Our study aims to evaluate the chemical profiles and antioxidant activities of a methanolic extract of Sterculia villosa bark (MESV) and a methanolic extract of the Vernonia patula whole plant (MEVP). The chemical profiling of MESV and MEVP was performed via gas chromatography-mass spectrometry (GC-MS), which identified 52 and 33 chemical compounds, respectively. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay indicated that both MESV and MEVP displayed concentration-dependent scavenging activities, and half-maximal inhibitory concentration (IC50) values for MEVP, MESV, and ascorbic acid were 305.30, 555.44, and 36.32 µg/mL, respectively. The total flavonoid content (TFC) and total phenolic content (TPC) of MESV were 81.44 ± 2.70 mg quercetin equivalents (QE)/g dry extract and 62.58 ± 1.93 mg gallic acid equivalent (GAE)/g dry extract, whereas these values for MEVP were 291.31 ± 6.61 mg QE/g dry extract and 58.99 ± 3.16 mg GAE/g dry extract, respectively. Molecular docking studies were also evaluated, and absorption, distribution, metabolism, and excretion (ADME) and toxicological properties were assessed. Therefore, these two plants, S. villosa and V. patula, showed potential options for further advanced studies into oxidative stress.
Lignin is an important commercially produced polymeric material. It is used extensively in both industrial and agricultural activities. Recently, it has drawn much attention from the scientific community. It is abundantly present in nature and has significant application in the production of biodegradable materials. Its wide usage includes drug delivery, polymers and several forms of emerging lignin nanoparticles. The synthesis of lignin nanoparticles is carried out in a controlled manner. The traditional manufacturing techniques are costly and often toxic and hazardous to the environment. This review article highlights simple, safe, climate-friendly and ecological approaches to the synthesis of lignin nanoparticles. The changeable, complex structure and recalcitrant nature of lignin makes it challenging to degrade. Researchers have discovered a small number of microorganisms that have developed enzymatic and non-enzymatic metabolic pathways to use lignin as a carbon source. These microbes show promising potential for the biodegradation of lignin. The degradation pathways of these microbes are also described, which makes the study of biological synthesis much easier. However, surface modification of lignin nanoparticles is something that is yet to be explored. This review elucidates the recent advances in the biodegradation of lignin in the ecological system. It includes the current approaches, methods for modification, new applications and research for the synthesis of lignin and lignin nanoparticles. Additionally, the intricacy of lignin's structure, along with its chemical nature, is well-described. This article will help increase the understanding of the utilization of lignin as an economical and alternative-resource material. It will also aid in the minimization of solid waste arising from lignin.
BACKGROUND: Typhoid fever is an acute systemic infection of humans caused by Salmonella enterica subspecies enterica serovar Typhi (S. Typhi). In chronic carriers, the bacteria survive the harsh environment of the gallbladder by producing biofilm. The phenotype of S. Typhi biofilm cells is significantly different from the free-swimming planktonic cells, and studies have shown that they are associated with antibiotic resistance, immune system evasion, and bacterial persistence. However, the mechanism of this transition and the events leading to biofilm formation are unknown. High throughput sequencing was performed to identify the genes involved in biofilm formation and to postulate the mechanism of action. RESULTS: Planktonic S. Typhi cells were cultured using standard nutrient broth whereas biofilm cells were cultured in a stressful environment using high shearing-force and bile to mimic the gallbladder. Sequencing libraries were prepared from S. Typhi planktonic cells and mature biofilm cells using the Illumina HiSeq 2500 platform, and the transcriptome data obtained were processed using Cufflinks bioinformatics suite of programs to investigate differential gene expression between the two phenotypes. A total of 35 up-regulated and 29 down-regulated genes were identified. The identities of the differentially expressed genes were confirmed using NCBI BLAST and their functions were analyzed. The results showed that the genes associated with metabolic processes and biofilm regulations were down-regulated while those associated with the membrane matrix and antibiotic resistance were highly up-regulated. CONCLUSIONS: It is proposed that the biofilm phenotype of S. Typhi allows the bacteria to increase production of the membrane matrix in order to serve as a physical shield and to adhere to surfaces, and enter an energy conservation state in response to the stressful environment. Conversely, the planktonic phenotype allows the bacteria to produce flagella and increase metabolic activity to enable the bacteria to migrate and form new colonies of infection. This data provide a basis for further studies to uncover the mechanism of biofilm formation in S. Typhi and to discover novel genes or pathways associated with the development of the typhoid carrier state.
Biofilms/growth & development , Gene Expression Profiling , Gene Expression Regulation, Bacterial , Salmonella typhi/growth & development , Salmonella typhi/genetics , Transcriptome , Gene Expression Profiling/methods , High-Throughput Nucleotide Sequencing , Humans
This research was performed based on a comparative study on fungal lipid production by a locally isolated strain Cunninghamella bainieri 2A1 in batch culture and repeated-batch culture using a nitrogen-limited medium. Lipid production in the batch culture was conducted to study the effect of different agitation rates on the simultaneous consumption of ammonium tartrate and glucose sources. Lipid production in the repeated-batch culture was studied by considering the effect of harvesting time and harvesting volume of the culture broth on the lipid accumulation. The batch cultivation was carried out in a 500 ml Erlenmeyer flask containing 200 ml of the fresh nitrogen-limited medium. Microbial culture was incubated at 30 °C under different agitation rates of 120, 180 and 250 rpm for 120 h. The repeated-batch culture was performed at three harvesting times of 12, 24 and 48 h using four harvesting cultures of 60%, 70%, 80% and 90%. Experimental results revealed that nitrogen source (ammonium tartrate) was fully utilized by C. bainieri 2A1 within 24 h in all agitation rates tested. It was also observed that a high amount of glucose in culture medium was consumed by C. bainieri 2A1 at 250 rpm agitation speed during the batch fermentation. Similar results showed that the highest lipid concentration of 2.96 g/L was obtained at an agitation rate of 250 rpm at 120 h cultivation time with the maximum lipid productivity of 7.0 × 10(-2) mg/ml/h. On the other hand, experimental results showed that the highest lipid concentration produced in the repeated-batch culture was 3.30 g/L at the first cycle of 48 h harvesting time using 70% harvesting volume, while 0.23 g/L gamma-linolenic acid (GLA) was produced at the last cycle of 48 h harvesting time using 80% harvesting volume.
BACKGROUND: Obesity or being overweight is a major health problem in Iran. Only few studies are available that compare the obesity prevalence by four different available criteria. The aim of this study was to determine the prevalence of overweight and obesity among Isfahani adolescents based on four different definitions. MATERIALS AND METHODS: This cross-sectional study was conducted on 3002 Isfahani students (1377 males; 1625 females) aged 11-18 years. Anthropometric measurements including weight and height were measured and body mass index (BMI) was calculated. Sex-specific BMI-for-age reference data of the Iranian national data, Center for Disease Control data (CDC2000), International Obesity taskforce data (IOTF), and recent World Health Organization (WHO) data was used to define overweight and obesity. RESULTS: The mean age of the studied population was 14.8 years and the mean BMI was 20.3 kg/m(2). Girls were on an average 1.4 years older and had almost one unit higher BMI than boys. Underweight was prevalent among almost 38.5% and 25.5% of adolescents as per WHO2007 and national Iranian cut-off points, respectively. The prevalence rates reached 39.5% and 45.8% by IOTF and CDC2000 criteria, respectively. The highest prevalence of overweight was obtained by IOTF cut-points (30.5%), while CDC2000 criteria, WHO2007, and national Iranian cut-points gave similar prevalence results (4.7%, 4.0%, and 4.4%); 2.4% of the studied population were found to be obese by WHO2007 definition, while this rate was 0.8%, 0.5%, and 0.8% by IOTF, CDC2000, and national Iranian cut-points. CONCLUSION: Almost all definitions revealed coexistence of underweight, overweight, and obesity among Isfahani adolescents. Huge differences exist between different criteria for assessing weight status among children. To understand the best appropriate criteria for Iranian adolescents, future studies should focus on the predictability of obesity related co-morbidities by these criteria.
