The Effects of Agrimonia pilosa Ledeb, Anemone chinensis Bunge, and Smilax glabra Roxb on Broiler Performance, Nutrient Digestibility, and Gastrointestinal Tract Microorganisms.

Poultry farming is growing globally, particularly in developing countries, to meet the demands of growing populations for poultry meat and eggs. This is likely to lead to an increase in the use of antibiotics in poultry feed, thus contributing to the development and spread of antibiotic resistance which, poses a serious threat to human and animal health worldwide. One way of reducing this threat is to reduce the use of antibiotics in poultry production by finding effective and sustainable antibiotic alternatives that can be used to support poultry health and productivity. Therefore, this study evaluates the incorporation of three medicinal plants, Anemone chinensis Bunge, Smilax glabra Roxb, and Agrimonia pilosa Ledeb, in poultry feed on production performance, nutrient digestibility, and bacteria in the chicken caecum in a 35-day performance trial with 420-day-old male Ross 308 broilers. Groups of randomly selected chicks received one of six dietary treatments. These included five experimental diets of reduced nutrient specifications as a negative control (NC); with amoxicillin as a positive antibiotic control (PC1); with A. pilosa Ledeb (NC1); with A. chinensis Bunge (NC2); and with S. glabra Roxb (NC3). One other positive control diet contained the recommended nutrient specification (PC2). Weight gain and feed intake were measured weekly and used to calculate the feed conversion ratio as performance parameters. Bacteria were enumerated from chicken caecum using a traditional plating method and selective agar. S. glabra Roxb and A. chinensis Bunge showed comparable effects to amoxicillin with significantly increased weight gain in birds offered these diets, compared to those offered the negative control from days 0 to 35 (p < 0.001). S. glabra Roxb exhibited effects similar to the amoxicillin control group with an improved feed conversion ratio (p < 0.001). In addition, S. glabra Roxb decreased numbers of E. coli and Campylobacter spp. on days 21 (p < 0.05) and 35 (p < 0.01) and increased numbers of lactic acid bacteria comparable to the antibiotic group on days 14 (p < 0.001) and 35 (p < 0.01). The findings of this in vivo trial highlight the potential of S. glabra Roxb and A. chinensis Bunge as beneficial feed material to promote poultry health and productivity in the absence of antibiotics.

In vitro bactericidal activity of diterpenoids isolated from Aframomum melegueta K.Schum against strains of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus.

ETHNOPHARMACOLOGICAL RELEVANCE: The ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity. MATERIALS AND METHODS: To substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against Escherichia coli K12; acetone extract and the fractions of acetone extracts were tested against Listeria monocytogenes. Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms. RESULTS: Four known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli, L. monocytogenes, methicillin resistant Staphylococus aureus (MRSA) and S. aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using nuclear magnetic resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed. CONCLUSION: The results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.

Antibacterial activities of naturally occurring compounds against Mycobacterium avium subsp. paratuberculosis.

The antibacterial activities of 18 naturally occurring compounds (including essential oils and some of their isolated constituents, apple and green tea polyphenols, and other plant extracts) against three strains of Mycobacterium avium subsp. paratuberculosis (a bovine isolate [NCTC 8578], a raw-milk isolate [806R], and a human isolate [ATCC 43015]) were evaluated using a macrobroth susceptibility testing method. M. avium subsp. paratuberculosis was grown in 4 ml Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase, 0.05% Tween 80 (or 0.2% glycerol), and 2 microg/ml mycobactin J supplemented with five concentrations of each test compound. The changes in the optical densities of the cultures at 600 nm as a measure of CFU were recorded at intervals over an incubation period of 42 days at 37 degrees C. Six of the compounds were found to inhibit the growth of M. avium subsp. paratuberculosis. The most effective compound was trans-cinnamaldehyde, with a MIC of 25.9 microg/ml, followed by cinnamon oil (26.2 microg/ml), oregano oil (68.2 microg/ml), carvacrol (72.2 microg/ml), 2,5-dihydroxybenzaldehyde (74 microg/ml), and 2-hydroxy-5-methoxybenzaldehyde (90.4 microg/ml). With the exception of carvacrol, a phenolic compound, three of the four most active compounds are aldehydes, suggesting that the structure of the phenolic group or the aldehyde group may be important to the antibacterial activity. No difference in compound activity was observed between the three M. avium subsp. paratuberculosis strains studied. Possible mechanisms of the antimicrobial effects are discussed.