Abstract Doxorubicin is a chemotherapy drug but its clinical using is limited because of its cardiotoxicity. Reactive oxygen species play an important role in the pathological process. The aim of this study is to evaluate the protective effect of Rheum turkestanicum Janisch., Polygonaceae, against doxorubicin-induced apoptosis and death in H9c2 cells. The cells were incubated with different concentrations of R. turkestanicum extract and N-acetylcysteine as positive control for 2 h, followed by incubation with 5 µM doxorubicin for 24 h. Cell viability and apoptotic induction were determined by using MTT and PI assays, respectively. The level of reactive oxygen species and lipid peroxidation was measured by fluorimetric methods. Doxorubicin significantly decreased cell viability which was accompanied by an increase in ROS production and lipid peroxidation. Pretreatment with R. turkestanicum increased the viability of cardiomyocytes and could decrease lipid peroxidation and reactive oxygen species generation. Also, R. turkestanicum attenuated apoptotic induction. N-acetylcysteine at 100 µM reduced the levels of reactive oxygen species and lipid peroxidation. But, treating H9c2 cells with N-acetylcysteine did little to protect H9c2 cells from doxorubicin-induced cell death. R. turkestanicum exerts protective effect against oxidative stress-induced cardiomyocytes damage. Our findings showed that R. turkestanicum could exert the cardioprotective effects against doxorubicin-induced toxicity partly by anti-apoptotic activity. Also, N-acetylcysteine prevented oxidative stress via reduction of reactive oxygen species and lipid peroxidation. N-acetylcysteine induced less protective effects than R. turkestanicum extract against doxorubicin-induced cytotoxicity.

Embora medicamentos disponíveis atualmente sejam úteis no controle de complicações da Diabetes, complicações aparecem em grande número de pacientes. Considerando-se a fisiopatologia do Diabetes, a prevenção da degeneração de células beta e o estímulo da regeneração endógena de ilhotas será abordagem essencial para o tratamento de diabetes mellitus insulino-dependente. A presente revisão aborda compostos fitoquímicos, cujo efeito é provado na proteção/regeneração de células beta de pâncreas. Entre centenas de plantas que têm sido investigadas para o diabetes, pequena fração tem mostrado propriedade regenerativa, que será descrita neste trabalho. Os processos de degeneração e de regeneração das células beta do pâncrease são descritos. Além disso, mecanismos propostos para efeitos de proteção e regeneração desses compostos fitoquímicos e seus possíveis efeitos colaterais também serão discutidos neste trabalho.

Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreatic beta cell protection/regeneration. Among the hundreds of plants that have been investigated for diabetes, a small fraction has shown the regenerative property and was described in this paper. Processes of pancreatic beta cell degeneration and regeneration were described. Also, the proposed mechanisms for the protective/regenerative effects of such phytochemicals and their potential side effects were discussed.