The notable increase in drug-resistant infections and the failure of the most potent antibiotics to establish their curative effect without side effect have presented a serious need for the discovery of new therapeutic agent and the study of dietary implications on the mode of entry of these therapeutic agents in the human system. This review provides insight into the forms and modes of action, and roles of beneficial but limited and underutilized antimicrobial peptides for use in dietary formulations, with particular focus on the technologies employed for their discovery as well as their dietary efficacy. The wide spectrum of activities of these peptides will allow the opportunity to explore their benefits as dietary supplements and additives.

Bacterial endophytes were isolated from the leaves of Bougainvillea spectabilis Willd. and screened for their in vitro antagonistic activity against three important phytopathogenic fungi viz., Neocosmospora keratoplastica, Stemphylium vesicarium and Rhizoctonia solani. Among the 36 endophytic bacterial isolates screened, three isolates designated as BEB1, BEB5 and BEB6 inhibited the mycelial growth of all the three plant pathogenic fungi tested and recorded more than 10% growth inhibition. Scanning electron microscopic observations of hyphae of the pathogenic fungi at the periphery of the inhibition zone in the dual culture plate revealed morphological abnormalities such as shrinkage, pit formation and loss of turgidity. These isolates were identified as Bacillus subtilis (BEB1) and Bacillus cereus (BEB5 and BEB6) based on the MALDI Biotyper analysis. The Bacillus subtilis strain BEB1, which exhibited the highest level of antagonism, was tested for its sensitivity to cyanide and potential to degrade NaCN. The results revealed that this strain was capable of growing in a medium containing 5 mM of NaCN with a degradation efficiency of 53.8%. This endophyte is valuable for exploitation as a biocontrol agent to control diseases especially in the cyanogenic plants and bioremediation of cyanide from the industrial effluent.

Pig farming is one of the major contributors to the livestock industry. In recent years, palm kernel cake (PKC) has increasingly been used in the feed industry as an alternative source of feed ingredient for pigs. As pigs have a great sense of smell, difference in volatile composition of PKC could affect its acceptance and inclusion rate in pig feed. In this study, a comparative study on the volatile profiles of palm kernel expeller (PKE) and palm kernel meal (PKM) was performed using GC-MS coupled with dynamic headspace (DHS) sampling techniques. Our aim is to understand the contribution of geographical origin, processing technology and moisture content to the volatile profiles of PKE and PKM by analysing a total of 56 samples using GC-MS-DHS. Using data analytics, we have obtained a ‘volatile fingerprint’ of PKE and PKM sourced from different processing plants. We have also gained insight into the potential odour-active compounds in palm kernel cakes of different processes. These results provide scientific basis for the development of more palatable and economical animal feed involving palm kernel cake.

Excessive reactive oxygen species (ROS) induced by myocardial ischemia reperfusion (IR) injury exert detrimental effects on cardiomyocytes. Antioxidant peptides can scavenge free radicals such as 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitic oxide (NO) in vitro, but little is known about their functions in vivo. Here, we evaluated the effects of an antioxidant peptide (antioxidant-RL) used at the beginning of reperfusion on myocardial IR injury. We performed 2, 3, 5-triphenyltetrazolium chloride staining (TTC) to determine myocardial infarct size. Creatine kinase isoenzyme-MB (CK-MB), cardiac troponin-T (CTnT), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) levels were determined with enzyme-linked immunosorbent assays (ELISAs). The levels of ROS were measured with a fluorometric Intracellular ROS kit. The expression levels of apoptosis-related proteins in cardiomyocytes were detected by western blotting. Antioxidant-RL (10 mg/kg) reduced the infarct size and levels of CK-MB and CTnT in rats. The levels of TNF-α and IL-6 also decreased. Furthermore, ROS levels were ameliorated and the expression of apoptosis-related proteins in myocytes was down-regulated by antioxidant-RL (100 µg/mL). Antioxidant-RL exerted protective effects on myocardial IR injury by scavenging excessive ROS, suppressing inflammatory factors, and inhibiting cardiomyocytes apoptosis. Thus, antioxidant-RL may serve as a potent candidate for the treatment of IR injury.