Isolation and Characterization of Antimicrobial Peptides Isolated from Fagonia bruguieri

Behavioral assessment to evaluate the analgesic and anti-inflammatory effects of Fagonia bruguieri var. laxa boiss by targeting pro-inflammatory cytokines and prostaglandin pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Fagonia bruguieri var. laxa Boiss., also known as Dhamansa or Dhamaran, is a well-known xerophyte traditionally used for managing pain, inflammation, fever, and related disease conditions.

AIMS OF THE STUDY

This study was designed to assess the chemical profile of hydromethanolic (70%) extract of F. bruguieri (HMEFB), its analgesic, anti-inflammatory, and antipyretic properties, and the possible mechanisms involved, using rats and mice as experimental animals.

MATERIALS AND METHODS

HMEFB was subjected to chemical profiling using polyphenolic quantification and HPLC analysis. An oral toxicity test in mice assessed the extract for safety and toxicity. The central analgesic effect of HMEFB was evaluated in rats subjected to hot plate and tail immersion tests. Formalin and capsaicin tests were carried out to further support the evidence of analgesic action. The test of acetic acid-induced writhing was performed in mice to estimate the peripheral analgesic potential. The anti-inflammatory effect was studied by the carrageenan-induced paw edema model, while, an antipyretic study was conducted following the yeast-induced pyrexia method. Moreover, inflammatory cytokines and prostaglandins were estimated in the blood samples of animals from various groups to assess the possible mechanism involved in the anti-inflammatory potential of the extract.

RESULTS

The chemical profiling of HMEFB revealed the presence of functionally important polyphenols. The oral toxicity test revealed the safety up to the dose of 5 mg/kg b.w. The extract was found to have significant analgesic activity at the doses of 300 and 500 mg/kg in hot plate, tail immersion, capsaicin, and formalin tests. Furthermore, HMEFB significantly reversed the acetic acid-induced writhing compared to the control group. Similarly, HMEFB showed a dose-dependent effect against carrageenan-induced paw edema. While, in the yeast-induced pyrexia model, HMEFB showed a decrease in rectal temperature at 300 and 500 mg/kg. The extract significantly modulated the levels of pro-inflammatory cytokines and prostaglandins in different treated groups.

CONCLUSION

The results reinforce the folkloric use of F. bruguieri in pain and inflammation by verifying its analgesic and anti-inflammatory activities both via central and peripheral anti-nociceptive mechanisms which authenticate the use of this plant species as a suitable alternative for the alleviation of pain and inflammatory disorders.

Antimicrobial Peptides From Different Sources: Isolation, Purification, and Characterization to Potential Applications

Antimicrobial peptides (AMPs) are excellent promising candidates for biomedical applications owing to their structural properties, high biocompatibility, good biodegradability, and functional diversity. Unlike conventional antibiotics, AMPs have been shown to have broad-spectrum antimicrobial activity toward Gram-positive/negative bacteria, as well as antifungal and antiviral activity. These peptides have also been found to be cytotoxic to sperm and cancer cells. A range of AMPs has been isolated from various organisms, such as bacteria, fungi, plants, and animals. This review summarizes the latest studies on AMPs, covering their isolation, purification, and characterization as well as their potential biomedical applications and beyond.

Mechanistic insight into the synergistic antimicrobial potential of Fagonia indica Burm.f. extracts with cefixime

Fagonia indica Burm.f. is known for its anti-infective character and has been studied in the present work as a synergistic remedy against resistant bacterial strains. Initially, phytochemicals were quantified in n-Hexane (n-Hex), ethyl acetate (E.A), methanol (MeOH), and aqueous (Aq.) extracts by Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis. Later, after establishing an antibacterial resistance profile for extracts and antibiotics against gram-positive and gram-negative strains, synergism was evaluated in combination with cefixime through time-kill kinetics and bacterial protein estimation studies. Topographic images depicting synergism were obtained by scanning electron microscopy for Methicilin-resistant Staphylococcus aureus (MRSA) and Resistant Escherichia coli (R.E. coli). Results showed the presence of maximum phenolic (28.4 ± 0.67 μg GAE/mg extract) and flavonoid (11 ± 0.42 μg QE/mg extract) contents in MeOH extract. RP-HPLC results also displayed maximum polyphenols in MeOH extract followed by E.A extract. Clinical strains were resistant to cefixime whereas these were moderately inhibited by all extracts (MIC 150-300 µg/ml) except Aq. extract. E.A and n-Hex extracts demonstrated maximum synergism (Fractional inhibitory concentration index (FICI) 0.31) against R.E. coli. The n-Hex extract displayed total synergism against R.P. a with a 4-fold reduction in cefixime dose. Time-kill kinetics showed maximum inhibition of gram-negative bacterial growth from 3 to 12 h when treated at FICI and 2FICI values with > 10-fold reduction of the extracts' dose. All combinations demonstrate > 70 % protein content inhibition with bacterial cell wall disruption in SEM images. Fortunately, FICI concentrations have low hemolytic potential (<5%). Conclusively, F. indica extracts can mitigate antimicrobial resistance against cefixime and can be investigated in detail by in vivo and mechanistic studies.

Genomic insights into antimicrobial potential and optimization of fermentation conditions of pig-derived Bacillus subtilis BS21

Bacillus spp. have been widely used as probiotic supplements in animal feed as alternatives to antibiotics. In the present study, we screened a Bacillus subtilis strain named BS21 from pig feces. Antimicrobial activities, whole genome mining and UHPLC-MS/MS analysis were used to explore its antimicrobial mechanism. Strain BS21 showed Significant growth inhibition against a variety of animal pathogens, including Escherichia coli, Salmonella enterica Pullorum, Salmonella enterica Typhimurium, Citrobacter rodentium, Shigella flexneri and Staphylococcus aureus. Seven gene clusters involved in antimicrobial biosynthesis of secondary metabolites were encoded by strain BS21 genome, including four non-ribosomal peptides (bacillibactin, fengycin, surfactin and zwittermicin A), one ribosomal peptide (subtilosin A), one dipeptide (bacilysin) and one polyketide (bacillaene). Among them, production of surfactin, fengycin, bacillibactin, bacilysin and bacillaene was detected in the supernatant of B. subtilis strain BS21. To develop the potential application of BS21 in animal production, medium components and fermentation parameters optimization was carried out using response surface methodology (RSM). Production of antimicrobial secondary metabolites of strain BS21 was increased by 43.4%, and the best medium formula after optimization was corn flour 2%, soybean meal 1.7% and NaCl 0.5% with optimum culture parameters of initial pH 7.0, temperature 30°C, rotating speed at 220 rpm for 26 h. Our results suggested that strain BS21 has the potential for large-scale production and application as a potential source of probiotics and alternative to antibiotics for animal production.

Exploring Marine as a Rich Source of Bioactive Peptides: Challenges and Opportunities from Marine Pharmacology

This review highlights the underexplored potential and promises of marine bioactive peptides (MBPs) with unique structural, physicochemical, and biological activities to fight against the current and future human pathologies. A particular focus is given to the marine environment as a significant source to obtain or extract high-value MBPs from touched/untouched sources. For instance, marine microorganisms, including microalgae, bacteria, fungi, and marine polysaccharides, are considered prolific sources of amino acids at large, and peptides/polypeptides in particular, with fundamental structural sequence and functional entities of a carboxyl group, amine, hydrogen, and a variety of R groups. Thus, MBPs with tunable features, both structural and functional entities, along with bioactive traits of clinical and therapeutic value, are of ultimate interest to reinforce biomedical settings in the 21st century. On the other front, as the largest biome globally, the marine biome is the so-called "epitome of untouched or underexploited natural resources" and a considerable source with significant potentialities. Therefore, considering their biological and biomedical importance, researchers around the globe are redirecting and/or regaining their interests in valorizing the marine biome-based MBPs. This review focuses on the widespread bioactivities of MBPs, FDA-approved MBPs in the market, sustainable development goals (SDGs), and legislation to valorize marine biome to underlying the impact role of bioactive elements with the related pathways. Finally, a detailed overview of current challenges, conclusions, and future perspectives is also given to satisfy the stimulating demands of the pharmaceutical sector of the modern world.