The toxicity assessment of extract of Peganum harmala L. seeds in Caenorhabditis elegans.

Background: Peganum harmala L. is a medicinal herb extensively used in traditional Chinese medicine (TCM). So far, relevant reports on the toxicity of Peganum harmala L. seeds (PHS) are hardly available. Especially, we still know little about the in vivo mechanism for PHS toxicity. This study aims to evaluate the toxicity effects of PHS in Caenorhabditis elegans (C. elegans), investigate the possible mechanism of the toxicity effects of PHS, and provide reference for the pharmacological research of PHS.

Methods: In the present study, the C. elegans was exposed to 0.25, 0.50, 1.00 mg/mL of PHS in nematode growth medium (NGM) at 22 °C in the presence of food. Lethality, lifespan, growth, reproduction, and locomotion behavior assays were performed to evaluate the toxicity effects of PHS in C. elegans. We then determined the mechanism of the toxicity effect of PHS by quantitative real-time polymerase chain reaction (qRT-PCR), acetylcholinesterase (AChE) activity assay, and oxidative stress resistance assays. The main components of PHS were detected by high performance liquid chromatography (HPLC).

Results: Compared with the control group, the lethality of C. elegans was significantly increased when they were exposed to the ethanol extract of PHS at 0.25, 0.50 and 1.00 mg/mL (P < 0.01), and the mean lifespan was significantly decreased (P < 0.01). We also observed that PHS exposure could induce the toxicity on body length, brood size, and locomotion behavior.

Conclusion: Our study shows that the ethanol extract of PHS exerts obvious toxic effects on C. elegans, which would provide new ideas and methods for the biological evaluation of the toxicity of Chinese medicinal materials.