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Antibiotics have transformed medicine, enabling effective treatments for infections that were once fatal and supporting significant advancements such as surgery and organ transplants. However, the growing spread of resistance reduces their effectiveness, making the discovery of new drugs crucial in the ongoing battle against human pathogens. Antibiotic resistance represents one of the greatest challenges of modern medicine, having a significant impact on the treatment of bacterial infections. The development of antibiotic resistance renders standard treatments ineffective, putting patients' lives at risk and limiting available therapeutic options. In the face of this global crisis, recent research is opening new directions in combating antibiotic resistance, focusing on the discovery of innovative antibiotics, alternative solutions, and strategies to prevent the spread of resistance. These advances are essential for addressing future health challenges. more...

Background and Aim: This study aims to investigate the antidepressant properties of Hispidulin, a flavonoid present in Scutellaria barbata D. Don. The selection of Hispidulin stems from its notable inhibitory activity against Xanthine Oxidase (XO), a parameter in the pathophysiology of depression., Material and Methods: Mice were subjected to a rigorous evaluation using a murine model of Chronic Unpredictable Mild Stress (CUMS) to induce depression for 21 days and antidepressant properties were rigorously assessed using the Tail Suspension Test (TST), Forced Swim Test (FST), and Open Field Test (OFT). Imipramine and fluoxetine were used as standard drugs. Additionally, neurochemical analyses were conducted to quantify serotonin (5-HT), norepinephrine (NE), and dopamine (DA) levels in the cortex, hippocampus, and hypothalamus. Further mechanistic insights were sought through the estimation of monoamine oxidase (MAO) activity and assessment of antioxidant enzyme levels in the brain. Plasma nitrite and corticosterone levels were also measured to delineate the underlying mechanism of action., Results: Hispidulin demonstrated significant antidepressant effects, as evidenced by reduced immobility time in TST and FST and increased exploratory behavior in OFT. Neurochemical analysis revealed restoration of 5-HT, NE, and DA levels in key brain regions. Furthermore, Hispidulin modulated MAO activity and enhanced antioxidant enzyme levels in the brain. Plasma nitrite levels were elevated, indicating enhanced nitric oxide synthesis, while corticosterone levels were reduced., Conclusion: Our findings indicate that Hispidulin exerts potent antidepressant effects, potentially mediated through its influence on monoaminergic neurotransmitters, MAO activity, and antioxidant defenses. These results provide valuable mechanistic insights into the antidepressant action of Hispidulin, supporting its potential therapeutic application in depressive disorders., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

Background: Insulin resistance is one of the main factors that lead to the development of type 2 diabetes mellitus (T2DM). The effect of alkaloids on insulin resistance has been extensively examined according to multiple scientific researches., Objective: In this work, we aimed to summarize the interesting results from preclinical and clinical studies that assessed the effects of natural alkaloids (berberine, nigelladine A, piperine, trigonelline, capsaicin, nuciferine, evodiamine, mahanine, and magnoflorine) on impaired insulin sensitivity and worsened insulin resistance, which play a pivotal role in the pathogenesis of type 2 diabetes., Methods: In the current review, PubMed, ScienceDirect, Springer, and Google Scholar databases were used. The inclusion criteria were based on the following keywords and phrases: insulin sensitivity, insulin resistance, alkaloids and insulin resistance, alkaloids and type 2 diabetes, mechanisms of action, and alkaloids., Results: The outcomes reported in this review demonstrated that the selected alkaloids increased insulin sensitivity and reduced insulin resistance in vitro and in vivo evidence, as well as in clinical trials, through improving insulin-signaling transduction mainly in hepatocytes, myocytes, and adipocytes, both at cellular and molecular levels. Insulin signaling components (InsR, IRS-1, PI3K, Akt, etc. ), protein kinases and phosphatases, receptors, ion channels, cytokines, adipokines, and microRNAs, are influenced by alkaloids at transcriptional and translational levels, also in terms of function (activity and/or phosphorylation). Multiple perturbations associated with insulin resistance, such as ectopic lipid accumulation, inflammation, ER stress, oxidative stress, mitochondrial dysfunction, gut microbiota dysbiosis, and β-cell failure, are reversed after treatment with alkaloids. Furthermore, various indices and tests are employed to assess insulin resistance, including the Matsuda index, insulin sensitivity index (ISI), oral glucose tolerance test (OGTT), and insulin tolerance test (ITT), which are all enhanced by alkaloids. These improvements extend to fasting blood glucose, fasting insulin, and HbA1c levels as well. Additionally, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and the Homeostasis Model Assessment of β-cell function (HOMA-β) are recognized as robust markers of insulin sensitivity and β-cell function, and it is noteworthy that alkaloids also lead to improvements in these two markers., Conclusion: Based on the findings of the current review, alkaloids may serve as both preventive and curative agents for metabolic disorders, specifically type 2 diabetes. Nonetheless, there is an urgent need for additional clinical trials to explore the potential benefits of alkaloids in both healthy individuals and those with type 2 diabetes. Additionally, it is crucial to assess any possible side effects and interactions with antidiabetic drugs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

The aim of this study was to determine the possible underlying mechanism of the hypoglycaemic activity of the ethanolic extract of Nauclea latifolia leaves in rats. The extract, glibenclamide or water was administered orally in a glucose, sucrose and maltose tolerance tests. In addition, the effect of the extract on ?-glucosidase enzymes was also studied. The ethanolic extract at 200mg/kg body weight inhibited the increase in glucose level after both oral and intraperitoneal glucose loads as did glibenclamide. The extract also dose dependently inhibited both maltase and sucrase activities in vitro but not in vivo. The hypoglycaemic effect of N. latifolia leaf ethanolic extract thus appears to be most probably exerted through a mechanism similar to that of glibenclamide which is related to increased insulin release from pancreatic ?-cells. [ABSTRACT FROM AUTHOR] more...

Background: For decades, the quinoxaline 1,4-di-N-oxide ring has been considered a privileged structure to develop new antibacterial, antitumoural, and antiprotozoal agents, among others; however, its mechanism of action is not clear., Objective: The main aim of this mini-review was to analyze the mechanism of action of quinoxaline 1,4-di-N-oxide derivatives reported as antibacterial, antitumoural, and antiprotozoal agents., Results: Initially, the mechanism of action of quinoxaline 1,4-di-N-oxide derivatives against bacteria, tumoural cell lines, and parasites have been described as nonspecific, but recently, the results against different organisms have shown that these compounds have an inhibitory action on specific targets such as trypanothione reductase, triosephosphate isomerase, and other essential enzymes., Conclusion: In summary, quinoxaline 1,4-di-N-oxide is a scaffold to develop new anti- Mycobacterium tuberculosis, antitumoural and antiprotozoal agents; however, understanding the mechanism of action of quinoxaline 1,4-di-N-oxide derivatives in each microorganism could contribute to the development of new and more potent selective drugs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

Naphthoquinone is a heterocyclic moiety whose natural derivatives are present as bioactive compounds in many plants and have stimulated a resurgence of interest in the past decades due to their wide range of pharmacological activities. Naphthoquinone agents have dynamic pharmacophores and privileged sub-structures in the chemistry of medicine. They have received much interest in drug discovery as trypanocidal because naphthoquinone and their derivatives revealed massive significance potential against the trypanosomes. Among natural naphthoquinones, lapachol, β-lapachone and its α-isomer exhibited useful trypanocidal activities. Some naphthoquinones have already been used commercially as an antiparasitic agent. Several naphthoquinones with diverse structural motifs have been synthesized and evaluated mainly against Trypanosoma cruzi and some studies have also been reported against Trypanosoma brucei and Trypanosoma evansi. This review summarized various mechanisms of action of naphthoquinone like reductive activation of quinone by the production of the semiquinone, generation of reactive oxygen species and free radicals such as superoxide anion radical and H2O2, and oxidative stress in the parasite. The information assembled in this review will help to understand the mechanism behind the activity and may also be useful to find the bio-efficacy of naphthoquinone compounds upon substitution against trypanosomatids., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

Background: Recent evidence has been demonstrated that Sinomenine (SIN) exerts antitumor activity in vitro. However, the clinical utility of SIN remains limited mainly because of its poor bioavailability. Exosomes are nanoscale vesicles that play crucial roles in intracellular communications through functionally active substances such as DNA and RNA. Exosomes have been utilized as nanocarriers for targeted drug delivery of different anticancer drugs., Methods: The present study aimed to evaluate the effectiveness of combined Exosomes-SIN for the treatment of hepatocellular carcinoma (HCC) in a rat model. To do so, we prepared a mixture of SIN and exosomes (Exo-SIN) to improve the bioavailability of SIN to treat liver cancer. The in vitro releasing profile of the Exo-SIN was examined., Results: We observed a continuous, slow release of SIN from Exo-SIN in simulated body fluid as well as tumor microenvironment. In the cytotoxicity test, Exo-SIN exhibited a significantly stronger inhibition in HepG2 cells compared to free SIN. The flow cytometry assessments showed that Exo-SIN could suppress HepG2 cell migration in a Transwell assay and induce cell cycle arrest and cellular apoptosis. Western blotting showed that survivin, a crucial protein for the survival of living cells, was significantly downregulated after treatment with Exo-SIN., Conclusion: In conclusion, our data suggested that Exo-SIN could serve as a potential, effective delivery platform for hepatic carcinoma therapy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

The coronavirus disease 2019 (COVID-19) pandemic, due to the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in December 2019 and has rapidly spread globally. As the confirmed number of cases has reached 83 million worldwide, the potential severity and the deadly complications of the disease requires urgent development of effective drugs for prevention and treatment. No proven effective treatment for this virus currently exists. Most of the antiviral discovery efforts are focused on the repurposing of approved or clinical stage drugs. This review highlights the small-molecule repurposed antiviral agents that are currently under investigation in clinical trials for COVID-19. These include viral polymerase and protease inhibitors remdesivir, galidesivir, favipiravir, ribavirin, sofosbuvir, tenofovir/emtricitabine, baloxavir marboxil, EIDD-2801, lopinavir/ritonavir; virus-/host-directed viral entry and fusion inhibitors arbidol chloroquine/hydroxychloroquine, chlorpromazine, camostat mesylate, nafamostat mesylate, bromhexine and agents with diverse/unclear mechanism of actions as oseltamivir, triazavirin, ivermectin, nitazoxanide, niclosamide and BLD-2660. The published preclinical and clinical data to date on these drugs as well as the mechanisms of action are reviewed., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

Cancer is the main cause of death, and the emergence of resistance by cancer cells towards existing anticancer agents is one of the major problems for effective chemotherapy, creating a great demand for the development of novel anticancer drugs. Coumarins, abundantly found in nature, constitute an important class of pharmacological agents possessing physiological activities. The mechanism investigations elucidated that coumarins could lead to self-programmed cancer cell death (apoptosis) via different mechanisms; thereby coumarin-based derivatives possess potential activity against various forms of cancers, including drug-resistant, even multidrug-resistant cancers. This review article describes the recent progress in the discovery, structural modification, structure-activity relationship, and mechanism of action studies of coumarin-based derivatives with potential activity against drug-resistant cancers, covering articles published between 2010 and 2020., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.) more...

Background: Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are a new class of oral antidiabetic drugs. So far, there are three agents approved for use in Europe and in the USA, two in Japan and another four agents under testing., Objective: The purpose of this study is to describe the mechanism of action and the favorable and adverse effects of SGLT-2 inhibitors., Method: A thorough review of literature indexed in PubMed, Scopus and Cochrane databases were conducted. Original papers, review papers and their relevant references in English, from 2005 to February 2017, were included., Results: The main mechanism of action is the glycosuria induced by the inhibition of SGLT-2, located in the early segment of the proximal convoluted tubule. Along with large amounts of glucose, sodium, water and uric acid are also excessively excreted in urine. These actions have various, both desired and adverse, consequent implications in kidneys, blood pressure, cardiovascular system and other systems. Moreover, SGLT-2 inhibitors act directly to organs other than the kidneys, as SGLT-2 can be expressed there., Conclusion: The underlying mechanisms responsible for the SGLT-2 inhibitor actions, are pleiotropic and occur in the kidneys, as well as in other target organs. The comprehension of these mechanisms, not only permits us to understand their actions better, but it could also help us to predict more of their undisclosed favorable actions, as well as their rare adverse effects., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.) more...