Toxicity of Anthraquinones: Differential Effects of Rumex Seed Extracts on Rat Organ Weights and Biochemical and Haematological Parameters

Abstract

The genus Rumex and related species such as Rheum and Polygonum are widely used as medicinal herbs and foods. They contain anthraquinones (AQ) such as emodin and chrysophanol as active ingredients, and there is concern about the toxicity of these compounds. This study evaluated the chronic effects of Rumex patientia seed aqueous and ethanolic extracts, in male and female rats separately, on organ weights and over 30 haematological, biochemical and histological parameters, immediately after 14-week administration and after a further period of 15 days without drug treatment. Adverse changes were associated with long-term AQ administration, and these focussed on the liver, lung and kidney, but after 15-day convalescence, most had reverted to normal. In general, male rats appeared to be more susceptible than female rats at similar doses. The water extract produced no irreversible changes, which may reflect the lower dose of the AQ constituents or the presence of different ancillary compounds, and supports the traditional method of extracting Rumex seeds with water. In conclusion, ethanolic extracts of R. patientia caused irreversible pathological changes at very high doses (4000mg/kg), but lower doses and aqueous extracts produced either non-significant or reversible changes. Long-term administration of high doses of AQ extracts over a long period of time should be avoided until further assurances can be given, and given other existing reports of reproductive toxicity, should be avoided altogether during pregnancy.

Emodin: A Review of its Pharmacology, Toxicity and Pharmacokinetics

“…Ethanol solution extracts of R . patientia , which contain anthraquinones, such as emodin and chrysophanol, as active ingredients, caused irreversible pathological changes at very high doses (4000 mg/kg), although lower doses and aqueous extracts produced either non‐significant or reversible changes (Islam et al ., ). Therefore, long‐term administration of high doses of anthraquinones extracts should be avoided altogether during pregnancy.…”

Natural Quinone Dyes: A Review on Structure, Extraction Techniques, Analysis and Application Potential

“…The natural origin of molecules, in this case quinones, does not guarantee that they are harmless. Indeed, some natural quinones, such as anthraquinones from Rumex patientia that are used in the pharmaceutical and food industries, can cause pathological effects in vivo if used at high doses (≥ 4000 mg/kg), whereas lower doses produce slight or nonsignificant effects [88]. One report on the toxicity of various natural anthraquinones indicated a potential health and genotoxic effect on animals and humans if these quinones, and especially their aglycones, are directly ingested into the body in large quantity (≥ 1000 mg/kg) for a longer period (at least 2 weeks), despite their low bioavailability (< 0.1) [89] Nevertheless, when compared with synthetic anthraquinone or azo dyes, the natural substances are less harmful.…”

Naturally occurring anthraquinones as potential inhibitors of SARS-CoV-2 main protease: an integrated computational study

“…In addition to the FDA-approved drug, boceprevir here we observed that the anthraquinones, particularly alterporriol Q possess significant inhibitory potential towards SARS-CoV-2 M pro . Naturally occurring anthraquinones have low toxicity and different biological activities (Chien et al 2015 ; Islam et al 2015 ). Therefore, these observations indicate promising potential for the use of natural anthraquinones for the treatment of COVID-19.…”