Structurally Related Monoterpenes p-Cymene, Carvacrol and Thymol Isolated from Essential Oil from Leaves of Lippia sidoides Cham. (Verbenaceae) Protect Mice against Elastase-Induced Emphysema

Abstract

Abstract:Background: Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction and inflammation. Natural products, such as monoterpenes, displayed anti-inflammatory and anti-oxidant activities and can be used as a source of new compounds to COPD treatment. Our aim was to evaluate, in an elastase-induced pulmonary emphysema in mice, the effects of and underlying mechanisms of three related natural monoterpenes (p-cymene, carvacrol and thymol) isolated from essential oil from leaves Lippia sidoides Cham. (Verbenaceae). Methods: Mices received porcine pancreatic elastase (PPE) and were treated with p-cymene, carvacrol, thymol or vehicle 30 min later and again on 7th, 14th and 28th days. Lung inflammatory profile and histological sections were evaluated. Results: In the elastase-instilled animals, the tested monoterpenes reduced alveolar enlargement, macrophages and the levels of IL-1β, IL-6, IL-8 and IL-17 in bronchoalveolar lavage fluid (BALF), and collagen fibers, MMP-9 and p-65-NF-κB-positive cells in lung parenchyma (p < 0.05). All treatments attenuated levels of 8-iso-PGF2α but only thymol was able to reduced exhaled nitric oxide (p < 0.05). Conclusion: Monoterpenes p-cymene, carvacrol and thymol reduced lung emphysema and inflammation in mice. No significant differences among the three monoterpenes treatments were found, suggesting that the presence of hydroxyl group in the molecular structure of thymol and carvacrol do not play a central role in the anti-inflammatory effects.

Effects of Carvacrol, Thymol and essential oils containing such monoterpenes on wound healing: a systematic review

“…In addition, it promoted the increase in IL‐10, an important anti‐inflammatory cytokine, as demonstrated by Lima et al . Studies with both isomers also reveal that these compounds singly reduce IL‐1β, IL‐6, IL‐8, IL‐17, IL‐25 and IL‐33 . Similar findings were reported by Meeran et al .…”

“…Carvacrol has been shown to inhibit the expression of IL-4, IL-17 and IL-1b, [38,39] COX-2 [39] and TNF-a. [40] In addition, it promoted the increase in IL-10, an important antiinflammatory cytokine, as demonstrated by Lima et al [39] Studies with both isomers also reveal that these compounds singly reduce IL-1b, IL-6, IL-8, IL-17, [41] IL-25 and IL-33. [42] Similar findings were reported by Meeran et al [43] who demonstrated that thymol is able to decrease the expressions of TNF-a, IL-6 and IL-1b, attenuate the lipoperoxidation and reduce inflammation.…”

“…[55,58] Similarly, high levels of MMP2 in venous leg ulcers and diabetic foot ulcers [58] also seem to hinder the wound healing. In this context, carvacrol and thymol are also able to downregulate MMP9 and MMP2 in several experimental conditions [41,[59][60][61][62] and these effects can be interesting to the management of chronic wounds.…”

A tiered approach to investigate the mechanism of anti-inflammatory activity of an herbal medicinal product containing a fixed combination of thyme herb and primula root extracts

“…For several individual chemical constituents from thyme extract different anti-inflammatory activities have been described. Of these, the terpenol phenols thymol and carvacrol have been most intensively studied with respect to their anti-inflammatory activity [28][29][30]. In addition, the tannin rosmarinic acid, has been described to possess anti-inflammatory activity and also to intervene with eicosanoid production [31].…”

Terpenes from Forests and Human Health

“…It reduced the alveolar enlargement, number of macrophages, and levels of proinflammatory cytokines such as IL-1β, IL-6, IL-8, and IL-17 in bronchoalveolar lavage fluid (BALF) (30). Similarly, p-cymene showed a protective effect in a mouse model of LPS-induced acute lung injury by reducing the number of inflammatory cells in the BALF and expression of NF-κB in the lungs (31) and by reducing production of proinflammatory cytokines and infiltration of inflammatory cells (32).…”