Effects Of Aristolochic Acid Research Articles

Aristolochic acid I exposure decreases oocyte quality.

Oocyte quality is a determinant of a successful pregnancy. The final step of oocyte development is oocyte maturation, which is susceptible to environmental exposures. Aristolochic acids (AAs), widely existing in Aristolochia and Asarum plants that have been used in traditional medicine, can result in a smaller ovary and fewer superovulated oocytes after in vivo exposure to mice. However, whether AAs affect oocyte maturation and the underlying mechanism(s) are unclear. In this study, we focused on the effect of Aristolochic acid I (AAI), a major compound of AAs, on the maturation of in vitro cultured mouse oocytes. We showed that AAI exposure significantly decreased oocyte quality, including elevated aneuploidy, accompanied by aberrant chiasma patterns and spindle organization, and decreased first polar body extrusion and fertilization capability. Moreover, embryo development potential was also dramatically decreased. Further analyses revealed that AAI exposure significantly decreased mitochondrial membrane potential and ATP synthesis and increased the level of reactive oxygen species (ROS), implying impaired mitochondrial function. Insufficient ATP supply can cause aberrant spindle assembly and excessive ROS can cause premature loss of sister chromatid cohesion and thus alterations in chiasma patterns. Both aberrant spindles and changed chiasma patterns can contribute to chromosome misalignment and thus aneuploidy. Therefore, AAI exposure decreases oocyte quality probably via impairing mitochondrial function.

Induction of Apoptosis from Exposure to Aristolochic acid

The genus Aristolochia gathers plants used in folk medicine, which present in their composition the Aristolochic acids I and II. Among the major toxicological events caused by Aristolochic acids is programmed cell death. Aristolochic acid induced apoptosis occurs in target organs such as the liver, kidney, pancreas, testis, ovary, intestine and lung. Although it is beneficial for the cure of various diseases Aristolochias or Aristolochic acids I and II can also cause necrosis. The objective of this work was to compile information about the effects of Aristolochic acids on the induction of apoptosis. The present work makes an alert when consuming this herb, and derivatives that possess Aristolochic acids.

Induction of apoptosis from exposure to aristolochic Acid

The genus Aristolochia gathers plants used in folk medicine which present in their composition the Aristolochic acids I and II Among the major toxicological events caused by Aristolochic acids is programmed cell death Aristolochic acid induced apoptosis occurs in target organs such as the liver kidney pancreas testis ovary intestine and lung Although it is beneficial for the cure of various diseases Aristolochias or Aristolochic acids I and II can also cause necrosis The objective of this work was to compile information about the effects of Aristolochic acids on the induction of apoptosis The present work makes an alert when consuming this herb and derivatives that possess Aristolochic acids

Study of the Effect of Aristolochic Acid on Mice Kidney and the Effect of Withdrawal: Histological and Immunohistochemical Study

Aristolochic acid (AA), one of the commonly used herbal medicines was reported to cause harmful effect on kidney. In this work, we aimed to study the effect of AA on renal tissue and to investigate the effect of its withdrawal. Methods: Forty five adult male mice were randomly assigned to three groups. Control group, Group 1 where mices were treated with aristolochic acid (AA) i.p. in a dose of 3 mg/kg every 3 days for 6 weeks. In group 2 the (remodeling group), AA was administered i.p. in a dose of 3 mg/kg every 3 days for 6 weeks, followed by 6 weeks remodeling (withdrawal) time. Urine and blood samples were collected; creatinine, BUN and P/C ratio were estimated. Renal specimens were processed for histological examination by H&E, Masson trichrome and immunohistochemical stain for PCNA. Results: in group 1 treated with AA, histological examination revealed that some tubules were atrophied collapsed while others were dilated. Tubular cells exhibited cytoplasmic vacuolation, flattening, necrosis and even shedding. The matrix between tubules was expanded. In the surrounding interstitial areas, mononuclear cell infiltration was observed. Tubulointerstitial cell proliferation was significantly increased as indicated by PCNA immunostaining. This correlates with worsening of renal parameters. However, in group 2, withdrawal of AA led to marked improvement of renal parameters, preservation of renal tissue and reduction of tubular damage and cellular infiltrate. Also, the number of PCNA-positive cells was significantly reduced. In conclusion, aristolochic acid is nephrotoxic and cessation of its administration leads to reduction of this toxicity as was evidenced by laboratory, histological and immunohistochemical methods.

Effects of aristolochic acid I and/or hypokalemia on tubular damage in C57BL/6 rat with aristolochic acid nephropathy

Background/AimsThis study was designed to investigate the roles of aristolochic acid I (AA-I) and hypokalemia in acute aristolochic acid nephropathy (AAN).MethodsAfter an adaptation period (1 week), a total of 40 C57BL/6 mice (male, 8 weeks old) were divided into four groups: I (control group), II (low potassium [K] diet), III (normal K diet with administration of AA-I [10 mg/kg weight]), and IV (low K diet with AA-I). After collecting 24 hours of urine at 2 weeks, the mice were sacrificed, and their blood and kidneys were obtained to perform immunochemical staining and/or Western blot analysis.ResultsProteinuria, glycosuria, and increased fractional excretion of sodium and K were prominent in groups III and IV (p < 0.05). Diffuse swelling and poor staining of collecting duct epithelial cells were evident in the medullas of group II. Typical lesions of toxic acute tubular injury were prominent in the cortices of groups III and IV. Α-Smooth muscle actin (α-SMA) was higher in the cortices of the mice in groups III and IV versus group II (p < 0.05), and higher in the medullas of group IV than groups I and III (p < 0.05). E-cadherin was higher in the cortices of groups III and IV compared to group I (p < 0.05). The F4/80 value was higher in the cortices and medullas of groups II, III, and IV compared to group I (p < 0.05), particularly in the case of group II.ConclusionsAA-I can induce acquired Fanconi syndrome in the acute stage of AAN. Macrophages appear to play a key role in the pathogenesis of AAN and hypokalemic nephropathy. It remains uncertain whether hypokalemia plays any role in AAN and hypokalemia.

The effect of aristolochic acid I on expression of NAD(P)H:quinone oxidoreductase in mice and rats—A comparative study

Aristolochic acid is the cause of aristolochic acid nephropathy (AAN) and Balkan endemic nephropathy (BEN) and their associated urothelial malignancies. Using Western blotting, we investigated the expression of NAD(P)H:quinone oxidoreductase (NQO1), the most efficient cytosolic enzyme that reductively activates aristolochic acid I (AAI) in mice and rats. In addition, the effect of AAI on the expression of the NQO1 protein and its enzymatic activity in these experimental animal models was examined.We found that NQO1 protein levels in cytosolic fractions isolated from liver, kidney and lung of mice differed from those expressed in these organs of rats. In mice, the highest levels of NQO1 protein and NQO1 activity were found in the kidney, followed by lung and liver. In contrast, the NQO1 protein levels and enzyme activity were lowest in rat-kidney cytosol, whereas the highest amounts of NQO1 protein and activity were found in lung cytosols, followed by those of liver.NQO1 protein and enzyme activity were induced in liver and kidney of AAI-pretreated mice compared with those of untreated mice. NQO1 protein and enzyme activity were also induced in rat kidney by AAI. Furthermore, the increase in hepatic and renal NQO1 enzyme activity was associated with AAI bio-activation and elevated AAI-DNA adduct levels were found in ex vivo incubations of cytosolic fractions with DNA and AAI. In conclusion, our results indicate that AAI can increase its own metabolic activation by inducing NQO1, thereby enhancing its own genotoxic potential.

Science Translational Medicine Podcast: 7 August 2013

In this podcast, Bin Tean Teh explains the carcinogenic effects of aristolochic acid, an herbal compound used in traditional Chinese medicine.

Transcriptome analysis identifies the carcinogenic effects of aristolochic acid in rat kidney

Transcriptome analysis identifies the carcinogenic effects of aristolochic acid in rat kidney

Study on the Nitric Oxide Generating Effects from Aristolochic Acid in vitro

In this study, an in vitro nitric oxide (NO)-assay system based on the Griess reaction was used to investigate the (NO)-generating effects of aristolochic acid (AA) for the first time. AA was separated into its different components, aristolochic acid I (AAI) and aristolochic acid II (AAII), by preparative HPLC. AAI and AAII were incubated with human intestine bacteria (HIB) or rat intestine bacteria (RIB). A NO mixture generated from AAI and AAII by intestinal bacteria was observed and denitroso metabolites of AAI or AAII were detected in vitro by liquid chromatography/tandem mass spectrometry. Therefore, NO generation might be closely related to the metabolic process of AA in vitro. It suggested that one possible mechanism for the toxicity of AA may be due to the generation of NO from these compounds by intestinal bacteria.

Effect of aristolochic acid on intracellular calcium concentration and its links with apoptosis in renal tubular cells

Aristolochic acid (AA) has been demonstrated to play a causal role in Chinese herbs nephropathy. However, the detailed mechanism for AA to induce apoptosis of renal tubular cells remains obscure. In this study, we show that AA evokes a rapid rise in the intracellular Ca(2+) concentration of renal tubular cells through release of intracellular endoplasmic reticulum Ca(2+) stores and influx of extracellular Ca(2+), which in turn causes endoplasmic reticulum stress and mitochondria stress, resulting in activation of caspases and finally apoptosis. Ca(2+) antagonists, including calbindin-D(28k) (an intracellular Ca(2+) buffering protein) and BAPTA-AM (a cell-permeable Ca(2+) chelator), are capable of ameliorating endoplasmic reticulum stress and mitochondria stress, and thereby enhance the resistance of the cells to AA. Moreover, we show that overexpression of the anti-apoptotic protein Bcl-2 in combination with BAPTA-AM treatment can provide renal tubular cells with almost full protection against AA-induced cytotoxicity. In conclusion, our results demonstrate an impact of AA to intracellular Ca(2+) concentration and its link with AA-induced cytotoxicity.

Effect of aristolochic acid on arachidonic acid cascade and in vivo models of inflammation

Recently, it has been reported that aristolochic acid inhibits phospholipase A2 (PLA2in vitro and also decrease either oedema induced by snake venom and human synovial fluid PLA2. The aim of this research was to study the antiiflammatory activity of aristolochic acid and to investigate the effect of the alkaloid on the enzymes involved in the release of eicosanoids. Our results demonstrate that aristolochic acid is able to inhibit inflammation induced by immunological, immune complexes, and nonimmunological agents such as carrageenan or croton oil. We suggest that one mechanism of the antiinflammatory activity of alkaloid may be directly blocking PLA2 catalyzed release of arachidonic acid. Moreover, this study demonstrates that aristolochic acid could also inhibit other steps involved in eicosanoids release such as cyclooxygenase and lipooxygenase pathways.

Characterization of three edema-inducing phospholipase A 2 enzymes from habu ( Trimeresurus flavoviridis) venom and their interaction with the alkaloid aristolochic acid

A basic phospholipase A 2 (PLA 2) enzyme, TFV PL-X (pI 9.2) and two acidic PLA 2 enzymes, TFV PL-Ia (pI 4.9) and TFV PL-Ib (pI 4.5) were purified from Trimeresurus flavoridis venom on CM-Sephadex C-25 and QAE-Sephadex A-25 columns, respectively. The basic enzyme exists as a monomer, whereas the acidic enzymes are dimers. These enzymes differ in properties such as molecular weight, K m , optimum pH and temperature and pharmacological properties. The basic enzyme hydrolysed purified phospholipids in the order of PC > PE > PS > PI = 0, while for TFV PL-Ia and TFV PL-Ib the order was PC > PE > PS = PI = 0. TFV PL-X was comparatively more toxic, with an ld 50 value of 4.2 μg/g (i.p.), while the acidic PLA 2 enzymes had ld 50 values above 8 μg/g (i.p.). All three enzymes induced edema when injected into the mouse foot pad. Aristolochic acid, an alkaloid (8-methoxy-6-nitrophenanthro(3,4-d)-1,3-dioxole-5-carboxylic acid) from the medicinal plant Aristolochia radix, interacts with these PLA 2 enzymes. It is a competitive inhibitor with varying affinity when PC is used as substrate. Aristolochic acid inhibits direct and indirect hemolytic activity, as well as edema-inducing activity, of TFV PL-X, but fails to neutralize the lethal potentcy of the enzyme. On the other hand, it inhibits direct and indirect lytic activity of TFV PL-Ia and TFV PL-Ib only at 10-fold higher concentrations and it enhances the edema-inducing activity of these enzymes. Such effects of aristolochic acid indicates that (1) different mechanisms may be involved in the edema-inducing activity of PLA 2 enzymes and (2) catalytic and pharmacological sites are separate on the PLA 2 molecule.