The Quinovic Acid Glycosides Purified Fraction from Uncaria tomentosa Protects against Hemorrhagic Cystitis Induced by Cyclophosphamide in Mice.

Uncaria tomentosa is widely used in folk medicine for the treatment of numerous diseases, such as urinary tract disease. Hemorrhagic cystitis (HE) is an inflammatory condition of the bladder associated with the use of anticancer drugs such as cyclophosphamide (CYP). Sodium 2-mercaptoethanesulfonate (Mesna) has been used to prevent the occurrence of HE, although this compound is not effective in established lesions. It has been demonstrated that the purinergic system is involved in several pathophysiological events. Among purinergic receptors, P2X7 deserves attention because it is involved in HE induced by CYP and, therefore, can be considered a therapeutic target. The objective of this study was to investigate the potential therapeutic effect of the quinovic acid glycosides purified fraction (QAPF) from U. tomentosa in the mouse model of CYP-induced HE. Pretreatment with QAPF not only had a protective effect on HE-induced urothelial damage (edema, hemorrhage and bladder wet weight) but was also able to control visceral pain, decrease IL-1ß levels and down-regulates P2X7 receptors, most likely by inhibit the neutrophils migration to the bladder. This research clearly demonstrates the promising anti-inflammatory properties of QAPF, supporting its use as complementary therapy. QAPF represents a promising therapeutic option for this pathological condition.

Decrease of serum adenine nucleotide hydrolysis in an irritant contact dermatitis mice model: potential P2X7R involvement.

Extracellular adenosine 5'-triphosphate (ATP) has significant effects on a variety of pathological conditions and it is the main physiological agonist of P2X7 purinergic receptor (P2X7R). It is known that ATP acting via purinergic receptors plays a relevant role on skin inflammation, and P2X7R is required to neutrophil recruitment in a mice model of irritant contact dermatitis (ICD).The present study investigated the effects of chemical irritant croton oil (CrO) upon ATP, ADP, and AMP hydrolysis in mice blood serum, and the potential involvement of P2X7R. The topical application CrO induced a decrease on soluble ATP/ADPase activities (~50 %), and the treatment with the selective P2X7R antagonist, A438079, reversed these effects to control level. Furthermore, we showed that CrO decreased cellular viability (52.6 % ± 3.9) in relation to the control and caused necrosis in keratinocytes (PI positive cells). The necrosis induced by CrO was prevented by the pre-treatment with the selective P2X7R antagonist A438079. The results presented herein suggest that CrO exerts an inhibitory effect on the activity of ATPDase in mouse serum, reinforcing the idea that ICD has a pathogenic mechanism dependent of CD39. Furthermore, it is tempting to suggest that P2X7R may act as a controller of the extracellular levels of ATP.

Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line.

Bladder cancer is the second most prevalent malignancy in the genitourinary tract and remains a therapeutic challenge. In the search for new treatments, researchers have attempted to find compounds with low toxicity. With this goal in mind, Uncaria tomentosa is noteworthy because the bark and root of this species are widely used in traditional medicine and in adjuvant therapy for the treatment of numerous diseases. The objective of this study was to investigate the antitumor effect of one purified bioactive fraction of U.tomentosa bark on cell proliferation in two human bladder cancer cell lines, T24 and RT4. Quinovic acid glycosides purified fraction (QAPF) of U.tomentosa decreased the growth and viability of both T24 and RT4 cell lines. In T24 cells, QAPF induced apoptosis by activating caspase-3 and NF-κB. Further study showed that this fraction does not induce cell cycle arrest and does not alter PTEN and ERK levels. In conclusion, we demonstrated that QAPF of U.tomentosa has a potent inhibitory effect on the growth of human bladder cancer cell lines by inducing apoptosis through modulation of NF-κB, and we suggest that QAPF may become a potential therapeutic agent for the prevention and/or treatment of this cancer.

Boldine induces cell cycle arrest and apoptosis in T24 human bladder cancer cell line via regulation of ERK, AKT, and GSK-3ß.

OBJECTIVE: Bladder cancer is one of the most prevalent genitourinary malignancies. Despite active chemotherapy regimens, patients with bladder cancer suffer from a high rate of tumor recurrence. Thus, new approaches and agents to improve quality of life and survival still need to be developed. The objective of the present study was to evaluate the effect and underlying mechanisms of boldine, an aporphine alkaloid of Peumus boldus, on bladder cancer proliferation and cell death. METHODS: Sulforhodamine B assay, Tetrazolium reduction assay, Flow Cytometry Analysis, Ecto-5'-nucleotidase activity and Western blot assay were performed. RESULTS: The results showed that boldine was able to reduce cell viability and cell proliferation in T24 cells. In addition, boldine arrests the cell cycle at G2/M-phase and cause cell death by apoptosis. Boldine-induced inhibition of cell growth and cell cycle arrest appears to be linked to inactivation of extracellular signal-regulated kinase protein (ERK). Additionally, the efficacy of boldine in apoptosis-induced in T24 cells is correlated with modulation of AKT (inactivation) and glycogen synthase kinase-3ß (GSK-3ß) (activation) proteins. CONCLUSIONS: The present findings may, in part, explain the therapeutic effects of boldine for treatment of urinary bladder cancer.

Cat's claw oxindole alkaloid isomerization induced by cell incubation and cytotoxic activity against T24 and RT4 human bladder cancer cell lines.

The antitumor activity of Uncaria tomentosa, a native vine from the Amazonian rainforest, has been ascribed to pentacyclic oxindole alkaloids occurring in its bark. Former studies have shown that this activity, as well as its intensity, depends on whether cat's claw alkaloids occur as original compounds or isomerized derivatives. This work addresses this aspect, using T24 and RT4 human bladder cancer cell lines for that purpose. Bark samples were extracted by dynamic maceration, prepurified with cross-linked polyvinylpyrrolidone and properly fractioned by an ion exchange process to obtain an oxindole alkaloid purified fraction. Alkaloid isomerization was induced by heating it under reflux at 85 °C. Samples collected after 5, 15, and 45 min of heating were analyzed by HPLC-PDA, freeze-dried at once, and separately assayed using the non-isomerized purified fraction for comparison purposes. The latter showed significant and dose-dependent cytotoxic activity against both T24 and RT4 cancer cell lines (IC50: 164.13 and 137.23 µg/mL, respectively). However, results for both cell lines were equivalent to those observed for isomerized samples (p > 0.05). The alkaloid isomerization induced by the incubation conditions (buffered medium pH 7.4 and temperature 37 °C) helps to explain the similar results obtained from non-isomerized and isomerized samples. Mitraphylline, speciophylline, uncarine F, and, to a lesser degree, pteropodine were more susceptible to isomerization under the incubation conditions. Thus, the alkaloid profile of all fractions and their cytotoxic activities against T24 and RT4 human bladder cancer cell lines are determined to a large extent by the incubation conditions.