Phytochemicals for the Management of Melanoma.

Melanoma claims approximately 80% of skin cancer-related deaths. Its life-threatening nature is primarily due to a propensity to metastasize. The prognosis for melanoma patients with distal metastasis is bleak, with median survival of six months even with the latest available treatments. The most commonly mutated oncogenes in melanoma are BRAF and NRAS accounting approximately 60% and 20% of cases, respectively. In malignant melanoma, accumulating evidence suggests that multiple signaling pathways are constitutively activated and play an important role in cell proliferation, cell survival, epithelial to mesenchymal transition, metastasis and resistance to therapeutic regimens. Phytochemicals are gaining considerable attention because of their low toxicity, low cost, and public acceptance as dietary supplements. Cell culture and animals studies have elucidated several cellular and molecular mechanisms by which phytochemicals act in the prevention and treatment of metastatic melanoma. Several promising phytochemicals, such as, fisetin, epigallocatechin-3-gallate, resveratrol, curcumin, proanthocyanidins, silymarin, apigenin, capsaicin, genistein, indole-3-carbinol, and luteolin are gaining considerable attention and found in a variety of fresh fruits, vegetables, roots, and herbs. In this review, we will discuss the preventive potential, therapeutic effects, bioavailability and structure activity relationship of these selected phytochemicals for the management of melanoma.

Enhanced anticancer potential of encapsulated solid lipid nanoparticles of TPD: a novel triterpenediol from Boswellia serrata.

A pentacyclic triterpenediol (TPD) from Boswellia serrata has significant cytotoxic and apoptotic potential in a large number of human cancer cell lines. To enhance its anticancer potential, it was successfully formulated into solid lipid nanoparticles (SLNs) by the microemulsion method with 75% drug entrapment efficiency. SEM and TEM studies indicated that TPD-SLNs were regular, solid, and spherical particles in the range of 100-200 nm, and the system indicated that they were more or less stable upon storing up to six months. TPD loaded SLNs showed significantly higher cytotoxic/antitumor potential than the parent drug. TPD-SLNs have 40-60% higher cytotoxic and apoptotic potential than the parent drug in terms of IC(50), extent of apoptosis, DNA damage, and expression of pro-apoptotic proteins like TNF-R1, cytochrome-c, and PARP cleavage in HL-60 cells. Moreover, blank SLNs did not have any cytotoxic effect on the cancer as well as in normal mouse peritoneal macrophages. The in vivo antitumor potential of TPD-SLNs was significantly higher than that of TPD alone in Sarcoma-180 solid tumor bearing mice. Therefore, SLNs of TPD successfully increased the apoptotic and anticancer potential of TPD at comparable doses (both in vitro and in vivo). This work provides new insight into improvising the therapeutic efficacy of TPD by adopting novel delivery strategies such as solid lipid nanoparticles.

Pomegranate fruit extract inhibits UVB-induced inflammation and proliferation by modulating NF-κB and MAPK signaling pathways in mouse skin.

There is considerable interest in the identification of natural agents capable of affording protection to skin from the adverse effects of solar ultraviolet B (UVB) radiation. Pomegranate (Punica granatum L.) fruit possesses as strong antioxidant, anti-inflammatory and antiproliferative properties. Recently, we have shown that oral feeding of pomegranate fruit extract (PFE) to mice afforded substantial protection from the adverse effects of single UVB radiation via modulation in early biomarkers of photocarcinogenesis. This study was designed to investigate the photochemopreventive effects of PFE (0.2%, wt/vol) after multiple UVB irradiations (180 mJ cm(-2), on alternative day, for a total of seven treatments) to the skin of SKH-1 hairless mice. Oral feeding of PFE to SKH-1 mice inhibited UVB-induced epidermal hyperplasia, infiltration of leukocytes, protein oxidation and lipid peroxidation. Immunoblot analysis demonstrated that oral feeding of PFE to mice inhibited UVB-induced (1) nuclear translocation and phosphorylation of nuclear factor kappa B/p65, (2) phosphorylation and degradation of IκBα, (3) activation of IKKα/ΙΚΚß and (4) phosphorylation of mitogen-activated protein kinase proteins and c-Jun. PFE consumption also inhibited UVB-induced protein expression of (1) COX-2 and iNOS, (2) PCNA and cyclin D1 and (3) matrix metalloproteinases-2,-3 and -9 in mouse skin. Taken together, these data show that PFE consumption afforded protection to mouse skin against the adverse effects of UVB radiation by modulating UVB-induced signaling pathways.

Cytotoxic evaluation and induction of mitochondria-mediated apoptosis in human leukaemia HL-60 cells by Carissa spinarum stem isolate.

OBJECTIVE: To evaluate Carissa spinarum stem isolate for its anti-cancer therapeutic potential. METHODS: The n-butanol fraction of aqueous extract from Carissa spinarum stem was assessed for its cytotoxic and pro-apoptotic activity. KEY FINDINGS: We report for the first time the anti-cancer potential of C. spinarum stem aqueous extract (CSE) and its n-butanol fraction (CSF). Both inhibited cell proliferation of various human cancer cell lines in which leukaemia HL-60 cells treated with CSF showed maximum growth inhibition having an inhibitory concentration (IC(50) ) value of 34.58±0.91 µg/ml. In addition, CSF induced concentration-dependent apoptosis in HL-60 cells as measured by various end-points (e.g. Annexin V binding, DNA laddering, apoptotic body formation and an increase in hypodiploid subG0 DNA content). Moreover, persistent levels of reactive oxygen species caused translocation of Bax to mitochondria and Bcl-2 degradation, which led to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. These events were associated with significant activation of caspase-3, caspase-6 and caspase-9 leading to poly (ADP-ribose) polymerase cleavage. CONCLUSION: All the above parameters revealed that CSF induced apoptosis through the mitochondrial dependent pathway in HL-60 cells.

Activation of caspases and poly (ADP-ribose) polymerase cleavage to induce apoptosis in leukemia HL-60 cells by Inula racemosa.

Inula racemosa Hook.f. commonly known as Pushkarmula (Compositae) has been used as a traditional drug in India, China and Europe. In the present study, 95% ethanolic extract of roots and its fractions (n-hexane, chloroform, n-butanol and aqueous) were evaluated for in vitro cytotoxicity against cancer cell lines of colon, ovary, prostate, lung, CNS and leukemia. The n-hexane fraction containing alantolactone and isoalantolactone as its major constituents was further studied for its mode of action in HL-60 cells. The lowest IC(50) value of n-hexane fraction was 10.25 microg/ml for Colo-205, a colon cancer cell line whereas, 17.86 microg/ml was the highest IC(50) value observed against CNS cancer cell line SF-295. Further studies on HL-60 cells treated with n-hexane fraction at 10, 25 and 50 microg/ml for 6h, revealed that it induces apoptosis through intrinsic as well as extrinsic pathways by generating reactive oxygen species (ROS) intermediates. Mitochondrial dysfunction prompted the release of cytochrome c, translocation of pro-apoptotic protein (Bax), activation of caspase cascade, resulting in the cleavage of some specific substrates for caspase-3 such as poly (ADP-ribose) polymerase (PARP), which eventually leads to apoptosis. The results of present study strongly support further research and development of bioactive constituents from Inula racemosa as potential anticancer agent with possible therapeutic implication.