This study was designed to determine the chemical constituents and evaluate the anti-pain properties of the essential oils from Thuja plicata var. Excelsa Van den Berk (Cupressaceae), Alstonia boonei De Wild (Apocynaceae), Curcuma longa L. (Zingiberaceae) and Allium sativum L (Alliaceae). The essential oils were isolated using hydrodistillation method in an all glass Clevenger-type apparatus and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The hot plate method was used to determine the anti-nociceptive property while the anti-inflammatory activity was established by means of carrageenan induced and formalin models. The yields of the essential oils were 1.31%, 1.49%, 0.80% and 0.75% (v/w) respectively, calculated on a dry weight basis. The major constituents of T. plicata var. Excelsa were - 3-carene (31.6%), -pinene (20.3%), cedrol (7.3%) and β-caryophyllene (6.7%). Its carrageenan-induced inflammation study showed a high activity consistent with dose and time. Inflammatory mediators were significantly suppressed within the 1st to the 3rd h at a level of p < 0.001 by the 200 and 400 mg/kg. In addition, the activity of the 100 mg/kg rises steadily from p > 0.05 (non-significant) to p < 0.001 for the 1st to the 3rd h respectively. The oil only displayed a slight inhibition of heat latency activity at 90th and 120th min (p < 0.05) by the 400 mg/kg. The main constituents of A. boonei were cedrol (32.2%), α-humulene (18.9%), β-caryophyllene (17.2%) and α-pinene (13.4%). The hot plate model (maximal pain threshold) displayed significant activity (p < 0.001) for the 200 and 400 mg/kg within the 60th and the 90th min. Inflammation was significantly inhibited by all doses at the 3rd and 4th h. The 100 mg/kg of A. boonei essential oil displayed a steady activity at the 1st and 2nd h (p < 0.01) and increased at 3rd and 4th h (p < 0.001). 200 mg/kg of the essential oil also showed steady activity at the 3rd and 4th h (p < 0.01). The result showed that 400 mg/kg of the essential oil was significant at the 1st h (p < 0.05) but there was a total loss of activity at the 2nd h (p > 0.05) then it was highly significant at the 3rd and 4th h (p < 0.001). Formalin model showed high inhibition (100% maximal) at the inflammatory phase than the neurogenic phase. The main constituents of the oil of C. longa were ar-tumerone (28.6%), β-atlantone (21.9%) and curlone (18.8%) while diallyl trisulfide (53.9%), diallyl disulfide (15.7%), diallyl tetrasulfide (11.7%), methylallyl trisulphide (9.2%) were the compounds identified in A. sativum oil. The essential oils of A. sativum and C. longa inhibited the proliferation of anti-nociceptors induced by hot plate method. There was prolonged activity (p < 0.001) independent of the time and the dose except for a reduced activity of the 400 mg/kg at the 90th min (p < 0.001 to p < 0.05) for A. sativum. The anti-inflammatory activity of the essential oils of A. sativum were only significant for the 100 mg/kg at the 2nd h (p < 0.001) and 3rd h (p < 0.05) of the analysis. Activity observed could be attributed to effect of absorption rate and inflammation mediators' modulation. In conclusion, results in this study indicated that the essential oils could be considered as potential alternative source for amelioration of inflammation and pain disorders.
Pharmacology of essential oils: chemical constituents, anti-inflammatory and anti-nociceptive activities of essential oils from Nigerian plants
Ascrizzi R.Penultimo
Investigation
;Flamini G.Ultimo
Investigation
2020-01-01
Abstract
This study was designed to determine the chemical constituents and evaluate the anti-pain properties of the essential oils from Thuja plicata var. Excelsa Van den Berk (Cupressaceae), Alstonia boonei De Wild (Apocynaceae), Curcuma longa L. (Zingiberaceae) and Allium sativum L (Alliaceae). The essential oils were isolated using hydrodistillation method in an all glass Clevenger-type apparatus and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The hot plate method was used to determine the anti-nociceptive property while the anti-inflammatory activity was established by means of carrageenan induced and formalin models. The yields of the essential oils were 1.31%, 1.49%, 0.80% and 0.75% (v/w) respectively, calculated on a dry weight basis. The major constituents of T. plicata var. Excelsa were - 3-carene (31.6%), -pinene (20.3%), cedrol (7.3%) and β-caryophyllene (6.7%). Its carrageenan-induced inflammation study showed a high activity consistent with dose and time. Inflammatory mediators were significantly suppressed within the 1st to the 3rd h at a level of p < 0.001 by the 200 and 400 mg/kg. In addition, the activity of the 100 mg/kg rises steadily from p > 0.05 (non-significant) to p < 0.001 for the 1st to the 3rd h respectively. The oil only displayed a slight inhibition of heat latency activity at 90th and 120th min (p < 0.05) by the 400 mg/kg. The main constituents of A. boonei were cedrol (32.2%), α-humulene (18.9%), β-caryophyllene (17.2%) and α-pinene (13.4%). The hot plate model (maximal pain threshold) displayed significant activity (p < 0.001) for the 200 and 400 mg/kg within the 60th and the 90th min. Inflammation was significantly inhibited by all doses at the 3rd and 4th h. The 100 mg/kg of A. boonei essential oil displayed a steady activity at the 1st and 2nd h (p < 0.01) and increased at 3rd and 4th h (p < 0.001). 200 mg/kg of the essential oil also showed steady activity at the 3rd and 4th h (p < 0.01). The result showed that 400 mg/kg of the essential oil was significant at the 1st h (p < 0.05) but there was a total loss of activity at the 2nd h (p > 0.05) then it was highly significant at the 3rd and 4th h (p < 0.001). Formalin model showed high inhibition (100% maximal) at the inflammatory phase than the neurogenic phase. The main constituents of the oil of C. longa were ar-tumerone (28.6%), β-atlantone (21.9%) and curlone (18.8%) while diallyl trisulfide (53.9%), diallyl disulfide (15.7%), diallyl tetrasulfide (11.7%), methylallyl trisulphide (9.2%) were the compounds identified in A. sativum oil. The essential oils of A. sativum and C. longa inhibited the proliferation of anti-nociceptors induced by hot plate method. There was prolonged activity (p < 0.001) independent of the time and the dose except for a reduced activity of the 400 mg/kg at the 90th min (p < 0.001 to p < 0.05) for A. sativum. The anti-inflammatory activity of the essential oils of A. sativum were only significant for the 100 mg/kg at the 2nd h (p < 0.001) and 3rd h (p < 0.05) of the analysis. Activity observed could be attributed to effect of absorption rate and inflammation mediators' modulation. In conclusion, results in this study indicated that the essential oils could be considered as potential alternative source for amelioration of inflammation and pain disorders.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
