Antimicrobial potential of Terminalia chebula Retz. fruit extracts against ear pathogens

Antimicrobial efficacy of select medicinal plant extracts from Bangladesh against food‐borne bacterial pathogens

We assessed the antimicrobial activity of extracts prepared with four solvents (hexane, acetone, ethanol, water) from 45 medicinal plants used in Bangladesh. Food pathogenic bacteria (Gram‐positive: Bacillus cereus, Listeria innocua, Streptococcus faecalis, and Gram‐negative: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and Shigella sonnei) were tested using a broth microdilution method. The extraction yield was highest (26%) for the water extract of Carica papaya and lowest (0.4%) for the acetone extract of Cynodon dactylon. In general, acetone extracts exhibited much more antibacterial activity than those obtained with the other three solvents (hexane, ethanol, and water). Gram‐positive bacteria were more sensitive than Gram‐negatives. Streptococcus faecalis was the most susceptible to inhibition by examined extracts, whereas E. coli and P. aeruginosa were the most resistant. Most inhibitory concentration‐50 (IC50) values ranged between 101 and 500 μg/mL (64 extracts, 35.5%), followed by the range of 501–1000 μg/mL (40 extracts, 22.2%). Based on IC50, the most effective plants were three species of Piper (Piper nigrum, Piper betle, and Piper chaba), followed by Nigella sativa, Psidium guajava, Syzygium cumini, C. dactylon, and Phyllanthus emblica. In addition, the toxicity of chosen extracts against normal and malignant cell lines was tested; the most effective extracts were toxic against the human lung carcinoma cell line A549, but less toxic against the human Caucasian foetal lung cell line WI26VA4. These findings suggest that some plant extracts could be employed to treat food‐borne bacterial infections, or as herbal preservatives in the food sector.

Preliminary Screening for the Anthelmintic Activity of Millettia zechiana Harms and Its Modifying Effect on Albendazole

Helminthic infections affect a greater proportion of the world's population. This study determined the anthelmintic activity of Millettia zechiana and its modifying effect on albendazole. Powdered leaves of M. zechiana were successively extracted with petroleum ether, ethyl acetate, and ethanol. The anthelmintic potential of the M. zechiana leaf extracts and the modifying effects of the extracts on albendazole were determined on Pheretima posthuma. Phytochemical and gas chromatography-mass spectroscopy (GC-MS) analyses were performed to determine the chemical composition of each extract. The plant extracts of M. zechiana had few or all phytoconstituents such as tannins, saponins, flavonoids, glycosides, terpenoids, phytosterols, and alkaloids present. The IC50 obtained for albendazole, petroleum ether, ethyl acetate, and ethanol extracts for paralysis time were 0.936, 1.722, 1.283, and 1.348 mg/mL, respectively. The IC50 obtained for albendazole and the ethanol extract for death time were 4.638 and 4.988 mg/mL. The ethanol extract at 10 and 5 mg/mL caused death in the worms after 152.5 ± 8.66 minutes and 304.8 ± 7.27 minutes of exposure, respectively. Ethanol, ethyl acetate, and petroleum ether extracts of M. zechiana significantly modified the activity of albendazole at concentrations of 2.5 and 1.25 mg/mL (P < 0.0001). The ethanol extract which exhibited the best anthelminthic activity was fractionated through column chromatography, and five (5) fractions were obtained. Fractions 1, 2, 4, and 5 had the best paralytic activities against the worms. Fractions 1 and 2 demonstrated better helminthicidal activity than albendazole, which had an IC50 of 3.915. The GC-MS analysis of the ethanol, ethyl acetate, and petroleum ether extracts showed the presence of 10, 10, and 37 compounds, respectively, with 9-octadecenamide, (Z)-, n-hexadecanoic acid, oleic acid, and some aromatic compounds being the most predominant. The results obtained indicate that M. zechiana leaf extract possesses anthelmintic activity.

Promising applications of phyto-fabricated silver nanoparticles: Recent trends in biomedicine

The prospective contribution of phyto-nanotechnology to the synthesis of silver nanomaterials for biomedical purposes is attracting increasing interest across the world. Green synthesis of silver nanoparticles (Ag-NPs) through plants has been extensively examined recently, and it is now seen to be a green and efficient path for future exploitation and development of practical nano-factories. Fabrication of Ag-NPs is the process involves use of plant extracts/phyto-compounds (e.g.alkaloids, terpenoids, flavonoids, and phenolic compounds) to synthesise nanoparticles in more economical and feasible. Several findings concluded that in the field of medicine, Ag-NPs play a major role in pharmacotherapy (infection and cancer). Indeed, they exhibits novel properties but the reason is unclear (except some theoretical interpretation e.g. size, shape and morphology). But recent technological advancements help to address these questions by predicting the unique properties (composition and origin) by characterizing physical, chemical and biological properties. Due to increased list of publications and their application in the field of agriculture, industries and pharmaceuticals, issues relating to toxicity are unavoidable and question of debate. The present reviews aim to find out the role of plant extracts to synthesise Ag-NPs. It provides an overview of various phytocompounds and their role in the field of biomedicine (antibacterial, antioxidant, anticancer, anti-inflammatory etc.). In addition, this review also especially focused on various applications such as role in infection, oxidative stress, application in medical engineering, diagnosis and therapy, medical devices, orthopedics, wound healing and dressings. Additionally, the toxic effects of Ag-NPs in cell culture, tissue of different model organism, type of toxic reactions and regulation implemented to reduce associated risk are discussed critically. Addressing all above explanations, this review focus on the detailed properties of plant mediated Ag-NPs, its impact on biology, medicine and their commercial properties as well as toxicity.

Antimicrobial screening of polyherbal formulations traditionally used against gastrointestinal diseases

Emerging antibiotic resistance has become a cosmopolitan problem and evoking researchers to search for new antimicrobials from natural constituents. The present study was intended to test the antimicrobial potential of traditionally used unexplored polyherbal recipes for curing digestive ailments. A total of 25 plants species were combined in different ratios to form 14 polyherbal recipes. After collecting and grinding plant parts, methanolic extracts of 14 polyherbal recipes were prepared by the cold maceration process. Antibacterial and antifungal activity of the polyherbal extracts was checked by agar well diffusion method at a concentration of 50 mg/ ml while minimum inhibitory concentration (MIC) was determined by serial dilution method. Polyherbal recipes B and D showed significant inhibition zone each against Vibrio cholerae (25.63; p < 0.001). Recipe G (23.33; p < 0.001) showed better efficacy against Escherichia coli. Recipe E and G significantly inhibited Proteus species (28.33; 24.33; p < 0.001). Recipe B was highly effective against Salmonella typhi. Recipe C, A and F had significant antifungal affect and inhibited Aspergillus nigar (28.67; p < 0.05), Aspergillus fumigatus (27; p < 0.01) Trichoderma (30; p < 0.001), Rhizopus (19.67; p < 0.01), and Fusarium graminearum (28.67;p < 0.001). Polyherbal formulations A, B, D, K, and N were active with the lowest concentration. MIC ranges within 3.12–25 mg/ml while minimum bactericidal concentration (MBC) between 12.5 and 50 mg/ml. Polyherbal recipes’ A, B, D, G, K and N have enhanced antimicrobial potential with better efficacy than tested antibiotics and should be evaluated for further scientific validation.

Plants of the Genus Terminalia: An Insight on Its Biological Potentials, Pre-Clinical and Clinical Studies

The evaluation and confirmation of healing properties of several plant species of genus Terminalia based on their traditional uses and the clinical claims are of utmost importance. Genus Terminalia has received more attention to assess and validate the therapeutic potential and clinical approval due to its immense folk medicinal and traditional applications. Various species of Terminalia genus are used in the form of herbal medicine and formulations, in treatment of diseases, including headache, fever, pneumonia, flu, geriatric, cancer, to improve memory, abdominal and back pain, cough and cold, conjunctivitis, diarrhea, heart disorder, leprosy, sexually transmitted diseases, and urinary tract disorders. These are reported to possess numerous biological properties, counting: antibacterial, antifungal, antiinflammatory, antiviral, antiretroviral, antioxidant, and antipa7rasitic. This current research review aims to update the detailed biological activities, pre-clinical and clinical studies of various extracts and secondary metabolites from several plant species under the genus Terminalia, along with information on the traditional uses and chemical composition to develop a promising strategy for their potential applications in the form of medicine or use in modern drug formulations for treating diseases like pneumonia, flu, and other types of viral infections or controlling human contagions.

In Vitro Antimicrobial Activity of Spices and Medicinal Herbs against Selected Microbes Associated with Juices

In the present investigation, comparison of antimicrobial activities of different spices, Curcuma longa, Zingiber officinale, and Mentha arvensis, and medicinal herbs, such as Withania somnifera, Rauvolfia serpentina, Emblica officinalis, Terminalia arjuna, and Centella asiatica, was evaluated. Different extraction solvents (acetone, methanol, ethanol, and water) were used and extracts were examined against Bacillus cereus, Serratia sp., Rhodotorula mucilaginosa, Aspergillus flavus, and Penicillium citrinum isolated from juices. Extracts from the medicinal herb and spices have significant activity. B. cereus was the most sensitive and R. mucilaginosa was the most resistant among the microorganisms tested. Ethanolic and methanolic extract of C. asiatica displayed maximum diameter of inhibition zone against bacteria and yeast and percentage mycelial inhibition against moulds. This study confirmed the potential of selected extracts of spices as effective natural food preservative in juices.

Chebulin: Terminalia chebula Retz. fruit-derived peptide with angiotensin-I-converting enzyme inhibitory activity

Angiotensin-I-converting enzyme (ACE) plays an important role in blood pressure regulation. In this study, an ACE-hexapeptide inhibitor (Asp-Glu-Asn-Ser-Lys-Phe) designated as chebulin was produced from the fruit protein of Terminalia chebula Retz. by pepsin digestion, ultrafiltrated through a 3 KDa cut-off membrane, a reverse-phase high-performance liquid chromatography, and nano-liquid chromatography tandem mass spectrometry analysis. Chebulin was found to inhibit ACE in a noncompetitive manner, as supported by the structural model. It bounds to ACE by the hydrogen bond, hydrophobic and ionic interactions via the interactions of C-terminal Phe (Phe-6), and N-terminal residues (Asp-1 and Glu-2) with the amino acid residues on noncatalytic sites of the ACE. The results showed that chebulin derived from fruits of T. chebula Retz. is a potential ACE-peptide inhibitor that could be used as a functional food additive for the prevention of hypertension and as an alternative to ACE inhibitor drug.