## 2 Phytonutrients
### Antimicrobial  
* Antiviral In vitro studies concluded that essential oil extracts from the leaves of _C. verum_ extract had an antiviral effect in cells infected with influenza type A (_HINI_) [160]. Similarly, a study by [PERSON] and colleagues suggests that a hydroalcoholic extract of _C. verum_ at 1 mg/mL significantly reduces the viral titer of the human herpes simplex virus type 1 -infected cells [161]. Furthermore, in silico studies by [PERSON] et al. suggest that cinnnaldehyde possesses a strong affinity to the S1 receptor binding domain of the spike (S) glycoprotein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Cinnamaldehyde could therefore be an efficient pharmacological agent to inhibit the entry of the virus into the host cells [162]. * Antibacterial [PERSON] et al. showed that aqueous, methanolic, and acetone extracts from _C. verum_ bark exerted significant antibacterial effects on _S. aureus_, _P. aeruginosa_, and _E. coli_. The inhibitory effect of the extracts was believed to be mediated by cinnnaldehyde [163]. Furthermore, in an in vivo study conducted on aquatic pathogens in zebrafish, [PERSON] et al. concluded significant antimicrobial effects of liposome-encapsulated cinnnaldehyde in fish infected by _A. hydroophilia_, _V. vulnificus_, _S. agalactique_, _V. parahaemolyticus_, and _V. alginolyticus_. The antimicrobial activity of cinnnaldehyde was associated with a decrease in the expression of pro-inflammatory interleukins, i.e., -18, -6, -15, and an increase in anti-inflammatory interleukin-10 [164]. * Antifungal In a 2019 study, [PERSON] et al. demonstrated the antifungal properties of 1% (_v/w_) aqueous _C. verum_ bark after a 6-day treatment against _Botrytis cinerea_, the mycelium responsible for the grey mold disease in tomato plants [165]. Furthermore, cinnamon seems to inhibit the growth of the microorganisms of the _Candida_ family, which are responsible for most of the fungal diseases in humans. In a clinical trial study, [PERSON] et al. showed that an oil extract from _C. verum_ significantly inhibited the growth of three species of _C. albicans_ (minimum inhibitory concentration (MIC) = 0.064 mg/mL), _C. tropicalis_ (MIC = 0.129 mg/mL), and _C. krusei_ (MIC = 0.129 mg/mL) [166]. Additionally, a study conducted on guinea pigs suggests that topical treatments with methanolic extracts of _C. verum_ inhibit the growth of _M. canis_ and _T. mentagrophyytes_, two fungi involved in skin infections in animals and humans [167]. Anti-Inflammatory  
A study conducted in an in vitro human skin model for chronic inflammation and fibrosis suggests that a cinnamon concentration of 0.0012% (v:v) significantly inhibits the expression of genes involved in the inflammation and immune DNA damage responses [168]. The authors attributed the effect to cinnamaldehyde and cinnaryl acetate, the two main chemical compounds present in the extract. Likewise, [PERSON] et al. have demonstrated that _C. verum_ and _C. cassia_ extracts inhibited the release of pro-inflammatory nitric oxide molecule and tumor necrosis factor protein in activated macrophages. From these results, the ethanolic extract from _C. verum_ showed more activity than the aqueous extract (IC\({}_{50}\) = 36.4 and 122 ug/mL, respectively). The phytochemicals with more potent anti-inflammatory effects were E-cinnamaldehyde and o-methoxycinnamaldehyde [169]. Furthermore, in an in vivo study, 4.5 mL/kg of the ethanolic cinnamon extract was orally administered to a mouse model for colitis. The treated mice exhibited significantly enhanced resorption of their colon fibrotic tissues and reduction in the fibrotic score associated with a decrease in the expression of extracellular matrix proteinases [170]. Immunomodulatory  
As previously described, cinnamon has antioxidant, antimicrobial, and anti-inflammatory properties leading to improved immune response. Several studies have concluded that the phytochemicals present in cinnamon extracts inhibit the immune response associated with allergies.