Ginkgo biloba Food Supplements on the European Market - Adulteration Patterns Revealed by Quality Control of Selected Samples.

The aim of this study was to prove whether Ginkgo biloba food supplements on the European market comply with pharmaceutical quality, and whether their composition satisfies the European Pharmacopoeia criteria. Medicinal products containing a standardised Ginkgo leaf extract are used for the improvement of cognitive impairment and quality of life in mild dementia. Further, Ginkgonis folium is used for the treatment of peripheral circulation disorders. Pharmacopoeial Ginkgo dry extract contains 22.0 - 27.0% flavonoids and 5.4 - 6.6% terpene lactones (ginkgolides, bilobalide). In addition to its widespread use as an herbal medicine (herbal medicinal product), the same extract can be an ingredient in food supplements. The content of active secondary metabolites was quantified in a number of European food supplements containing Ginkgo dry extract or Ginkgo leaf. Flavonoids were quantified using a modified pharmacopoeial HPLC-UV method, and terpene lactones (ginkgolides A, B, C, and bilobalide) using LC-MS/MS. Some Ginkgo leaf supplement samples were also analysed by microscopy. The quality of food supplements on the European market is dubious. In this paper, we present selected examples of several methods of adulteration and falsification, including higher/lower doses of Ginkgo dry extract or Ginkgo leaf than declared and the addition of undeclared extraneous materials. These examples reveal several patterns in the manufacturing of adulterated products.

Elemental analysis of Ginkgo biloba leaf samples collected during one vegetation period.

The object of our work was the identification and quantification of inorganic elements in Ginkgo biloba L. leaves (Ginkgonis folium, Ginkgoaceae) by X-ray fluorescence analysis. The plant material was obtained from a 50-years-old female tree at the Comenius University Botanical Garden (Bratislava, Slovakia). Leaves were collected from early May to late September, with the last sample consisting of fallen leaves. The elements analyzed were: phosphorus, sulfur, potassium, calcium, scandium, iron, zinc, yttrium, molybdenum, tellurium, samarium, gadolinium, dysprosium, iridium, thallium and lead. The amounts of the monitored heavy metals were below the limits specified in Ph. Eur. 7 and PhS 1.

Black currant phytoconstituents exert chemoprevention of diethylnitrosamine-initiated hepatocarcinogenesis by suppression of the inflammatory response.

Black currant fruits containing high amounts of anthocyanins are known to possess potent antioxidant and anti-inflammatory properties. We have previously reported that anthocyanin-rich black currant skin extract (BCSE) inhibits diethylnitrosamine (DENA)-initiated hepatocarcinogenesis in rats although the underlying mechanisms are not fully understood. Our present study investigates the anti-inflammatory mechanisms of BCSE during DENA rat liver carcinogenesis. Dietary BCSE (100 or 500 mg/kg) treatment for 22 wk afforded a striking inhibition of DENA-induced hepatic gamma-glutamyl transpeptidase-positive preneoplastic foci in a dose-responsive fashion. There was a significant increase in hepatic expression of heat shock proteins (HSP70 and HSP90), cyclooxygenase-2, and nuclear factor-κB (NF-κB) in DENA-exposed rat livers. Dietary BCSE dose-dependently abrogated all these elevated inflammatory markers. The possible cardiotoxicity of BCSE was assessed by monitoring cardiac functions using transthoracic echocardiography. BCSE-mediated anti-inflammatory effects during rat liver carcinogenesis have been achieved without any cardiotoxicity. Our results provide convincing evidence, for the very first time, that suppression of the inflammatory cascade through modulation of the NF-κB signaling pathway could be implicated, at least in part, in the chemopreventive effects of black currant bioactive phytoconstituents against experimental hepatocarcinogenesis. These results coupled with an excellent safety profile of BCSE support the development of black currant phytochemicals for the chemoprevention of inflammation-driven hepatocellular cancer.

Identification of triterpenes from milkweed (Asclepias syriaca).

The chloroform extract of Asclepias syriaca stem were investigated. Three triterpenes were isolated by TLC, VLC, and preparative chromatography, and their structures established by one and two-dimensional NMR spectroscopy. Lupenyl acetate has been isolated for the first time from A. syriaca; this is thefirst representative of a triterpene bearing a lupane skeleton in this species. In addition, alpha-amyrin acetate and alpha-amyrin butyrate were isolated.

Black currant anthocyanins abrogate oxidative stress through Nrf2- mediated antioxidant mechanisms in a rat model of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC), considered to be one of the most lethal cancers with almost > 1 million deaths reported annually worldwide, remains a devastating disease with no known effective cure. Hence, chemopreventive strategies come into play, offering an effective and safe mode of treatment, ideal to ward off potential cancer risks and mortality. A major predisposing condition, pertinent to the development and progression of HCC is oxidative stress. We previously reported a striking chemopreventive effect of anthocyanin-rich black currant skin extract (BCSE) against diethylnitrosamine (DENA)-initiated hepatocarcinogenesis in rats. The current study aims to elucidate the underlying antioxidant mechanisms of black currant anthocyanins implicated in the previously observed chemopreventive effects against experimental hepatocarcinogenesis. Dietary BCSE (100 and 500 mg/kg) administered four weeks before and 18 weeks after DENA challenge decreased abnormal lipid peroxidation, protein oxidation, and expression of inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (3-NT) in a dose-responsive fashion. Mechanistic studies revealed that BCSE upregulated the gene expression of a number of hepatic antioxidant and carcinogen detoxifying enzymes, such as NAD(P)H:quinone oxidoreductase, glutathione S-transferase, and uridine diphosphate-glucuronosyltransferase isoenzymes, in DENA-initiated animals. Protein and mRNA expressions of nuclear factor E2-related factor 2 (Nrf2) were substantially elevated with BCSE treatment, providing a direct evidence of a coordinated activation of the Nrf2-regulated antioxidant pathway, which led to the upregulation of a variety of housekeeping genes. The results of our study provide substantial evidence that black currant bioactive anthocyanins exert chemopreventive actions against DENA-inflicted hepatocarcinogenesis by attenuating oxidative stress through activation of Nrf2 signaling pathway.

Antiinflammatory activities of Hungarian Stachys species and their iridoids.

The antiinflammatory activities of aqueous extracts prepared from the aerial parts of ten Hungarian Stachys species were investigated in vivo in the carrageenan-induced paw oedema test after intraperitoneal and oral administration to rats. Some of the extracts were found to display significant antiphlogistic effects when administered intraperitoneally and orally; in particular, the extracts of S. alpina, S. germanica, S. officinalis and S. recta demonstrated high activity following intraperitoneal administration. At the same dose of 5.0 mg/kg, these extracts exhibited similar or greater potency than that of the positive control diclofenac-Na. The main iridoids present in the investigated extracts, ajugoside, aucubin, acetylharpagide, harpagide and harpagoside, were also assayed in the same test, and high dose-dependent antiphlogistic effects were recorded for aucubin and harpagoside. These results led to the conclusion that most probably iridoids are responsible for the antiinflammatory effect of Stachys species, but other active constituents or their synergism must also be implicated in the antiinflammatory effect.

Analysis of the essential oil of Amsonia illustris.

The root and leaf essential oils, present in trace amounts in Amsonia illustris Woods. (Apocynaceae), were isolated by steam distillation and their chemical constituents identified by GC-FID and GC-MS. More than 80% of the thirty volatile compounds in the leaf oil were identified, the major constituents being mainly sesquiterpenes like a-humulene (14.5%), beta-caryophyllene (12.4%) and guaiol (11.6%). The volatile ingredients of the root oil were pinocampheol, methyl salicylate, (2E,4E)- decadienal, eugenol and trans-isoeugenol.

Anthocyanin-rich black currant (Ribes nigrum L.) extract affords chemoprevention against diethylnitrosamine-induced hepatocellular carcinogenesis in rats.

Anthocyanins are known to possess potent anticarcinogenic properties against several cancers thus demonstrating potential for cancer prevention. Black currant (Ribes nigrum L., Grossulariaceae) fruits have a high anthocyanin content. This "superfruit" is known to possess various pharmacological effects including alleviation of chronic oxidative stress and inflammation. In contrast to a large volume of literature on the health benefits of black currant, limited evidence on antitumor effects of black currant exists with virtually no data on the prevention of experimental carcinogenesis. In the current study, we have investigated the chemopreventive effects of an anthocyanin-rich black currant skin extract (BCSE) utilizing our well-characterized model of rat liver carcinogenesis. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary BCSE for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. BCSE dose-dependently decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules. The antihepatocarcinogenic effect of BCSE was confirmed by histopathological examination of liver sections. Immunohistochemical analysis of proliferating cell nuclear antigen and DNA fragmentation revealed BCSE-mediated inhibition of abnormal cell proliferation and induction of apoptosis in DENA-induced rat liver tumorigenesis respectively. Mechanistic studies revealed that BCSE-mediated proapototic signal during experimental hepatocarcinogenesis may be propagated via the up-regulation of Bax and down-regulation of Bcl-2 expression at the translational level. These results along with a safety profile of BCSE encourage the development of black currant bioactive constituents as chemopreventive agents for human liver cancer.

Anthocyanin-rich black currant extract suppresses the growth of human hepatocellular carcinoma cells.

Dietary antioxidants, such as anthocyanins, are helpful in the prevention and control of various diseases by counteracting the imbalance of oxidative and antioxidative factors in the living systems. Black currant (Ribes nigrum L., Grossulariaceae) is known to contain high amounts of anthocyanins (250 mg/100 g fresh fruit). Black currant fruits have been used in Asian and European traditional medicine for the treatment of a variety of diseases. Black currant extract has recently been found to be the second most effective amongst nine different berry extracts studied for their free radical scavenging activity. Constituents present in black currant juice have been found to exert a number of health-promoting effects, including immunomodulatory, antimicrobial and antiinflammatory actions, inhibition of low-density lipoprotein, and reduction of cardiovascular diseases. Although antioxidant and antiinflammatory effects of black currant juice could be of value in preventing and treating oxidative stress- and inflammation-driven cancers, no experimental evidence is available to now. The objective of the present study was to evaluate the potential antiproliferative effects of black currant fruit skin extract against HepG2 human liver cancer cells. The aqueous extract yielded an anthocyanin-rich fraction with cyanidin-3-O-rutinoside as one of the major anthocyanins. This fraction exhibited a potent cytotoxic effect on HepG2 cells and this effect was more pronounced than that of delphinidin and cyanidin, two major aglycones of anthocyanins present in black currant. Our results indicate, for the first time, that black currant skin containing an anthocyanin-rich fraction inhibits the proliferation of liver cancer cells, possibly due to additive as well as synergistic effects. This product could be useful in the prevention and treatment of human hepatocellular carcinoma.