A new cytotoxic prenylated chalcone from Sophora flavescens

Ultrasound assisted synthesis and cytotoxicity evaluation of known 2',4'-dihydroxychalcone derivatives against cancer cell lines

This work reports on the development of an efficient and ecofriendly ultrasound assisted method for the high yield synthesis (70.0-94.0%) of eighteen oxyalkylated derivatives of 2',4'-dihydroxychalcone. Synthesized compounds were subjected to in vitro biological assays against HT-29 (colorectal), MCF-7 (breast), and PC-3 (prostate) human tumor cell lines, these cell lines are among the ten most aggressive malignancies diagnosed in the world. Cytotoxicity evaluations showed that four of the synthesized compounds exhibited moderate to very high toxic activity against MCF-7 (IC₅₀ = 8.4-34.3 μM) and PC-3 (IC₅₀ = 9.3-29.4 μM) - comparable to 5-fluorouracil (IC₅₀ 16.4-22.3 μM). The same compounds only showed moderate activity against HT-29 (IC₅₀ 15.3-36.3 μM), closer to daunorubicin (IC₅₀ 15.1 μM). Next, although selectivity index (SI) of compounds was weak, compound 18 exhibited a remarkable and selective cytotoxic activity (5.8-10.57) against cancer cells. Outside of these, most compounds significantly reduced cell survival, increased reactive oxygen species (ROS) and caspase activity, and decreased mitochondrial membrane permeability. In this sense, a portion of anti-proliferative activity is due to apoptosis. Notwithstanding, due to its remarkable response, chalcone 18 may be a potential alternative as a chemotherapeutic anti-carcinogen.

Sophopterocarpan A, a novel pterocarpine derivative with a benzotetrahydrofuran-fused bicyclo [3.3.1] nonane from Sophora flavescens

Sophopterocarpan A (1), with a novel benzotetrahydrofuran-fused bicyclo [3.3.1] nonane ring, was isolated from the roots of Sophora flavescens Ait. Its unusual structure, including its stereochemistry, was determined on the basis of a comprehensive spectroscopic data analysis. A plausible biogenetic pathway for 1 is presented. Sophopterocarpan A was identified as a potential autophagy activator. Additionally, it was found that 1 exhibited cytotoxic activity in MCF-7 cells with an IC₅₀ of 29.36 μM.

Characterization of Chalcones from Medicago sativa L. and Their Hypolipidemic and Antiangiogenic Activities

Medicago sativa L. is the most important cultivated herbage, known as "the king of forage" and "feed queen", in the world. A total of 8 new chalcones (1-8), and 12 known chalcones (9-20) were isolated from the aerial parts of M. sativa for the first time. Their structures were identified by extensive spectral data and references. The hypolipidemic and antiangiogenic activities of compounds (1-20) were evaluated for the first time. Compounds 3, 4, 11, 12, and 20 (10 μM) exhibited significant hypolipidemic activities by measuring the triglyceride content in HepG2 cells, with simvastatin as the positive control. Moreover, compounds 6, 8, 18, and 19 exhibited moderate antiangiogenic activities, which inhibited vascular-endothelial-growth-factor-induced human umbilical vein endothelial cell proliferation in vitro, with IC₅₀ values of 13.86 ± 0.43, 15.53 ± 0.19, 39.52 ± 0.24, and 45.04 ± 0.51 μM, respectively. These research results may guide the search for new natural products with hypolipidemic and antiangiogenic attributes.

Targeting apoptosis pathways in cancer with alantolactone and isoalantolactone

Alantolactone and isoalantolactone, main bioactive compounds that are present in many medicinal plants such as Inula helenium, L. Inula japonica, Aucklandia lappa, Inula racemosa, and Radix inulae, have been found to have various pharmacological actions including anti-inflammatory, antimicrobial, and anticancer properties, with no significant toxicity. Recently, the anticancer activity of alantolactone and isoalantolactone has been extensively investigated. Here, our aim is to review their natural sources and their anticancer activity with specific emphasis on mechanism of actions, by which these compounds act on apoptosis pathways. Based on the literature and also on our previous results, alantolactone and isoalantolactone induce apoptosis by targeting multiple cellular signaling pathways that are frequently deregulated in cancers and suggest that their simultaneous targeting by these compounds could result in efficacious and selective killing of cancer cells. This review suggests that alantolactone and isoalantolactone are potential promising anticancer candidates, but additional studies and clinical trials are required to determine their specific intracellular sites of actions and derivative targets in order to fully understand the mechanisms of therapeutic effects to further validate in cancer chemotherapy.

Reactive oxygen species mediate isoalantolactone-induced apoptosis in human prostate cancer cells

Isoalantolactone, a medicinal plant-derived natural compound, is known to induce apoptosis in various cancer cell lines. However, its effect on apoptosis in prostate cancer cells has not been addressed. Thus, we examined the effects of isoalantolactone on prostate cancer cells. It was found that isoalantolactone inhibits growth of both androgen-sensitive (LNCaP) as well as androgen-independent (PC3 and DU-145) prostate cancer cells in a dose-dependent manner. Furthermore, our results indicate that isoalantolactone-induced apoptosis in prostate cancer PC3 cells is associated with the generation of ROS and dissipation of mitochondrial membrane potential (Δψm). In addition, isoalantolactone triggers apoptosis in prostate cancer cells via up-regulation of Bax, down-regulation of Bcl-2, survivin, and significant activation of caspase-3. Isoalantolactone-induced apoptosis is markedly abrogated when the cells were pretreated with N-acetylcysteine (NAC), a specific ROS inhibitor, suggesting that the apoptosis-inducing effect of isoalantolactone in prostate cancer cells is mediated by reactive oxygen species. These findings indicate that isoalantolactone induces reactive oxygen species-dependent apoptosis in prostate cancer cells via a novel mechanism involving inhibition of survivin and provide the rationale for further in vivo and preclinical investigation of isoalantolactone against human prostate cancer.

An update on antitumor activity of naturally occurring chalcones

Chalcones, which have characteristic 1,3-diaryl-2-propen-1-one skeleton, are mainly produced in roots, rhizomes, heartwood, leaves, and seeds of genera Angelica, Sophora, Glycyrrhiza, Humulus, Scutellaria, Parartocarpus, Ficus, Dorstenia, Morus, Artocarpus, and so forth. They have become of interest in the research and development of natural antitumor agents over the past decades due to their broad range of mechanisms including anti-initiation, induction of apoptosis, antiproliferation, antimetastasis, antiangiogenesis, and so forth. This review summarizes the studies on the antitumor activity of naturally occurring chalcones and their underlying mechanisms in detail during the past decades.

Induction of apoptosis by costunolide in bladder cancer cells is mediated through ROS generation and mitochondrial dysfunction

Despite the availability of several therapeutic options, a safer and more effective modality is urgently needed for treatment of bladder cancer. Costunolide, a member of sesquiterpene lactone family, possesses potent anticancer properties. In this study, for the first time we investigated the effects of costunolide on the cell viability and apoptosis in human bladder cancer T24 cells. Treatment of T24 cells with costunolide resulted in a dose-dependent inhibition of cell viability and induction of apoptosis which was associated with the generation of ROS and disruption of mitochondrial membrane potential (Δψm). These effects were significantly blocked when the cells were pretreated with N-acetyl- cysteine (NAC), a specific ROS inhibitor. Exposure of T24 cells to costunolide was also associated with increased expression of Bax, down-regulation of Bcl-2, survivin and significant activation of caspase-3, and its downstream target PARP. These findings provide the rationale for further in vivo and clinical investigation of costunolide against human bladder cancer.