Cytoprotective effects of creosote bush (Larrea tridentata) and Southern live oak (Quercus virginiana) extracts against toxicity induced by venom of the black-tailed rattlesnake (Crotalus ornatus)

Abstract

The venom of Crotalus ornatus (vCo) poses a threat to human health, as it contains a mixture of toxins that can cause cytotoxic, necrotic, and hemolytic effects. The present study assessed methanolic and acetone extracts from leaves and flowers of Larrea tridentata, as well as the bark of Quercus virginiana as potential suppressors of the toxic effects of vCo in vitro. The content of total phenols, flavonoids, and tannins of the plant extracts were quantified for the suppression of vCo cytotoxicity in two cell culture models, human lymphocytes and porcine aortic endothelial (PAE) cells. Extracts from Q. virginiana displayed a greater concentration of total phenols, flavonoids, and tannins. Co-incubation of lymphocytes and PAE cells with fixed concentrations of vCo and plant extracts resulted in decreased vCo-induced cytotoxicity. A 24-hour co-incubation of lymphocytes with vCo (2.36 ± 0.17 µg/mL) and 0.5 µg/mL of methanolic leaf extract from L. tridentata (LLM) significantly suppressed the venom-induced cytotoxicity by 37.33 ± 8.33%. Similarly, the LLM extract (4 µg/mL) caused a significant decrease in vCo cytotoxicity after 24 hours in PAE cells. In contrast, while the acetone extract of Q. virginiana bark (QA) suppressed cytotoxicity by 29.20 ± 3.51% (p < 0.001) in lymphocytes, it failed to protect PAE cells against vCo after 24 hours. In PAE cells, a shorter 4-hour co-incubation showed significant suppression of cytotoxicity with both extracts. Our results collectively suggest that LLM and QA possess cytoprotective properties against the in vitro toxic effects of vCo, and thus establish extracts from these plants as potential therapeutic interventions against Crotalus envenomation.

Keywords:

• Snake venom
• phytochemicals
• cytotoxicity
• cytoprotection
• crotalids
• plant extracts

Acknowledgements

This project was partially funded by Proyecto de Ciencia Básica from CONACyT (#256009). We are grateful to UACJ authorities and members of the laboratories of Chemistry (T-116), Molecular Biology and Biochemistry (T-216), and Academy of Biochemistry at UACJ. We also wish to thank Dr. Coyolxauhqui Figueroa Batalla from the Herbario at UACJ, for providing technical assistance to properly identify the collected plant specimens.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The present research was financially supported by Consejo Nacional de Ciencia y Tecnología.