Asian hornet Vespa velutina nigrithorax venom: Evaluation and identification of the bioactive compound responsible for human keratinocyte protection against oxidative stress

Nhi Thao Le (1) , David D. da Silva (2) , Cyril Colas (3) , Éric Darrouzet (4) , Patrick Baril (5) , Lucie Leseurre (6) , Benoît Maunit (1, 7)

1 ICOA - Institut de Chimie Organique et Analytique
2 UC Davis - University of California [Davis]
3 DCMR - Laboratoire des mécanismes réactionnels
4 UT - Université de Tours
5 CBM - Centre de biophysique moléculaire
6 ICM - Institut de Chimie Moléculaire de Paris Centre
7 IMoST - Imagerie Moléculaire et Stratégies Théranostiques

The present study aimed to explore the potential antioxidant molecules of the Asian hornet venom (Vespa velutina nigrithorax) responsible for radical scavenging activity and human keratinocyte protection against oxidative stress. We developed a first technical platform that combined a DPPH radical scavenging chemical assay and cytotoxicity and ROS (reactive oxygen species) production in HaCaT keratinocyte cells exposed to UVB to evaluate the antioxidant property of V. velutina venom. We further employed Thin Layer Chromatography (TLC) combined with the DPPH assay as a targeted separation approach to isolate the antioxidant compounds responsible for the free radical scavenging property of V. velutina venom. In parallel, the latter was fractionated by a HPLC-DAD non-targeted separation approach. From this experiment, nine fractions were generated which were again evaluated separately for their antioxidant properties using DPPH assays. Results showed that only one fraction exhibited significant antioxidant activity in which serotonin was identified as the major compound by a UHPLC-ESI-QTOF HRMS/MS approach. We finally demonstrated, using purified serotonin molecule that this bioactive structure is mostly responsible for the free radical scavenging property of the crude venom as evidenced by DPPH and ROS assays in HaCaT cells exposed to UVB.

Keywords: Vespa Velutina Venom; Antioxidant activity; Reactive 45 oxygen species; Keratinocyte; Mass spectrometry; Thin Layer Chromatography

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Biochemistry [q-bio.BM]

Nhi Thao Le, David D. da Silva, Cyril Colas, Éric Darrouzet, Patrick Baril, et al.. Asian hornet Vespa velutina nigrithorax venom: Evaluation and identification of the bioactive compound responsible for human keratinocyte protection against oxidative stress. Toxicon, 2020, 176, pp.1-9. ⟨10.1016/j.toxicon.2020.01.001⟩. ⟨hal-02794316⟩