Extensive use of classical antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence has suggested that cationic antimicrobial peptides (AMP’s) are of greatest potential to represent a new class of antibiotics. These peptides have a good scope in current antibiotic research. During the past two decades several AMPs have been isolated from a wide variety of animals (both vertebrates and invertebrates), and plants as well as from bacteria and fungi. These are relatively small (<10kDa), cationic and amphipathic peptides of variable length, sequence and structure. These peptides exhibit broad-spectrum activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, protozoa, yeast, fungi and viruses. Most of these peptides are believed to act by disrupting the plasma membrane leading to the lysis of the cell. Antimicrobial peptides encompass a wide variety of structural motifs such as α -helical peptides, β -sheet peptides, looped peptides and extended peptides. Preparations enriched by a specific protein are rarely easily obtained from natural host cells. Hence, recombinant protein production is frequently the sole applicable procedure. Several fusion strategies have been developed for the expression and purification of small antimicrobial peptides (AMPs) in recombinant bacterial expression systems which were produced by cloning. This article aims to review in brief the sources of antimicrobial peptides, diversity in structural features, mode of action, production strategies and insight into the current data on their antimicrobial activity followed by a brief comment on the peptides that have entered clinical trials.

Traditional Medicines derived from medicinal plants are used by about 60% of the world’s population. This review focuses on Indian Herbal drugs and plants used in the treatment of diabetes, especially in India. Diabetes is an important human ailment afflicting many from various walks of life in different countries. In India it is proving to be a major health problem, especially in the urban areas. Though there are various approaches to reduce the ill effects of diabetes and its secondary complications, herbal formulations are preferred due to lesser side effects and low cost. A list of medicinal plants with proven antidiabetic and related beneficial effects and of herbal drugs used in treatment of diabetes is compiled. These include, Allium sativum, Eugenia jambolana, Momordica charantia Ocimum sanctum, Phyllanthus amarus, Pterocarpus marsupium, Tinospora cordifolia, Trigonella foenum graecum and Withania somnifera. One of the etiologic factors implicated in the development of diabetes and its complications is the damage induced by free radicals and hence an antidiabetic compound with antioxidant properties would be more beneficial. Therefore information on antioxidant effects of these medicinal plants is also included.

In recent years scientific and technological advancement have been made in the rate controlled oral drug delivery system by overcoming physiological adversities, such as short gastric residence time (GRT) and unpredictable gastric emptying time (GET). So an interest increased towards novel dosage forms, that can retained in the stomach for a prolonged and predictable period of time. The concept of such novel dosage forms is to decrease the GI transit rate of the drug delivery system by attachment to the mucus layer, thereby increasing the overall time for drug absorption. A further advantage of such delivery systems is that the drug no longer must diffuse through the luminal contents in order to reach the mucosal epithelium. Various polymers have been used in the formulation of stomach specific mucoadhesive nanoparticles for drug delivery to increase therapeutic benefit, while minimizing side effects. Here we have discussed about concept of gastric emptying, absorption window, potential drug candidates, technological development evaluation and applications for stomach-specific mucoadhesive nanoparticles. Marketed products for oral nanoparticulate drug delivery systems are also discussed in this review.