Bactericidal activity of selected medicinal plants against multidrug resistant bacterial strains from clinical isolates

Antimicrobial Activity of Melanin Isolated from Wine Waste

Melanins have immense application potential in the fields of agriculture, cosmetics and pharmaceutical industries. To determine the antimicrobial properties of melanin, conditionally pathogenic bacteria, belonging to different taxonomic groups were used. The results have shown that melanin solution exhibited bacteriostatic or bactericide activity depending on test culture and melanin concentration. Melanin at concentration of 20 mg/ml reduced the total number of cells of the Bacillus subtilis G 17-89, Salmonella typhimurium G 38 and Escherichia coli K 12 to about 20 percent. Melanin at the concentration of 40 mg/ml suppressed the growth of B. subtilis G17-89 and Candida gropengiesseri 10228 almost 100 percent. In the case of E. coli K 12 30 mg/ml concentration has the same effect as the 40 mg/ml and cell count decrease occurs about 50 percent. Lowest efficiency melanin showed against S. typhimurium G 38 and after 72 h of incubation the cell count decreases by log 1 degree. 30 mg/ml concentration of melanin on the growth of Candida bovina 10118 decreases about 80 percent. On the growth of the Fungi of Aspergillus fumigatus 8444, Aspergillus flavus 10559, Cladosporium herbarium 8270, Cladosporium elatum 8192, Fusarium oxysporum 12017, Fusarium solani 12018, Mucor hiemalis 12020, Mucor plumbeus 12021, Penicillium chrysogenum 8203, Penicillium expansum 8281 genus low concentration of melanin possessed bacteriostatic activity. The investigation of the efficiency of melanin to inhibit the growth of food-spoilage microorganisms shown, that it can be used as natural preservative agent for prevention contamination of food products and for extending of their shelf-life.

Phytochemical Analysis and Antioxidant, Antimicrobial, and Antibiofilm Effects of a New Himalayan Lichen Placidium deosaiense Usman and Khalid Growing in Pakistan

Phytochemical composition and antimicrobial, antibiofilm, and antioxidant effects of a newly described Himalayan lichen Placidium deosaiense Usman and Khalid growing in Pakistan were investigated. HPLC-DAD methods were used for identification of secondary metabolites in acetone and methanol extracts. The total phenolics content was measured using a spectrophotometric method. The study investigated the antioxidant (DPPH-scavenging activity assay and reducing-power assay), antibacterial (minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)), and antibiofilm (inhibition of biofilm formation and reduction in mature biofilm) activities of extracts of the lichen P. deosaiense and isolated parietin. The chemical constituents olivetol, olivetolic acid, haematommic acid, fallacinol, and parietin were identified as major compounds in the tested extracts of the lichen. Parietin was isolated from the acetone extract on a separation column. The methanol extract had higher values of TPC (21.67 mg GAE/g) than the acetone extract. Isolated parietin showed the best antioxidant activity measures, according to the DPPH-scavenging activity assay (IC50 = 51.616 μg/mL) and reducing-power assay. Although the extracts showed the best antibacterial activity (especially against Proteus mirabilis ATCC 12453), parietin demonstrated superior antibiofilm activity (especially against Staphylococcus aureus ATCC 25923). This is the first report on the phytochemical composition of the lichen Placidium deosaiense and the first description of the chemical composition of some of the 45 species of the genus Placidium. This research will pave the way for further exploration of new activities of this lichen and its metabolites, which are important for medicine and pharmacy.

The mechanism, biopolymers and active compounds for the production of nanoparticles by anti-solvent precipitation: A review

The anti-solvent precipitation method has been investigated to produce biopolymeric nanoparticles in recent years. Biopolymeric nanoparticles have better water solubility and stability when compared with unmodified biopolymers. This review article focuses on the analysis of the state of the art available in the last ten years about the production mechanism and biopolymer type, as well as the used of these nanomaterials to encapsulate biological compounds, and the potential applications of biopolymeric nanoparticles in food sector. The revised literature revealed the importance to understand the anti-solvent precipitation mechanism since biopolymer and solvent types, as well as anti-solvent and surfactants used, can alter the biopolymeric nanoparticles properties. In general, these nanoparticles have been produced using polysaccharides and proteins as biopolymers, especially starch, chitosan and zein. Finally, it was identified that those biopolymers produced by anti-solvent precipitation were used to stabilize essential oils, plant extracts, pigments, and nutraceutical compounds, promoting their application in functional foods.

Antibacterial activity of Punica granatum L. and Areca nut (P.A) combined extracts against some food born pathogenic bacteria

The antibacterial effects of combined extracts of Punica granatum L. and Areca nut (P.A) against resistant bacteria, a gram-positive bacterium, Staphylococcus aureus and three gram-negative bacteria, Escherichia coli, Salmonella, and Enterobacter aerogenes, in individual and biofilm forms was studied. Antibacterial activity was studied using disk diffusion method, microbroth dilution, and microtiter plate methods. Given the disc diffusion test (Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC)), the extracts had inhibitory effects on the individual forms of bacteria. However, the ethanolic extract had greater effectiveness than the methanolic extract. Generally, ethanol efficiently extracts flavonoids and their glycosides, catechol and tannins. This fact due to the ethanol polarity that is equal 0.654. The results indicated that the ability of extracts in inhibiting the formation of biofilms, destruction of biofilms, and prevention of metabolic activity of bacteria had a direct relationship with concentration and the highest inhibitory was seen on Staphylococcus aureus (98.98%), Staphylococcus aureus (94.98%), and Enterobacter aerogenes (88.55%). Based on the results, the P.A. combined extract can be used as an alternative combination with the ability to inhibit antibiotic-resistant bacteria in single and biofilm forms.

Tinospora cordifolia (Willd.) Miers: Protection mechanisms and strategies against oxidative stress-related diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora cordifolia (Willd.) Miers (Menispermaceae) is a Mediterranean herb, used in Ayurvedic, Siddha, Unani, and folk medicines. The herb is also used in conventional medicine to treat oxidative stress-related diseases and conditions, including inflammation, pain, diarrhea, asthma, respiratory infections, cancer, diabetes, and gastrointestinal disorders.

AIM OF THE REVIEW

The taxonomy, botanical classification, geographical distribution, and ethnobotanical uses of T. cordifolia, as well as the phytochemical compounds found in the herb, the toxicology of and pharmacological and clinical studies on the effects of T. cordifolia are all covered in this study.

MATERIALS AND METHODS

To gather information on T. cordifolia, we used a variety of scientific databases, including Scopus, Google Scholar, PubMed, and Science Direct. The information discussed focuses on biologically active compounds found in T. cordifolia, and common applications and pharmacological activity of the herb, as well as toxicological and clinical studies on its properties.

RESULTS

The findings of this study reveal a connection between the use of T. cordifolia in conventional medicine and its antioxidant, anti-inflammatory, antihypertensive, antidiabetic, anticancer, immunomodulatory, and other biological effects. The entire plant, stem, leaves, root, and extracts of T. cordifolia have been shown to have a variety of biological activities, including antioxidant, antimicrobial, antiviral, antiparasitic, antidiabetic, anticancer, anti-inflammatory, analgesic and antipyretic, hepatoprotective, and cardioprotective impact. Toxicological testing demonstrated that this plant may have medicinal applications. T. cordifolia contains a variety of biologically active compounds from various chemical classes, including alkaloids, terpenoids, sitosterols, flavonoids, and phenolic acids. Based on the reports researched for this review, we believe that chemicals in T. cordifolia may activate Nrf2, which leads to the overexpression of antioxidant enzymes such as CAT, GPx, GST, and GR, and thereby induces the adaptive response to oxidative stress. T. cordifolia is also able to reduce NF-κB signalling by inhibiting PI3K/Akt, activating AMPK and sirtuins, and downregulating PI3K/Akt.

CONCLUSIONS

Our findings indicate that the pharmacological properties displayed by T. cordifolia back up its conventional uses. Antimicrobial, antiviral, antioxidant, anticancer, anti-inflammatory, antimutagenic, antidiabetic, nephroprotective, gastroprotective, hepatoprotective, and cardioprotective activities were all demonstrated in T. cordifolia stem extracts. To validate pharmacodynamic targets, further research is needed to evaluate the molecular mechanisms of the known compounds against gastrointestinal diseases, inflammatory processes, and microbial infections, as immunostimulants, and in chemotherapy. The T. cordifolia safety profile was confirmed in a toxicological analysis, which prompted pharmacokinetic assessment testing to confirm its bioavailability.

Study to Explore Plant-Derived Trimethylamine Lyase Enzyme Inhibitors to Address Gut Dysbiosis

Lifestyle complications are major health concerns around the globe and are recognized as a major factor for the development of various chronic diseases such as obesity, diabetes, inflammatory bowel diseases, cancer, and cardiac diseases. An unhealthy diet and poor lifestyle impose a serious threat to human health. Numerous studies have suggested the role of human microbiota in human health and diseases. Microbiota resides in the human body symbiotically and the composition of microorganisms is crucial for maintaining the healthy state of an individual. A dysbiotic gut microbiome is responsible for the release of toxic metabolites such as trimethylamine, lipopolysaccharides, bile acids, and uremic toxins and is associated with impaired organ functions. Dietary and herbal intervention of dysbiosis proposes a promising strategy to counteract gut alterations and repairing of the microbial ecosystem and health. The objective of the present comparative study was to observe the effect of therapeutic herbs in gut dysbiosis. In silico studies were performed to identify human microbiota associated with various diseases, ADME, and toxicity properties of phytoconstituents of "Tinospora cordifolia" and "Ocimum sanctum." Furthermore, co-interaction studies were performed to observe the affinity of selected phytochemicals against choline trimethylamine lyase, a critical enzyme involved in dysbiosis-induced human diseases. The antimicrobial potential of phytocompounds was done by the disc diffusion method. In conclusion, our work discusses the herbal intervention of gut dysbiosis and proposes a natural, safe, and effective herbal formulation to correct microbial dysbiosis and associated diseases.

Exploring Phytochemicals for Combating Antibiotic Resistance in Microbial Pathogens

Antibiotic resistance or microbial drug resistance is emerging as a serious threat to human healthcare globally, and the multidrug-resistant (MDR) strains are imposing major hurdles to the progression of drug discovery programs. Newer antibiotic-resistance mechanisms in microbes contribute to the inefficacy of the existing drugs along with the prolonged illness and escalating expenditures. The injudicious usage of the conventional and commonly available antibiotics in human health, hygiene, veterinary and agricultural practices is proving to be a major driver for evolution, persistence and spread of antibiotic-resistance at a frightening rate. The drying pipeline of new and potent antibiotics is adding to the severity. Therefore, novel and effective new drugs and innovative therapies to treat MDR infections are urgently needed. Apart from the different natural and synthetic drugs being tested, plant secondary metabolites or phytochemicals are proving efficient in combating the drug-resistant strains. Various phytochemicals from classes including alkaloids, phenols, coumarins, terpenes have been successfully demonstrated their inhibitory potential against the drug-resistant pathogens. Several phytochemicals have proved effective against the molecular determinants responsible for attaining the drug resistance in pathogens like membrane proteins, biofilms, efflux pumps and bacterial cell communications. However, translational success rate needs to be improved, but the trends are encouraging. This review highlights current knowledge and developments associated challenges and future prospects for the successful application of phytochemicals in combating antibiotic resistance and the resistant microbial pathogens.

Traditional Uses, Phytochemistry, and Pharmacological Properties of Zingiber officinale Essential Oil and Extracts

Ginger (Zingiber officinale) has been traditionally employed in south East Asia as well as India and China for treatment of nausea, asthma, fever, vomiting, cough, constipation, pain, arthritis, inflammation, etc. This chapter discusses the phytochemical composition and pharmacological studies of ginger extracts, ginger essential oil (GEO), and active bioactive constituents. The essential oil of fresh and dry ginger was ranged between 0.2% - 2.62% and 0.72% - 4.17% respectively. The bioactive constituent zingiberene, β-sesquiphellandrene, curcumene, β-bisabolene, β-farnesene, camphene, and gingerol and shogal are the major constituents in ginger extracts. These compounds are chief bioactive substances responsible for pharmacological activities such antioxidant, antidiabetic, anticancer, anticoagulant, antiradiation, anti-inflammatory, gastrointestinal, antimicrobial, cardiovascular, anti-obesity, and weight loss effects. Future research needs to investigate the suitable duration, maximum dosage of ginger, concerns of overdosage, and its side effects in animal models and humans.

A new dimeric protoberberine alkaloid and other compounds from the tubers of Tinospora dentata

A new dimeric quaternary protoberberine alkaloid, bispalmatrubine (1), and thirteen known compounds (2-14) were purified from the tubers of Tinospora dentata. Their structures were determined by spectroscopic and spectrometric analytical methods. Among the isolates, eight compounds were examined for their in vitro anti-inflammatory potential and several tested alkaloids displayed moderate inhibitory effects of N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release.

Combinations of herbs and probiotics as an alternative growth promoter: An in vitro study

Background and Aim:

Antibiotic growth promoters (AGPs) are added to animal feed to stimulate growth and increase livestock productivity. However, the regular use of antibiotics in animal diets has a considerable contribution to the occurrence of antibiotic resistance in livestock and humans. This study aimed to investigate the feasibility of red ginger (Zingiber officinale var. Rubrum), turmeric (Curcuma domestica), and wild ginger (Curcuma xanthorrhiza), Lactobacillus acidophilus, and Lactobacillus brevis as an alternative to AGPs.

Materials and Methods:

The antibacterial activities and probiotic stimulatory effects of herbs were screened through the disk diffusion method and optical densitometry. The inhibitory ability of probiotics against pathogens was also tested through the disk diffusion method. The adhesion ability of probiotics was tested by mixing the optimal herbal combinations with broiler intestinal epithelial cells (10⁵ cells/ml). The cells were then subjected to Gram staining, and the number of adherent bacteria was calculated.

Results:

The test results showed that 3.13% ethanolic wild ginger extract had the highest inhibitory activity against Salmonella Enteritidis, followed by ethanolic red ginger extract and aqueous wild ginger extract at the same concentration. The three extracts also supported the growth of L. acidophilus and L. brevis. Further tests showed that the combination of 3.13% ethanolic red ginger extract had the highest inhibitory activity against S. Enteritidis, followed by ethanolic and aqueous wild ginger extract at the same concentration. The three extracts also supported the growth of L. acidophilus and L. brevis. Further tests showed that the combination of 3.13% ethanolic red ginger extract and 3.13% aqueous wild ginger extract had the best inhibitory effect on the growth of S. Enteritidis. The stimulatory effect of the combinations of herbal extract on the growth of L. acidophilus (0.18±0.00) and L. brevis (0.21±0.01) was better than those of individual extract, positive controls, and the glucose control. L. acidophilus and L. brevis had a weak inhibitory effect on the growth of S. Enteritidis (<6 mm). The adhesion ability of L. acidophilus (420.00±28.21) and L. brevis (259.33±24.03) was stronger than that of S. Enteritidis (202.00±14.00) under treatment with combined extracts.

Conclusion:

The tested combinations of herbs and probiotics can adhere to the intestinal tract. Given this characteristic, herb and probiotic combinations may be developed as an alternative to conventional AGPs.

Application of Chromatographic and Spectroscopic Methods towards the Quality Assessment of Ginger (Zingiber officinale) Rhizomes from Ecological Plantations

The usefulness of ginger in the food industry and pharmacotherapy is strictly related to its content of various components. The study elucidates the chemical composition of Zingiber officinale rhizomes cultivated on ecological plantations on Shikoku Island (Japan). GC-MS analysis of terpene content, LC-MS determination of phenolic content, and the determination of 12 elements using AAS spectrometry were performed to give more detailed insight into the samples. Ninety-five percent of terpene composition was elucidated, with zingiberene as the most abundant sesquiterpene (37.9%); the quantification of gingerols and shogaols was performed, showing the highest contribution of 6-gingerol (268.3 mg/kg); a significant K (43,963 mg/kg of dry mass) and Mn (758.4 mg/kg of dry mass) content was determined in the elemental analysis of the rhizomes and low concentration of toxic elements (Cd, Ni and Pb) remaining below the safe level values recommended by European Commission Directives. The main phenolic compound was (6)-gingerol, which is characteristic of fresh rhizomes and is responsible for their taste and aroma. Surprisingly, high amounts of (6)-shogaol were determined, even though this phenolic compound usually occurs in old or processed material and not in fresh rhizomes. Sesquiterpenes were the major fraction of volatiles. The highest concentrations were determined for α-zingiberene, β-sesquiphellandrene, (E,E)-α-farnesene, geranial, and ar-curcumene. The volatiles composition of ginger cultivated on Shikoku Island is specific and strongly differs from plants cultivated in China, Nigeria, or Australia. The elemental composition of ginger rhizomes grown in ecological plantations is more beneficial for human health compared to products grown in normal cultivars, as the products contain high amounts of potassium and manganese and are characterized by low sodium content and lower levels of toxic heavy metals.

Plant extracts: from encapsulation to application

INTRODUCTION

Plants are a natural source of various products with diverse biological activities offering treatment for several diseases. Plant extract is a complex mixture of compounds, which can have antioxidant, antibiotic, antiviral, anticancer, antiparasitic, antifungal, hypoglycemic, anti-hypertensive and insecticide properties. The extraction of these extracts requires the use of organic solvents, which not only complicates the formulations but also makes it difficult to directly use the extracts for humans. To overcome these problems, recent research has been focused on developing new ways to formulate the plant extracts and delivering them safely with enhanced therapeutic efficacy.

AREAS COVERED

This review focuses on the research done in the development and use of polymeric nanoparticles for the encapsulation and administration of plant extracts. It describes in detail, the different encapsulation techniques, main physicochemical characteristics of the nanoparticles, toxicity tests and results obtained from in vivo or in vitro assays.

EXPERT OPINION

Major obstacles associated with the use of plant extracts for clinical applications include their complex composition, toxicity risks and extract instability. It is observed that encapsulation can be successfully used to decrease plant extracts toxicity, to provide targeted drug delivery and to solve stability related problems.