Acute and subacute toxicity tests of madder root, natural colorant extracted from madder (Rubia tinctorum), in (C57BL/6 X C3H)F1 mice

Molecular characterization and ecotoxicological evaluation of the natural dye madder and its chlorinated products

There has been increased interest in the use of natural dyes for textile coloration as alternatives to synthetic dyes, due to the general belief that natural dyes are more environmentally friendly. However, natural dyes have poor affinity for textiles, which can lead to high dye levels in the resultant wastewater. While chlorine treatment has proven to be effective for dye wastewater disinfection and decolorization, this process can also lead to the formation of more toxic degradation products for certain synthetic dyes. On the other hand, little information is available regarding the ecotoxicity of natural dyes and their chlorination products. To advance knowledge in this area, madder was selected due to its historical importance and wide application in the textile industry. Specifically, we sought to characterize the chlorine-induced degradation products of an aqueous madder solution and to assess their ecotoxicity. The main component of the present madder sample was Alizarin (89.8%). Chlorination led to complete decolorization, and 2-hydroxynaphthalene-1,4-dione and phthalic anhydride were identified as key degradation products. Chlorination of madder decreased toxicity to Daphnia similis (microcrustacean) 10-fold and removed the toxicity to Raphidocellis subcapitata (algae), when compared to the parent dye.

Anti-adipogenic and anti-obesity activities of purpurin in 3T3-L1 preadipocyte cells and in mice fed a high-fat diet

BACKGROUND

The body responds to overnutrition by converting stem cells to adipocytes. In vitro and in vivo studies have shown polyphenols and other natural compounds to be anti-adipogenic, presumably due in part to their antioxidant properties. Purpurin is a highly antioxidative anthraquinone and previous studies on anthraquinones have reported numerous biological activities in cells and animals. Anthraquinones have also been used to stimulate osteoblast differentiation, an inversely-related process to that of adipocyte differentiation. We propose that due to its high antioxidative properties, purpurin administration might attenuate adipogenesis in cells and in mice.

METHODS

Our study will test the effect purpurin has on adipogenesis using both in vitro and in vivo models. The in vitro model consists of tracking with various biomarkers, the differentiation of pre-adipocyte to adipocytes in cell culture. The compound will then be tested in mice fed a high-fat diet. Murine 3T3-L1 preadipocyte cells were stimulated to differentiate in the presence or absence of purpurin. The following cellular parameters were measured: intracellular reactive oxygen species (ROS), membrane potential of the mitochondria, ATP production, activation of AMPK (adenosine 5'-monophosphate-activated protein kinase), insulin-induced lipid accumulation, triglyceride accumulation, and expression of PPARγ (peroxisome proliferator activated receptor-γ) and C/EBPα (CCAAT enhancer binding protein α). In vivo, mice were fed high fat diets supplemented with various levels of purpurin. Data collected from the animals included anthropometric data, glucose tolerance test results, and postmortem plasma glucose, lipid levels, and organ examinations.

RESULTS

The administration of purpurin at 50 and 100 μM in 3T3-L1 cells, and at 40 and 80 mg/kg in mice proved to be a sensitive range: the lower concentrations affected several measured parameters, whereas at the higher doses purpurin consistently mitigated biomarkers associated with adipogenesis, and weight gain in mice. Purpurin appears to be an effective antiadipogenic compound.

CONCLUSION

The anthraquinone purpurin has potent in vitro anti-adipogenic effects in cells and in vivo anti-obesity effects in mice consuming a high-fat diet. Differentiation of 3T3-L1 cells was dose-dependently inhibited by purpurin, apparently by AMPK activation. Mice on a high-fat diet experienced a dose-dependent reduction in induced weight gain of up to 55%.

Medicinal plants of the Russian Pharmacopoeia; their history and applications

ETHNOPHARMACOLOGICAL RELEVANCE

Due to the location of Russia between West and East, Russian phytotherapy has accumulated and adopted approaches that originated in European and Asian traditional medicine. Phytotherapy is an official and separate branch of medicine in Russia; thus, herbal medicinal preparations are considered official medicaments. The aim of the present review is to summarize and critically appraise data concerning plants used in Russian medicine. This review describes the history of herbal medicine in Russia, the current situation and the pharmacological effects of specific plants in the Russian Pharmacopoeia that are not included in the European Pharmacopoeia.

MATERIALS AND METHODS

Based on the State Pharmacopoeia of the USSR (11(th) edition), we selected plant species that have not yet been adopted in Western and Central Europe (e.g., selected for inclusion in the European Pharmacopoeia) and systematically searched the scientific literature for data using library catalogs, the online service E-library.ru, and databases such as Medline/Pubmed, Scopus, and the Web of Science regarding species, effectiveness, pharmacological effects, and safety.

RESULTS

The Russian Federation follows the State Pharmacopoeia of the USSR (11(th) edition), which contains 83 individual plant monographs. Fifty-one of these plants are also found in the European Pharmacopoeia and have been well studied, but 32 plants are found only in the Pharmacopoeia of the USSR. Many articles about these medicinal plants were never translated in English, and much of the information collected by Russian scientists has never been made available to the international community. Such knowledge can be applied in future studies aimed at a safe, evidence-based use of traditional Russian medicinal plants in European and global phytopharmacotherapy as well as for the discovery of novel leads for drug development.

CONCLUSION

The review highlights the therapeutic potential of these Russian phytopharmaceuticals but also highlights cases where concern has been raised about product safety and tolerability, which would aid in supporting their safe use.

Anthraquinone distribution in the hypogeal apparatus of Rubia peregrina L. growing wild in Sardinia

The isolation, characterisation and quantification of anthraquinones, from hypogeal apparatus of Rubia peregrina L. (Wild Madder) growing wild in Sardinia (Italy) are described. The present study allowed us to perform an easy and fast HPLC analytical method for the detection of anthraquinones in all underground parts of plant. Concentrations of these compounds are variable in the different hypogeal parts before and after hydrolysis of the crude methanolic extracts. Before hydrolysis, we found that pseudopurpurin was 0.18% in rhizomes, alizarin 0.02% in rhizomes and principal stolons, and purpurin 0.56% in stolons of second order. Rubiadin is the major constituent of R. peregrina and reached a higher concentration in principal stolons of up to 4.8%. After hydrolysis, we found some drastic changes: an increase of purpurin in rhizomes (0.04%) and pseudopurpurin in all hypogeal parts (around 0.57%), and a decrease of purpurin in all parts of hypogeal apparatus. The most important change was found in rubiadin concentration, which reached its maximum in principal stolons (11.3%). No anthraquinones were found in the aerial parts of the plant.

A 13-week subchronic toxicity study of madder color in F344 rats

A 13-week repeated oral dose toxicity study of madder color (MC), a natural food colorant extracted from the roots of Rubia tinctorum L., was performed using F344 rats. Five groups of animals, each consisting of 10 males and 10 females, were fed diet containing 0, 0.6, 1.2, 2.5 or 5.0% MC for 13 weeks. During the experiment, lower body weight was evident from the 2.5% dose. Hematologically, fluctuation in red blood cell (RBC) parameters suggestive of weak anemia (females), and slight increases of platelet counts (both sexes) and white blood cell (WBC) counts (males) were observed at higher doses. Serum biochemically, slight fluctuations were observed in many parameters, including increased total protein (TP), conjugated bilirubin, Ca, and inorganic phosphate, and decrease of the albumin/globulin (A/G) ratio in both sexes, with dose-dependence for TP and A/G from 0.6% in females. Histopathological changes were mainly observed in the renal proximal tubules, such as microvesicular vacuolar degeneration in the cortex and karyomegaly in the outer medulla involving both sexes, lesions being evident even with 0.6%. In the outer medulla, elevation of cell proliferation activity as assessed with proliferating cell nuclear antigen was observed in males from 2.5%. Severity of focal necrosis of hepatocytes was increased only in females at 5.0%, while the increased relative liver weight as with the increased conjugated bilirubin was evident in both sexes from 1.2%. The results thus suggest that MC exerts mild toxicity, targeting liver, kidneys, and possibly RBCs and WBCs, some renal changes being evident from 0.6% in diet, that is attributable to be the lowest-observed adverse effect level (305.8-309.2mg/kg body weight/day).

Two validated HPLC methods for the quantification of alizarin and other anthraquinones in Rubia tinctorum cultivars

Direct and indirect HPLC-UV methods for the quantitative determination of anthraquinones in dried madder root have been developed, validated and compared. In the direct method, madder root was extracted twice with refluxing ethanol-water. This method allowed the determination of the two major native anthraquinone glycosides lucidin primeveroside and ruberythric acid. In the indirect extraction method, the anthraquinone glycosides were first converted into aglycones by endogenous enzymes and the aglycones were subsequently extracted with tetrahydrofuran-water and then analysed. In this case the anthraquinones alizarin, purpurin and nordamnacanthal may be determined. The content of nordamnacanthal is proportional to the amount of lucidin primeveroside originally present. The indirect extraction method is easier to apply. Different madder cultivars were screened for their anthraquinone content.

Chemical and enzymatic hydrolysis of anthraquinone glycosides from madder roots

For the production of a commercially useful dye extract from madder, the glycoside ruberythric acid has to be hydrolysed to the aglycone alizarin which is the main dye component. An intrinsic problem is the simultaneous hydrolysis of the glycoside lucidin primeveroside to the unwanted mutagenic aglycone lucidin. Madder root was treated with strong acid, strong base or enzymes to convert ruberythric acid into alizarin and the anthraquinone compositions of the suspensions were analysed by HPLC. A cheap and easy method to hydrolyse ruberythric acid in madder root to alizarin without the formation of lucidin turned out to be the stirring of dried madder roots in water at room temperature for 90 min: this gave a suspension containing pseudopurpurin, munjistin, alizarin and nordamnacanthal. Native enzymes are responsible for the hydrolysis, after which lucidin is converted to nordamnacanthal by an endogenous oxidase.