Evaluation of the anti-inflammatory, anti-catabolic and pro-anabolic effects of E-caryophyllene, myrcene and limonene in a cell model of osteoarthritis

TLDR: Data show that myrcene has significant anti-inflammatory and anti-catabolic effects in human chondrocytes and, thus, its ability to halt or, at least, slow down cartilage destruction and osteoarthritis progression warrants further investigation.

About: This article is published in European Journal of Pharmacology.The article was published on 2015-03-05 and is currently open access. It has received 150 citations till now. The article focuses on the topics: Myrcene.

Figures

Fig. 4. Effects of myrcene and limonene on IL-1β-induced NF-κB activation, evaluated as the levels of phosphorylated (panel A) and total (panel B) IκB-α and NF-κB–DNA complexes (panel C). C28/I2 cells were left untreated (Control, Ctrl) or treated with IL-1β, 10 ng/ml, for 5 min (panel A) or 30 min (panels B and C) following pretreatment with or without the test compounds or the specific NF-κB inhibitor, Bay 11-7082 (Bay, 5 mM). Each column represents the mean7S. E. M. of 3 to 5 independent experiments. nPo0.05, nnPo0.01 nnnPo0.001 relative to IL-1β-treated cells; §Po0.05, §§§Po0.001 relative to control cells.

Fig. 5. Effects of myrcene and limonene on IL-1β- induced activation of JNK, p38 and ERK1/2 in human chondrocytes. Phosphorylated levels of JNK (panel A), p38 (panel B) and ERK (1/2) (panel C) were analyzed in total cell extracts of human chondrocytes left untreated (Control, Ctrl) or treated for 5 min with IL-1β, 10 ng/ml, following a pretreatment for 30 min with the indicated concentrations of myrcene, limonene or a specific inhibitor of the activation of each MAPK. Each column represents the mean7S. E. M. of, at least, 4 independent experiments. Representative images are shown. nnPo0.01, nnnPo0.001 relative to IL-1β-treated cells and §§§Po0.001 relative to control cells. iJNK: JNK inhibitor, SP600125 (20 mM); ip38: p38 inhibitor, SB203580 (20 mM); iERK: ERK1/2 inhibitor, U0126 (10 mM).

Fig. 6. Effects of myrcene and limonene on IL-1β-induced changes in the expression of catabolic and anti-catabolic genes. mRNA levels of MMP-1 and MMP-13 (panel A) and TIMP-1 and TIMP-3 (panel B) were evaluated by qRT-PCR. Each bar represents the mean7S. E. M. of, at least, 4 independent experiments in which human chondrocytes were left untreated (Control, Ctrl) or treated for 12 h (panel A) or 24 h (panel B) with IL-1β, 10 ng/ml, in the presence or absence of the indicated compounds added to the cell cultures 30 min before IL-1β. nPo0.05, nnPo0.01, nnnPo0.001 relative to IL-1β-treated cells and §Po0.05, §§Po0.01, §§§Po0.001 relative to control cells.

Table 1 Oligonucleotide primer pairs used for qRT-PCR.

Fig. 7. Effects of myrcene and limonene on IL-1β-induced changes in the expression of extracellular matrix genes. mRNA levels of collagens I and II (panel A) and aggrecan (panel B) were evaluated by qRT-PCR. Each bar represents the mean7S. E. M. of, at least, 4 independent experiments in which human chondrocytes were left untreated (Control, Ctrl) or treated for 24 h with IL-1β, 10 ng/ml, in the presence or absence of the indicated compounds added to the cell cultures 30 min before IL-1β. nPo0.05, nnnPo0.001 relative to IL-1β-treated cells and §§Po0.01, §§§Po0.001 relative to control cells.

Table 2 Composition of the fractions of the essential oils of E. duriaei subsp juresianum and Lavandula luisieri.

Frequently asked questions

Q1. What are the contributions mentioned in the paper "Evaluation of the anti-inflammatory, anti-catabolic and pro-anabolic effects of e-caryophyllene, myrcene and limonene in a cell model of osteoarthritis" ?

To identify compounds with potential anti-osteoarthritic properties, in this study, the authors screened one sesquiterpene, E-caryophyllene, and two monoterpenes, myrcene and limonene, hydrocarbon compounds for anti-inflammatory, anti-catabolic and pro-anabolic activities in human chondrocytes. These data show that myrcene has significant anti-inflammatory and anti-catabolic effects in human chondrocytes and, thus, its ability to halt or, at least, slow down cartilage destruction and osteoarthritis progression warrants further investigation. 

Q2. What future works have the authors mentioned in the paper "Evaluation of the anti-inflammatory, anti-catabolic and pro-anabolic effects of e-caryophyllene, myrcene and limonene in a cell model of osteoarthritis" ?

Future studies in in vivo models of OA are thus warranted to evaluate its potential as a disease-modifying osteoarthritis drug. 

Q3. What are the main enzymes responsible for hydrolyzing the major articular cartilage components?

Matrix metalloproteases (MMPs) and aggrecanases are the main enzymes responsible for hydrolyzing the major articular cartilagespecific matrix components, collagen II and aggrecan. 

Q4. What is the role of myrcene in OA?

Myrcene has significant anti-inflammatory and anti-catabolic properties in vitro suggesting that it may be useful to halt or, at least, slow down cartilage destruction and, thus, OA progression. 

Q5. What is the effect of limonene on chondrocytes?

since ERK1/2 has also been shown to inhibit proteoglycan synthesis and to promote inflammatory and catabolic responses in chondrocytes (Scherle et al., 1997), the net effect resulting from its induction by limonene is likely undesirable, compromising its potential utility as a therapeutic agent in OA. 

Q6. What is the effect of the active compounds in the two fractions?

since both fractions contain several distinct compounds, none of which is present in sufficiently high amounts to justify the effects observed, either the active compound in those fractions is significantly more potent than myrcene and limonene or various active compounds, including these two, act synergistically, or at least, additively, to achieve a similar or even higher degree of inhibition of IL-1-induced NO production. 

Q7. What was the nitrite concentration in primary chondrocyte cultures?

Nitric oxide production was evaluated as the amount of nitrite accumulated in primary chondrocyte culture supernatants after 24 h treatment with IL-1β, following pre-treatment with noncytotoxic concentrations of the fractions of the essential oils or the test compounds. 

Q8. what is the effect of limonene on chondrocytes?

Whether increased activation of ERK1/2 by limonene contributes to enhance chondrocyte survival was not addressed in this study, but is an interesting possibility to study further, as increased chondrocyte death is a relevant feature of OA (Johnson et al., 2008). 

Q9. How was the RNA extracted from human condrocytes?

Total RNA was extracted from human condrocytes using TRIzols Reagent (Invitrogen, Life Technologies, Co; Paisley, UK) and quantified using a NanoDrop ND-1000 spectrophotometer at 260 nm. 

Q10. What is the IC50 value of myrcene and limonene?

Since myrcene and limonene showed inhibitory activity towards IL-1β-induced NO production, various non-cytotoxic concentrations were then tested to determine the respective concentration required to inhibit NO production by 50% (IC50) and thus, to compare their relative potencies.