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The rhizome essential oil of Curcuma sahuynhensis from Quang Ngai Province, Vietnam, was obtained by hydrodistillation and analyzed by gas chromatographic techniques. The major components in the es...

Herein the chemical constituents and the anti-pain properties of the essential oil from the stem bark of Casuarina equisetifolia L. (Casuarinaceae) grown in Nigeria were evaluated. The essential oil was obtained by 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 whereas the anti-inflammatory activity was evaluated by carrageenan-induced and formalin experimental models. The pale-yellow essential oil was obtained in yield of 0.21% (v/w), calculated on a dry weight basis. The main constituents of the essential oil were methyl salicylate (30.4%), a-zingiberene (15.5%), (E)-anethole (9.5%), b-bisabolene (8.6%), b- sesquiphellandrene (6.9%), and ar-curcumene (6.2%). In the anti-nociceptive study, the rate of inhibition increases as the doses of essential oil increases with optimum activity at the 30th and 60th min for all tested doses. The essential oil displayed anti-nociceptive activity independently of reaction time at the highest tested dose (200 mg/kg). The essential oil of C. equisetifolia moderately reduced pain responses in early and late phases of the formalin test. The oil inhibited the paw licking in the neurogenic phase (60-63%) compared to the late phase of the formalin test. The carrageenan- induced oedema model revealed the suppression of inflammatory mediators within the 1st - 3rd h. Thus, C. equisetifolia essential oil displayed both anti-nociceptive and anti-inflammatory activities independent of the dose tested. The anti-inflammatory and anti-nociceptive activities of C. equisetifolia essential oil are herein reported for the first time.

In this paper, we report the chemical constituents, larvicidal and antimicrobial activities of essential oils from Zingiber castaneum Škorničk. & Q.B. Nguyễn and Zingiber nitens M.F. Newman growing in Vietnam. The main constituents of Z. castaneum leaf were bicyclogermacrene (24.8%), germacrene D (12.9%), cis -β-elemene (11.2%) and β-pinene (10.3%), while the pseudo-stem contained bicyclogermacrene (15.8%), cis -β-elemene (9.8%) and germacrene D (9.2%). The significant compound of the rhizome oil was sabinene (22.9%), along with α-pinene (7.8%), β-pinene (6.5%), bornyl acetate (6.1%) and γ-terpinene (5.5%). However, β-pinene (45.8%), α-pinene (10.7%) and bicyclogermacrene (7.8%) were the dominant compounds in the leaf oil of Z. nitens . Terpinen-4-ol (77.9%) occurred as the compound occurring in higher amount in the rhizome oil. The rhizome oil of Z. castaneum exhibited 100% mortality towards Ae. aegypti (concentration, 200 µg/mL; 24 h and 48 h) and Ae. albopictus (concentration, 100 µg/mL; 24 h and 48 h). However, mortality of 81.3% was observed against Cx. quinquefasciatus at 48 h (concentration 100 µg/mL). The leaf also exhibited 100% mortality against Ae. aegypti (concentration, 100 µg/mL; 24 h and 48 h) and Cx. quinquefasciatus (concentration, 150 µg/mL; 24 h and 48 h). The rhizome oil displayed a minimum lethal concentration LC 50 of 121.43 µg/mL and 110.31 µg/mL against Ae. aegypti respectively at 24 h and 48 h while values of 49.85 µg/mL and 43.93 µg/mL at 24 h and 48 h were observed against Ae. albopictus respectively. In addition, LC 50 values of 88.86 µg/mL and 48.08 µg/mL were recorded respectively against Cx. quinquefasciatus . Also, the leaf oil displayed significant larvicidal activity against Ae. aegypti with LC 50 of 39.30 µg/mL (24 h) and 31.78 µg/mL (48 h) while LC 50 values of 84.97 µg/mL (24 h) and 47.40 µg/mL (48 h) were recorded respectively against Cx. quinquefasciatus . The leaf oil of Z. nitens exhibited 100% mortality against Ae. aegypti at 24 h and 48 h period (concentration 50 µg/mL) while the rhizome oil displayed maximum mortality at concentration of 100 µg/mL. The rhizome oil attained only mortality of 93% against Cx. quinquefasciatus at test period. No significant mortality was recorded against Cx. quinquefasciatus by the leaf oil. The LC 50 values of 17.58 µg/mL (24 h) and 15.12 µg/mL (48 h) were displayed by the leaf oil against Ae. aegypti while values of 29.60 µg/mL (24 h) and 26.21 (48 h) were exhibited by the rhizome oil. Only the rhizome oil was toxic against Cx. quinquefasciatus with LC 50 of of 64.18 µg/mL (24 h) and 59.06 µg/mL (48 h). The pseudo-stem oil of Z. castaneum inhibited the growth of Pseudomonas aeruginosa (ATCC 25923) with minimum inhibitory concentration (MIC) of 12.5 µg/mL, while all other tested samples recorded MIC of 50 µg/mL. However, only the pseudo-stem oil of Z. castaneum displayed antimicrobial activity against Aspergillus niger (ATCC 9763) and Fusarium oxysporum (ATCC 48112) with MIC of 50 µg/mL.