Insect pests and pathogens (fungi, bacteria and viruses) are responsible for severe crop losses. Insects feed directly on the plant tissues, while the pathogens lead to damage or death of the plant. Plants have evolved a certain degree of resistance through the production of defence compounds, which may be aproteic, e.g. antibiotics, alkaloids, terpenes, cyanogenic glucosides or proteic, e.g. chitinases, b-1,3-glucanases, lectins, arcelins, vicilins, systemins and enzyme inhibitors. The enzyme inhibitors impede digestion through their action on insect gut digestive a-amylases and proteinases, which play a key role in the digestion of plant starch and proteins. The natural defences of crop plants may be improved through the use of transgenic technology. Current research in the area focuses particularly on weevils as these are highly dependent on starch for their energy supply. Six dierent a-amylase inhibitor classes, lectin-like, knottin-like, cereal-type, Kunitz-like, c-purothionin-like and thaumatin-like could be used in pest control. These classes of inhibitors show remarkable structural variety leading to dierent modes of inhibition and dierent speci®city pro®les against diverse a-amylases. Speci®city of inhibition is an important issue as the introduced inhibitor must not adversely aect the plant's own a-amylases, nor the nutritional value of the crop. Of particular interest are some bifunctional inhibitors with additional favourable properties, such as proteinase inhibitory activity or chitinase activity. The area has bene®ted from the recent determination of many structures of a-amylases, inhibitors and complexes. These structures highlight the remarkable variety in structural modes of a-amylase inhibition. The continuing discovery of new classes of a-amylase inhibitor ensures that exciting discoveries remain to be made. In this review, we summarize existing knowledge of insect a-amylases, plant a-amylase inhibitors and their interaction. Positive results recently obtained for transgenic plants and future prospects in the area are reviewed.Keywords: a-amylase inhibitors; knottin-like; lectin-like; thaumatin-like; Kunitz; cereal-type; bean weevils; bifunctional inhibitors.Insect pests and pathogens such as fungi, bacteria and viruses are together, responsible for severe crop losses. Worldwide, losses in agricultural production due to pest attack are around 37%, with small-scale farmers hardest hit [1]. Starchy leguminous seeds are an important staple food and a source of dietary protein in many countries. These seeds are rich in protein, carbohydrate and lipid and therefore suffer extensive predation by bruchids (weevils) and other pests. The larvae of the weevil burrow into the seedpods and seeds and the insects usually continue to multiply during seed storage. The damage causes extensive losses, especially if the seeds are stored for long periods.In general, plants contain a certain degree of resistance against insect predation, which is re¯ected in the limited number of insects capable of feeding on a gi...

In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewise, the physical debility associated with cancer or with anticancer therapy itself often paves the way for opportunistic infections. It is urgent to develop new therapeutic methods, with higher efficiency and lower side effects. Antimicrobial peptides (AMPs) are found in the innate immune system of a wide range of organisms. Identified as the most promising alternative to conventional molecules used nowadays against infections, some of them have been shown to have dual activity, both as antimicrobial and anticancer peptides (ACPs). Highly cationic and amphipathic, they have demonstrated efficacy against both conditions, with the number of nature-driven or synthetically designed peptides increasing year by year. With similar properties, AMPs that can also act as ACPs are viewed as future chemotherapeutic drugs, with the advantage of low propensity to resistance, which started this paradigm in the pharmaceutical market. These peptides have already been described as molecules presenting killing mechanisms at the membrane level, but also acting toward intracellular targets, which increases their success compartively to one-target specific drugs. This review will approach the desirable characteristics of small peptides that demonstrated dual activity against microbial infections and cancer, as well as the peptides engaged in clinical trials.

A wound is damage of a tissue usually caused by laceration of a membrane, generally the skin. Wound healing is accomplished in three stages in healthy individuals, including inflammatory, proliferative, and remodeling stages. Healing of wounds normally starts from the inflammatory phase and ends up in the remodeling phase, but chronic wounds remain in an inflammatory stage and do not show progression due to some specific reasons. Chronic wounds are classified in different categories, such as diabetic foot ulcer (DFU), venous leg ulcers (VLU) and pressure ulcer (PU), surgical site infection (SSI), abscess, or trauma ulcers. Globally, the incidence rate of DFU is 1-4 % and prevalence rate is 5.3-10.5 %. However, colonization of pathogenic bacteria at the wound site is associated with wound chronicity. Most chronic wounds contain more than one bacterial species and produce a synergetic effect that results in previously non-virulent bacterial species becoming virulent and causing damage to the host. While investigating bacterial diversity in chronic wounds, Staphylococcus, Pseudomonas, Peptoniphilus, Enterobacter, Stenotrophomonas, Finegoldia, and Serratia were found most frequently in chronic wounds. Recently, it has been observed that bacteria in chronic wounds develop biofilms that contribute to a delay in healing. In a mature biofilm, bacteria grow slowly due to deficiency of nutrients that results in the resistance of bacteria to antibiotics. The present review reflects the reasons why acute wounds become chronic. Interesting findings include the bacterial load, which forms biofilms and shows high-level resistance toward antibiotics, which is a threat to human health in general and particularly to some patients who have acute wounds.

BackgroundObesity is a multifactor disease associated with cardiovascular disorders such as hypertension. Recently, gut microbiota was linked to obesity pathogenesisand shown to influence the host metabolism. Moreover, several factors such as host-genotype and life-style have been shown to modulate gut microbiota composition. Exercise is a well-known agent used for the treatment of numerous pathologies, such as obesity and hypertension; it has recently been demonstrated to shape gut microbiota consortia. Since exercise-altered microbiota could possibly improve the treatment of diseases related to dysfunctional microbiota, this study aimed to examine the effect of controlled exercise training on gut microbial composition in Obese rats (n = 3), non-obese Wistar rats (n = 3) and Spontaneously Hypertensive rats (n = 3). Pyrosequencing of 16S rRNA genes from fecal samples collected before and after exercise training was used for this purpose.ResultsExercise altered the composition and diversity of gut bacteria at genus level in all rat lineages. Allobaculum (Hypertensive rats), Pseudomonas and Lactobacillus (Obese rats) were shown to be enriched after exercise, while Streptococcus (Wistar rats), Aggregatibacter and Sutturella (Hypertensive rats) were more enhanced before exercise. A significant correlation was seen in the Clostridiaceae and Bacteroidaceae families and Oscillospira and Ruminococcus genera with blood lactate accumulation. Moreover, Wistar and Hypertensive rats were shown to share a similar microbiota composition, as opposed to Obese rats. Finally, Streptococcus alactolyticus, Bifidobacterium animalis, Ruminococcus gnavus, Aggregatibacter pneumotropica and Bifidobacterium pseudolongum were enriched in Obese rats.ConclusionsThese data indicate that non-obese and hypertensive rats harbor a different gut microbiota from obese rats and that exercise training alters gut microbiota from an obese and hypertensive genotype background.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-511) contains supplementary material, which is available to authorized users.