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Ramesa Shafi Bhat

Bio: Ramesa Shafi Bhat is an academic researcher from King Saud University. The author has contributed to research in topics: Autism & Gut flora. The author has an hindex of 13, co-authored 59 publications receiving 552 citations.

Papers published on a yearly basis

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Journal ArticleDOI
TL;DR: Methanolic extracts of almost all samples dominated aqueous extracts in inhibiting the growth of the pathogenic bacteria under study, but were less potent when compared to those of kanamycin used as positive controls.

85 citations

Journal ArticleDOI
TL;DR: Overall analysis of the antibacterial activities of various extracts revealed that the highest inhibitory activity was produced by the fruit extract as compared to the leaf, bark and seed extracts, and on the whole, aqueous extracts have the least antibacterial activity asCompared to methanol and acetone extracts.
Abstract: The antibacterial activities of different parts of local Phoenix dactylifera were investigated in vitro. Dried leaf, fruit, seed and tree bark were extracted with water, methanol and acetone. Antibacterial property of the extracts was evaluated against Staphylococcus aureus , Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa using the disc diffusion method. Overall analysis of the antibacterial activity of various extracts revealed that the highest inhibitory activity was produced by the fruit extract (18.2 ± 0.55 mm) as compared to the leaf, bark and seed extracts. All the extracts from the different parts of the plant showed antibacterial activity against most tested microorganisms. On the whole, aqueous extracts have the least antibacterial activity as compared to methanol and acetone extracts. The antibacterial activity against the Gram-positive strains was the highest in the acetone fruit extract against S. aureus (18.2 ± 0.55 mm). The most active extract against Gram-negative bacteria was methanol extract from the leaves with a 13.5 ± 0.33 mm inhibition zone for E. coli followed by 12.5 ± 0.88 mm for P. aeruginosa. Phytochemical analysis revealed the presence of carbohydrates and alkaloids in all parts, and flavonoids, steroids, saponins and tannins were present in some parts. Key words : Antibacterial activity, Phoenix dactylifera, disc diffusion assay, extracts, inhibition zone.

74 citations

Journal ArticleDOI
TL;DR: Overall analysis of the antibacterial activity of tested samples revealed that the highest inhibitory activity was produced by Litchi chinensis (15 ± 0.55 mm) against S. pyogenes.

56 citations

Journal ArticleDOI
TL;DR: The study indicates that probiotics can be used safely to ameliorate glutamate excitotoxicity mostly through increasing depleted GABA and Mg2+ and decreasing the excitatory neurotransmitter, glutamate.
Abstract: Increasing evidence suggests that the gut microbiota plays a key role in the central nervous system (CNS), and alterations of the gut microbiota composition due to environmental factors can contribute to neurodevelopmental disorders. Animal modeling may help to identify drugs that can normalize the altered gut microbiota and thereby ameliorate abnormal brain signaling pathways. The purpose of the present study was to investigate the therapeutic potency of probiotics such as Bifidobacteria and Lactobacilli on glutamate excitotoxicity as a neurotoxic effect induced by clindamycin and propionic acid (PPA) in juvenile hamsters. Fifty young golden Syrian hamsters weighing between 60 and 70 g were enrolled in the study. The hamsters were randomly divided into five groups, each with ten hamsters. The hamsters in the control group only received phosphate-buffered saline orally. The PPA-treated group received a neurotoxic dose of 250 mg PPA/kg body weight (BW)/day for three days. The clindamycin-treated group received 30 mg clindamycin/kg BW as a single orogastric dose on the day the experiment started. The two therapeutic groups received the same doses of PPA and clindamycin followed by 0.2 g probiotic/kg BW for three weeks. Biochemical parameters related to glutamate excitotoxicity were investigated in brain homogenates from each group of hamsters. Additionally, the development of pathogenic bacteria was monitored in stool samples from all groups. The microbiology results of the present study revealed descriptive changes in the fecal microbiota and the appearance of Clostridium species in the hamsters treated with clindamycin and PPA. Additionally, the effectiveness of the probiotic in the restoration of the normal gut microbiota was demonstrated. Moreover, clindamycin and PPA were found to induce a significant depletion of Mg2+ and γ-aminobutyric acid (GABA) and a remarkable increase in the Na+/Mg2+ and glutamate/GABA ratios but non-significant changes in the absolute levels of K+, Na+ and glutamate. The bacteria overgrowth induced by PPA and clindamycin in the present study effectively showed signs of neuronal toxicity. The study indicates that probiotics can be used safely to ameliorate glutamate excitotoxicity mostly through increasing depleted GABA and Mg2+ and decreasing the excitatory neurotransmitter, glutamate.

47 citations

Journal ArticleDOI
TL;DR: The findings indicate that the extract of Agaricus blazei Murill can protect the liver against carbon tetrachloride induced oxidative damage in rats and is an efficient hepatoprotective and antioxidant agent against carbon gaelic acid induced liver injury.

46 citations


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TL;DR: Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.
Abstract: The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within ...

1,775 citations

Journal ArticleDOI
TL;DR: Animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases, and various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.
Abstract: A complex antioxidant system has been developed in mammals to relieve oxidative stress. However, excessive reactive species derived from oxygen and nitrogen may still lead to oxidative damage to tissue and organs. Oxidative stress has been considered as a conjoint pathological mechanism, and it contributes to initiation and progression of liver injury. A lot of risk factors, including alcohol, drugs, environmental pollutants and irradiation, may induce oxidative stress in liver, which in turn results in severe liver diseases, such as alcoholic liver disease and non-alcoholic steatohepatitis. Application of antioxidants signifies a rational curative strategy to prevent and cure liver diseases involving oxidative stress. Although conclusions drawn from clinical studies remain uncertain, animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases. Natural antioxidants contained in edible or medicinal plants often possess strong antioxidant and free radical scavenging abilities as well as anti-inflammatory action, which are also supposed to be the basis of other bioactivities and health benefits. In this review, PubMed was extensively searched for literature research. The keywords for searching oxidative stress were free radicals, reactive oxygen, nitrogen species, anti-oxidative therapy, Chinese medicines, natural products, antioxidants and liver diseases. The literature, including ours, with studies on oxidative stress and anti-oxidative therapy in liver diseases were the focus. Various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.

1,112 citations

Journal ArticleDOI
TL;DR: This Consensus Statement outlines the definition and scope of the term ‘synbiotics’ as determined by an expert panel convened by the International Scientific Association for Probiotics and Prebiotics in May 2019 and explores the levels of evidence, safety, effects upon targets and implications for stakeholders of the synbiotic concept.
Abstract: In May 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel of nutritionists, physiologists and microbiologists to review the definition and scope of synbiotics. The panel updated the definition of a synbiotic to “a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host”. The panel concluded that defining synbiotics as simply a mixture of probiotics and prebiotics could suppress the innovation of synbiotics that are designed to function cooperatively. Requiring that each component must meet the evidence and dose requirements for probiotics and prebiotics individually could also present an obstacle. Rather, the panel clarified that a complementary synbiotic, which has not been designed so that its component parts function cooperatively, must be composed of a probiotic plus a prebiotic, whereas a synergistic synbiotic does not need to be so. A synergistic synbiotic is a synbiotic for which the substrate is designed to be selectively utilized by the co-administered microorganisms. This Consensus Statement further explores the levels of evidence (existing and required), safety, effects upon targets and implications for stakeholders of the synbiotic concept. Gut microbiota can be manipulated to benefit host health, including the use of probiotics, prebiotics and synbiotics. This Consensus Statement outlines the definition and scope of the term ‘synbiotics’ as determined by an expert panel convened by the International Scientific Association for Probiotics and Prebiotics in May 2019.

953 citations

Journal Article
TL;DR: The hypothesis that omega-3 (omega-3) long-chain polyunsaturated fatty acids (LCPUFAs) exhibit cytoprotective and cytotherapeutic actions contributing to a number of anti-angiogenic and neuroprotective mechanisms within the retina is advanced.
Abstract: In this work we advance the hypothesis that omega-3 (omega-3) long-chain polyunsaturated fatty acids (LCPUFAs) exhibit cytoprotective and cytotherapeutic actions contributing to a number of anti-angiogenic and neuroprotective mechanisms within the retina. omega-3 LCPUFAs may modulate metabolic processes and attenuate effects of environmental exposures that activate molecules implicated in pathogenesis of vasoproliferative and neurodegenerative retinal diseases. These processes and exposures include ischemia, chronic light exposure, oxidative stress, inflammation, cellular signaling mechanisms, and aging. A number of bioactive molecules within the retina affect, and are effected by such conditions. These molecules operate within complex systems and include compounds classified as eicosanoids, angiogenic factors, matrix metalloproteinases, reactive oxygen species, cyclic nucleotides, neurotransmitters and neuromodulators, pro-inflammatory and immunoregulatory cytokines, and inflammatory phospholipids. We discuss the relationship of LCPUFAs with these bioactivators and bioactive compounds in the context of three blinding retinal diseases of public health significance that exhibit both vascular and neural pathology. How is omega-3 LCPUFA status related to retinal structure and function? Docosahexaenoic acid (DHA), a major dietary omega-3 LCPUFA, is also a major structural lipid of retinal photoreceptor outer segment membranes. Biophysical and biochemical properties of DHA may affect photoreceptor membrane function by altering permeability, fluidity, thickness, and lipid phase properties. Tissue DHA status affects retinal cell signaling mechanisms involved in phototransduction. DHA may operate in signaling cascades to enhance activation of membrane-bound retinal proteins and may also be involved in rhodopsin regeneration. Tissue DHA insufficiency is associated with alterations in retinal function. Visual processing deficits have been ameliorated with DHA supplementation in some cases. What evidence exists to suggest that LCPUFAs modulate factors and processes implicated in diseases of the vascular and neural retina? Tissue status of LCPUFAs is modifiable by and dependent upon dietary intake. Certain LCPUFAs are selectively accreted and efficiently conserved within the neural retina. On the most basic level, omega-3 LCPUFAs influence retinal cell gene expression, cellular differentiation, and cellular survival. DHA activates a number of nuclear hormone receptors that operate as transcription factors for molecules that modulate reduction-oxidation-sensitive and proinflammatory genes; these include the peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and the retinoid X receptor. In the case of PPAR-alpha, this action is thought to prevent endothelial cell dysfunction and vascular remodeling through inhibition of: vascular smooth muscle cell proliferation, inducible nitric oxide synthase production, interleukin-1 induced cyclooxygenase (COX)-2 production, and thrombin-induced endothelin 1 production. Research on model systems demonstrates that omega-3 LCPUFAs also have the capacity to affect production and activation of angiogenic growth factors, arachidonic acid (AA)-based vasoregulatory eicosanoids, and MMPs. Eicosapentaenoic acid (EPA), a substrate for DHA, is the parent fatty acid for a family of eicosanoids that have the potential to affect AA-derived eicosanoids implicated in abnormal retinal neovascularization, vascular permeability, and inflammation. EPA depresses vascular endothelial growth factor (VEGF)-specific tyrosine kinase receptor activation and expression. VEGF plays an essential role in induction of: endothelial cell migration and proliferation, microvascular permeability, endothelial cell release of metalloproteinases and interstitial collagenases, and endothelial cell tube formation. The mechanism of VEGF receptor down-regulation is believed to occur at the tyrosine kinase nuclear factor-kappa B (NFkappaB). NFkappaB is a nuclear transcription factor that up-regulates COX-2 expression, intracellular adhesion molecule, thrombin, and nitric oxide synthase. All four factors are associated with vascular instability. COX-2 drives conversion of AA to a number angiogenic and proinflammatory eicosanoids. Our general conclusion is that there is consistent evidence to suggest that omega-3 LCPUFAs may act in a protective role against ischemia-, light-, oxygen-, inflammatory-, and age-associated pathology of the vascular and neural retina.

665 citations