Plant growth promoting rhizobacteria (PGPR) shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism) of the PGPR for plant growth and the role of the PGPR as biofertilizer-thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

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BackgroundHepatology research has focused on developing traditional therapies as pharmacological medicines to treat liver cirrhosis. Thus, this study evaluated mechanisms of the hepatoprotective activity of Curcuma longa rhizome ethanolic extract (CLRE) on thioacetamide-induced liver cirrhosis in rats.MethodsThe hepatoprotective effect of CLRE was measured in a rat model of thioacetamide-induced liver cirrhosis over 8 weeks. Hepatic cytochrome P450 2E1 and serum levels of TGF-β1 and TNF-α were evaluated. Oxidative stress was measured by malondialdehyde, urinary 8-hydroxyguanosine and nitrotyrosine levels. The protective activity of CLRE free-radical scavenging mechanisms were evaluated through antioxidant enzymes. Protein expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins in animal blood sera was studied and confirmed by immunohistochemistry of Bax, Bcl2 proteins and proliferating cell nuclear antigen.ResultsHistopathology, immunohistochemistry and liver biochemistry were significantly lower in the Curcuma longa-treated groups compared with controls. CLRE induced apoptosis, inhibited hepatocytes proliferation but had no effect on hepatic CYP2E1 levels.ConclusionThe progression of liver cirrhosis could be inhibited by the antioxidant and anti-inflammatory activities of CLRE and the normal status of the liver could be preserved.

Orthosiphon stamineus as medicinal plant is commonly used in Malaysia for treatment of hepatitis and jaundice; in this study, the ethanol extracts were applied to evaluate the hepatoprotective effects in a thioacetamide-induced hepatotoxic model in Sprague Dawley rats. Five groups of adult rats were arranged as follows: Group 1 (normal control group), Group 2 Thioacetamide (TAA) as positive control (hepatotoxic group), Group 3 Silymarin as a well-known standard drug (hepatoprotective group), and Groups 4 and 5 as high and low dose (treatment groups). After 60-day treatment, all rats were sacrificed. The hepatotoxic group showed a coarse granulation on the liver surface when compared to the smooth aspect observed on the liver surface of the other groups. Histopathological study confirmed the result; moreover, there was a significant increase in serum liver biochemical parameters (ALT, AST, ALP, and Bilirubin) and the level of liver Malondialdehyde (MDA), accompanied by a significant decrease in the level of total protein and Albumin in the TAA control group when compared with that of the normal group. The high-dose treatment group (200 mg/kg) significantly restored the elevated liver function enzymes near to normal. This study revealed that 200 mg/kg extracts of O. stamineus exerted a hepatoprotective effect.

BackgroundThe aim of this study was to investigate the prevalence and characterization of Listeria species and Listeria monocytogenes isolated from raw fish and open-air fish market environments. Eight hundred and sixty two samples including raw fish and fish market environments (samples from workers’ hands, workers’ knives, containers and work surface) were collected from the open-air fish markets in the Northern region of Iran.ResultsListeria spp. was isolated from 104/488 (21.3 %) raw fish and 29/374 (7.8 %) of samples from open-air fish market environment. The isolates of Listeria spp. included L. innocua (35.3 %), L. monocytogenes (32.3 %), L. seeligeri (18 %), and L. ivanovii (14.3 %). Of the 43 L. monocytogenes isolates, 31 (72.1 %), 10 (23.3 %) and 2 (4.7 %) belonged to serovars 1/2a, 4b, and 1/2b, respectively. The inlA, inlB, inlC, inlJ, actA, hlyA, iap, plcA, and prfA virulence-associated genes were detected in almost all of the L. monocytogenes isolates. The Listeria spp. isolates showed high resistance against tetracycline (23.3 %), penicillin G, and cephalothin (each 16.5 %). Besides, we observed significant resistance level to tetracycline (27.9 %), ampicillin (20.9 %), cephalothin, penicillin G, and streptomycin (each 16.3 %) in the L. monocytogenes isolates. All of the isolates were susceptible to cefotaxime, gentamicin, kanamycin, and pefloxacin. We found that tetM (25.6 %), tetA (23.3 %), ampC (14 %), and penA (11.6 %) were the most prevalent antibiotic resistance genes in the L. monocytogenes isolates.ConclusionsRecovery of potentially pathogenic L. monocytogenes from raw fish and environment of open-air fish market samples in this study is a convincing evidence for the zoonotic potential of listeriosis.

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This study was based on screening antibacterial activity of the ethanol extract of Baeckea frutescens L. against MRSA clinical isolates, analyzes the potential antibacterial compound, and assesses the cytotoxicity effect of the extract in tissue culture. Leaves of Baeckea frutescens L. were shade dried, powdered, and extracted using solvent ethanol. Preliminary phytochemical screening of the crude extracts revealed the presence of alkaloids, flavonoids, steroids, terpenoids, phenols, and carbohydrates. The presence of these bioactive constituents is related to the antibacterial activity of the plant. Disc diffusion method revealed a high degree of activity against microorganisms. The results confirm that Baeckea frutescens L. can be used as a source of drugs to fight infections caused by susceptible bacteria.

BackgroundImmunomodulators are substances that modify immune system response to a threat. Immunomodulators modulate and potentiate the immune system, keeping it highly prepared for any threat. The immunomodulatory effect of the traditional medicine Tinospora crispa is investigated in this work.MethodsT. crispa ethanol extract was fractionated by using different solvents. The ethanol extract and effective isolated fraction were used to investigate the potential immunomodulatory effect of different T. crispa doses ranging from 25 μg/mL to 1000 μg/mL on RAW 246.7 cells by detecting intracellular INF-γ, IL-6, and IL-8 expressions. The antioxidant activity of T. crispa was evaluated through FRAP and DPPH. The total phenolic and total flavonoid contents were also quantified.ResultsResults show that T. crispa extract has higher antioxidant potential than ascorbic acid. The FRAP value of T. crispa extract is 11011.11 ± 1145.42 μmol Fe+2/g, and its DPPH inhibition percentage is 55.79 ± 7.9, with 22 μg/mL IC50. The results also reveal that the total phenolic content of T. crispa extract is 213.16- ± 1.31 mg GAE/g dry stem weight, and the total flavonoid content is 62.07- ± 39.76 mg QE/g dry stem weight. T. crispa crude extract and its isolated fraction significantly stimulate RAW264.7 cell viability (P ≤ 0.05) and intracellular INF-γ, IL-6, and IL-8 expressions. The results of LC-MS show that four of the active compounds detected in the T. crispa isolated fraction are cordioside, quercetin, eicosenoic acid (paullinic acid), and boldine.ConclusionsThe results of this study obviously indicate that T. crispa has immunomodulatory effects through the stimulation of INF-γ, IL-6, and IL-8 expressions. LC-MS phytochemical analysis showed that the T. crispa fraction has cordioside, quercetin, eicosenoic acid (paullinic acid), and boldine, which may be responsible for the immunostimulator effect of T. crispa.