Targeted metabolomics assisted rapid screening and characterization of aristolochic acids and their DNA adducts in aristolochia plants by ultra-high performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry.

Aristolochic acids are one of the major compounds in aristolochia plants, which are nephrotoxic and carcinogenic. A method was established for the detection and identification of aristolochic acids and their DNA adducts in four different herbs using ultra-high performance liquid chromatography-ion mobility quadrupole time-of flight mass spectrometry. Solid phase extraction conditions were optimized to improve the sensitivity of the experiment by using 40 mg of C18 as adsorbent and 100 µL ethanol as elution solvent. At a collision energy of 10-40 eV, these compounds and cleavage patterns were precisely identified and analyzed by secondary fragmentation and collision cross section values. The obtained mass spectrometry data were then analyzed by targeted metabolomics, including principal component analysis, partial least squares-discriminant analysis and hierarchical clustering analysis, and importing the samples in the established model, the confidence values can reach 0.61 and 0.76. All in all, this method can provide a useful tool for the detection of aristolochic acids and deoxyribonucleic acid adducts. In conclusion, this method was successfully used for the detection and identification of aristolochic acids and their DNA adducts.

Combustion-Derived Pollutants Linked with Kidney Disease in Low-Lying Flood-Affected Areas in the Balkans.

Tens of thousands of people in southern Europe suffer from Balkan endemic nephropathy (BEN), and four times as many are at risk. Incidental ingestion of aristolochic acids (AAs), stemming from the ubiquitousAristolochia clematitis(birthwort) weed in the region, leads to DNA adduct-induced toxicity in kidney cells, the primary cause of BEN. Numerous cofactors, including toxic organics and metals, have been investigated, but all have shown small contributions to the overall BEN relative to non-BEN village distribution gradients. Here, we reveal that combustion-derived pollutants from wood and coal burning in Serbia also contaminate arable soil and test as plausible causative factors of BEN. Using a GC-MS screening method, biomass-burning-derived furfural and coal-burning-derived medium-chain alkanes were detected in soil samples from BEN endemic areas levels at up to 63-times and 14-times higher, respectively, than in nonendemic areas. Significantly higher amounts were also detected in colocated wheat grains. Coexposure studies with cultured kidney cells showed that these pollutants enhance DNA adduct formation by AA, - the cause of AA nephrotoxicity and carcinogenicity. With the coincidence of birthwort-derived AAs and the widespread practice of biomass and coal burning for household cooking and heating purposes and agricultural burning in rural low-lying flood-affected areas in the Balkans, these results implicate combustion-derived pollutants in promoting the development of BEN.

Chemical imitation of yeast fermentation by the drosophilid-pollinated deceptive trap-flower Aristolochia baetica (Aristolochiaceae).

Deceptive flowers, unlike in mutualistic pollination systems, mislead their pollinators by advertising rewards which ultimately are not provided. Although our understanding of deceptive pollination systems increased in recent years, the attractive signals and deceptive strategies in the majority of species remain unknown. This is also true for the genus Aristolochia, famous for its deceptive and fly-pollinated trap flowers. Representatives of this genus were generally assumed to be oviposition-site mimics, imitating vertebrate carrion or mushrooms. However, recent studies found a broader spectrum of strategies, including kleptomyiophily and imitation of invertebrate carrion. A different deceptive strategy is presented here for the western Mediterranean Aristolochia baetica L. We found that this species is mostly pollinated by drosophilid flies (Drosophilidae, mostly Drosophila spp.), which typically feed on fermenting fruit infested by yeasts. The flowers of A. baetica emitted mostly typical yeast volatiles, predominantly the aliphatic compounds acetoin and 2,3-butandiol, and derived acetates, as well as the aromatic compound 2-phenylethanol. Analyses of the absolute configurations of the chiral volatiles revealed weakly (acetoin, 2,3-butanediol) to strongly (mono- and diacetates) biased stereoisomer-ratios. Electrophysiological (GC-EAD) experiments and lab bioassays demonstrated that most of the floral volatiles, although not all stereoisomers of chiral compounds, were physiologically active and attractive in drosophilid pollinators; a synthetic mixture thereof successfully attracted them in field and lab bioassays. We conclude that A. baetica chemically mimics yeast fermentation to deceive its pollinators. This deceptive strategy (scent chemistry, pollinators, trapping function) is also known from more distantly related plants, such as Arum palaestinum Boiss. (Araceae) and Ceropegia spp. (Apocynaceae), suggesting convergent evolution. In contrast to other studies working on floral scents in plants imitating breeding sites, the present study considered the absolute configuration of chiral compounds.

Effects of bioconversion by Battus polydamas on the chemical composition of Aristolochia spp. and evaluation of antimicrobial activity and biocompatibility.

Aristolochia plants are emblematic from an ethnopharmacological viewpoint and are know to possess numerous biological properties, including antiseptic. However, the medicinal potential of these species is debatable because of their representative chemical constituents, aristolochic acids (AAs) and aristolactams (ALs), which are associated, for instance, with nephropathy and cancer. These contrasting issues have stimulated the development of approaches intended to detoxification of aristoloquiaceous biomasses, among which is included the bioconversion method using larvae of the specialist phytophagous insect Battus polydamas, previously shown to be viable for chemical diversification and to reduce toxicity. Thus, eleven Aristolochia spp. were bioconverted, and the antimicrobial activities of the plant methanolic extracts and its respective bioconversion products were evaluated. The best results were found for Aristolochia esperanzae, Aristolochia gibertii, and Aristolochia ringens against Bacillus cereus, with MIC ranging from 7.8 to 31.25 µg/mL. These three species were selected for chemical, antioxidant, cytotoxic, hemolytic, and mutagenic analyses. Chemical analysis revealed 65 compounds, 21 of them possible bioconversion products. The extracts showed potential to inhibit the formation and degradation of B. cereus biofilms. Extracts of A. gibertii and its bioconverted biomass showed antioxidant activity comparable to dibutylhydroxytoluene (BHT) standard. Bioconversion decreased the hemolytic activity of A. esperanzae and the cytotoxicities of A. esperanzae and A. gibertii. None of the extracts was found to be mutagenic. The bioactivities of the fecal extracts were maintained, and biocompatibility was improved. Therefore, the results obtained in this study reveal positive expectations about the natural detoxification process of the Aristolochia species.

Aristolochia bracteolata flower extract based phytosynthesis and characterization of AgNPs: Antimicrobial, antidiabetic, and antioxidant activities potential assessment.

The study was carried out to evaluate the effectiveness of the Aristolochia bracteolata water flower extract-mediated AgNPs synthesis and assess their antimicrobial potential. According to the experimental and analytical results, A. bracteolata flower extract can produce valuable AgNPs. The characteristic features of these AgNPs were assessed with UV-visible spectrophotometer, Fourier transform-infrared spectroscopy, Transmission Electron Microscope, Scanning Electron Microscopy, as well as. Under UV-vis. spectrum results, showed major peak at 430 nm and recorded essential functional groups responsible for reducing, capping, and stabilizing AgNPs by FT-IR analysis. In addition, the size and shape of the synthesized AgNPs were found as 21.11-25.17 nm and spherical/octahedral shape. The A. bracteolata fabricated NPs showed remarkable antimicrobial activity against fish bacterial pathogens (V. parahaemolytics, Serratia sp., B. subtilis, and E. coli) as well as common fungal pathogens (A. niger, C. albicans, A. flavus, and A. terreus) at the quantity of 100 µg mL-1 than positive controls. Nevertheless, it was not effective against human bacterial pathogens. It concludes that AgNPs synthesized from A. bracteolata aqueous flower extract have excellent antimicrobial activity and may have a variety of biomedical applications.

Characterization of two CYP80 enzymes provides insights into aporphine alkaloid skeleton formation in Aristolochia contorta.

Aporphine alkaloids are a large group of natural compounds with extensive pharmaceutical application prospects. The biosynthesis of aporphine alkaloids has been paid attentions in the past decades. Here, we determined the contents of four 1-benzylisoquinoline alkaloids and five aporphine alkaloids in root, stem, leaf, and flower of Aristolochia contorta Bunge, which belongs to magnoliids. Two CYP80 enzymes were identified and characterized from A. contorta. Both of them catalyze the unusual C-C phenol coupling reactions and directly form the aporphine alkaloid skeleton. AcCYP80G7 catalyzed the formation of hexacyclic aporphine corytuberine. AcCYP80Q8 catalyzed the formation of pentacyclic proaporphine glaziovine. Kingdom-wide phylogenetic analysis of the CYP80 family suggested that CYP80 first appeared in Nymphaeales. The functional divergence of hydroxylation and C-C (or C-O) phenol coupling preceded the divergence of magnoliids and eudicots. Probable crucial residues of AcCYP80Q8 were selected through sequence alignment and molecular docking. Site-directed mutagenesis revealed two crucial residues E284 and Y106 for the catalytic reaction. Identification and characterization of two aporphine skeleton-forming enzymes provide insights into the biosynthesis of aporphine alkaloids.

The complete chloroplast genome of Aristolochia fangchi provided insights into the phylogeny and species identification of Aristolochia.

Aristolochia fangchi is an important species within the family Aristolochiaceae, most of which contain nephrotoxic aristolochic acid. The inadvertent use of Aristolochiaceae plants as raw ingredients in the manufacturing of patent medicine poses a significant risk warranting considerable attention. In this study, we assembled and analyzed the complete chloroplast genome of Aristolochia fangchi, which is a 159 867 bp long circular molecule. Functional annotation of the A. fangchi plastome unveiled a total of 113 genes, including 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Subsequently, a series of genome structure and characteristic evaluations were conducted against the A. fangchi plastome. Further phylogenetic analysis suggested that a plausible phylogenetic relationship among Aristolochiaceae derived from the concatenated sequences of shared conserved genes rather than from the entire chloroplast genome with one IR copy. Finally, a DNA polymorphism assessment against a dozen Aristolochia plastomes yielded multiple potential regions for biomarker designation. Six pairs of primers were generated and underwent both in silico and actual PCR validations. In conclusion, this study identified the unique characteristics of the A. fangchi plastome, providing invaluable insights for further investigations on species identification and the phylogeny evolution between A. fangchi and its related species.

Aristolochia mimics stink bugs to repel vertebrate herbivores via TRPA1 activation.

Mimicry is the phenomenon in which one species (the mimic) closely resembles another (the model), enhancing its own fitness by deceiving a third party into interacting with it as if it were the model. In plants, mimicry is used primarily to gain fitness by withholding rewards from mutualists or deterring herbivores cost-effectively. While extensive work has been documented on putative defence mimicry, limited investigation has been conducted in the field of chemical mimicry. In this study, we used field experiments, chemical analyses, behavioural assays, and electrophysiology, to test the hypothesis that the birthwort Aristolochia delavayi employs chemical mimicry by releasing leaf scent that closely resembles stink bug defensive compounds and repels vertebrate herbivores. We show that A. delavayi leaf scent is chemically and functionally similar to the generalized defensive volatiles of stink bugs and that the scent effectively deters vertebrate herbivores, likely through the activation of TRPA1 channels via (E)-2-alkenal compounds. This study provides an unequivocal example of chemical mimicry in plants, revealing intricate dynamics between plants and vertebrate herbivores. Our study underscores the potency of chemical volatiles in countering vertebrate herbivory, urging further research to uncover their potentially underestimated importance.

Rapid simultaneous determination of thirteen aristolochic acids analogs in Aristolochiaceae plants by Ultra-High-Performance liquid Chromatography- tandem mass spectrometry in dynamic multiple reaction monitoring mode.

Asarum and Aristolochia are two large genera of Aristolochiaceae plants containing typical toxicant aristolochic acid analogs(AAAs), AAAs can be deemed as toxicity markers of Aristolochiaceae plants. Based on the least AAAs in dry roots and rhizomes of Asarum heterotropoides, Asarum sieboldii Miq and Asarum sieboldii var, all of which are enrolled in the Chinese pharmacopeia up to now. AAAs distribution in Aristolochiaceae plants, especially Asarum L. plants, is still obscure and controversial due to few AAAs measured, unverified species of Asarum, and complicated pretreatment in analytical samples making the results more challenging to reproduce. In the present study, a simple ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method in dynamic multiple reaction monitoring mode for simultaneous determination of thirteen AAAs was developed for evaluating the distribution of toxicity phytochemicals in Aristolochiaceae plants. The sample was prepared by extracting Asarum and Aristolochia powder with methanol, and the supernatant was analyzed using the Agilent 6410 system on an ACQUITY UPLC HSS PFP column with gradient elution of water and acetonitrile, containing 1% v/v formic acid (FA) each, at a flow rate of 0.3 mL/min. The chromatographic condition provided good peak shape and resolution. The method was linear over the specific ranges with the coefficient of determination (R2) > 0.990. Satisfactory intra- and inter-day precisions were achieved with RSD less than 9.79%, and the average recovery factors obtained were in the range of 88.50%～105.49%%. The proposed method was successfully applied for simultaneous quantification of the 13 AAAs in 19 samples from 5 Aristolochiaceae species, especially three Asarum L. species enrolled in the Chinese Pharmacopoeia. Except Asarum heterotropoides, the results supported that the Chinese Pharmacopoeia (2020 Edition) adopting the root with rhizome as medicinal parts of Herba Asari instead of the whole herb for drug safety by providing scientific data.

Study on the difference and correlation between the contents and toxicity of aristolochic acid analogues in Aristolochia plants.

ETHNOPHARMACOLOGICAL RELEVANCE: The nephrotoxicity and carcinogenicity induced by traditional Chinese medicines (TCMs) containing aristolochic acids (AAs) and related compound preparations have greatly limited their clinical application. While the toxicity of AA-I and AA-II is relatively clear, there are marked differences in the toxic effects of different types of aristolochic acid analogues (AAAs). Thus, the toxicity of TCMs containing AAAs cannot be evaluated based on the toxicity of a single compound. AIM OF THE STUDY: To systematically investigate the toxicity induced by Zhushalian (ZSL), Madouling (MDL) and Tianxianteng (TXT) as representative TCMs derived from Aristolochia. MATERIALS AND METHODS: AAA contents in ZSL, MDL and TXT were determined using HPLC. Subsequently, mice were treated for 2 weeks with high (H) and low (L) dosages of TCMs containing total AAA contents of 3 mg/kg and 1.5 mg/kg, respectively. Toxicity was evaluated using biochemical and pathological examination and was based on organ indices. Correlations between AAA contents and induced toxicity were analysed using multiple methods. RESULTS: Of the total AAA content, ZSL contained mainly AA-I and AA-II (>90%, of which AA-I accounted for 49.55%). AA-I accounted for 35.45% in MDL. TXT mainly contained AA-IVa (76.84%) and other AAAs accounted for <10%. Short-term toxicity tests indicated that ZSL and high-dose MDL induced obvious renal interstitial fibrosis and gastric injury, whereas TXT (high and low dosages) caused only slight toxicity. Correlation analysis suggested that AA-I might be the critical hazard factor for toxicity. CONCLUSIONS: The toxicity of TCMs containing AAAs cannot be generalised. The toxicity of TXT is relatively low compared with those of ZSL and MDL. The toxicity of Aristolochia depends mainly on the AA-I content; therefore, control of AA-I levels in TCMs and related compound preparations is required to reduce the risk of toxicity associated with the use of Aristolochia herbs in clinical settings.

Characterization of two putative norlaudanosoline methyltransferases from Aristolochia debilis.

In view of the nephrotoxicity, hepatotoxicity, and carcinogenicity of aristolochic acids (AAs), the removal of AAs from plants becomes an urgent priority for ensuring the safety of Aristolochia herbal materials. In this study, based on the root-predominant distribution of aristolochic acid I (AAI) in Aristolochia debilis, transcriptome sequencing, in combination with phylogenetic analyses, and gene expression pattern analysis together provided five candidate genes for investigating AAI biosynthesis. Comprehensive in vitro and in vivo enzymatic assays revealed that Ab6OMT1 (6-O-methyltransferase) and AbNMT1 (N-methyltransferase) exhibit promiscuity in substrate recognition, and they could act in a cooperative fashion to achieve conversion of norlaudanosoline, a predicted intermediate in AAI biosynthetic route, into 3'-hydroxy-N-methylcoclaurine through two different methylation reaction sequences. These results shed light on the molecular basis for AAI biosynthesis in Aristolochia herbs. More importantly, Ab6OMT1 and AbNMT1 may be employed as targets for the metabolic engineering of AAI biosynthesis to produce AAs-free Aristolochia herbal materials.

Genetic diversity assessment and biotechnological aspects in Aristolochia spp.

Aristolochia, belonging to the family Aristolochiaceae, has immense ecological significance due to its large size and huge geographic distribution. In the context of dealing with a genus with a huge number of species like Aristolochia, these markers come in handy to precisely identify a particular species and enumerate the genetic diversity. Also, certain species of Aristolochia are economically important due to the presence of secondary metabolites and vast use in traditional and modern medicine. But, the presence of profitable biochemical constituents in Aristolochia is very low and the breeding process of the plant is highly dependable on pollinators. Hence, identifying different biotechnological approaches to fasten the reproductive cycle of Aristolochia and increase the secondary metabolites is of great interest to the researchers. In this study, a comprehensive review has been established on different types of morphological/anatomical markers (starch grains with "Maltese cross"), phytochemical markers (aristolochic acid, triterpenoid, aristolactam etc.) and genetic markers (ISSR, SSR, DNA bar-coding) for various Aristolochia spp. We have also discussed the applications of different biotechnological tools in Aristolochia spp. which include discrete approaches to promote in vitro germination, in vitro shooting, root induction, somatic embryogenesis, synthetic seed production, acclimatization and hardening and sustainable production of secondary metabolites. In a nutshell, the present review is a first of kind approach to comprehensively demonstrate the genetic diversity studies and biotechnological aspects in Aristolochia spp. KEY POINTS: • Insights into the in vitro propagation of Aristolochia spp. • In vitro production and optimization of secondary metabolites. • Assessment of genetic diversity by molecular markers.

[Risk assessment, safe medication and scientific supervision of traditional Chinese medicine containing aristolochic acids--toxicity is different among aristolochic acids, and detection and control of aristolochic acid â /â ¡ is critical].

The safety problem of traditional Chinese medicine containing aristolochic acid is of great concern in China and abraod, which poses a challenge in clinical application and supervision. There are many types of aristolochic acid analogues(AAAs) and 178 have been reported. According to the structure, they are classified into aristolochic acids(AAs) and aristololactams(ALs). The toxi-city is remarkably different among AAAs of different types. For example, AA-Ⅰ has strong nephrotoxicity and carcinogenicity, and the toxicity of AA-Ⅱ is lower than that of AA-Ⅰ. Besides, AA-Ⅳa and AA-Ⅰa are considered to have no obvious nephrotoxicity and carcinogenicity. The types and content of AAAs are significantly different among traditional Chinese medicines derived from different Aristolochiaceae species. For example, Asari Radix et Rhizoma and Aristolochiae Herba mainly consist of AAAs without obvious toxicity(such as AA-Ⅳa). The content of AAAs in compound preparations is related to the proportions of the medicinals and the processing method. The content of AA-Ⅰ in some compound preparations is very low or below the detection limit. Therefore, the author concludes that AAAs of different types have different toxicity, but not all AAAs has nephrotoxicity and carcinogenicity. Moreover, the toxicity of traditional Chinese medicines containing AAAs should not be generalized and AA-Ⅰ and AA-Ⅱ should be emphasized. In this paper, it is suggested that traditional Chinese medicine containing AAAs should be used rationally and research, analysis, and toxicological study of AAAs species and content should be strengthened. In addition, limit standards of AA-Ⅰ and AA-Ⅱ should be formulated and science-based supervision should be performed.

Consumption of nephrotoxic plants among chronic hemodialysis patients in the Eastern region of Morocco: A multicentric cross-sectional study.

ETHNOPHARMACOLOGICAL RELEVANCE: The consumption of nephrotoxic plants is quite frequent in Morocco and could explain the high prevalence of indeterminate nephropathy in patients with End-Stage Kidney Disease (ESKD). AIM OF THE STUDY: to determine, in a population of chronic hemodialysis (CHD) patients and before the occurrence of ESKD, the prevalence of the use of nephrotoxic plants, in particular, Aristolochia longa L. (Bereztam) and the etiological role of plants in the rapid progression of known and unknown nephropathy toward the end stage of chronic hemodialysis. MATERIALS AND METHODS: This was a multicentric cross-sectional study spread over 12 months (May 2019-May 2020), carried out in public hemodialysis centers in the eastern region of Morocco. Clinical data were collected from medical records. Herbal and sociodemographic data were collected from a detailed and precise interview with each enrolled CHD patient. RESULTS: A total of 404 CHD patients participated in the study. 71.5%, had used medicinal plants before the occurrence of ESKD and 32.9% had indeterminate nephropathy. Among the plants consumed, we identified plants whose kidney toxicity was well demonstrated, mainly Rhamnus alaternus L. (Mlilas) in 66.7%, Artemisia herba alba Asso (Chih) in 54.32%, Aristolochia longa L.(Bereztam) in 52.6%, and Rubia tinctorum L. (Fowa) in 47.4%. 27.7% of CHD patients had presented complications following the use of the plants before the occurrence of ESKD. In multivariate analysis, the use of plants to treat digestive disorders (OR 9.57; 95%CI [4.49-20.37], P < 0.001) and asthenia associated with anemia (OR 8.59; 95%CI [3.92-18.81], P < 0.001), as well as side effects observed after taking the plants (OR 4; 95%CI [1.09, 14.7], P = 0.03), were identified as significant risk factors for the occurrence of severe indeterminate nephropathy. CONCLUSIONS: This study showed the high prevalence of consumption of nephrotoxic herbs which may be the root cause of chronic renal failure in CHD patients.

Ethno medical knowledge and traditional use of Aristolochia bracteolata Lam. for malaria among local communities in Jubek State of South Sudan: A cross-sectional survey.

ETHNOPHARMACOLOGICAL RELEVANCE: The recognized challenges to access conventional antimalarial medicines could have contributed to the extensive use of Aristolochia bracteolata Lam. (Aristolochiaceae)to manage malaria in South Sudan traditionally. However, the use and acquired experiences are notwell documented. AIM OF THE STUDY: This study aimed to document the traditional use of A. bracteolata for malaria treatment and experiences among the local communities in Jubek State of South Sudan. METHODS: We performed a cross-sectional study in four counties in Jubek State and interviewed 396 community members, including traditional healers, using a semi-structured questionnaire. Four focused group discussions (FGDs) were also conducted using the interviewer guide. The inclusion criteria were; adults 18 years and older, men andwomen participants, at least one year residing in the study area before the study, and those with a history of medicinal plant use. Data were summarized and presented as proportions. Qualitative data were analyzed using a thematic content approach. The major themes that emerged were discussed. We applied the Pearson Chi-Square test at α = 0.05 to test the study's significant differences in responses. The statistical package for social sciences version 21 software was used for data analysis. RESULTS: Women accounted for 208 (52.5%) of participants, with the majority 321 (81.1%) were between 18 and 45 years. Interestingly, most 312 (78.8%) had formal education. Moreover, about 208 (52.5%) participants collect the plant in their vicinity, where leaves were the most commonly used part 277 (46.4%), followed by the roots, seeds, and stems at 245(41.0%), 71 (11.9%), and 4 (0.7%), respectively. Furthermore, about 63 (15.9%) of the participants experienced side effects, including early abortions, heartburns, sweating, and stomach discomforts. Conversely, a total of 387 (96.0%) reported getting cured of malaria. Generally, the quantity of medicine taken per day differs concerning parts of the plant, with leaves ranging from 1 to 10 pieces, roots at 0.4-1 g, and seeds at 0.1-0.5 g. The locals used these plant parts to prepare infusion and decoction traditional dosage forms for oral use. CONCLUSION: The documented medicinal plant's therapeutic uses provided critical information on the traditional use of A. bracteolata by the community in Jubek state of South Sudan to treat malaria. Although most users reported getting cured of malaria, a notable proportion of them experienced side effects, including early-stage abortion and stomach discomforts. Thus, the use of A. bracteolata preparations, particularly in pregnant women, should be avoided. Finally, further studies are needed to devise a strategy to neutralize the toxic compounds and create community awareness on best practices to minimize side effects.

Rapid characterization and pharmacokinetic study of aristolochic acid analogues using ion mobility mass spectrometry.

Aristolochic acid analogues (AAAs), naturally existing in herbal Aristolochia and Asarum genera, were once widely used in traditional pharmacopeias because of their anti-inflammatory properties, but lately they were identified as potential nephrotoxins and mutagens. A method for rapid characterization of AAAs in serum was developed using ion mobility spectrometry coupled with mass spectrometry (IMS-MS). Five AAAs, containing four aristolochic acids and one aristolactam, were separated and identified within milliseconds. AAAs were separated in gas phase based on the difference of their ion mobility (K0), and then identified based on their K0 values, m/z, and product ions from MS/MS. Quantitative analysis of AAAs was performed using an internal standard with a satisfactory sensitivity. Limits of detection (signal-to-noise = 3) and quantification (signal-to-noise = 10) were 1-5 ng/mL and 3-8 ng/mL, respectively. The method was validated and successfully applied to the pharmacokinetics study of AAAs in rats, offering a promising way for fast screening and evaluation of AAAs in biological samples.

Chemotaxonomy of the ethnic antidote Aristolochia indica for aristolochic acid content: Implications of anti-phospholipase activity and genotoxicity study.

ETHNOPHARMACOLOGICAL RELEVANCE: Aristolochia indica L. (Aristolochiaceae) is a common medicinal plant described in many traditional medicine as well as in Ayurveda used against snakebites. Besides, the plant has also been reported traditionally against fever, rheumatic arthritis, madness, liver ailments, dyspepsia, oedema, leishmaniasis, leprosy, dysmenorrhoea, sexual diseases etc. The plant is known to contain its major bioactive constituent aristolochic acid (AA) known for its anti-snake venom, abortifacient, antimicrobial and antioxidant properties. MATERIALS AND METHODS: This present work describes a validated, fast and reproducible high performance thin layer chromatography (HPTLC) method to estimate AA from the roots of 20 chemotypes of A. indica procured from 20 diverse geographical locations from the state of West Bengal, India. Further, an evidence-based approach was adopted to investigate the reported anti-venom activity of the aqueous extracts of the A. indica roots by assessing its phospholipase A2 (PLA2) inhibitory properties since PLA2 is a major component of many snake-venoms. Finally, the cytotoxicity and genotoxicity of the aqueous root extract of the Purulia (AI 1) chemotype were assessed at various concentrations using Allium cepa root meristematic cells. RESULTS: The highest amount of AA (7643.67 µg/g) was determined in the roots of A. indica chemotype collected from Purulia district followed by the chemotypes collected from Murshidabad, Jalpaiguri and Birbhum districts (7398.34, 7345.09 and 6809.97 µg/g respectively). This study not only determines AA in the plants to select pharmacologically elite chemotypes of A. indica, but it also identifies high AA producing A. indica for further domestication and propagation of the plants for pharmacological and industrial applications. The method was validated via analyzing inter-day and intra-day precision, repeatability, reproducibility, instrumental precision, limit of detection (LOD) and limit of quantification (LOQ) and specificity. Chemotypes with high AA content exhibited superior anti-PLA2 activity by selectively inhibiting human-group PLA2. Moreover, A. indica root extract significantly inhibited mitosis in Allium cepa root tips as a potent clastogen. CONCLUSIONS: The present quick, reproducible and validated HPTLC method provides an easy tool to determine AA in natural A. indica plant populations as well as in food and dietary supplements, a potential antivenin at one hand and a possible cause of aristolochic acid nephropathy (AAN) at another. Besides, the cytotoxic and mitotoxic properties of the root extracts should be used with caution especially for oral administration.

Two New Aristolochic Acid Analogues from the Roots of Aristolochia contorta with Significant Cytotoxic Activity.

Twelve compounds, including two new aristolochic acid analogues with a formyloxy moiety (9-10) and 10 known aristolochic acid derivates (1-8 and 11-12), were obtained from the roots of Aristolochiacontorta. Their structures were elucidated using extensive spectroscopic methods. Their cytotoxic activity in human proximal tubular cells HK-2 was evaluated by the MTT method, which has been widely used to assess cell viability. Among these molecules, compounds 3 and 9 were found to be more cytotoxic. Furthermore, molecular modeling was used to evaluate, for the first time, the interactions of compounds 3 and 9 with the target protein organic anionic transporter 1 (OAT1) that plays a key role in mediating aristolochic acid nephropathy. Structure-activity relationships are briefly discussed.

Determination of Aristolochic Acids in Vegetables: Nephrotoxic and Carcinogenic Environmental Pollutants Contaminating a Broad Swath of the Food Supply and Driving Incidence of Balkan Endemic Nephropathy.

Balkan endemic nephropathy (BEN) is a slowly progressive interstitial fibrotic disease affecting numerous people living along the Danube River in the Balkan Peninsula, of which aristolochic acids (AAs) produced naturally in Aristolochia plants are key etiological agents. However, the exposure biology of the disease remains poorly understood. Initially, the high incidence of BEN in the Balkan Peninsula was thought to occur through ingestion of bread prepared from flour made with wheat grains comingled with the seeds of Aristolochia clematitis L., an AA-containing weed that grows abundantly in the wheat fields of the affected areas. In this study, by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, we show for the first time that vegetables, in particular root vegetables of endemic areas, are extensively contaminated with AAs taken up through root absorption from the AA-tainted soil. Furthermore, we found a pH dependence of the n-octanol/water partition coefficient (Kow) of AAs, which resulted in a dramatically higher hydrophobicity-driven plant uptake efficiency of AAs into food crops in endemic areas, characterized by higher acidity levels, compared to non-endemic areas. We believe the results of this study have significantly unraveled the mystery surrounding the uneven distribution of BEN incidence.