Table 2.
Effect of different ligands on invertebrates’ TRP channels.
| Concentration | Effect | Species | Literature |
|---|---|---|---|
| Camphor | |||
| 3 mM | proboscis extension reflex reduction | honey bee | [18] |
| 4.3 mM (EC50) | AmHsTRPA activation | honey bee | [18] |
| 3 mM | heat-induced activation of Painless inhibition | Drosophila | [24] |
| 10 mM | TRPL activation | Drosophila | [27] |
| 15 mM (repeated doses) | desensitization to heat | Periplaneta americana | [7] |
| Allyl isothiocyanate | |||
| 50 µM | HarmTRPA1 activation | Helicoverpa armigera | [28] |
| 1 mM | AmHsTRPA activation proboscis extension reflex reduction | honey bee | [18] |
| 2 mM | proboscis extension reflex reduction through Painless | Drosophila | [25] |
| 2 mM | proboscis extension reflex reduction through dTRPA1 | Drosophila | [26] |
| Menthol | |||
| 100 nM (EC50) | AmHsTRPA inhibition | honey bee | [18] |
| 0.5 mM | increased fraction of bees in warmer regions | honey bee | [18] |
| 1.8 mM | TRPL inhibition | Drosophila | [27] |
| Thymol | |||
| 1 mM | TRPL inhibition | Drosophila | [27] |
| Capsazepine | |||
| 0.1 µM | preference for warmer regions | Periplaneta americana | [5] |
| 0.1 µM (repeated doses) | desensitization to heat | Periplaneta americana | [7] |
| 0.1 µM 100 µM | preference for warmer regions preference for cooler regions | mealworm Tenebrio molitor larvae | [23] |
| 26 µM | preference for cooler regions (1–1.5 °C); increase in proboscis extension reflex | Rhodnius prolixus | [22] |
| 1 mg/kg | increase in heat-evoked latencies | snail Megalobulimus abbreviatus | [8] |
| 18 µM | block TRPM8 response to menthol | HEK293 cells | [29] |
| Capsaicin | |||
| 0.1 µM | preference for cooler environments | Periplaneta americana | [5] |
| 100 µM | preference for warmer environments | Periplaneta americana | [30] |
| 0.1 µM and 100 µM (repeated doses) | desensitization to heat | Periplaneta americana | [7] |
| 0.1 µM 100 µM | preference for cooler environments | mealworm Tenebrio molitor larvae | [23] |
| 3–12 µM | positive preference for capsaicin, also in painless mutants | Drosophila | [25] |
| 0.34 mM | preference for higher temperatures (2.6 °C); less responsiveness to heat | Rhodnius prolixus | [22] |
| 0.5% | decreased latency for withdrawal behavior from 50 °C | snail Megalobulimus abbreviatus | [8] |
| 0.5 mM | elicited nocifensive behavioral responses | medicinal leech | [9] |