Evaluation of the toxicological effects of Neltuma alpataco (Prosopis alpataco) pod alkaloid extract

Authors: CHOLICH, LUCIANA - National University Of The Northeast Argentina; PISTAN, MARIA - National University Of The Northeast Argentina; BENITEZ, ANGELICA - National University Of The Northeast Argentina; TORRES, ANA - National University Of The Northeast Argentina; GARCIA, ENRIQUE - National University Of The Northeast Argentina; MARTINEZ, AGUSTIN - Instituto De Clima Y Agua (INTA); GARDNER, DALE - Retired ARS Employee; BUSTILLO, SOLEDAD - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)

Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2024
Publication Date: 2/28/2024
Citation: Cholich, L., Pistan, M., Benitez, A.C., Torres, A., Garcia, E.N., Martinez, A., Gardner, D., Bustillo, S. 2024. Evaluation of the toxicological effects of Neltuma alpataco (Prosopis alpataco) pod alkaloid extract. Toxicon. 241. Article 107665. https://doi.org/10.1016/j.toxicon.2024.107665.
DOI: https://doi.org/10.1016/j.toxicon.2024.107665

Interpretive Summary: The pods of Neltuma spp. have shown potential as a source of protein and energy in livestock. However, prolonged consumption of some of these species can lead to neurological symptoms in ruminants. This study aimed to determine the alkaloid content, as well as the in vitro and in vivo effects of an alkaloid-enriched extract (AEE) from N. alpataco pods. High performance liquid chromatography-high resolution mass spectrometry (HPLCHRMS) identified juliprosine and juliprosopine as primary alkaloids, with juliprosine being most abundant. AEE from N. alpataco demonstrated dose-dependent cytotoxicity on glioma cells after 48 h, with a 50% cytotoxic concentration (CC50) of 24.69 µg/mL. However, the release of LDH was observed only at the highest tested concentration, indicating cellular damage. Further examination through phase-contrast microscopy and dual acridine orange/ethidium bromide fluorescence staining revealed morphological changes consistent with an apoptotic mechanism of cell death, ultimately leading to secondary necrosis. Finally, the LD50 after intraperitoneal injection in mice was determined to be 12.98 mg/kg. Taken together, these findings demonstrated for the first time the in vivo and in vitro toxicity of the AEE from N. alpataco pods.

Technical Abstract: The pods of Neltuma spp. have shown potential as a source of protein and energy in livestock. However, prolonged consumption of some of these species can lead to neurological symptoms in ruminants. This study aimed to determine the alkaloid content, as well as the in vitro and in vivo effects of an alkaloid-enriched extract (AEE) from N. alpataco pods. High performance liquid chromatography-high resolution mass spectrometry (HPLCHRMS) identified juliprosine and juliprosopine as primary alkaloids, with juliprosine being most abundant. AEE from N. alpataco demonstrated dose-dependent cytotoxicity on glioma cells after 48 h, with a 50% cytotoxic concentration (CC50) of 24.69 µg/mL. However, the release of LDH was observed only at the highest tested concentration, indicating cellular damage. Further examination through phase-contrast microscopy and dual acridine orange/ethidium bromide fluorescence staining revealed morphological changes consistent with an apoptotic mechanism of cell death, ultimately leading to secondary necrosis. Finally, the LD50 after intraperitoneal injection in mice was determined to be 12.98 mg/kg. Taken together, these findings demonstrated for the first time the in vivo and in vitro toxicity of the AEE from N. alpataco pods.