Antibacterial Natural Peptide Fractions from Indian <Emphasis Type="Italic">Ganoderma lucidum</Emphasis>

Natural peptides are emerging as a leading alternative to conventional drugs and antibiotics, owing to their remarkable potency, better stability and less toxicity. Such peptides encompass numerous healing properties such as antimicrobial, anti-inflammatory, immunomodulatory, etc. Though plant- derived peptides have been widely studied for their therapeutic benefits, however, fungal peptides are still lesser explored. Ganoderma lucidum, a highly medicinal oriental mushroom comprises a vast array of phytoconstituents, namely flavonoids, phenolics, terpenoids, polysaccharides, proteins, glycolipids, etc and hence, is being used since several decades in traditional Chinese medicine (TCM) for its various ameliorative effects e.g. anti-inflammatory, antimicrobial, anti-proliferative and antioxidant properties. This study presents the isolation and characterization of antibacterial peptide fractions from fruiting body (GLF) and mycelium (GLM) of Indian G. lucidum. Representative amide bonds were identified in the fractions using established standard techniques. Peptide mass fingerprinting and HPLC confirmed the presence of cationic and hydrophobic amino acids in the peptide fractions which are known to be major structural features of antimicrobial peptides. Secondary structure prediction showed abundance of α-helices and random coils in GLF and GLM fractions respectively. The fractions exhibited appreciable antioxidant potential. Besides, these also possessed substantial antibacterial activity against Escherichia coli and Salmonella typhi wherein it was observed that generation of reactive oxygen species and induction of intracellular protein leakage within the bacterial cells were the possible mechanisms of inhibitory action.     

GC/MS Profiling and Evaluation of Leaf Essential Oil for Bactericidal Effect and Free Radical Scavenging Activity of Plectranthus amboinicus (Lour.) Spreng Collected from Odisha,India

Plectranthus amboinicus (Lour.) Spreng, known as the Indian borage or Mexican mint, is one of the most documented species in the family Lamiaceae for its therapeutic and pharmaceutical values. It is found in the tropical and subtropical regions of the world. The leaf essential oil has immense medicinal benefits like treating illnesses of the skin and disorders like colds, asthma, constipation, headaches, coughs, and fevers. After analyzing earlier reports with regard to the quantity and quality of leaf oil yield, we discovered that the germplasm taken from Odisha is preferable to other germplasms. The objective of the present work is to evaluate the free radical scavenging activity and bactericidal effect of leaf essential oil (EO) of Plectranthus amboinicus (Lour.) Spreng collected from the state of Odisha, India. The hydro distillation technique has been used for essential oil extraction. Upon GC/MS analysis, approximately 57 compounds were identified with Carvacrol as the major compound (peak area=20.25 %), followed by p-thymol (peak area=20.17 %), o-cymene (peak area=19.41 %) and carene (peak area=15.89 %). On evaluation of free radical scavenging activity, it was recorded that the best value of inhibitory concentration, was for DPPH with IC₅₀=18.64 ppm and for H₂O₂ with IC₅₀=9.35 ppm. The EO showed efficient bactericidal effect against both gram positive (Mycobacterium smegmatis, Staphylococcus aureus, Enterococcus faecium) and gram negative (Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae) bacteria studied through well diffusion method. Fumigatory action of the essential oil was found against M. smegmatis, the model organism for tuberculosis study. Alamar Blue assay, gave a result with MIC value for M. smegmatis i. e., 0.12 μg/ml and the MBC value of 0.12 μg/ml. Hence, P. amboinicus found in Odisha can be suggested as an elite variety and should be further investigated for efficient administration in drug formulation.     

Serotonin in the central nervous system of the cockroach, Periplaneta americana

Studies on serotonin in the insect nervous system has long been neglected, although serotonin is a putative neurotransmitter. During the course of this study the serotonin content was found to be significantly higher than that found in mammalian midbrain. Parachlorophenylalanine was found to inhibit the first step of the biosynthetic pathway by inhibiting tryptophan-hydroxylase enzyme and leading to alterations in the concentrations of metabolites such as 5-hydroxy tryptophan, 5-hydroxy indole acetic acid and tryptophan. Using a dose of 15 μg/g the inhibitory effect was not long lasting and recovery was observed to restore the normal levels. Higher trytophan levels were observed after a certain period of P-chlorophenylalanine treatment because there was a block in the biosynthetic path and tryptophan could not be utilized for 5-HT synthesis. A negative correlation between brain tryptophan and protein content was observed in both the cases of P-chlorophenylalanine and reserpine treatments.     

Mutagenic and genotoxic effects of theophylline and theobromine in Salmonella assay and in vivo sister chromatid exchanges in bone marrow cells of mice.

The mutagenic and genotoxic effects of two methylxanthines, theophylline (TH) and theobromine (TB), were assessed in the Ames mutagenicity assay (in strains TA97a, TA100, TA102 and TA104) and in vivo sister chromatid exchanges (SCEs) in bone marrow cells of mice. These are the two most commonly used nervous system stimulators throughout the world. TH is used in the long-term treatment of asthma. Bacterial mutagenicity assay showed very weak mutagenic effects of both drugs in Salmonella strains TA102 and TA104 only in certain concentrations when S9 was added to it. No mutagenic effects were observed in any other strains used in this assay either with or without metabolic activation. But results of in vivo SCE assay indicate that these two drugs can induce significant SCE in bone marrow cells of mice.     

Larval mosquito control through deployment of xiphidiocercariae

Larval trematodes (xiphidiocercariae) have been found to encyst in mosquito larvae. When the number of cysts is high, this results in the death of the mosquito larva. It is suggested that populating waters containing mosquito larvae with xiphidiocercariae can be developed as a mosquito control measure.     

Inhibition of ribosome assembly factor PNO1 by CRISPR/Cas9 technique suppresses lung adenocarcinoma and Notch pathway: Clinical application

Growth is crucially controlled by the functional ribosomes available in cells. To meet the enhanced energy demand, cancer cells re-wire and increase their ribosome biogenesis. The RNA-binding protein PNO1, a ribosome assembly factor, plays an essential role in ribosome biogenesis. The purpose of this study was to examine whether PNO1 can be used as a biomarker for lung adenocarcinoma and also examine the molecular mechanisms by which PNO1 knockdown by CRISPR/Cas9 inhibited growth and epithelial–mesenchymal transition (EMT). The expression of PNO1 was significantly higher in lung adenocarcinoma compared to normal lung tissues. PNO1 expression in lung adenocarcinoma patients increased with stage, nodal metastasis, and smoking. Lung adenocarcinoma tissues from males expressed higher PNO1 than those from females. Furthermore, lung adenocarcinoma tissues with mutant Tp53 expressed higher PNO1 than those with wild-type Tp53, suggesting the influence of Tp53 status on PNO1 expression. PNO1 knockdown inhibited cell viability, colony formation, and EMT, and induced apoptosis. Since dysregulated signalling through the Notch receptors promotes lung adenocarcinoma, we measured the effects of PNO1 inhibition on the Notch pathway. PNO1 knockdown inhibited Notch signalling by suppressing the expression of Notch receptors, their ligands, and downstream targets. PNO1 knockdown also suppressed CCND1, p21, PTGS-2, IL-1α, IL-8, and CXCL-8 genes. Overall, our data suggest that PNO1 can be used as a diagnostic biomarker, and also can be an attractive therapeutic target for the treatment of lung adenocarcinoma.