Comparison of enterotoxicity between autumn crocus (Colchicum autumnale L.) and colchicine in the guinea pig and mouse : enterotoxicity in the guinea pig differs from that in the mouse

Rejection behaviour of horses for hay contaminated with meadow saffron (Colchicum autumnale L.)

BACKGROUND

Extensively used grasslands are frequently utilised for hay production for equines. Especially, extensive meadows have a great variety of plant species, which may include plants that are poisonous for equines such as meadow saffron (Colchicum autumnale L.). To authors' knowledge investigations about horses` avoidance behaviour towards dried meadow saffron in hay are missing. Reports of farmers are contrary to clinical symptoms described in case reports and associated with meadow saffron in hay.

OBJECTIVES

The aim of this study was to determine the rejection behaviour of horses for hay contaminated with meadow saffron (MS) when fed ad libitum.

STUDY DESIGN

An 18-day feeding trial with six adult geldings to observe the rejection behaviour for hay contaminated with MS.

METHODS

The horses were fed a basal diet containing hay ad libitum and a mineral supplement during the feeding trial. At six different daytimes, hay contaminated with 1% or 2% dried MS was provided to the horses over a duration of 1 h. The rejection behaviour was observed personally and by video recordings. If a horse ingested more than two plants of MS during one observation period, the observation was stopped and repeated at another day. When the observation period had to be stopped twice, the horse was excluded from the experiment.

RESULTS

Five of six horses ingested MS during the first feeding periods. One horse rejected leaves and capsules at the beginning of the study, but it showed repeated ingestion of MS after the seventh observation period.

MAIN LIMITATIONS

Lack of knowledge about secondary plant metabolites affecting taste and their variability between fresh and dried plants.

CONCLUSIONS

The intake of MS in hay by horses could not be ruled out with certainty. Therefore, feeding hay contaminated with MS should be avoided for equids.

Colchicine increases intestinal permeability, suppresses inflammatory responses, and alters gut microbiota in mice

Although colchicine (COL) has been used to treat gout for more than a thousand years, it has been shrouded in a dark history for a long time due to its high toxicity, especially for the gastrointestinal tract. With the widespread clinical application of COL, COL's toxicity to the gastrointestinal tract has raised concerns. This study's objective was to address the exact intestinal toxicity of COL, with particular attention to the effects of COL on gut microbiota homeostasis. The mice were exposed to various dosages of COL (0.1, 0.5, and 2.5 mg kg^-1 body weight per day) for a week, and the results showed that COL exposure caused serious intestinal injuries, reducing the relative expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and tight junction proteins (zo-1, claudin-1, and occludin) in the ileum and colon tissue. The 16S rRNA gene sequencing analysis of mice feces samples revealed that the composition and diversity of intestinal microbiome underwent a profound remodeling at the dosage of 2.5 mg kg^-1 body weight per day, which may increase the toxic load in the gut. In addition, elevated levels of diamine oxidase (DAO) and lipopolysaccharide (LPS) in serum indicated that COL increased intestinal permeability, impairing intestinal barrier. In conclusion, our results demonstrate that COL's toxicity to the gut microbiome is compatible with intestinal injuries, inflammatory pathway inhibition, and increased intestinal permeability; our results also represent a novel insight to uncover the adverse reactions of COL in the gastrointestinal tract.

Acute Colchicine Poisoning Causes Endotoxemia via the Destruction of Intestinal Barrier Function: The Curative Effect of Endotoxin Prevention in a Murine Model

BACKGROUND

Colchicine binds to intracellular tubulin and prevents mitosis. Colchicine is also used as an anti-inflammatory drug. Meanwhile, excess administration of medication or accidental ingestion of colchicine-containing plants can cause acute colchicine poisoning, which initially results in gastrointestinal effects that may be followed by multiorgan dysfunction. However, the mechanism of colchicine poisoning remains unclear, and there are no standard therapeutic strategies.

AIMS

We focused on intestinal barrier function and attempted to reveal the underlying mechanism of colchicine poisoning using an animal model.

METHODS

Colchicine was orally administered to C57Bl/6 mice. Then, we performed histopathological analysis, serum endotoxin assays, and intestinal permeability testing. Additionally, the LPS-TLR4 signaling inhibitor TAK-242 was intraperitoneally injected after colchicine administration to analyze the therapeutic effect.

RESULTS

We observed villus height reduction and increased numbers of apoptotic cells in the gastrointestinal epithelium of colchicine-treated mice. Both intestinal permeability and serum endotoxin levels were higher in colchicine-treated mice than in control mice. Although colchicine-poisoned mice died within 25 h, those that also received TAK-242 treatment survived for more than 48 h.

CONCLUSION

Colchicine disrupted intestinal barrier function and caused endotoxin shock. Therapeutic inhibition of LPS-TLR4 signaling might be beneficial for treating acute colchicine poisoning.

Grasslands: A Source of Secondary Metabolites for Livestock Health

The need for environmentally friendly practices in animal husbandry, in conjunction with the reduction of the use of synthetic chemicals, leads us to reconsider our agricultural production systems. In that context, grassland secondary metabolites (GSMs) could offer an alternative way to support to livestock health. In fact, grasslands, especially those with high dicotyledonous plant species, present a large, pharmacologically active reservoir of secondary metabolites (e.g., phenolic compounds, alkaloids, saponins, terpenoids, carotenoids, and quinones). These molecules have activities that could improve or deteriorate health and production. This Review presents the main families of GSMs and uses examples to describe their known impact on animal health in husbandry. Techniques involved for their study are also described. A particular focus is put on anti-oxidant activities of GSMs. In fact, numerous husbandry pathologies, such as inflammation, are linked to oxidative stress and can be managed by a diet rich in anti-oxidants. The different approaches and techniques used to evaluate grassland quality for livestock health highlight the lack of efficient and reliable technics to study the activities of this complex phytococktail. Better knowledge and management of this animal health resource constitute a new multidisciplinary research field and a challenge to maintain and valorize grasslands.