Abstract. The clinical use of doxorubicin (DOX), a potent antineoplastic agent, is limited by its serious side-effects, which include acute and chronic cumulative dose-related cardiotoxicity. Berberine (BER), a botanical alkaloid, has been reported to possess cardioprotective and antitumor effects. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-tetrazolium bromide (MTT) assay was used to detect the cell viability of A549, HeLa and HepG2 cells after each cell line was treated with DOX, BER or a combination of DOX and BER for 24 h. Apoptosis was evaluated by acridine orange staining. The results showed that BER and DOX exhibited dose-dependent inhibitory effects on A549 and HeLa cells which were likely mediated by inducing apoptosis. The same result was found in the combination group. Isobologram illustration and combination index (CI) analyses revealed that the combination of DOX and BER generates synergistic effects in A549 (CI=0.61) and HeLa (CI= 0.73) cells. These findings indicate that BER sensitizes cells to the anticancer effects of DOX. IntroductionDoxorubicin (DOX), an anthracycline antibiotic and antineoplastic agent, was first isolated from Streptomyces peucetius (1). DOX is a potent chemotherapeutic agent that is used in the treatment of solid tumors and malignant hematological diseases (2). DOX exerts its antitumor activity by inserting into DNA, leading to double-stranded DNA breaks (DSB), and intercepting DNA topoisomerase II activity (3,4). However, the clinical use of DOX has been largely restricted due to its cardiotoxicity, which may lead to the development of cardiomyopathy and ultimately congestive heart failure (5). The molecular mechanisms underlying DOX-induced cardiotoxicity include the formation of free radicals, activation of transcription factor NF-κB, increased lipid peroxidation and Ca 2+ overloading (6-8). The use of cardioprotective drugs is an alternative approach to reduce the cardiotoxicity of DOX. Pharmacological and clinical attempts to reduce the cardiotoxicity of DOX have had little success thus far. Consequently, it is important to develop a therapy to reduce DOX-induced cardiotoxicity and increase the antitumor effect of DOX.Berberine (BER), a botanical alkaloid, is purified from the roots and bark of the Berberis species (9). BER reportedly possesses multiple biological and pharmacological properties, including anti-diarrheal, anti-fungal, anti-diabetic (10-12), hepatoprotective and cardioprotective effects. The possible mechanism of the hepatoprotective effect is that BER inhibits the activity of CYP 2E1 and CYP 1A2, reduces the production of nitric oxide and lowers the AST and ALT levels in serum (13,14). For the cardioprotective property, BER is known to modulate Cdk9 and cyclin T1 protein expression. BER possesses muscarinic agonist-like properties which may contribute to a reduction in myocardial damage (15-17). BER also suppresses tumor growth through the induction of apoptosis and cell cycle arrest in cancer cells (18)(19)(20)(21). Notably, it has been reported tha...

Doxorubicin, a very potent and often used anti-cancer drug, is largely limited due to the dose-related toxic effects. The present study investigated whether berberine, a natural product alkaloid, can reduce the liver injury induced by doxorubicin. Mice of either gender were randomly divided into four groups: the control group, doxorubicin group, berberine group, and berberine doxorubicin group. In the tests, body weight, general condition and mortality of the mice were observed, and serum alanine aminotransferase and aspartate transaminase levels were determined to evaluate liver function. Furthermore, the liver was excised for determination of the weight changes, as well as histopathological analysis in the tissues. Mortality rate and significant decline in body weight, and increased plasma alanine aminotransferase and aspartate transaminase activities were observed in doxorubicin-treated mice. These changes were significantly prevented by pretreatment with berberine. Histopathological studies showed that doxorubicin caused structural injuries, such as vascular congestion, inflammatory cell infiltration, hepatocellular degeneration and necrosis, fibrosis in the liver. These histopathological changes were largely attenuated by berberine pretreatment. These findings indicate that berberine has the hepatoprotective effect on doxorubicin-induced liver injury in mice.

Background and AimsArsenic trioxide (As2O3), which used as an effective agent in the treatment of leukaemia and other solid tumors, is largely limited by its toxicity. QT prolongation, torsades de pointes and sudden heart death have been implicated in the cardiotoxicity of As2O3. The present study was designed to explore whether the combination of As2O3 and resveratrol could generate a more powerful anti-cancer effect both in vitro and in vivo.Materials and MethodsMTT assay was performed to assess the proliferation of Hela, MCF-7 and NB4 cells. Isobolographic analysis was used to evaluate combination index values from cell viability data. The apoptosis and the cellular reactive oxygen species (ROS) level were assessed by fluorescent microscopy and flow cytometry separately in vitro. The effect of As2O3, alone and in combination with resveratrol on Hela tumor growth in an orthotopic nude mouse model was also investigated. The tumor volume and the immunohistochemical analysis of CD31, CD34 and VEGF were determined.ResultsResveratrol dramatically enhanced the anti-cancer effect induced by As2O3 in vitro. In addition, isobolographic analysis further demonstrated that As2O3 and resveratrol generated a synergistic action. More apoptosis and ROS generation were observed in the combination treatment group. Similar synergistic effects were found in nude mice in vivo. The combination of As2O3 and resveratrol dramatically suppressed both tumor growth and angiogenesis in nude mice.ConclusionsCombining As2O3 with resveratrol would be a novel strategy to treat cancer in clinical practice.

Taken together, the present study suggested that ART and Res possessed the synergistic anti-tumor effect. ART in combination with Res could be an effective therapeutic strategy for cancer.

Arsenic trioxide (As2O3), an effective agent to treat leukemia and other solid tumors, is largely limited by its toxicity. QT prolongation, torsades de pointes and sudden death have been implicated in the cardiotoxicity of As2O3. The present study was designed to assess whether the combination of As2O3 and tetrandrine could generate a more powerful anti-cancer effect. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed for detecting the proliferation of HepG2 and A549 cells treated with tetrandrine and As2O3. Fluorescent microscopy measurements and flow cytometry were carried out to evaluate the apoptosis in HepG2 cells. The cell cycle arrest of HepG2 cells was also determined by flow cytometry. The cell proliferation assay in HepG2 and A549 cells indicated that tetrandrine significantly enhanced the inhibit effect of As2O3. In addition, the following Isobolograms further demonstrated that combining As2O3 with tetrandrine generated synergism action. Tetrandrine also enhanced the apoptosis, necrosis and cell cycle arrest in As2O3-treated HepG2 cells. Our present study showed that tetrandrine can dramatically enhance the anti- cancer effect induced by As2O3. Combining As2O3 with tetrandrine would be a novel strategy to treat cancer in clinical practice.