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Copper-sensitive chemically modified electrodes (CMEs) were constructed by incorporating 2,9-dlmethyl-1,10-phenanthrollne Into a conventional carbon-paste mixture composed of graphite powder and Nujol oil. Copper was chemically deposited on these CMEs by Immersion In a Cu(I) solution, and the

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Cancer is the second leading cause of death, for which current therapeutic approaches are still very limited. Chemoprevention is an important approach to decreasing cancer morbidity and mortality by the use of non-toxic natural or synthetic substances to reverse the processes of initiation and subsequent progression of cancer. A substantial amount of evidence from human, animal and cell line studies has shown that many herbal products used for traditional Chinese medicine (TCM) can exert chemopreventive effects. The underlying theory for TCM to treat or prevent cancer is to bring the patient back to a healthy state by modifying multiple cancer-causing events. Since carcinogenesis involves multiple abnormal genes/pathways, using TCM in cancer chemoprevention may be superior to the agents targeting a single molecular target alone. However, before TCM can be accepted universally as complementary and alternative medicine for cancer treatment and prevention, it is crucial to understand the molecular basis for their effects. This review highlights several known molecular mechanisms of selected TCM in chemoprevention. Many TCM products or single active components have been reported to inhibit a variety of processes in cancer cell growth, invasion and metastasis by modulating a wide range of molecular targets, including cyclooxygenase-2 (COX-2), nuclear factor-Kappa B (NF-kappaB) and nuclear factor erythroid 2 -related factor 2 (Nrf2)-mediated antioxidant signaling pathways. The TCM and their active components with potent chemopreventive effects can be considered as promising lead agents for the design of more effective and less toxic agents for cancer chemoprevention.

Pancreatic cancer is a lethal disease with a dreadful 5-year survival rate of only 5%. In spite of several treatment options, the prognosis still remains extremely poor. Therefore, novel therapy strategies with combinations of drugs are urgently required to combat this fatal disease. Tripto-lide (TPL) and celastrol (CL), two main compounds in traditional Chinese medicine isolated from Thunder God Vine, have a broad range of bioactivities including anticancer activity. Silk fibroin (SF), a naturally occurring protein with several unique properties, is an ideal carrier mate-rial. In this study, we prepared TPL and CL loaded silk fibroin nanoparticles (TPL-SFNPs and CL-SFNPs) by a modified desolvation method and evaluated their synergistic effects against human pancreatic cancer cells. Both SFNPs were characterized for particle size and zeta poten-tial. The entrapment efficiency, drug loading, and drug release profiles were evaluated by HPLC. The cytotoxicity and synergistic effect of SFNPs were investigated in MIA PaCa-2 and PANC-1 human pancreatic cells. The results showed that the particle sizes of TPL-SFNPs and CL-SFNPs were 166.4 ± 4.6 nm and 170.4 ± 2.3 nm, with a mean zeta potential −27.2 ± 2.0 mV and −25.5 ± 2.57 mV, respectively. TPL-SFNPs and CL-SFNPs have a drug loading of 57.0 ± 4.7 μg/mg and 63.5 ± 3.8 μg/mg along with an encapsulation efficiency of 81.8 ± 2.8% and 87.0 ± 5.1%, respectively. Drug release studies revealed that a rapid release of the drugs from SFNPs was observed at pH 4.5 (lysosomal pH) and a delayed release was observed at pH 7.4 (plasma pH). TPL-SFNPs (IC50 3.80 and 4.75 nM) and CL-SFNPs (IC50 0.38 and 0.64 μM) were 2–3 fold more potent against MIA PaCa-2 and PANC-1 cells than free TPL (IC50 11.25 and 11.58 nM) and CL (IC50 0.84 and 1.23 μM). Furthermore, co-treatment with TPL-SFNPs and CL-SFNPs increased the growth inhibition of the same cells significantly in comparison with TPL-SFNPs or CL-SFNPs alone. Almost all combination index (CI) values, calculated using the Compusyn software, were < 1, suggesting that the growth inhibition effect of TPL-SFNPs in combination with CL-SFNPs was synergistic rather than additive, further suggesting that this novel combination may offer a potential treatment for pancreatic cancer.