countries [151]. The pungencyof red pepper is derived from a group of compounds called capsaici‐ noids, which possess an array of biological properties and give it its spicy flavor. Two major capsaicinoids, dihydrocapsaicin (DHC) and capsaicin (CAP) are responsible for up to 90% of the total pungency of pepper fruits. Red pepper has several uses as a fruit stimulant and ru‐ bifacient in traditional medicine; it is also used in the treatment of some diseases such as scarlatina, putrid sore throat, hoarseness, dispepsia, yellow fever, piles and snakebite [152]. Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a fundamental component of *Capsicum* fruits. Capsaicin is known to have antioxidant properties and has therefore been associated with potent antimutagenic and anticarcinogenic activities [153]. Early studies have reported that capsaicin strongly inhibited the constitutive enzymes CYP 2A2, 3A1, 2C11, 2B1, 2B2 and 2C6 [154]. There is also a report indicating that capsaicin is a substrate of CYP1A2 [155]. Pharmacokinetic studies in animals have shown that a single dose of *Capsicum* fruit could affect the pharmacokinetic parameters of theophylline, while a repeated dose affected the metabolic pathway of xanthine oxidase [156]. Therefore, a potential interaction may occur when is taken along with some medicines that are CYP450 substrates. Recently, it has been evidenced that red pepper induces alterations in intestinal brush border fluidity and passive permeability properties associated with the induction of increased microvilli length and pe‐ rimeter, resulting in an increased absorptive surface for the small intestine and an increased bioavailability not only of micronutrients but also of drugs [157]. Cruz et al. have shown that pepper ingestion reduces oral salicylate bioavailability, a likely result of the gastrointes‐ tinal effects of capsaicin [158]. On the other hand, Imaizumi et al. have reported capsaici‐ noid-induced changes of glucose in rats. Therefore, there is a possible interaction risk between red pepper and hypoglycemic drugs in diabetic patients [159]. Patients consuming red pepper and taking antidiabetic therapy could suffer potential drug-food interaction.
