The recent search for new anti-cancer drugs focuses more on natural compounds from the regular human diet because these compounds rarely exhibit severe side-effects yet efficiently act on a wide range of molecular targets involved in carcinogenesis. One promising compound, which is now being tested in clinical studies, is the tomato-derived carotenoid lycopene. This review summarizes the current knowledge about the cellular action of lycopene and presents the molecular targets responsible for its remarkable chemopreventive and anti-proliferative activity. Its antioxidant effects include a considerable reactive oxygen species (ROS) scavenging activity, which allows lycopene to prevent lipid peroxidation and DNA damage. Simultaneously, lycopene induces enzymes of the cellular antioxidant defense systems by activating the antioxidant response element transcription system. As another chemopreventive strategy, lycopene increases gap junctional communication, which is suppressed during carcinogenesis. This review focuses also on the synergistic effects of lycopene with other natural antioxidants that might be important for its future application in anti-cancer treatment. Lastly, this review provides evidence for the biological activity of some oxidized lycopene metabolites, which seem to be partially responsible for the strong and manifold anti-cancer potential of lycopene.

Despite considerable improvements in the tolerance and efficacy of novel chemotherapeutic agents, the mortality of hematological malignancies is still high due to therapy relapse, which is associated with bad prognosis. Dietary polyphenolic compounds are of growing interest as an alternative approach, especially in cancer treatment, as they have been proven to be safe and display strong antioxidant properties. Here, we provide evidence that both resveratrol and curcumin possess huge potential for application as both chemopreventive agents and anticancer drugs and might represent promising candidates for future treatment of leukemia. Both polyphenols are currently being tested in clinical trials. We describe the underlying mechanisms, but also focus on possible limitations and how they might be overcome in future clinical use – either by chemically synthesized derivatives or special formulations that improve bioavailability and pharmacokinetics.

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Many sulfur compounds are known to exhibit widespread antimicrobial activity. The latter is often the result of an intricate redox biochemistry whereby reactive sulfur species, such as organic polysulfanes, interact with pivotal cellular signaling pathways. The S 8 unit in elemental sulfur resembles certain aspects of the chemistry of polysulfanes. As a consequence, water-soluble S 8 -sulfur nanoparticles are active against some smaller organisms, including nematodes, yet are non-toxic against human cells. In contrast, selenium and tellurium nanoparticles are less active. Together, the ease of production of the sulfur nanoparticles, their chemical stability in aqueous dispersion, amenable physical properties and selective toxicity, turn sulfur nanoparticles into promising antimicrobial prototypes for medical as well as agricultural applications.

Garlic-derived organosulfur compounds including diallyl polysulfides are well known for various health-beneficial properties and recent reports even point to a potential role of diallyl polysulfides as chemopreventive and therapeutic agents in cancer treatment due to their selective antiproliferative effects. In this respect, diallyl tri- and tetrasulfide are reported as strong inducers of an early mitotic arrest and subsequent apoptosis, but the underlying molecular mechanisms and the link between these two events are not yet fully elucidated. Our data revealed that diallyl tetrasulfide acts independently of reactive oxygen species and tubulin represents one of its major cellular targets. Tubulin depolymerization prevents the formation of normal spindle microtubules, thereby leading to G2/M arrest. Here, we provide evidence that c-jun N-terminal kinase, which is activated early in response to diallyl tetrasulfide treatment, mediates multisite phosphorylation and subsequent proteolysis of the anti-apoptotic protein B-cell lymphoma 2. As the latter event occurs concomitantly with the onset of apoptosis and the chemical c-jun N-terminal kinase inhibitor SP600125 not only prevented B-cell lymphoma 2 phosphorylation and proteolysis but also apoptosis following diallyl tetrasulfide treatment, we suggest that these c-jun N-terminal kinase-mediated modulations of B-cell lymphoma 2 represent the missing link connecting early microtubule inactivation to the induction of apoptosis.