In Vitro and In Vivo Antibiofilm Activity of Red Onion Scales: An Agro-Food Waste

Antimicrobial effects of a multimodal wound matrix against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in an in vitro and an in vivo porcine wound model

Chronic non-healing wounds pose significant challenges due to an elevated inflammatory response caused in part by bacterial contamination (Physiol Rev. 2019;99:665). These wounds lead to billions being spent in the health care system worldwide (N Engl J Med. 2017;376:2367, Int J Pharm. 2014;463:119). We studied the in-vitro and in-vivo antimicrobial effects of a multimodal wound matrix (MWM) against two common wound pathogens, Methicillin-Resistant Staphylococcus aureus (MRSA USA300) and Pseudomonas aeruginosa ATCC 27312 (PA27312) (Int Wound J. 2019;16:634). The in-vitro study conducted was a zone of inhibition test with the two microbes at 104 Log CFU/mL inoculated on Tryptic soy agar with 5% sheep blood (TSAII) plates. Treatments used were MWM, Mupirocin (Positive control for MRSA), Silver Sulfadiazine (Positive Control for PA), Petrolatum and Sterile Saline (both serving as Negative Controls). Treatments were allowed to diffuse into the agar for 3 h and then were incubated for 24 h at 37°C. The in-vivo study utilized a deep dermal porcine wound model (22 × 22 × 3 mm) created on six animals. Three animals were inoculated with MRSA USA300 and the other three with PA27312 with each allowing a 72-h biofilm formation. After 72 h, baseline wounds were assessed for bacterial concentration and all remaining wounds were treated with either MWM alone, Silver Treatment or Untreated Control. Wounds were assessed on days 4, 8 and 12 after treatment application for microbiological analysis. In-vitro, MWM exhibited significant inhibition of MRSA USA300 and PA27312 growth when compared to negative controls (p ≤ 0.05). Likewise, in-vivo, the MWM-treated wounds exhibited a significant (p ≤ 0.05) bacterial reduction compared to all other treatment groups, especially on days 8 and 12 for both pathogens. MWM demonstrated promise in addressing colonized wounds with biofilms. Additional studies on MWM's benefits and comparisons with existing treatments are warranted to optimize wound care strategies (Adv Wound Care. 2021;10:281).

Chitosan decorated oleosomes loaded propranolol hydrochloride hydrogel repurposed for Candida albicans-vaginal infection

Aim: Our investigation aims to estimate the antifungal effect of propranolol hydrochloride (PNL). Methods: Oleosomes (OLs) were fabricated by thin-film hydration and evaluated for entrapment efficiency (EE%), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and amount of drug released after 6 h Q6h (%). Results: The optimal OL showed a rounded shape with optimum characteristics. The ex-vivo permeation and confocal laser scanning microscopy verified the prolonged release and well deposition of PNL-loaded OLs-gel. The in-silico assessment demonstrated the good stability of PNL with OLs' ingredients. In vivo evaluations for PNL-loaded OLs-gel showed a good antifungal impact against Candida albicans with good safety. Conclusion: This work highlights the potential of PNL-loaded OLs-gel as a potential treatment for candida vaginal infection.

Irvingia gabonensis baill. (African Mango): A comprehensive review of its ethnopharmacological significance, unveiling its long-standing history and therapeutic potential

ETHNOPHARMACOLOGICAL RELEVANCE

Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. (IG) is a multipurpose tree native to tropical Africa such as Equatorial Guinea, Nigeria, Gabon, and Cameroon with high ethnomedicinal values.

AIM OF THE STUDY

This review emphasizes the ethnopharmacological significance, phytochemical, and functional properties of African mango, focusing on its potential for human health and industrial applications.

MATERIALS AND METHODS

Literature published on IG was traced by different databases, including the Egyptian Knowledge Bank database (EKB), ScienceDirect, PubMed, Google Scholars, Research Gate, Web of Science, Elsevier, and Scopus. Numerous keywords were used to achieve an inclusive search in the databases, like 'African Mango', 'Bush Mango', 'Irvingia gabonensis', 'Wild Mango', 'Dika Nut', 'Phytochemistry', 'Traditional uses', 'Functional foods', 'Polyphenols', 'Ogbono', 'Ellagic acid and its derivatives', and 'Pharmacological activities'.

RESULTS

Different parts of IG have been employed in traditional medicine and recorded a great success. The ripe fruit pulp was consumed fresh or processed into juice and wine documented for anti-diarrheal, anti-diabetic, anti-ulcer, hepatoprotective, antimicrobial, and anti-inflammatory properties. The kernels, which are widely traded and incorporated into traditional dishes, remain an integral part of culinary traditions. Seeds have folkloric uses for weight loss and are popular as blood thinners and anti-diabetics. Where the bark is reported for dysentery, colic, scabies, toothache, and various skin conditions. In Senegal, the stem bark is employed for gonorrhea, hepatic disorders, and gastrointestinal ailments. The leaves possess the potential to enhance renal and hepatic functions, safeguarding these vital organs against the detrimental effects of toxic substances. Pulp is rich in vitamin C, carbohydrates, and proteins. Oil is the major constituent of the seed, which is mainly composed of myristic and lauric acids. The defatted extracts are characterized by flavonoid glycosides and ellagic acid derivatives. Despite their widespread use, IG extracts are still inadequately characterized phytochemically and merit further investigation within the realm of scientific research. Encouragingly, toxicity studies have demonstrated the relative safety of IG extract at the administered doses.

CONCLUSION

The review extends our knowledge of the health benefits of IG, where these effects could be attributed to the phytochemicals present.

Nanocomposite alginate hydrogel loaded with propranolol hydrochloride kolliphor® based cerosomes as a repurposed platform for Methicillin-Resistant Staphylococcus aureus-(MRSA)-induced skin infection; in-vitro, ex-vivo, in-silico, and in-vivo evaluation

Nanocomposite alginate hydrogel containing Propranolol hydrochloride (PNL) cerosomes (CERs) was prepared as a repurposed remedy for topical skin Methicillin-Resistant Staphylococcus aureus (MRSA) infection. CERs were formed via an ethanol injection technique using different ceramides, Kolliphores® as a surfactant, and Didodecyldimethylammonium bromide (DDAB) as a positive charge inducer. CERs were optimized utilizing 13. 22 mixed-factorial design employing Design-Expert® software, the assessed responses were entrapment efficiency (EE%), particle size (PS), and zeta potential (ZP). The optimum CER, composed of 5 mg DDAB, ceramide VI, and Kolliphor® RH40 showed tubular vesicles with EE% of 92.91 ± 0.98%, PS of 388.75 ± 18.99 nm, PDI of 0.363 ± 0.01, and ZP of 30.36 ± 0.69 mV. Also, it remained stable for 90 days and manifested great mucoadhesive aspects. The optimum CER was incorporated into calcium alginate to prepare nanocomposite hydrogel. The ex-vivo evaluation illustrated that PNL was permeated in a more prolonged pattern from PNL-loaded CERs nanocomposite related to PNL-composite, optimum CER, and PNL solution. Confocal laser scanning microscopy revealed a perfect accumulation of fluorescein-labeled CERs in the skin. The in-silico investigation illustrated that the PNL was stable when mixed with other ingredients in the CERs and confirmed that PNL is a promising candidate for curing MRSA. Moreover, the PNL-loaded CERs nanocomposite revealed superiority over the PNL solution in inhibiting biofilm formation and eradication. The PNL-loaded CERs nanocomposite showed superiority over the PNL-composite for treating MRSA infection in the in-vivo mice model. Histopathological studies revealed the safety of the tested formulations. In conclusion, PNL-loaded CERs nanocomposite provided a promising, safe cure for MRSA bacterial skin infection.

Gastroprotective potential of red onion (Allium cepa L.) peel in ethanol-induced gastric injury in rats: Involvement of Nrf2/HO-1 and HMGB-1/NF-κB trajectories

ETHNOPHARMACOLOGICAL RELEVANCE

The utilization of plants with therapeutic properties in traditional medicine has a longstanding practice. Among them, the well-known Allium cepa L. commonly known as onion has been valued for its anti-inflammatory and antioxidant potential in the treatment of various ailments, including gastric ulcers.

AIM OF THE STUDY

This study investigated the gastroprotective potential of red onion peel extract and its fractions in a rat model of ethanol-induced gastric ulcer. Moreover, their phytochemical profiles were compared to identify the active metabolites.

MATERIALS AND METHODS

Mass spectrometry-based metabolomics and chemometrics were performed for phytochemical analysis. Ethanol-induced gastric ulcer model was used to assess the gastroprotective activity. Nine groups of rats were allocated as follows: Group 1 was the normal control; Group 2 rats were used as a positive control/model and received 1 mL of absolute ethanol; and Group 3 rats were treated with famotidine at a dose of 20 mg/kg orally. Group 4 and 5 rats were treated with total acidified ethanolic extract (T1, T2). Group 6 and 7 rats were treated with anthocyanins-rich fractions (P1, P2). Groups 8 and 9 were the flavonoids-rich fraction (S1, S2) treatment. Prior to scarification, the ulcer index in mm was obtained from gastric tissues photographed beside a ruler with further analysis using ImageJ software.

RESULTS

Seventy key major and discriminatory metabolites were identified including flavonoids, anthocyanins, phenolic acids, and miscellaneous compounds. The examined extract and its fractions significantly reduced the ulcer index and inflammatory cytokines via downregulating HMGB-1/NF-κB. Also, they augmented the expression of Nrf2/HO-1 and reduced NOX1/4 mRNA expression. Moreover, there was a significant reduction in the oxidative stress and apoptotic biomarkers as well as a noticeable enhancement in histopathological changes of the stomach tissues.

CONCLUSION

Red onion peels have a promising dose dependent gastroprotective potential in alcohol-induced ulcers via modulating Nrf2/HO-1 and HMGB-1/NF-κB trajectories. This highlights the potential of red onion peels in treating gastric ulcers.

In vitro biofilm inhibition efficacy of Aerva lanata flower extract against Gram negative and Gram-positive biofilm forming bacteria and toxicity analysis using Artemia salina

A biofilm consists of Gram positive and Gram-negative bacteria enclosed in a matrix. Industrial biofouling is caused by biofilms, which can exhibit antimicrobial resistance during infections. Many biofilm studies find that nearly all biofilm communities consist of Gram positive and Gram-negative bacteria. It is therefore necessary to better understand the conserved themes in biofilm formation to develop therapeutics based on biofilm formation. Plant extracts can effectively combat pathogenic bacterial biofilms. This study evaluated the antibacterial and antibiofilm activity of Aerva lanata flower extract against Staphylococcus aureus and Pseudomonas aeruginosa. Methanol extract of dried A. lanata flower was tested against S. aureus and P. aeruginosa to determine the antibacterial activity (10, 25, 50, 75, 100 μg/mL) resulted in a maximum of 0.5-1 log reduction and 2 log reduction in comparison to the control or untreated bacterial cells respectively. A. lanata showed maximum biofilm inhibition up to 1.5-fold and 1-fold against P. aeruginosa and S. aureus. Light microscopic analysis of biofilm treated with A. lanata extract showed efficient distortion of the biofilm matrix. Further, the in vivo analysis of A. lanata in the Artemia salina brine shrimp model showed >50% survival and thus proving the efficacy of A. lanata extract in rescuing the brine shrimps against P. aeruginosa and S. aureus infection.

Unlocking the Power of Onion Peel Extracts: Antimicrobial and Anti-Inflammatory Effects Improve Wound Healing through Repressing Notch-1/NLRP3/Caspase-1 Signaling

Onion peels are often discarded, representing an unlimited amount of food by-products; however, they are a valuable source of bioactive phenolics. Thus, we utilized UPLC-MS/MS to analyze the metabolomic profiles of red (RO) and yellow (YO) onion peel extracts. The cytotoxic (SRB assay), anti-inflammatory (Griess assay), and antimicrobial (sensitivity test, MIC, antibiofilm, and SP-SDS tests) properties were assessed in vitro. Additionally, histological analysis, immunohistochemistry, and ELISA tests were conducted to investigate the healing potential in excisional skin wound injury and Candida albicans infection in vivo. RO extract demonstrated antibacterial activity, limited skin infection with C. albicans, and improved the skin's appearance due to the abundance of quercetin and anthocyanin derivatives. Both extracts reduced lipopolysaccharide-induced nitric oxide release in vitro and showed a negligible cytotoxic effect on MCF-7 and HT29 cells. When extracts were tested in vivo for their ability to promote tissue regeneration, it was found that YO peel extract had the greatest impact. Further biochemical analysis revealed that YO extract suppressed NLRP3/caspase-1 signaling and decreased inflammatory cytokines. Furthermore, YO extract decreased Notch-1 levels and boosted VEGF-mediated angiogenesis. Our findings imply that onion peel extract can effectively treat wounds by reducing microbial infection, reducing inflammation, and promoting tissue regeneration.

Investigation of the phytochemical composition, antioxidant, antibacterial, anti-osteoarthritis, and wound healing activities of selected vegetable waste

Agri-food wastes, produced following industrial food processing, are mostly discarded, leading to environmental hazards and losing the nutritional and medicinal values associated with their bioactive constituents. In this study, we performed a comprehensive analytical and biological evaluation of selected vegetable by-products (potato, onion, and garlic peels). The phytochemical analysis included UHPLC-ESI-qTOF-MS/MS in combination with molecular networking and determination of the total flavonoid and phenolic contents. Further, the antimicrobial, anti-osteoarthritis and wound healing potentials were also evaluated. In total, 47 compounds were identified, belonging to phenolic acids, flavonoids, saponins, and alkaloids as representative chemical classes. Onion peel extract (OPE) showed the higher polyphenolic contents, the promising antioxidant activity, the potential anti-osteoarthritis activity, and promising antimicrobial activity, especially against methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, OPE revealed to have promising in vivo wound healing activity, restoring tissue physiology and integrity, mainly through the activation of AP-1 signaling pathway. Lastly, when OPE was loaded with nanocapsule based hydrogel, the nano-formulation revealed enhanced cellular viability. The affinities of the OPE major metabolites were evaluated against both p65 and ATF-2 targets using two different molecular docking processes revealing quercetin-3,4'-O-diglucoside, alliospiroside C, and alliospiroside D as the most promising entities with superior binding scores. These results demonstrate that vegetable by-products, particularly, those derived from onion peels can be incorporated as natural by-product for future evaluation against wounds and osteoarthritis.

9-Methoxyellipticine: Antibacterial Bioactive Compound Isolated from Ochrosia elliptica Labill. Roots

Antibacterial resistance bears a major threat to human health worldwide, causing about 1.2 million deaths per year. It is noteworthy that carbazole derivatives have shown a potential antibacterial activity, for example, 9-methoxyellipticine, which was isolated from Ochrosia elliptica Labill. roots (Apocynaceae) in the present study. An in vitro screening of the antibacterial activity of 9-methoxyellipticine was investigated against four multidrug-resistant (MDR) Klebsiella pneumoniae and Shiga toxin-producing Escherichia coli (STEC O157) as Gram-negative bacteria, in addition to Methicillin-resistant Staphylococcus aureus (MRSA) with Bacillus cereus as Gram-positive bacteria. The compound had significant antibacterial activity against the two Gram-negative isolates and lower activity against the Gram-positive ones. The synergistic use of 9-methoxyellipticine and antibiotics was successfully effective in reducing the MDR microorganisms. Lung pneumonia and kidney infection mice models were used to investigate the compound's efficacy in vivo for the first time. Noteworthy reductions in K. pneumoniae and STEC shedding and the colonization were observed, with a reduction in pro-inflammatory factors and immunoglobulin levels. Other related lesions such as inflammatory cell infiltration, alveolar interstitial congestion, and edema were noticed to occur, lessened to different limits. The anti-STEC and anti-K. pneumoniae activities of 9-methoxyellipticine were revealed, providing a new alternative against MDR nosocomial infections.