Synthesis and biological evaluation of novel demethylzeylasteral derivatives as potential anticancer agents.

Demethylzeylasteral (DEM), a class of terpenoids isolated from natural plants, frequently exhibits moderate or limited inhibitory effect on tumor growth across multiple cancer types. Thus, here we attempted to elevate the anti-tumor efficacy of DEM by altering active groups in its chemical structure. Initially, we synthesized a series of novel DEM derivatives 1-21 through performing a series of modifications of its phenolic hydroxyl groups at C-2/3, C-4 and C-29 positions. The anti-proliferative activities of these new compounds were subsequently assessed using three human cancer cell line models (A549, HCT116 and HeLa) and CCK-8 assay. Our data showed that compared to original DEM compound, derivative 7 exhibited remarkable inhibition effect on A549 (16.73 ± 1.07 µM), HCT116 (16.26 ± 1.94 µM) and HeLa (17.07 ± 1.09 µM), almost reaching to the same level of DOX. Moreover, the structure-activity relationships (SARs) of the synthesized DEM derivatives were discussed in detail. We found that treatment with derivative 7 only led to moderate cell cycle arrest at S-phase in a concentration-dependent manner. Meanwhile, derivative 7 treatment markedly induced apoptosis in tumor cells. Consistent with this observation, our subsequent docking analysis showed that derivative 7 is capable of activating caspase-3 through interaction with the His 121 and Gly 122 residues of the enzyme. Overall, we have developed a new series of DEM derivatives with elevated anti-tumor efficacy relative to its parent form. The results suggested that derivative 7 has great potential to be employed as an anticancer agent candidate for natural product-based cancer chemotherapy.

Chemomodulatory effect of neferine on DMBA-induced squamous cell carcinogenesis: Biochemical and molecular approach.

BACKGROUND: Neferine (NEF) is nontoxic, bisbenzylisoquinoline alkaloid is derived from the seed embryo of lotus, a familiar medicinal plant. Although several mechanisms have been planned, an evident antitumor action pathway of NEF on the oral tumor is still not known. In the current study, we aimed at investigating the protecting effect of NEF against experimental oral carcinoma and clarify its possible mechanism through the induction of apoptosis, proliferation, and inflammatory signaling pathways. METHODS: The experimental hamsters were divided into four groups (I-IV) containing six hamsters each. The group I was control group, group II and III hamsters treated with 7,12-dimethylbenz(a)anthracene (DMBA) (0.5%) alone, thrice in a week for 10 weeks, and group III and IV hamsters received oral supplementation of NEF at a concentration of 15 mg/kg bw. All the hamsters were sacrificed after 16 weeks. RESULTS: Our results revealed that DMBA treated hamsters exhibited 100% oral tumor cell formation with high-tumor incidence (TI), tumor number (TN), tumor volume (TV), decreased levels of antioxidants, increased status of lipid peroxidation (LPO), and modulated the activities of liver marker agents as well as NF-kB, cell proliferation (PCNA), and p53 proteins. NEF supplementation in DMBA treated hamsters, resulted in delayed lesion synthesis, and brought back the levels of the biochemical parameters. In addition, immunostaining of NF-kB, PCNA, and p53 showed that they were inhibited by NEF. CONCLUSION: Thus, NEF might be considered a better chemopreventive drug in an experimental model of home-based primary care (HBPC). More research is necessary to study other pathways implicated in oral carcinomas and their modulation by NEF.