Chemometric analysis of Amaranthus retroflexus in relation to livestock toxicity in southern Australia

Amaranthus hybridus (syn. quitensis) intoxication in cattle in Argentina: Case report

Amaranthus spp. is a nephrotoxic plant with unknown toxic principle, affecting production animals worldwide, mainly in South America. The aim of this paper is to describe 5 spontaneous outbreaks of A. hybridus intoxication in beef cattle, where 7 autopsies were performed. Main gross findings were pale diffuse and enlarged kidneys. Microscopically, kidneys were characterized by severe tubular acute to subacute nephrosis, with dilatated tubules showing different degrees of epithelial degeneration and necrosis, and containing intraluminal eosinophilic hyaline casts. Intratubular birefringent crystals, compatible with oxalate, were observed under polarized light in kidneys from 3 autopsies. Positive von Kossa and red alizarin S staining confirmed the intratubular crystals as calcium deposits. This intoxication occurs mainly in stubble paddocks during summer and early autumn. The data from the present study suggests that oxalates were related to nephrotoxicity due to Amaranthus consumption.

Seed Size, Not Dispersal Syndrome, Determines Potential for Spread of Ricefield Weeds by Gulls

Recent field data suggest that migratory gulls disperse many rice field weeds by gut passage (endozoochory), most of which are dry fruited and widely assumed to have no long-distance dispersal mechanisms, except via human activity. We investigated this mechanism with a feeding experiment, in which seeds of five common rice field weeds (in order of increasing seed size: Juncus bufonius, Cyperus difformis, Polypogon monspeliensis, Amaranthus retroflexus, and the fleshy-fruited Solanum nigrum) were fed to seven individuals of lesser black-backed gulls Larus fuscus held in captivity. We quantified seed survival after collecting faeces at intervals for 33 h after ingestion, then extracting intact seeds and running germination tests, which were also conducted for control seeds. All five species showed high seed survival after gut passage, of >70%. Gut retention times averaged 2-4 h, but maxima exceeded 23 h for all species. Germinability after gut passage was 16-54%, and gut passage accelerated germination in J. bufonius and S. nigrum, but slowed it down in the other species. All species had lower germinability after gut passage compared to control seeds (likely due to stratification prior to the experiment), but the loss of germinability was higher in smaller seeds. There was no evidence that the different dispersal syndromes assigned to the five species (endozoochory, epizoochory or barochory) had any influence on our results. In contrast, mean gut retention time was strongly and positively related to seed size, likely because small seeds pass more quickly from the gizzard into the intestines. Non-classical endozoochory of dry-fruited seeds by waterbirds is a major but overlooked mechanism for potential long-distance dispersal, and more research into this process is likely essential for effective weed management.

In Vitro Potently Active Anti-Plasmodium and Anti-Toxoplasma Mongolian Plant Extracts

PURPOSE

Malaria and toxoplasmosis are important public health diseases affecting millions of people and animals each year, and there is a continuing need for new and improved treatments for them. Plants have provided many opportunities for new drug leads in pharmacology.

METHODS

We examined 43 crude extracts from Mongolian plants for their activities against the Plasmodium falciparum 3D7 strain and the Toxoplasma gondii RH strain using a SYBR Green-based fluorescence assay and a fluorescence-based assay, respectively. The potential toxicity of these extracts was also assessed on human foreskin fibroblast cells (HFF) using a cell viability assay.

RESULTS

From the initial screenings, 11 and 7 crude extracts were effective against T. gondii and P. falciparum, respectively, at 100 µg/ml concentration (≥ 80% inhibition activity). The 50% cytotoxic concentrations of the extracts were estimated on HFF cells, and their 50% inhibitory concentrations (IC₅₀s) were calculated. According to our lead criteria (selective index, SI; value ≥ 10), six plants (Galatella dahurica leaf + flower, Leonurus deminutus leaf + flower, Oxytropis trichophysa aerial part, Schultzia crinita whole plant, Leontopodium campestre root, Spirea salicifolia aerial part) inhibited P. falciparum growth at IC₅₀ values of 5.99-64.15 µg/ml (SI values: 10.11-17.02). Amaranthus retroflexus root was highly active against T. gondii (IC₅₀, 19.89 µg/ml; SI value, 38).

CONCLUSION

This first observation of the anti-Plasmodium and anti-Toxoplasma activities of Mongolian plant extracts shows them to be interesting potential candidates for drug discovery.

Underutilization Versus Nutritional-Nutraceutical Potential of the Amaranthus Food Plant: A Mini-Review

Amaranthus is a C4 plant tolerant to drought, and plant diseases and a suitable option for climate change. This plant could form part of every region’s cultural heritage and can be transferred to the next generation. Moreover, Amaranthus is a multipurpose plant that has been identified as a traditional edible vegetable endowed with nutritional value, besides its fodder, medicinal, nutraceutical, industrial, and ornamental potentials. In recent decade Amaranthus has received increased research interest. Despite its endowment, there is a dearth of awareness of its numerous potential benefits hence, it is being underutilized. Suitable cultivation systems, innovative processing, and value-adding techniques to promote its utilization are scarce. However, a food-based approach has been suggested as a sustainable measure that tackles food-related problem, especially in harsh weather. Thus, in this review, a literature search for updated progress and potential uses of Amaranthus from online databases of peer-reviewed articles and books was conducted. In addition, the nomenclature, nutritional, and nutraceutical value, was reviewed. The species of focus highlighted in the review include, A. blitum, A. caudatus, A. cruentus, A. dubius, A. hypochondriacus, A. spinosus, A. thunbergii, A. tricolor, and A. viridis.