Ligand-protein interactions of plant-isolated (9z,12z)-octadeca-9,12-dienoic acid with Β-ketoacyl-Acp synthase (KasA) in potential anti-tubercular drug designing

Thermodynamic binding properties of a novel umami octapeptide K1ADEDSLA8 and its mutational variants p.A2G, p.D5E, and p.A2G + p.D5E (BMP) in complex with the umami receptor hT1R1/hT1R3

Umami taste properties of a novel octameric peptide K1ADEDSLA8 and its mutants p.A2G, p.D5E, and BMP (KGDEESLA, beef meaty peptide) were assessed by molecular docking, and molecular dynamics (MD) (>1 μsec), MM-PBSA, and Mutational Affinity Prediction (MAP) methods. 3D-structure of the human umami taste receptor (hT1R1/hT1R3) was homology modeled and refined MD. Docking studies yielded three primary binding sites (PBS) for K1ADEDSLA8 and BMP, one on hT1R1 and two on hT1R3. Upto 1200 nsec of MD studies revealed that K1ADEDSLA8 binds only to Venus Flytrap Domains (VFTD) region of hT1R1 at high affinity (ΔGo = -11.94 kcal/mol), while BMP does not exhibit affinity towards hT1R1/hT1R3 in the absence of glutamate. MAP analysis for p.A2G (ΔGo = -7.77 kcal/mol) and p.D5E (ΔGo = -2.88 kcal/mol) strongly suggest that A2 and D5 in KA2DED5SLA increase the affinity and specificity of binding, posing great potential for the development of a novel umami peptide in future studies.

Unlocking the anti-diabetic potential of Gymnema sylvestre, Trigonella foenum-graecum, and their combination thereof: An in-vivo evaluation

The current study aimed to explore the anti-diabetic effect of aqueous extracts of Gymnema sylvestre, Trigonella foenum-graecum and mixture of both the plants in alloxan-induced diabetic rabbits. A total of 30 rabbits were grouped into six equal groups as: normal control, diabetic control, diabetic treated with 300 mg/kg body weight (bw) G. sylvestre, diabetic treated with 300 mg/kg bw T. foenum-graecum, diabetic treated with 300 mg/kg bw mixture of both the plants and diabetic treated with 500 mg/kg bw metformin for 4 weeks. Diabetes was induced to all the study group animals except normal control by intravenous administration of alloxan monohydrate (80 mg/kg bw). Blood glucose was measured by glucometer and other biochemical parameters were determined through various kit methods. Serum insulin was measured through ELISA kit method. Results showed that both the plants and metformin significantly (p < .05) decreased the fasting blood glucose. Hypoglycemic activity of aqueous extract of G. sylvestre and metformin was found slightly higher than aqueous extract of T. foenum-graecum and the mixture of both the plants. However, a significant (p < .05) rise in insulin secretion was observed in studied plants extract treated rabbits. Serum urea, creatinine, and liver enzymes were found reduced significantly (p < .05) in treated rabbits whereas packed cell volume was also returned to normal in treated animals as compared to control group. The study concluded that G. sylvestre and T. foenum-graecum extracts have comparable effects with metformin in normalizing the blood glucose level and have more pronounced effect than metformin in restoring the serum biochemical parameters to normal levels. Hence, these plants may be the good alternative medicine in managing the diabetes mellitus.

ADMET profiling and molecular docking of potential antimicrobial peptides previously isolated from African catfish, Clarias gariepinus

Amidst rising cases of antimicrobial resistance, antimicrobial peptides (AMPs) are regarded as a promising alternative to traditional antibiotics. Even so, poor pharmacokinetic profiles of certain AMPs impede their utility necessitating, a careful assessment of potential AMPs' absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties during novel lead exploration. Accordingly, the present study utilized ADMET scores to profile seven previously isolated African catfish antimicrobial peptides (ACAPs). After profiling, the peptides were docked against approved bacterial protein targets to gain insight into their possible mode of action. Promising ACAPs were then chemically synthesized, and their antibacterial activity was validated in vitro utilizing the broth dilution method. All seven examined antimicrobial peptides passed the ADMET screening, with two (ACAP-IV and ACAP-V) exhibiting the best ADMET profile scores. The ACAP-V had a higher average binding energy (-8.47 kcal/mol) and average global energy (-70.78 kcal/mol) compared to ACAP-IV (-7.60 kcal/mol and -57.53 kcal/mol), with the potential to penetrate and disrupt bacterial cell membrane (PDB Id: 2w6d). Conversely, ACAP-IV peptide had higher antibacterial activity against E. coli and S. aureus (Minimum Inhibitory Concentration, 520.7 ± 104.3 μg/ml and 1666.7 ± 416.7 μg/ml, respectively) compared to ACAP-V. Collectively, the two antimicrobial peptides (ACAP-IV and ACAP-V) are potential novel leads for the food, cosmetic and pharmaceutical industries. Future research is recommended to optimize the expression of such peptides in biological systems for extended evaluation.

Identification of Antimicrobial Peptides Isolated From the Skin Mucus of African Catfish, Clarias gariepinus (Burchell, 1822)

Antimicrobial peptides (AMPs) constitute a broad range of bioactive compounds in diverse organisms, including fish. They are effector molecules for the innate immune response, against pathogens, tissue damage and infections. Still, AMPs from African Catfish, Clarias gariepinus, skin mucus are largely unexplored despite their possible therapeutic role in combating antimicrobial resistance. In this study, African Catfish Antimicrobial peptides (ACAPs) were identified from the skin mucus of African Catfish, C. gariepinus. Native peptides were extracted from fish mucus scrapings in 10% acetic acid (v/v) and ultra-filtered using 5 kDa molecular weight cut-off membrane. The extract was purified using C18 Solid-Phase Extraction. The antibacterial activity was determined using the Agar Well Diffusion method and broth-dilution method utilizing Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). Thereafter, Sephadex G-25 gel filtration was further utilized in bio-guided isolation of the most active fractions prior to peptide identification using Orbitrap Fusion Lumos Tribrid Mass Spectrometry. The skin mucus extracted from African Catfish from all the three major lakes of Uganda exhibited antimicrobial activity on E. coli and S. aureus. Lake Albert's C. gariepinus demonstrated the best activity with the lowest MIC of 2.84 and 0.71 μg/ml on S. aureus and E. coli, respectively. Sephadex G-25 peak I mass spectrometry analysis (Data are available via ProteomeXchange with identifier PXD029193) alongside in silico analysis revealed seven short peptides (11-16 amino acid residues) of high antimicrobial scores (0.561-0.905 units). In addition, these peptides had a low molecular weight (1005.57-1622.05 Da) and had percentage hydrophobicity above 54%. Up to four of these AMPs demonstrated α-helix structure conformation, rendering them amphipathic. The findings of this study indicate that novel AMPs can be sourced from the skin mucus of C. gariepinus. Such AMPs are potential alternatives to the traditional antibiotics and can be of great application to food and pharmaceutical industries; however, further studies are still needed to establish their drug-likeness and safety profiles.