## 5 Essential Oils from _Lamiaceae_ Family
### Selected Compounds as Essential Oils from Lamiaceae Family

Table 1: Anti-inflammatory effects of selected compounds of Essential Oils from _Lamiaceae_ family. Figure 1: General Scheme of the effect of the main EOs derived from _Lamiaceae_ family on the periodontitis. Figure 2: Selected compounds from Essential Oils from Lamiaceae family. Terpineols: \(\alpha\)- terpineol (**A**), \(\beta\)- terpineol (**B**), \(\gamma\)-terpineol (**C**), and terpinen-4-ol (**D**). Limonene (1-Methyl-4-(prop-1-en-2-yl)cyclohex-1-ene) is a cyclic monoterpene and one of the most common terpen in nature as well as the main constituent of citrus Eos (Figure 3B). Its anti-inflammatory effects are principally linked to the modulation of cytokines and the interference with the inflammatory-related pathways, as demonstrated by in vitro and in vivo assays. Limonene decreases leukocytes infiltration and neutrophils migration, as well as the levels of TNF-\(\alpha\) in cell derived from the peritoneal cavity and in the peritoneal exudate of zymosan-induced peritonitis BALB/C mice [104]. In LPS inflammation-induced RAW 264.7 macrophages, limonene reduced in a dose-dependent manner the levels of proinflammatory cytokines TNF-\(\alpha\), IL-6 and IL-1\(\beta\), together with the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX) and prostaglandin E2 (PGE2) [105]. Similarly, in vitro model of osteoarthritis with IL-18-stimulated human chondrocytes, limonene negatively modulated nitric oxide (NO) production by decreasing iNOS, matrix metalloproteinase (MMP)-1 and MMP-13 expression, besides NF-kB and p38 activation [106]. Carvacrol (5-isopropyl-2-methylphenol) is a cyclic monoterpene mainly present in the EO of plants from _Lamiaceae_ family (Figure 3C). In an experimental rat model of periodontal disease, carvacrol maintained alveolar bone resorption and decreased tissue lesion at histopathology, with preservation of the gingival tissue also demonstrating anti-inflammatory and antibacterial activities [107]. In addition, in vitro in murine macrophages carvacrol (1, 10, and 100 \(\upmu\)g/mL) reduced the LPS-induced nitrite production as well as in vivo in a model of carrageenan-induced pleurisy with a pretreatment 50 or 100 mg/kg, i.e., carvacrol reduced the levels of TNF-\(\alpha\) and suppressed leukocytes recruitment in pleural lavage [108]. In human macrophage-like U937 cells, carvacrol suppressed LPS-induced COX-2 expression, activating PPARy, indicating its anti-inflammatory properties [109] and having no selectivity for both COX-1 and COX-2 enzyme isoforms [110]. Furthermore, it has been shown that carvacrol induces Nav blockade in DRG neurons [123; 124], and [PERSON] et al. also reported significant analgesic activity and dose-dependency of _T. capitatus_ EO. It is suggest that it is the main active molecule behind the antinociceptive effects of _T. capitatus_ through peripheral nervous excitability blockade [125]. Other study showed that  
Figure 3: Selected compounds from Essential Oils from _Lamiaceae_ family. Linalool (**A**), Limonene (**B**), Carvacrol (**C**), Eucalypt (**D**), Thymol (**E**). carvacrol and thymol have the most potent antimicrobial activity against _Escherichia coli_, _Sta. aureus_, _Str. epidermidis_, _Enterococcus faecalis_, _Yersinia enterocolitia_, _Candida albicans_, _Bacillus cereus_, _Listeria monocytogenes_, _Salmonella typhimurium_ and _Saccharomyces cerevisiae_, with the exception of _Pseudomonas aeruginosa_[126]. Taking into account that _T. capitatus_ fractions are characterized by the presence of carvacrol as dominant constituent, the antibacterial properties may be attributed to this oxygenated monoterpene. Thymol (2-isopropyl-5-methylphenol), a monoterpene phenol, is a typical compound in EOs from thyme species (Figure 3E). Thymol also ameliorates inflammation in vitro in LPS-induced inflammation in murine macrophage cells [116] as well as in LPS- and interferon (IFN)-\(\gamma\)-induced macrophage inflammation, besides inhibition of the iNO RNA expression in J77A.1 cells [117].