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Cancer, a challenging medical problem, affects millions of people around the world. Cancer cell resistance is one of the main drawbacks in the complete prosperity of even more sophisticated therapies. Pore-forming peptides (PFPs), a group of natural defense system proteins are used by nearly all living organisms as anti-bacterial and anti-- fungal agents, and could also be regarded as novel tumoricidal peptides. PFPs approach entails using soluble peptides by assembling them mainly on the target cell membrane and forming potential death-causing pores. Physical damage induction by natural PFPs or their synthetic derivatives could conquer the resistance mechanisms of tumor cells. Given that peptide drugs involve a significant proportion of the pharmaceutical market primarily because of easy synthesis and safety, evaluating this nature provided a model system as a group of anticancer peptides seems a valuable approach. Here, the mode of action of PFPs and their anticancer mechanism are highlighted, followed by addressing the anticancer studies using PFPs from different sources along with various strategies applied to obtain selective action of PFPs against cancer cells. Challenges and future perspectives of these promising bioactive molecules in cancer treatment are also provided.

Background: Neglected tropical diseases are a group of infections caused by microorganisms and viruses that affect mainly poor regions of the world. In addition, most available drugs are associated with long periods of treatment and high toxicity which limits the application and patient compliance. Investment in research and development is not seen as an attractive deal by the pharmaceutical industry since the final product must ideally be cheap, not returning the amount invested. Natural products have always been an important source for bioactive compounds and are advantageous over synthetic compounds when considering the unique structural variety and biological activities. On the other hand, isolation difficulties and low yields, environmental impact and high cost usually limit their application as drug per se. Objective: In this review, the use of natural products as prototypes for the semi-synthesis or total synthesis, as well as natural products as promising hits is covered, specifically regarding compounds with activities against trypanosomatids such as Trypanosoma spp. and Leishmania spp. Methods: Selected reports from literature with this approach were retrieved. Conclusion: As summary, it can be concluded that natural products are an underestimated source for designing novel agents against these parasites.

Background The generic name "flavonolignan" was created in 1968 for a relatively small class of naturally occurring hybrid molecules biogenetically originated from ubiquitous flavonoids and lignans (phenylpropanoids). The first group of flavonolignans was extracted from Silybum marianum that has long been used for hepatoprotection. Recently, the medicinal merit of flavonolignans has been extended to the prostate cancer management. Methods Systematic interpretation and summarization of the relevant literature. Results Over forty naturally occurring flavonolignans have so far been obtained from various plants. Certain flavonolignans have been demonstrated by in vitro cell-based and in vivo animal-based experiments, and human clinical studies i) to possess effective chemopreventive function against various tumor promoters; ii) to show the anti-angiogenic efficacy; iii) to have potential in treating prostate cancer; iv) to sensitize prostate tumors to chemotherapeutic agents through down-regulation of P-glycoprotein and other mechanisms; and v) to be used by prostate cancer patients to protect or treat the hepatotoxicity caused by several chemotherapies. Certain flavonolignans can synergize with well-established chemotherapeutic agents for prostate cancer. Conclusion This review provides a systematic and in-depth overview of the promise and potential of flavonolignans in prostate cancer management, which covers their chemopreventive effect, chemotherapeutic treatment, mechanisms of actions, synthetic derivatives, structure-activity relationships, and the difference in inhibiting prostate cancer cell proliferation between certain flavonoligans and their respective flavonoid counterpart. This summarization aims to provide valuable insights into further and rational development of flavonolignans for prostate cancer management by interpreting the data reported in the literature.

Malaria is one of the most severe tropical parasitic disease causing 1-3 million deaths annually. In the last 25 years very few new antimalarial molecules have been developed and only a limited number of them are currently in various stages of clinical development. The presently available antimalarial drugs include artemisinin analogs, quinoline derivatives and antifolates. This review summarizes recent advances in antimalarial drug development and world patents published between 2000-2006 claiming new synthetic antimalarial compounds and their activities. The most over-represented classes of compounds in malaria patent literature in order of frequency are artemisinin analogs, quinoline derivatives, DOXP reductoisomerase inhibitors, antifolates and febrifugine analogues. Many of these patents describe the novelty and potential of these synthetic derivatives with an attempt to identify the next generation antimalarials that may have potential commercial advantages.

Synthetic heterocyclic compounds have remarkable potential activity against diseases; thioamides, benzimidazoles, quinolones and derivatives with carboxylic acid and esters moieties have shown excellent activity against Mycobacterium tuberculosis. We reviewed antituberculosis activities of above compounds with reference to half maximal inhibitory concentration, minimum inhibitory concentration and structural-activity relationship which clearly indicate that electron-withdrawing groups are the main inducers of antimycobacterium activity. Comparison between clinically used drugs and new synthetic derivatives showed recent advances made in the last decade.