Bioactive compounds: a goldmine for defining new strategies against pathogenic bacterial biofilms?

Most human infectious diseases are caused by microorganisms growing as biofilms. These three-dimensional self-organized communities are embedded in a dense matrix allowing microorganisms to persistently inhabit abiotic and biotic surfaces due to increased resistance to both antibiotics and effectors of the immune system. Consequently, there is an urgent need for novel strategies to control biofilm-associated infections. Natural products offer a vast array of chemical structures and possess a wide variety of biological properties; therefore, they have been and continue to be exploited in the search for potential biofilm inhibitors with a specific or multi-locus mechanism of action. This review provides an updated discussion of the major bioactive compounds isolated from several natural sources - such as plants, lichens, algae, microorganisms, animals, and humans - with the potential to inhibit biofilm formation and/or to disperse established biofilms by bacterial pathogens. Despite the very large number of bioactive products, their exact mechanism of action often remains to be clarified and, in some cases, the identity of the active molecule is still unknown. This knowledge gap should be filled thus allowing development of these products not only as novel drugs to combat bacterial biofilms, but also as antibiotic adjuvants to restore the therapeutic efficacy of current antibiotics.

The role of saffron in improvement of ocular surface disease in a mouse model of Lacrimal Gland Excision-induced dry eye disease.

One of the most prevalent eye disorders is dry eye disease (DED), described by ocular dryness due to the tear insufficiency. Prolonged dry eye causes damage and ulcer to the surface of the cornea. The core of the DED mechanism is inflammation which is a biological response of the body to pathogens. Several studies have indicated that saffron has many beneficial biological effects, such as anti-inflammatory and free radical scavenging. This research aims to examine possible positive impact of saffron in the mice model of DED. The animals were divided into 4 groups. Induction of DED was done by right Lacrimal Gland Excision (LGE). Treatment was done by intraperitoneal (i.p.) injection of saffron (1 mg/kg/day, for 28 days after induction of DED) in the SAF group, betamethasone (the BET group) (i.p., 1 mg/kg/day, for 28 days after induction of DED), the LGE group (received normal saline i.p. for 28 days after induction of DED) and the sham group (no induction of DED). Ophthalmological assay with fluorescein staining on the 0, 14 and, 28 days, histopathological analysis (H & E assay) on the last day and, pro-inflammatory cytokine assays of eyes were done. Saffron and betamethasone reduced the fluorescein score of the eyes (P < 0.0001) and improved the ocular surface disease in H & E assay as well as reduced the eye levels of TNF-α (P < 0.01), IL-1ß (P < 0.0001) and, IL-6 (P < 0.001) compared to those of the LGE group. The current study indicated that treatment with saffron has a beneficial effect on LGE (Lacrimal gland excision)-induced DED in mice via its anti-inflammatory properties.

Regulation of DAPK1 by Natural Products: An Important Target in Treatment of Stroke.

Stroke is a sudden neurological disorder that occurs due to impaired blood flow to an area of the brain. Stroke can be caused by the blockage or rupture of a blood vessel in the brain, called ischemic stroke and hemorrhagic stroke, respectively. Stroke is more common in men than women. Atrial fibrillation, hypertension, kidney disease, high cholesterol and lipids, genetic predisposition, inactivity, poor nutrition, diabetes mellitus, family history and smoking are factors that increase the risk of stroke. Restoring blood flow by repositioning blocked arteries using thrombolytic agents or endovascular therapy are the most effective treatments for stroke. However, restoring circulation after thrombolysis can cause fatal edema or intracranial hemorrhage, and worsen brain damage in a process known as ischemia-reperfusion injury. Therefore, there is a pressing need to find and develop more effective treatments for stroke. In the past, the first choice of treatment was based on natural compounds. Natural compounds are able to reduce the symptoms and reduce various diseases including stroke that attract the attention of the pharmaceutical industry. Nowadays, as a result of the numerous studies carried out in the field of herbal medicine, many useful and valuable effects of plants have been identified. The death-associated protein kinase (DAPK) family is one of the vital families of serine/threonine kinases involved in the regulation of some biological functions in human cells. DAPK1 is the most studied kinase within the DAPKs family as it is involved in neuronal and recovery processes. Dysregulation of DAPK1 in the brain is involved in the developing neurological diseases such as stroke. Natural products can function in a variety of ways, including reducing cerebral edema, reducing brain endothelial cell death, and inhibiting TNFα and interleukin-1ß (IL-1ß) through regulating the DAPK1 signal against stroke. Due to the role of DAPK1 in neurological disorders, the aim of this article was to investigate the role of DAPK1 in stroke and its modulation by natural compounds.

Protective effect of dapsone against bleomycin-induced lung fibrosis in rat.

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial disease of the lung tissue that causes symptoms such as coughing and asthma. It is caused by inflammatory factors and oxidative stress. In vivo model of IPF is induced by bleomycin (BLM,) a chemotherapeutic agent. We have investigated the effect of dapsone on bleomycin-induced IPF in adult male Wistar rats due to its anti-inflammatory and anti-oxidative stress effects. The animals were randomly divided into 5 groups (Control, BLM, BLM + dapsone 1, BLM + Dapsone 3, BLM + Dapsone 10). The control group received normal water and food. In the fibrosis group, bleomycin (BLM) (5 mg/kg) was used to induce pulmonary fibrosis by intratracheal administration. Three groups of animals were treated daily with single doses of 1, 3, and 10 mg dapsone by intraperitoneal injection 1 h after receiving BLM for 2 weeks. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and oxidative stress markers such as myeloperoxidase (MPO), malondialdehyde (MDA), protein carbonyl (PC) and nitrite were measured to evaluate bleomycin and therapeutic effect of dapsone. The histological assays of lung tissues were done by Hematoxylin-eosin (H & E) and Masson's trichrome staining. BLM reduced the activity of oxidative enzymes and increased the oxidative stress markers, while treatment with dapsone has reversed the results. In addition, the total number of cells as inflammatory cells such as neutrophils and eosinophils were examined. It has been indicated BLM increased these cells, and dapsone decreased them. The results of H & E and Masson's trichrome staining showed that dapsone reduced inflammation and alveolar wall thickness and BLM-induced pulmonary fibrosis. According to the findings of this study, dapsone seems to have therapeutic effects on pulmonary fibrosis through its anti-inflammatory and anti-oxidative stress properties and reduction of the toxic effects of bleomycin.

The potential of pumpkin seed oil as a functional food-A comprehensive review of chemical composition, health benefits, and safety.

The growing interest in foods that can be beneficial to human health is bringing into focus some products that have been used locally for centuries but have recently gained worldwide attention. One of these foods is pumpkin seed oil, which has been used in culinary and traditional medicine, but recent data also show its use in the pharmaceutical and cosmetic industries. In addition, some sources refer to it as a potential functional food, mainly because it is obtained from pumpkin seeds, which contain many functional components. However, the production process of the oil may affect the content of these components and consequently the biological activity of the oil. In this review, we have focused on summarizing scientific data that explore the potential of pumpkin seed oil as a functional food ingredient. We provide a comprehensive overview of pumpkin seed oil chemical composition, phytochemical content, biological activity, and safety, as well as the overview of production processes and contemporary use. The main phytochemicals in pumpkin seed oil with health-related properties are polyphenols, phytoestrogens, and fatty acids, but carotenoids, squalene, tocopherols, and minerals may also contribute to health benefits. Most studies have been conducted in vitro and support the claim that pumpkin seed oil has antioxidant and antimicrobial activities. Clinical studies have shown that pumpkin seed oil may be beneficial in the treatment of cardiovascular problems of menopausal women and ailments associated with imbalance of sex hormones.

Sodium butyrate enhances fear extinction and rescues hippocampal acetylcholinesterase activity in a rat model of posttraumatic stress disorder.

It is believed that impaired extinction of fear memories is an underlying cause for the development of posttraumatic stress disorder (PTSD). Histone deacetylases (HDAC) are enzymes that modulate extinction by changing the chromatin structure and altering protein synthesis in the brain. Studies show that stress modifies both HDAC activity and cerebral cholinergic neurotransmission. The present work aims to evaluate the effect of sodium butyrate (NaBu), an HDAC inhibitor, on behavioral markers of extinction and biochemical changes in HDAC and acetylcholinesterase activity in the hippocampus. NaBu was administered for 7 days in a group of rats that were exposed to single prolonged stress (SPS), as a model for PTSD. Contextual fear conditioning was performed on the 8th day, and fear extinction was measured in the next 4 consecutive days. Other behavioral tests to measure anxiety, locomotor activity and working memory were performed for further interpretation of the results. Hippocampal acetylcholinesterase and HDAC activity were also measured through biochemical tests. Behavioral results showed that treatment with NaBu can reverse the SPS-induced extinction deficits. Biochemical data indicated that while SPS induced overactivity in hippocampal HDAC, it decreased acetylcholinesterase activity in the region. Both effects were reversed after NaBu treatment. It seems that at least part of extinction deficiency in SPS exposed rats is related to hypoacetylation of acetylcholinesterase in the hippocampus. Preemptive therapy with an HDAC inhibitor reverses this process and is worth further evaluation as a possible therapeutic approach in PTSD.

Toll-like receptors as novel therapeutic targets for herpes simplex virus infection.

Seropositivity for HSV reaches more than 70% within the world population, and yet no approved vaccine exists. While HSV1 is responsible for keratitis, encephalitis, and labialis, HSV2 carriers have a high susceptibility to other STD infections, such as HIV. Induction of antiviral innate immune responses upon infection depends on a family of pattern recognition receptors called Toll-like receptors (TLR). TLRs bridge innate and adaptive immunity by sensing virus infection and activating antiviral immune responses. HSV adopts smart tricks to evade innate immunity and can also manipulate TLR signaling to evade the immune system or even confer destructive effects in favor of virus replication. Here, we review mechanisms by which HSV can trick TLR signaling to impair innate immunity. Then, we analyze the role of HSV-mediated molecular cues, in particular, NF-κB signaling, in promoting protective versus destructive effects of TLRs. Finally, TLR-based therapeutic opportunities with the goal of preventing or treating HSV infection will be discussed.

Hepatoprotective Effects of Standardized Extracts from an Ancient Italian Apple Variety (Mela Rosa dei Monti Sibillini) against Carbon Tetrachloride (CCl4)-Induced Hepatotoxicity in Rats.

The aim of this research was to examine the effect of the hydroalcoholic extracts from the peel (APE) and pulp (APP) of a traditional apple cultivar from central Italy (Mela Rosa dei Monti Sibillini) on CCl4-induced hepatotoxicity in rats. Phytoconstituents were determined by liquid chromatography-mass spectrometry (LC-MS) analysis showing an abundance of proanthocyanidins and flavonol derivatives together with the presence of annurcoic acid in APE. Wistar rats received APE/APP (30 mg/kg oral administration) for three days before CCl4 injection (2 mL/kg intraperitoneal once on the third day). Treatment with both APE and APP prior to CCl4 injection significantly decreased the serum levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) compared to the CCl4 group. Besides, pretreatment with APE reversed the CCl4 effects on superoxide dismutase (SOD), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α) and interleukin-1beta (IL-1ß) levels in liver tissue in rats and reduced tissue damage as shown in hematoxylin and eosin staining. These results showed that this ancient Italian apple is worthy of use in nutraceuticals and dietary supplements to prevent and/or protect against liver disorders.

In vitro evaluation of effects of metformin on morphine and methadone tolerance through mammalian target of rapamycin signaling pathway.

The chronic use of opioids leads to tolerance, psychological, and physical dependence that limits their use as an effective long-term pain control. Several studies have shown that mammalian target of rapamycin (mTOR) plays a crucial role in the development of opioid tolerance. Metformin activates 5' adenosine monophosphate-activated protein kinase (AMPK) which directly suppresses the mTOR complex 1 signaling pathway. On the other hand, metformin can also inhibit mTOR directly and in an AMPK-independent manner. Thus, in the current study, we aimed to investigate the effects of metformin on the development of morphine and/or methadone-induced tolerance in human glioblastoma (T98G) cell line. We examined the effects of chronic treatment of morphine and/or methadone in the presence or absence of metformin with or without AMPK inhibitor (dorsomorphin hydrochloride) on levels of nitric oxide and cyclic adenosine monophosphate (cAMP), phosphorylated and dephosphorylated ribosomal protein S6 kinase ß-1 (S6K1) and 4E-binding protein 1 (4E-BP1) in T98G cells. Pretreatment of cells with metformin (40 µM) with or without AMPK inhibitor (dorsomorphin hydrochloride; 1 µM) before adding of morphine (2.5 µM) or methadone (1 µM) revealed a protective effects on the development of opioid tolerance. Prior administration of metformin reversed the elevation of nitric oxide levels induced by morphine (p < 0.001) and methadone (p < 0.001) and also prevented the raise of cAMP levels induced by morphine in T98G cells (p < 0.05). Contribution of mTOR signaling pathway in metformin-induced effect was shown by the inhibition of phosphorylation of S6K1 and 4E-BP1, the downstream targets of mTOR. mTOR activation suppresses opioid-induced antinociception, and its activity has also been increased during opioid tolerance.

Novel therapeutic strategies for stroke: The role of autophagy.

Autophagy is an important biological mechanism involved in the regulation of numerous fundamental cellular processes that are mainly associated with cellular growth and differentiation. Autophagic pathways are vital for maintaining cellular homeostasis by enhancing the turnover of nonfunctional proteins and organelles. Neuronal cells, like other eukaryotic cells, are dependent on autophagy for neuroprotection in response to stress, but can also induce cell death in cerebral ischemia. Recent studies have demonstrated that autophagy may induce neuroprotection following acute brain injury, including ischemic stroke. However in some special circumstances, activation of autophagy can induce cell death, playing a deleterious role in the etiology and progression of ischemic stroke. Currently, there are no therapeutic options against stroke that demonstrate efficient neuroprotective abilities. In the present work, we will review the significance of autophagy in the context of ischemic stroke by first outlining its role in ischemic neuronal death. We will also highlight the potential therapeutic applications of pharmacological modulators of autophagy, including some naturally occurring polyphenolic compounds that can target this catabolic process. Our findings provide renewed insight on the mechanism of action of autophagy in stroke together with potential neuroprotective compounds, which may partially exert their function through enhancing mitochondrial function and attenuating damaging autophagic processes.

Hepatoprotective effects of phosphatidylserine liposomes on carbon tetrachloride-induced hepatotoxicity in rats.

It has been proposed carbon tetrachloride (CCl4 ) intoxication due to the production of free radicals and serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) overload results hepatotoxicity. Phosphatidylserine (PS) has shown antioxidant activity in numerous studies. Therefore, this study was aimed to investigate the effects of PS liposomes treatment against the CCl4 -induced hepatotoxicity in a rat model. Male Wistar rats were treated with PS (10 mg/kg, oral) or phosphatidylcholine liposomes (PC) (10 mg/kg, oral) for 3 days before CCl4 (2 ml/kg; ip once on the third day) injection. The serum level of ALT, AST, and ALP were measured. Also, antioxidant assays were performed. Administration of PS with CCl4 significantly inhibited alterations in the serum levels of AST, ALP (** P < 0.01), and ALT (*** P < 0.001) compared with control group. Furthermore, measurement of malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) levels indicated that PS significantly reduced reactive oxygen species. The results of the present study showed the hepatoprotective effects of PS against CCl4 -induced hepatotoxicity in rats.

Targeting BDNF signaling by natural products: Novel synaptic repair therapeutics for neurodegeneration and behavior disorders.

Neurodegenerative disorders like Alzheimer's disease, Huntington's disease, Parkinson's disease, spinocerebellar ataxias, amyotrophic lateral sclerosis, frontotemporal dementia to prion diseases, Friedreich's ataxia, hereditary spastic paraplegia and optic atrophy type 1, and behavior disorders like neuropsychiatric, hyperactivity and autism spectrum disorders are closely associated with neurobiological deficits. Brain derived neurotrophic factor (BDNF) is an extensively studied neurotrophin. BDNF is essential for neuronal genesis, differentiation, survival, growth, plasticity, synaptic viability and transmission. BDNF has emerged as a promising target for regulating synaptic activity and plasticity. An overview of effects and mechanisms of the natural products targeting BDNF is described. This review is an attempt to enumerate the effects of various natural products on BDNF as a novel therapeutic approach for neurodegenerative and neuropsychiatric disorders.

Targeting Hedgehog signaling pathway: Paving the road for cancer therapy.

The Hedgehog pathway is essential for embryonic development but also for tissue and organ homeostasis in adult organisms. Activation of this pathway leads to the expression of target genes involved in proliferation, angiogenesis and stem cell self-renewal. Moreover, abnormal persistence of Hedgehog signaling is directly involved in a wide range of human cancers. Development of novel strategies targeting the Hedgehog pathway has become a subject of increased interest in anticancer therapy. These data are sustained by pre-clinical studies demonstrating that Hedgehog pathway inhibitors could represent an effective strategy against a heterogeneous panel of malignancies. Limited activity in other tumor types could be explained by the existence of crosstalk between the Hedgehog pathway and other signaling pathways that can compensate for its function. This review describes the Hedgehog pathway in detail, with its physiological roles during embryogenesis and adult tissues, and summarizing the preclinical evidence on its inhibition, the crosstalk between Hedgehog and other cancer-related pathways and finally the potential therapeutic effects of emerging compounds.

Targeting STATs in neuroinflammation: The road less traveled!

JAK/STAT transduction pathway is a highly conserved pathway implicated in regulating cellular proliferation, differentiation, survival and apoptosis. Dysregulation of this pathway is involved in the onset of autoimmune, haematological, oncological, metabolic and neurological diseases. Over the last few years, the research of anti-neuroinflammatory agents has gained considerable attention. The ability to diminish the STAT-induced transcription of inflammatory genes is documented for both natural compounds (such as polyphenols) and chemical drugs. Among polyphenols, quercetin and curcumin directly inhibit STAT, while Berberis vulgaris L. and Sophora alopecuroides L extracts act indirectly. Also, the Food and Drug Administration has approved several JAK/STAT inhibitors (direct or indirect) for treating inflammatory diseases, indicating STAT can be considered as a therapeutic target for neuroinflammatory pathologies. Considering the encouraging data obtained so far, clinical trials are warranted to demonstrate the effectiveness and potential use in the clinical practice of STAT inhibitors to treat inflammation-associated neurodegenerative pathologies.

Anti-inflammatory effects of Melatonin: A mechanistic review.

N-acetyl-5-methoxy-tryptamine (melatonin) is a natural substance produced both by plants, as a secondary metabolite, and animals, by the pineal gland and other tissues. In humans, melatonin participates in numerous functions including the regulation of mood, sleep, reproduction, promotion of immunomodulation, antioxidant defense and as an anti-inflammatory agent. The anti-inflammatory activity of melatonin could yield beneficial effects on intake, particularly against the chronic inflammation which underlies many chronic diseases. This review aims to provide an assessment of the literature data on the anti-inflammatory activity of melatonin, with a particular focus on the mechanisms responsible for this behavior. We can conclude that many in vitro studies and in vivo studies in experimental animal model systems show that melatonin exerts anti-inflammatory activity in a number of chronic diseases which affect different organs in different circumstances. Clinical trials, however, often fail to reach positive results and are thus far inconclusive. Thus, in the future, long-term well-designed investigations on melatonin-rich foods or melatonin food supplements could provide valuable information towards public health recommendations on melatonin, taking into account both the nature of the compound and the optimal dose, for protection from long-term inflammation linked to chronic diseases.

Protective effects of modafinil administration on testicular torsion/detorsion damage in rats.

Testicular torsion is a pathological condition which leads to sever scrotal pain and ischemia. After surgical reperfusion, oxidative stress factors cause to germ cell apoptosis. Thus, adjuvant therapy to surgery should be useful to decrease of ischemia/reperfusion (I/R) injury of testis. Modafinil, a drug to treat sleepiness, has been indicated to have anti-inflammatory effects. The aim was to evaluate the efficiency of modafinil administration after reperfusion surgery in a rat model of testicular torsion/detorsion (T/D). Male wistar rats were divided into three groups and each group contained 10 animals. To induce torsion right testis was rotated 720° clockwise and was left for 1 h. Modafinil group received modafinil (10 mg/kg) once daily intraperitoneally for 7 days after the surgery and the control group received physiologic saline once daily intraperitoneally for 7 days after the surgery. Thereafter, MDA, IL-1ß and TNF-α levels and histopathological changes were investigated. MDA, IL-1ß and TNF-α levels significantly increased in T/D group compared to the control group (⁎⁎P < .01 and ⁎⁎⁎P < .001, respectively). Moreover, modafinil administration significantly reduced these values compared to T/D group (#P < .05 and ##P < .01, respectively). Histopathological changes such as degeneration in germinal cells were detected in testis T/D group of rats whereas modafinil administration prevented degeneration in germinal cells, edema and hemorrhage compared with T/D group. In conclusion, administration of modafinil after reperfusion surgery had protective role on testicular torsion in rat and reduced ischemia/reperfusion cellular injury via anti-inflammatory and decrease of oxidative stress.

Therapeutic effects of modafinil in ischemic stroke; possible role of NF-κB downregulation.

Background: The phenomenon of ischemic stroke receives maximal attention nowadays. Many studies are designed to discover new therapies for reducing debilitating consequences of this disorder. Development of stroke-related tissue damage is due to the combination of blood flow occlusion and reperfusion phase. Inflammatory pathways participate in excess oxidative stress formation after reperfusion. Modafinil is a well-known medication prescribed for sleep disorders. Recently, several studies have focused on finding new indications for modafinil treatment. Anti-inflammatory effects of modafinil through disrupting NF-κB signaling pathway is reported previously. Downregulation of inflammatory cytokines and further oxidative damage have also been mentioned in various experiments. So far, no specific experiment had been conducted to assess the anti-inflammatory effects of modafinil on ischemic stroke. Material and methods: We evaluated outcomes of acutely administered modafinil on post-stroke behaviors and histopathological features (including apoptotic caspase-3 expressing neurons) through bilateral common carotid artery occlusion in rats. Alterations in concentrations of TNFɑ and IL-1ß were assessed, together with malon di-aldehyde (MDA) to represent oxidation level. Western blotting was used to reveal the involvement of NF-κB downregulation. Considering possible alterations in blood flow and neuronal metabolism, we also assessed the effects of modafinil on cerebral glucose metabolism through PET scan. Results and discussion: Modafinil exhibited promising effects on remission of behavioral deficits and the number of degenerated neurons in ischemic hippocampus CA1 region. IL-1ß and MDA levels were downregulated in treated animals. However, no significant alteration was observed in PET results and TNFɑ between treated and non-treated ischemic brains. Decreased protein levels of NF-κB was also measured in modafinil treated animals. Conclusion: Our findings demonstrate a promising therapeutic effect of modafinil for animal models of stroke.

Apigenin as neuroprotective agent: Of mice and men.

Neurodegenerative disorders (NDDs) such as Alzheimer's and Parkinson's diseases are the most common age-related pathologies that affect millions of people all over the world. To date, effective therapy for NDDs is not available and current approaches to disease management include neuroprotection strategy with a hope of maintaining and enhancing the function of survising neurons. Of course, such an approach by its own will not offer a cure but is likely to delay the disease progression by ameliorating the increase of neurotoxic agents such reactive oxygen species (ROS) as well as the associated inflammatory cascades. In this regard, natural products including flavonods that offer neuroprotection through multiple mechanisms have gained a lot of interest in recent years. In this communication, evidences from the various experimental models and clinical trials on the therapeutic potential of one promising flavonod, apigenin, is presented. Its chemistry, mechanism of action and potential benefits in the various examples of NDDs are discussed in the light of drug discovery aspects.

Targeting mTORs by omega-3 fatty acids: A possible novel therapeutic strategy for neurodegeneration?

Neurodegenerative diseases (NDs) such as Parkinson's (PD), Alzheimer's (AD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) cause significant world-wide morbidity and mortality. To date, there is no drug of cure for these, mostly age-related diseases, although approaches in delaying the pathology and/or giving patients some symptomatic relief have been adopted for the last few decades. Various studies in recent years have shown the beneficial effects of omega-3 poly unsaturated fatty acids (PUFAs) through diverse mechanisms including anti-inflammatory effects. This review now assesses the potential of this class of compounds in NDs therapy through specific action against the mammalian target of rapamycin (mTOR) signaling pathway. The role of mTOR in neurodegenerative diseases and targeted therapies by PUFAs are discussed.

Role of natural mTOR inhibitors in treatment of diabetes mellitus.

Diabetes mellitus is one of the most common and complex problems in today's society and is responsible for many socio-economic problems. Type 1 diabetes is due to a defect in insulin secretion caused by a destruction of pancreatic ß cells. In contrast, the pathogenesis of type 2 diabetes is associated with the development of insulin resistance in the liver and peripheral tissues, a decrease in ß-cell mass, and a defect in insulin secretion. Various factors such as inflammation, stress, obesity, and lifestyle are involved in diabetes. Long-term or chronic increase in glucose in these patients is the leading causes of secondary disorders such as micro- and macro-angiopathy, weakness of the antioxidant defense system, and metabolic disorders and altered lipid profile. The above conditions lead to short-term and long-term complications. These complications cause damage to the physical and physiological function of diverse organs of the body and threaten human health. Late complications of diabetes, including nephropathy, retinopathy, cardiovascular complications, neuropathy, hypertension, and weight gain, are common, and more research has been done on them. Numerous drugs such as meglitinides, biguanides, and thiazolidinedione have been proposed to reduce high blood sugar, but due to the lack of complete cure of this disease with the use of existing drugs, the tendency to use alternative and traditional therapies has increased. In the meantime, the role of herbs with hypoglycemic properties in the treatment of diabetic patients cannot be ignored. The consumption of herbs by people with diabetes has become widespread even in Western countries. The use of herbs could be considered when conventional therapies cannot control the disease, and the patient needs to be prescribed insulin. The mammalian target of rapamycin, mTOR, plays a significant role in regulating cell growth, cellular metabolic status in response to nutrients, many extracellular cues, and growth factors. Impaired insulin secretion can lead to altered mTOR signaling. The mTOR pathway has shown different behaviors depending on the situation. It has been shown that mTOR can regulate the adaptation of ß cells to blood sugar, and chronic inhibition of the mTOR pathway can also induce diabetes. Here, we have reviewed recent findings on the role of mTOR in major metabolic organs, such as the liver, pancreas, brain, and adipose tissue and muscle, and discussed its potential as a diabetes-related drug target.