Toxicity of Kaempferia galanga rhizome constituents to Meloidogyne incognita juveniles and eggs

Abstract

The toxicity of Kaempferia galanga rhizome constituents to second-stage juveniles (J2) and eggs of Meloidogyne incognita was examined in vitro and in container experiments. Results were compared with those of three nematicides: carbofuran, fosthiazate and metam sodium. Ethyl cinnamate (EC) and ethyl p-methoxycinnamate (EMC) were the nematicidal and hatch inhibitory principles. In direct-contact mortality bioassays, EC (0.037 mg ml −1 ) and EMC (0.041 mg ml −1 ) were more toxic than carbofuran (0.092 mg ml −1 ) but less toxic than fosthiazate (0.002 mg ml −1 ) towards J2 based upon 48 h LC 50 values. EC and EMC treatments resulted in 100% and 93 and 81% inhibition of hatch at 125.0 and 62.5 μg ml −1 , respectively. Inhibition of these compounds was higher than carbofuran and metam sodium but significantly lower than fosthiazate. In contact + fumigant mortality bioassays with J2, EC and EMC applied at 0.25 and 0.125 mg (g soil) −1 resulted in 81 and 80% and 77 and 73% mortality, respectively, while carbofuran and metam sodium treatments resulted in 86 and 96% and 57 and 73% mortality, respectively. Fosthiazate resulted in 92% mortality at 0.063 mg (g soil) −1 . In vapour-phase mortality bioassays with J2, EC and EMC were more effective in a closed container than in an open one, indicating that mode of delivery was, in part, a result of vapour action. Global efforts to reduce the level of highly toxic synthetic nematicides in the agricultural environment justify further studies on K. galanga rhizome-derived materials, particularly ethyl cinnamate and ethyl p-methoxycinnamate, as potential nematicides and hatching inhibitors for the control of M. incognita as fumigants with contact action.

Isolation of nematicidal constituents from essential oil of <i>Kaempferia galanga</i> L rhizome and their activity against <i>Heterodera avenae</i> Wollenweber

“…White needle, C-11). The data matched with previous reports [14,18]. [27], and Valeriana amurensis (311.6 μg/mL) [22].…”

“…It is suggested that acute toxicity of the essential oil of K. galanga rhizomes maybe attributed to the three cinnamate derivatives (ethyl ρ-methoxy cinnamate, trans-cinnamaldehyde, ethyl cinnamate). Moreover, in the previous reports, the three cinnamate derivatives (ethyl ρ-methoxy cinnamate, trans-cinnamaldehyde, ethyl cinnamate) were revealed to exhibit nematicidal activity against the pine wood nematode, B. xylophilus and the southern root-knot nematode, M. incognita [18,28,29].…”

“…It also has a long history of fragrance use to help restlessness, stress, anxiety and depression [13]. This herb has broad-spectrum biological activities including larvicidal [14], amebicidal [15], nematicidal [16][17][18], antimicrobial [19] and repellent effects [20]. However, to the best of our knowledge, there have been no reports to date which describe nematicidal activity of the essential oil of K. galanga rhizomes against the cereal cyst nematodes.…”

Phytochemistry and medicinal properties of Kaempferia galanga L. (Zingiberaceae) extracts

“…At a dose of 62 µg/ml, ethylcinnamate shows 100% hatch inhibition; however ethyl-pmethoxycinnamate shows 81% hatch inhibition that rises to a maximum of 93% at a dose of 125 µg/ml. This hatch inhibition dose is lesser (more efficient) than carbofuran and metham sodium (Hong et al, 2011). Hong et al (2011) have further demonstrated that the efficiency of ethyl-cinnamate and ethyl-p-methoxycinnamate in steam phase mortality bioassay is greater in closed container than in open container which suggests that mode of delivery of these constituents is partly through vapour phase.…”

“…The capacity of the extracts to block abdominal constriction, hot plate and formaline test indicates that analgesic activity has both central mechanism, involving opioid receptors, and peripheral mechanism that involves cyclooxygenase pathway (Ridtitid et al, 2008;Sulaiman et al, 2008). incognita is 37 and 41 µg/ml, respectively that is greater than Carbofuran (92 µg/ml) but lesser than fosthiazate (2 µg/ml) (Hong et al, 2011). At a dose of 62 µg/ml, ethylcinnamate shows 100% hatch inhibition; however ethyl-pmethoxycinnamate shows 81% hatch inhibition that rises to a maximum of 93% at a dose of 125 µg/ml.…”