α-phellandrene

The featured study came out of Brazil. Many of the plant species the authors cited as being good sources of (32%) as well as limonene (28%) and carvone (28%). [2] Hydro are natives of Brazil Dill is also a good source of α-phellandrene (32%) as well as limonene (28%) and carvone (28%). [2] Hydro distillation was used to extract 2% of the dry weight of dill. [2] Could dill extracts be good immuo modulators?

Previous posts on this website have presented evidence that γ Terpinene may be an agonist for  CB1/2 and limonene an agonist of the adenosine  AdA2A receptor.  Seiquerira and coworkers studied the influence of phyllandrene on the immune response to carragean, a compound that activates the same tlr4 receptor that binds to lipopolysaccharide. [1] We turn to proteinatlas.org to get an idea of mRNA transcripts in various human immune cells.

A Brazilian study tested the anti-inflammatory properties of α-phllandrene

2.3. In vivo neutrophil migration induced by carrageenan in air pouch cavities

Air pouches were produced in six-day old rats and maintained that way by injecting more sterile air.  Afterwards, sterile phosphate buffered saline or 1% carrageenan (100 μL/pouch) were injected into the air pouch: vehicle (3% Tween 80, 10 mL/kg, p.o.), α-phellandrene (50, 100, or 200 mg/kg, p.o.), or dexamethasone (0.5 mg/kg, p.o.). 4 h after the carrageenan injection into the air pouches, the animals were killed, and the air pouches were washed and cells counted.

Dexamethasone is best known nowadays as a steroid anti-inflammatory.

2.4. Carrageenan-induced peritonitis

Mice were first treated with saline (10 mL/kg, p.o.), vehicle (3% Tween 80, 10 mL/kg, p.o.), α-phellandrene (50, 100, or 200 mg/kg,p.o.), or dexamethasone (0.5 mg/kg, p.o.). After 1 h, peritonitis was induced in the mice by intraperitoneal injection of carrageenan diluted in sterile saline (500 μg/500 μL/cavity).  After killing the mice, the peritoneal cavity was rinsed with 3-mL sterile saline and the cells in the rinse counted.  The proinflammatory levels of TNF-α and IL-6 cytokines were also measured in the rinse.

The image of mesenteric lymph nodes was added to illustrate that the peritoneum is also a region rich in immune cells. Cytokines were also measured. [1]

Quoting from the materials section, α-Phellandrene attenuates the production of pro-inflammatory cytokines. The mice were pretreated with vehicle (3% tween 80 diluted in PBS, 10 mL/kg, p.o.) α-phellandrene (α-phe, 50 mg/kg, p.o.) or dexamethasone (Dex 0.5 mg/kg, p.o.) and 1 h later carrageenan was injected into the peritoneal cavity. A normal control group injected only with saline (10 mL/kg, p.o.) was added. 4 h after the carrageenan injection, the cavities were washed with heparinized PBS in order to determine the levels of TNF-α”

Fig. 3. Leukocytes rolling and adhesion are prevented by α-phellandrene.

The mice were pretreated with

• saline (10 mL/kg, p.o.)
• vehicle (3% tween 80 diluted in PBS, 10 mL/kg, p.o.)
• α-phellandrene (α-phe, 50 mg/kg, p.o.)
• dexamethasone (Dex 0.5 mg/kg, p.o.)

One hour later carrageenan was injected into the peritoneal cavity. After an additional four hours the mesenteric tissue was “exteriorized.” An ” intravital” microscopy was used to observe leucocyte adhesion and rolling count (cell/min). [1]

Fig. 4. α-phellandrene prevents mast cells degranulation.

Compound 48/80 is a polymer produced by the condensation of N-methyl-methyl-p-methoxyphenylamine with formaldehyde.  It causes mast cell degranulation by binding to the MRGPRX2 G protein coupled receptor. Ketoefin is an H1 histamine receptor antagonist.  According to the authors on Wikipedia, the H1 receptor is coupled to Gq resulting in an increase in intracellular Ca²⁺ The rats were pretreated with

• vehicle (3% tween 80 diluted in PBS, 10 mL/kg, p.o.)
• α-phellandrene (α-phe, 50, 100 or 200 mg/kg, p.o.)
• ketotifen (Keto, 2 mg/kg, p.o.). ***P < 0.001 vs compound 48/
• 80-incubated tissue group (One-Way ANOVA and Student Newman Keul’s test).

After two hours the animals were killed. The mesenteric tissue was excised incubated with saline or with the compound 48/80 (0.4 μg/mL) for 30 min. Compound 48/80 seems to activate Mrgprx2 PLCγ pathways, hence signalling via Gq. Likewise, the CB2 agonist JWH133 reduced mast cell degranulation in mouse skin after treatment with compound 48/80. The cartoon was taken from an mrgprx2 review in skin diseases.

In general, the Gq increase in intra cellular Ca²⁺ is what causes the mast cell. If degranulation. Could α-phellandrene be acting through Gαi pathways by binding to CB2? Similar results have been observed with specific CB2 agonists. [3,4] α-Phellandrene will be tentatively classified as a possibleCB2 agonist.

References

1. Siqueira HDS, Neto BS, Sousa DP, Gomes BS, da Silva FV, Cunha FVM, Wanderley CWS, Pinheiro G, Cândido AGF, Wong DVT, Ribeiro RA, Lima-Júnior RCP, Oliveira FA. α-Phellandrene, a cyclic monoterpene, attenuates inflammatory response through neutrophil migration inhibition and mast cell degranulation. Life Sci. 2016 Sep 1;160:27-33. PMC free article
2. Hajhashemi V, Abbasi N (2008) Hypolipidemic activity of Anethum graveolens in rats Phytother. Res., 22 (3) , pp. 372-375 free article
3. Capozzi, A., Caissutti, D., Mattei, V., Gado, F., Martellucci, S., Longo, A., Recalchi, S., Manganelli, V., Riitano, G., Garofalo, T., Sorice, M., Manera, C., & Misasi, R. (2021). Anti-Inflammatory Activity of a CB2 Selective Cannabinoid Receptor Agonist: Signaling and Cytokines Release in Blood Mononuclear Cells. Molecules (Basel, Switzerland), 27(1), 64. PMC free article
4. Jonsson KO, Persson E, Fowler CJ. The cannabinoid CB2 receptor selective agonist JWH133 reduces mast cell oedema in response to compound 48/80 in vivo but not the release of beta-hexosaminidase from skin slices in vitro. Life Sci. 2006 Jan 2;78(6):598-606