Free Radical Metabolism Research Articles

Characterization of Differences in Chemical Profiles and Antioxidant Activities of Schisandra chinensis and Schisandra sphenanthera Based on Multi-Technique Data Fusion

Schisandra chinensis (Turcz.) Baill. (S. chinensis) and Schisandra sphenanthera Rehd. et Wils (S. sphenanthera) are called “Wuweizi” in traditional Chinese medicine, and they have distinct clinical applications. To systematically compare the differential characteristics of S. chinensis and S. sphenanthera, this study employed ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatography–mass spectrometry (GC-MS) to construct chemical profiles of these two species from different regions. In total, 31 non-volatiles and 37 volatiles were identified in S. chinensis, whereas 40 non-volatiles and 34 volatiles were detected in S. sphenanthera. A multivariate statistical analysis showed that the non-volatiles tigloygomisin P, schisandrol A, schisantherin C, and 6-O-benzoylgomisin O and the volatiles ylangene, γ-muurolene, and β-pinene distinguish these species. Additionally, the metabolism of oxygen free radicals can contribute to the development of various diseases, including cardiovascular and neurodegenerative diseases. Therefore, antioxidant activities were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) scavenging assays. The results showed that S. sphenanthera exhibited significantly higher antioxidant potential. A gray relational analysis indicated that the key contributors to the antioxidant activity of S. chinensis were schisandrol A, gomisin G, schisantherin C, pregomisin, gomisin J, and schisantherin B. For S. sphenanthera, the key contributors included gomisin K2, schisantherin B, gomisin J, pregomisin, schisantherin C, schisandrin, gomisin G, schisantherin A, schisanhenol, and α-pinene. The identification of the differential chemical markers and the evaluation of the antioxidant activities provide a foundation for further research into the therapeutic applications of these species. This innovative study provides a robust framework for the quality control and therapeutic application of S. chinensis and S. sphenanthera, offering new insights into their medicinal potential.

Water‐Dispersible BODIPY Multifunctionalized Silicon Oxide Nanoparticles for Glutathione Sensing

AbstractGlutathione (GSH), a thiol containing small peptide, plays pivotal roles in maintaining cellular redox balance, metabolism, detoxification, and scavenging of free radicals. Aberrant GSH levels in cells and tissues are associated with various disorders, underscoring the importance of accurate GSH detection for clinical diagnosis and therapy monitoring. Several molecular probes have been designed as fluorescent‐based GSH sensors. However, their water insolubility and the need of using organic cosolvents hinder their applicability on biological samples. Alternatively, nanomaterials have proven to be highly promising for boosting the precision of treatments and enhancing the accuracy of diagnosing diseases, thanks to their compatibility with biological environments and improved cell uptake. Here, the synthesis and characterization of a boron‐dipyrromethene (BODIPY)‐based probe (PB) are reported, incorporating a fluorescent BODIPY core, chlorine substituents for reaction with GSH, and a linking moiety for conjugation to the surface of silicon oxide nanoparticles (SONPs). Functionalized SONPs with PB are also characterized at the nanoscale using high‐resolution transmission electron microscopy (HR‐TEM), dynamic light scattering (DLS), Zeta potential, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV–Vis absorption, and fluorescence spectroscopies, confirming the surface functionalization and water‐dispersibility of functionalized SONPs with PB. GSH sensing is evaluated in aqueous solution, conjugated to SONPs, and in living cells, showing promising potential for ratiometric GSH detection.

Role of trace minerals in bull reproductive physiology and semen quality

Testicular dysfunction is often associated with an imbalance in antioxidant/oxidant homeostasis, leading to negative effects of oxidative stress on germ cell proliferation, steroidogenesis, and sperm function. Trace minerals (TM) are involved in basic homeostatic and enzymatic processes like free radical detoxification, cellular respiration, carbohydrates, lipids, nucleic acids, synthesis and metabolism of proteins, and stabilization of membranes and DNA. Dietary source of TM is necessary to support these processes. Supplementing cattle with TM is nowadays a common practice to help support growth, reproduction, and immunity. This review provides information on roles of TM in bulls testicular and sperm functions, and effects of TM mineral supplementation on bull reproductive parameters.

Effects of repeated doses of paracetamol administration during pregnancy on lung, kidney, and liver tissues of pregnant rats.

Paracetamol is one of the most widely used analgesics and antipyretics in the world. It is the most commonly used analgesic and antipyretic agent in pregnancy. Paracetamol is known to have toxic effects on the liver, lung, and kidney. In this study, we investigated the effects of long-term chronic paracetamol exposure on the lung, liver, and kidney in newborn rats at different trimesters of pregnancy. In our study, we formed control (group C), first trimester (group A), and third trimester (group B) groups. Group A had the first seven days of pregnancy and group B had days 15-21. Paracetamol was given orally during the specified periods. On the third postnatal day, pups were euthanized by applying 50 mg/kg ketamine intraperitoneally, and then lung, liver, and kidney tissues were kept under appropriate conditions for examination. A total of 70 pups underwent histopathological examination. The lung revealed congestion (p<0.0001), and erythrocytes (p<0.0001), the liver revealed significant histopathological findings in terms of the presence of inflammation (p<0.0001), vacuolar degeneration (p<0.0001), and sinusoidal dilatation in groups A and B compared to the control group under light microscopy. MDA and free radical metabolism enzyme activities, CAT, GSH, and SOD were evaluated. While there were no significant differences between the groups in lung and kidney tissues, oxidant parameters were significant in liver tissues. Our data point out that subacute doses of paracetamol used chronically in different trimesters caused damage to the lung, liver, and kidney tissues of pups.

Unraveling a mysterious skin eruption in a case of Down syndrome

Collagenoma, also known as collagen naevus, is a connective tissue hamartoma which manifests as a single or localized group of fibrous dermal papules and plaques on the skin, and is characterized by increase in dermal collagen with normal or reduced elastin on histopathology. Cases have been reported in Down syndrome, as isolated or localized lesions, and were presumed to be due to altered free radical metabolism by the enzyme superoxide dismutase, its gene being located on chromosome 21. However, eruptive collagenoma in Down syndrome patients are rarely reported. We present a 22-year-old male Down syndrome patient with asymptomatic eruption of skin lesions on trunk and upper extremities since the past 18 months. He was offered surgical and laser therapy, but at his request, we kept him on regular follow-up.

Effects of moxibustion on acupoints at "opening" time on testicular tissue apoptosis in aging rats

To observe the effect of "lingguibafa" moxibustion at "opening" time on the level of superoxide dismutase(SOD), malondialdehyde(MDA), the protein expressions of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in aging model rats. SD rats were randomly divided into blank control, model and lingguibafa groups, with 8 rats in each group. The aging model was established by daily intraperitoneal injection of D-galactose (500 mg/kg) for 42 consecutive days. After successful modeling, moxibustion intervention was applied at"lingguibafa" acupoints, 3 moxa-cone for each acupoint, once a day for 28 consecutive days. The contents of SOD and MDA in serum were detected by ELISA. Morphological changes of testicular tissue and the number of Leydig cells were observed after HE staining. Apoptosis rate of testicular cells was detected by TUNEL staining. The protein expression levels of Bcl-2 and Bax in testis were detected by Western blot. Compared with the blank control group, the SOD content in the serum, the number of testicular Leydig cells, the expression level of Bcl-2 protein in testis were significantly decreased (P<0.01) in the model group, while the MDA content in the serum, the apoptosis rate of testicular cells and the expression level of Bax protein in testis were significantly increased (P<0.01). Compared with the model group, the SOD content in serum, the number of testicular Leydig cells, the Bcl-2 protein expression in testis were significantly increased (P<0.01), while the MDA content in serum, the apoptosis rate of testicular cells, the expression level of Bax protein in testis were significantly decreased(P<0.01) in the lingguibafa group. Moxibustion on acupoints at "opening" time can delay testicular aging, and the mechanism may be related to balancing the metabolism of free radicals, reducing oxidative damage, and inhibiting the apoptosis of testicular cells.

A typical phenotypes due to NDUFV1 mutations

Mitochondria have a critical role in energy metabolism, generating and scavenging of free radicals, intracellular Ca2+ regulation, and cell mitophagy. Dysfunction of the mitochondrial oxidative phosphorylation complex is the most frequent inborn errors of metabolism. Mitochondrial diseases are highly diverse in etiology, age of the disease onset, involvement of multiple organ systems, and genetic causes. NDUFV1 is a core subunit of mitochondrial Complex I (CI), and mutations cause CI deficiency. Clinically, CI deficiency is associated with severe infantile lactic acidosis, cardiomyopathy, encephalomyopathy, leukoencephalopathy, and Leigh syndrome. The cellular biology and molecular mechanisms of mitochondrial diseases are still elusive due to the heterogeneous genetic background and lack of phenotype-genotype correlation. Neurological abnormalities are the second most frequent presentations of mitochondrial diseases, including white matter abnormalities, psychomotor regression, and mental disability. The defects in myelin sheath or glial cells cause leukodystrophy which is a progressive genetical syndrome. To date, no therapy is available to cure mitochondrial diseases; exploration of the phenotype and molecular background are crucial for disease diagnosis, supportive treatments, proper genetic counselling, prenatal diagnosis, and experimental treatments. This article underscores the atypical clinical presentations of NDUFV1 mutations and the importance of a multidisciplinary approach to correlate phenotypes, biochemical, radiological, and molecular diagnosis. Implementation of multidisciplinary approach will enhance the possibility of discovering the therapeutic targets to treat mitochondrial disorders and ensure prenatal diagnosis to prevent inherited diseases.

Retracted: Cervical Spondylopathy and Lumbar Intervertebral Disc Herniation Coexist in Free Radical Metabolism and Focus Separation in the Body.

[This retracts the article DOI: 10.1155/2021/1480282.].

Effects of Sports Functional Food on Physical Function of Athletes under Ultrasound Observation.

In order to improve the physical function of athletes under hypoxic training, the authors propose to observe the effect of functional food with active ingredients of polypeptide polyamines in deer antler on the physical function of athletes under ultrasound observation. According to the characteristics of physiological changes during hypoxic training, functional foods containing the active ingredients of polypeptide polyamines in deer antler were selected and given to athletes under simulated hypoxic training, observe the changes of red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), blood lactic acid, free radical metabolism and immune function of athletes, and musculoskeletal under ultrasound observation, discuss how to improve the physical function and athletic ability of athletes under hypoxic training. Experimental results show that athletes after 6 weeks of hypoxic training, red blood cells and hemoglobin were significantly increased, there was a significant difference compared to the control group (P < 0.05 or P < 0.01). After 6 weeks of hypoxic training, hemoglobin increased by 10.1%, a 5.6 percentage point increase compared to the control group. Conclusion. The antler peptides used by the authors can enhance the effect of hypoxic training.

Synthesis of γ-Aminobutyric Acid-Modified Chitooligosaccharide Derivative and Enhancing Salt Resistance of Wheat Seedlings.

Salinity is one of the major abiotic stresses limiting crop growth and productivity worldwide. Salt stress during germination degenerates crop establishment and declines yield in wheat, therefore alleviating the damage of salt stress to wheat seedlings is crucial. Chitooligosaccharide (COS) was grafted with γ-aminobutyric acid based on the idea of bioactive molecular splicing, and the differences in salt resistance before and after grafting were compared. The expected derivative was successfully synthesized and exhibited better salt resistance-inducing activity than the raw materials. By activating antioxidant enzymes such as superoxide dismutases (SOD), catalase (CAT) and phenylalanine ammonia-lyase (PAL) and subsequently eliminating reactive oxygen species (ROS) in a timely manner, the rate of O−2 production and H2O2 content of wheat seedlings were reduced, and the dynamic balance of free radical metabolism in the plant body was maintained. A significantly reduced MDA content, reduced relative permeability of the cell membrane, and decreased degree of damage to the cell membrane were observed. A significant increase in the content of soluble sugar, maintenance of osmotic regulation and the stability of the cell membrane structure, effective reduction in the salt stress-induced damage to wheat, and the induction of wheat seedling growth were also observed, thereby improving the salt tolerance of wheat seedlings.

The Effects of Ozone Therapy on the Expression of IL-8, IL-10, CXCL9 and CXCL11 in Joint Fluid in Patients with Knee Osteoarthritis

Knee joint is one of the common sites of osteoarthritis (OA) with manifestation of localized joint swelling, pain and deformity, often seriously affecting daily work and life. It was found that the activation of Janus kinase / signal transducer and activator of transcription 3 (JAK / STAT3) signal pathway can lead to osteoarthritis. JAK-STAT signal transduction pathway is closely related to painful diabetic peripheral neuropathy and participates in neuropathic pain. Ozone therapy is often used for alleviating pain in neck, shoulder, waist and leg due to its oxidative, anti-inflammatory and analgesic effects. In recent years, ozone therapy is promising in treating knee osteoarthritis, which can significantly reduce the pain and swelling of the joints. The mechanism of ozone for knee osteoarthritis remains unclear and might associated with inhibition of inflammatory factors and matrix metalloproteinase activity, and intervention of free radical metabolism. In this study, the efficacy of ozone in the treatment of OA and its effect on inflammatory factors were evaluated by knee joint cavity ozone injection and detecting the expression of inflammatory factors IL-8, IL-10, CXCL9 and CXCL11 in joint fluid.

The role of glutathione transferase polymorphisms in the development of diabetic nephropathy

&amp;lt;p&amp;gt;Genetic and environmental factors play an important role in the development of type 2 diabetes mellitus (DM2) and its complications. Diabetic nephropathy (DN) is one of the most common microangiopathic chronic complications of diabetes. Oxidative stress occurs under condition of increased production of free radicals and/or decreased activity of antioxidant defense mechanisms and it is an important link in the complex mechanism of diabetic vascular changes. Glutathione transferases (GST) are enzymes involved in xenobiotic metabolism and they are part of complex antioxidant defense mechanisms. Numerous studies have found an association of GST gene polymorphism to a predisposition to various diseases, including diabetes and diabetic nephropathy. Our and other authors' results suggest that genetic variations in enzymes involved in free radical metabolism are associated with the development of end-stage kidney disease in patients with diabetes, which could become the basis for the development of preventive and early therapeutic strategies in high risk people.&amp;lt;/p&amp;gt;

Cervical Spondylopathy and Lumbar Intervertebral Disc Herniation Coexist in Free Radical Metabolism and Focus Separation in the Body.

Lumbar disc herniation is a common lumbar disease in clinics, which is related to improper use of lumbar vertebrae and osteoporosis. Surgical removal of nucleus pulposus and maintenance of lumbar structural stability are important for the treatment of lumbar disc herniation. At present, in clinical percutaneous intervertebral foramen endoscopic surgery for lumbar disc herniation, interlaminar and intervertebral foramen approaches can be selected. Different approaches have different degrees of difficulty in the treatment of lumbar disc herniation, and the clinical effects that may be obtained are different. In this study, we observed the influencing factors of plasma nitric oxide (NO) and free radical metabolism in patients with lumbar disc herniation and the correlation between the effects of focus separation. The organic combination of local and total illness differentiation and dialectics, conventional acupuncture, and electrical stimulation was highlighted in this study, which linked local acupoints squeezed by nerve roots with distant acupoints along meridians. The use of authoritative quantitative standards and a multifactor assessment of the disease can accurately represent the disease's severity. The patient's condition changes in each period may be expressed more accurately, thoroughly, and objectively through the rise or reduction of the score, making self-evaluation easier for the patient. Electroacupuncture at point may be one of the most important strategies to minimize free radical damage, based on changes in plasma levels.

Research progress and thinking on the mechanism of acupuncture in treatment of perimenopausal syndrome

The potential effect mechanism of acupuncture for perimenopausal syndrome is analyzed and summarized from five aspects, i.e. the influence on reproductive endocrine system, the regulation on nervous system, the improvement of immune function, the intervention on free radical metabolism and the regulation of adverse emotions. It is believed the mechanism research of acupuncture in the treatment of perimenopausal syndrome should be deepened in terms of acupoint specificity and the influence of acupoint compatibility based on the characteristics of acupuncture therapy itself. In clinic, the research on therapeuticmethods and treatment frequency should be enhanced.

Effects of hyperbaric oxygen pretreatment on brain antioxidant capacity in rats with decompression sickness

Objective: Decompression sickness (DCS) causes serious brain hypoxic-ischemic injury. This experiment was designed to observe whether hyperbaric oxygen (HBO2) pretreatment played a neuroprotective effect in decompression sickness rat models and to explore the mechanism of protective effects. Methods: Sprague-Dawley (SD) male rats were pretreated with HBO2 and then underwent decompression to establish the DCS rat model. Antioxidant capacities were evaluated by detecting peroxides (GPx), superoxide dismutase (SOD), catalase (CAT) activity and malondialdehyde (MDA) content in brains. The levels of metal elements manganese (Mn), zinc (Zn), iron (Fe) and magnesium (Mg) in brain tissues were assessed by flame atomic absorption spectrometry. Necrosis and apoptosis of neurons were assessed by H-E staining and immunohistochemical staining. Results: HBO2 pretreatment reduced the degree of necrosis and apoptosis in brain tissues of decompression sickness rat models. In addition, HBO2 pretreatment increased GPx, SOD and CAT activities and reduced MDA accumulation. It also increased the content of Mn, Zn, Fe and Mg in brain tissue, which are all related to free radical metabolism. Conclusion: These results suggested that HBO2 pretreatment has protective effects on brain injury of rats with decompression sickness. The mechanism of the protective effects may be related to reducing oxidative damage by affecting metal elements in vivo.

The Image Analysis of the Visual Sensor and the Effect of Vitamin E Supplementation on Football Players’ Free Radicals and Their Physical Strength Supplement

With the help of image analysis technology of visual sensors, the research discusses the supplementation of vitamin E on free radicals and physical strength of football players after intensive exercise. The free radical supplementation and physical strength supplementation of athletes after strenuous exercise by taking a proper amount of vitamin E were studied and discussed. The effects of vitamin E on free radical metabolism, serum antioxidant level, and antioxidant enzyme activity and serum lipid peroxide metabolism after acute exercise can be generalized. 40 football players were recruited from the sports department of a physical education college in our province and randomly divided into the experimental group and the control group. The experimental group was divided into the T1 group and the T2 group, and the control group was also divided into the C1 group and the C2 group accordingly, with 10 players in each group. After the football league, the C1 and T1 groups will perform maximal aerobic exercise, and the C2 and T2 groups will perform intermittent anaerobic exercise. Serum malondialdehyde (MDA), total antioxidant capacity (T‐AOC), glutathione peroxidase (GSH‐PX), and superoxide dismutase (SOD) were determined. The comparison between the control group taking placebo and the experimental group taking vitamin E for a period of time shows that the average values of MDA are 3.25 ± 0.31 (nm/ml) and 4.20 ± 0.78 (nm/ml), respectively. After taking vitamin E, the antioxidant level of the experimental group was significantly higher than that of the control group, serum antioxidant enzyme activity decreased, serum lipid peroxidation products decreased significantly, and more free radicals were generated immediately after aerobic exercise. Vitamin E can significantly reduce the generation of free radicals during football players’ intermittent anaerobic exercise and improve the body’s antioxidant capacity.

Comparison of Biochemical and Oxidative Stress Parameters in Hypo and Hyperthyroid Rat Models

Background: Thyroid functional disorders are relatively common in the general population. Different factors play a role in the development of thyroid disorders. These factors can be associated with the deterioration of the oxidation state of the body and the induction of oxidative stress. Thyroid hormones play an important role in the oxidation state. Objectives: Regarding the role of oxidative stress in different pathologies and the development of various complications, including thyroid disorders, we aimed to compare the biochemical and oxidative stress parameters in hypo and hyperthyroid rat models. Methods: Twenty-one male Wistar rats were assigned into three groups of control, hypothyroid, and hyperthyroid. Hypothyroidism and hyperthyroidism were inducted with PTU (propylthiouracil) and LTX (levothyroxine), respectively. After five weeks of induction, serum biochemical factors and oxidative stress parameters, such as TAC (total antioxidant capacity), MDA (Malondialdehyde), and the thiol group, were measured in these groups. Results: The means of TAC, MDA and UA (uric acid) in the hyperthyroid group were significantly higher than those in the hypothyroid group (P &lt; 0.01, P &lt; 0.01, P &lt; 0.05) but the mean of thiol in the hypothyroid group was significantly higher than that of the hyperthyroid group (P &lt; 0.01). Also, the mean of TAC level in the hypothyroid group was significantly lower than the control group (P &lt; 0.05) and the mean of thiol group in the hypothyroid group was significantly higher than the control group (P &lt; 0.05), but there was no other significant difference between the groups compared to the control group. Among the biochemical parameters, the mean LDH (lactate dehydrogenase) in the hyperthyroid group also showed a significant difference in comparison to the hypothyroid group (P &lt; 0.05), but there was no significant difference between the groups in the mean of the other biochemical parameters. Conclusions: According to the results of this study, hypothyroidism and hyperthyroidism are associated with a disturbance in the oxidation state of the body, and the use of antioxidants can help improve these diseases, especially in hyperthyroidism, due to enhanced metabolism and production of more free radicals.

SLEEP AND IMMUNITY

Abstract: Sleep has been reported in several studies as an important function of the organism, as well as its deprivation as harmful to the production of defense cells, which affects our immunity. It is also demonstrated in the literature that sleep is fundamental for the metabolism of free radicals and for the body to be able to restore cardiorespiratory functions. The weakened immune system implies an increase in the chances of contracting infectious diseases, in addition to having difficulty recovering from relatively simple illnesses such as colds and flu. This study discusses sleep and its implications for organismic immunity. The results highlighted the need to perform sleep hygiene, defined as the change from dysfunctional patterns to a new organization of habits and activities that allow better sleep induction and quality. Keywords: Sleep; Immunity; Quality of life.

Effects of acorus tatarinowii Schott and alpha asarone on free radicals and nNOS/NO in hippocampus of rats with fatigue movement

To study the effects of acorus tatarinowii Schott and its active ingredient-alpha-asarone on learning and memory, free radical metabolism and nNOS/NO signal in hippocampus of rats with fatigue movement. Eighty SD male rats were randomly divided into eight groups: control group(A), exercise group(B), exercise + alpha-asarone low, middle and high dose treatment group (C, D, E), exercise + acorus tatarinowii Schott low, middle and high dose treatment group (F, G, H),with ten rats in each group. The rats in group C, D and E were administered with alpha-asarone at the doses of 0.10, 0.50 and 1.00 mg.kg-1.WT-1 by ig. The rats in group F, G and H were administered with the extracts of Acorus tatarinowii Schott of at the doses of 0.12, 1.20 and 4.80 g.kg-1.WT-1 by ig. Learning and memory of rats were tested by the method of water maze experiment, and the activities of SOD and NOS, the contents of MDA were detected by the biochemical methods, and the expression levels of nNOS protein in hippocampus of rats were tested by the method of Western blot in at the end of the experiment. The escape latency and MDA content in hippocampus of rats in groups E and H were lower than those in groups B, C, D, F and G and the numbers of Plateau crossing, SOD and NOS activities and the expression levels of nNOS protein in hippocampus of rats were higher than those in groups B, C, D, F and G(P＜0.01). The activities of SOD in hippocampus of rats in groups A, E and H were A＞E＞H, whereas the contents of MDA were opposite (P＜0.01); the activities of NOS and the expression levels of nNOS protein in hippocampus of group E were lower than those of groups A and H (P＜0.01 or P＜0.05), but there was no significant difference between groups A and H (P＞0.05). There were no significant difference in escape latency and numbers of crossing platform among groups A, E and H (P＞0.05). Acorus tatarinowii Schott and alpha-asarone can significantly improve learning and memory of rats with fatigue movement. The mechanism is related to reclaiming the imbalance of free radical metabolism and up-regulating nNOS/NO signal in hippocampus of the rats.

Diversity of nitrogen-fixing rhizobacteria associated with sugarcane: a comprehensive study of plant-microbe interactions for growth enhancement in Saccharum spp.

BackgroundNitrogen is an essential element for sugarcane growth and development and is generally applied in the form of urea often much more than at recommended rates, causing serious soil degradation, particularly soil acidification, as well as groundwater and air pollution. In spite of the importance of nitrogen for plant growth, fewer reports are available to understand the application and biological role of N2 fixing bacteria to improve N2 nutrition in the sugarcane plant.ResultsIn this study, a total of 350 different bacterial strains were isolated from rhizospheric soil samples of the sugarcane plants. Out of these, 22 isolates were selected based on plant growth promotion traits, biocontrol, and nitrogenase activity. The presence and activity of the nifH gene and the ability of nitrogen-fixation proved that all 22 selected strains have the ability to fix nitrogen. These strains were used to perform 16S rRNA and rpoB genes for their identification. The resulted amplicons were sequenced and phylogenetic analysis was constructed. Among the screened strains for nitrogen fixation, CY5 (Bacillus megaterium) and CA1 (Bacillus mycoides) were the most prominent. These two strains were examined for functional diversity using Biolog phenotyping, which confirmed the consumption of diverse carbon and nitrogen sources and tolerance to low pH and osmotic stress. The inoculated bacterial strains colonized the sugarcane rhizosphere successfully and were mostly located in root and leaf. The expression of the nifH gene in both sugarcane varieties (GT11 and GXB9) inoculated with CY5 and CA1 was confirmed. The gene expression studies showed enhanced expression of genes of various enzymes such as catalase, phenylalanine-ammonia-lyase, superoxide dismutase, chitinase and glucanase in bacterial-inoculated sugarcane plants.ConclusionThe results showed that a substantial number of Bacillus isolates have N-fixation and biocontrol property against two sugarcane pathogens Sporisorium scitamineum and Ceratocystis paradoxa. The increased activity of genes controlling free radical metabolism may at least in part accounts for the increased tolerance to pathogens. Nitrogen-fixation was confirmed in sugarcane inoculated with B. megaterium and B. mycoides strains using N-balance and 15N2 isotope dilution in different plant parts of sugarcane. This is the first report of Bacillus mycoides as a nitrogen-fixing rhizobacterium in sugarcane.