Is herbal tea consumption a factor in endemic nephropathy?

Abstract

Endemic (Balkan) nephropathy (EN) is a chronic tubulointerstitial nephropathy frequently associated with upper urothelial cancer exclusively affecting farming villagers [1,2,3]. Based on our results, EN is considered to be an environmental form of aristolochic acid nephropathy (AAN) [1,2.3]. AAN was first reported in 1993 in Belgium and subsequently more AAN cases were reported worldwide as AA has been an integral part of traditional herbal medicines [4]. The extent of this problem was recently documented in Taiwan where precise data on prescriptions of herbal products containing AA is available [5]. Aristolochia spp. has been used for more than 2000 years in the practice of traditional medicine and European physicians were familiar with the use of this plant as well. After its intrinsic toxicity became known, importing Aristolochia herbs was banned in many countries, including Croatia. Nevertheless, products containing AA remain a part of traditional medicine and are sold in many countries that do not have strict control protocols. Recently we reported that AA DNA adducts were present in 95% of patients with EN who underwent surgery for upper urothelial cancers [2] and affirmed the idea that bread contaminated with AA might be the cause of EN [6,7]. However, the causative relationship between AA and EN again raised the question whether bread intake is the only route of ingestion or whether AA was ingested also in EN as a part of folkloric medicine. Gluhovschi et al. reported that although therapeutic remedies based on AA products are used in the EN affected area, no relationship between these remedies and the development of EN or of tumors was observed [8]. However, they used HPLC for detection of AA in plasma, which is less sensitive than the mass spectrometry we recently used [1,2]. In addition, when re-analyzing their data, it does appear that AA was used more frequently in the endemic area. In our opinion, this leaves the question whether herbal tea may play a role in EN still unanswered. In our preliminary study we failed to find any evidence in the group of 1041 Croatian farmers that herbal tea or traditional medicine use is related to EN [9]. The observed differences between Romania and Croatia might reflect cultural and historical differences in traditional medicine. Aiming to resolve this disagreement more conclusively we analyzed whether herbal teas, including those prepared from Aristolochia clematitis, were used more frequently in Croatian and Bosnian residents of an endemic area than in farmers from non-endemic villages. A total of 3168 adults from nine endemic and three non-endemic villages were enrolled (the participation rate was 76.73%). The epidemiological survey was designed to collect demographic, medical, and family history information, as well as dietary and environmental exposures, with an emphasis on the exposure to AA through drinking teas prepared from A. clematitis. Farmers were asked questions: 1): Did you ever use any herbal teas when you were sick?; 2): Did you ever buy, prepare or...

The Rotterdam Study: 2014 objectives and design update

“…For additional EJE references see [10,126,128,142,240,[453][454][455][456][457][458][459][460][461][462][463][464][465][466][467][468].…”

Balkan Endemic Nephropathy and the Causative Role of Aristolochic Acid

“…34 It was questioned whether bread consumption was the only route of AA ingestion in BEN patients in the past. Although reports from Romania suggested that herbal medicine also might be a risk factor for AA exposure in BEN, 35 Ivkovi c et al, 36 in a large cohort of more than 2,500 Croatian farmers, rejected this hypothesis and confirmed that the use of herbs and herbal teas was not associated with BEN. Gruia et al 37 and Pavlovi c et al 38 speculated whether other plants (maize and cucumber) were capable of absorbing AA and thus being a secondary source of food poisoning.…”

Nitroreduction: A Critical Metabolic Pathway for Drugs, Environmental Pollutants, and Explosives

“…Aristolochic acid, AAI (8-methoxy-6-nitro-phenthro-(3,4- d )-1,3-dioxole-5-carboxylic acid) and aristolochic acid, AAII (6-nitro-phenthro-(3,4- d )-1,3-dioxole-5-carboxylic acid) are major components of aristolochic acid derived from Aristolochia species. They are contaminants of wheat grown in the Balkans and are also constituents of herbal teas . AAI is the cause of a rapidly progressive renal fibrosis and predisposes exposed individuals to urothelial tract carcinoma and bladder cancer .…”