24 research outputs found
Daniellia oliveri (Rolfe) Hutch and Dalziel : Antimicrobial Activities, Cytotoxicity Evaluation, and Phytochemical Identification by GC-MS
During a previous study that identified plants used in traditional medicine in Togo to
treat infectious diseases, Daniellia oliveri was specifically reported to treat intertrigo and candidiasis.
Consequently, to explore the anti-infective potential of this plant, we investigated the antibacterial
and the antifungal activity of the plantâs parts, as well as the cytotoxic activities of raw extracts
and subsequent fractions, and the chemical composition of the most active fractions. In order to
evaluate the antimicrobial activity, MICs were determined using the broth dilution method. Then,
the most active fractions were evaluated for cytotoxicity by using normal human cells (MRC-5 cells)
via the MTT assay. Finally, the most active and not toxic fractions were phytochemically investigated
by GC-MS. Interestingly, all the raw extracts and fractions were active against the bacteria tested,
with MICs ranging from 16 ”g/mL to 256 ”g/mL, while no antifungal activity was observed at
256 ”g/mL, the highest tested concentration. Moreover, no toxicity was observed with most of
the active fractions. The subsequent chemical investigation of the most interesting fractions led to
identifying terpenes, phytosterols, phenolic compounds, and fatty acids as the main compounds.
In conclusion, this study demonstrated that D. oliveri possesses valuable antibacterial activities in
accordance with traditional use
Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities
Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude âwasteâ plant materials for specific practical applications, especiallyâbut not exclusivelyâin developing countries lacking a more sophisticated industrial infrastructure
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Limitations of Recent Studies Dealing with the Antibacterial Properties of Silver Nanoparticles: Fact and Opinion
Due to the constant increase in the number of infectious diseases and the concomitant lack of treatment available, metallic nanoparticles (e.g., silver nanoparticles) have been of particular interest in the last decades. Indeed, several studies suggest that silver nanoparticles have valuable antimicrobial activities, especially against bacteria, which may lead us to think that these nanoparticles may one day be an attractive therapeutic option for the treatment of bacterial infections. Unfortunately, when we look a little closer to these studies, we can see a very great heterogeneity (e.g., in the study design, in the synthetic process of nanoparticles, in the methods that explore the antibacterial properties of nanoparticles and in the bacteria chosen) making cross-interpretation between these studies impossible, and significantly limiting the interest of silver nanoparticles as promising antibacterial agents. We have selected forty-nine international publications published since 2015, and propose to discuss, not the results obtained, but precisely the different methodologies developed in these publications. Through this discussion, we highlighted the aspects to improve, or at least to homogenize, in order to definitively establish the interest of silver nanoparticles as valuable antibacterial agents
Investigation of Nanoparticle Metallic Core Antibacterial Activity: Gold and Silver Nanoparticles against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>
Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing Staphylococcus aureus and Escherichia coli have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on S. aureus but demonstrate a high antibacterial activity against Escherichia coli, with a minimum inhibitory concentration of 128 ”mol/L. This high antibacterial activity is also maintained against two MDR-E. coli strains
Ursolic Acidâs Alluring Journey: One Triterpenoid vs. Cancer Hallmarks
Cancer is a multifactorial disease characterized by various hallmarks, including uncontrolled cell growth, evasion of apoptosis, sustained angiogenesis, tissue invasion, and metastasis, among others. Traditional cancer therapies often target specific hallmarks, leading to limited efficacy and the development of resistance. Thus, there is a growing need for alternative strategies that can address multiple hallmarks concomitantly. Ursolic acid (UA), a naturally occurring pentacyclic triterpenoid, has recently emerged as a promising candidate for multitargeted cancer therapy. This review aims to summarize the current knowledge on the anticancer properties of UA, focusing on its ability to modulate various cancer hallmarks. The literature reveals that UA exhibits potent anticancer effects through diverse mechanisms, including the inhibition of cell proliferation, induction of apoptosis, suppression of angiogenesis, inhibition of metastasis, and modulation of the tumor microenvironment. Additionally, UA has demonstrated promising activity against different cancer types (e.g., breast, lung, prostate, colon, and liver) by targeting various cancer hallmarks. This review discusses the molecular targets and signaling pathways involved in the anticancer effects of UA. Notably, UA has been found to modulate key signaling pathways, such as PI3K/Akt, MAPK/ERK, NF-ÎșB, and Wnt/ÎČ-catenin, which play crucial roles in cancer development and progression. Moreover, the ability of UA to destroy cancer cells through various mechanisms (e.g., apoptosis, autophagy, inhibiting cell growth, dysregulating cancer cell metabolism, etc.) contributes to its multitargeted effects on cancer hallmarks. Despite promising anticancer effects, this review acknowledges hurdles related to UAâs low bioavailability, emphasizing the need for enhanced therapeutic strategies
pH- and glutathione-responsive release of curcumin from mesoporous silica nanoparticles coated using tannic acid-Fe(III) complex
International audienceA novel pH-and glutathione-responsive drug delivery system has been developed by deposition of tannic acid (TA)-Fe(III) complex on the surface of mesoporous silica nanoparticles (MSN). The coating was easily accomplished within 30 seconds by successive addition of iron chloride (FeCl3) and tannic acid in aqueous dispersion of MSN (e.g. MCM-41). A hydrophobic model drug, curcumin, showed sustainable drug release under physiological condition (pH 7.4), while a rapid curcumin release was triggered by lowering the pH to 6.0 or 4.5. Moreover, curcumin release could be controlled by adjusting the glutathione level, which accelerate the decomposition of TA-Fe(III) complex by competitive liganding. Therefore, these results would allow developing novel and simple pH-and glutathione-responsive drug delivery systems with potential applications such as in biomedicine
Shining a Light on Prostate Cancer: Photodynamic Therapy and Combination Approaches
International audienceProstate cancer is a major health concern worldwide, and current treatments, such as surgery, radiation therapy, and chemotherapy, are associated with significant side effects and limitations. Photodynamic therapy (PDT) is a promising alternative that has the potential to provide a minimally invasive and highly targeted approach to treating prostate cancer. PDT involves the use of photosensitizers (PSs) that are activated by light to produce reactive oxygen species (ROS), which can induce tumor cell death. There are two main types of PSs: synthetic and natural. Synthetic PSs are classified into four generations based on their structural and photophysical properties, while natural PSs are derived from plant and bacterial sources. Combining PDT with other therapies, such as photothermal therapy (PTT), photoimmunotherapy (PIT), and chemotherapy (CT), is also being explored as a way to improve its efficacy. This review provides an overview of conventional treatments for prostate cancer, the underlying principles of PDT, and the different types of PSs used in PDT as well as ongoing clinical studies. It also discusses the various forms of combination therapy being explored in the context of PDT for prostate cancer, as well as the challenges and opportunities associated with this approach. Overall, PDT has the potential to provide a more effective and less invasive treatment option for prostate cancer, and ongoing research is aimed at improving its selectivity and efficacy in clinical settings
Shining a Light on Prostate Cancer: Photodynamic Therapy and Combination Approaches
Prostate cancer is a major health concern worldwide, and current treatments, such as surgery, radiation therapy, and chemotherapy, are associated with significant side effects and limitations. Photodynamic therapy (PDT) is a promising alternative that has the potential to provide a minimally invasive and highly targeted approach to treating prostate cancer. PDT involves the use of photosensitizers (PSs) that are activated by light to produce reactive oxygen species (ROS), which can induce tumor cell death. There are two main types of PSs: synthetic and natural. Synthetic PSs are classified into four generations based on their structural and photophysical properties, while natural PSs are derived from plant and bacterial sources. Combining PDT with other therapies, such as photothermal therapy (PTT), photoimmunotherapy (PIT), and chemotherapy (CT), is also being explored as a way to improve its efficacy. This review provides an overview of conventional treatments for prostate cancer, the underlying principles of PDT, and the different types of PSs used in PDT as well as ongoing clinical studies. It also discusses the various forms of combination therapy being explored in the context of PDT for prostate cancer, as well as the challenges and opportunities associated with this approach. Overall, PDT has the potential to provide a more effective and less invasive treatment option for prostate cancer, and ongoing research is aimed at improving its selectivity and efficacy in clinical settings
The expectations of transgender people in the face of their health-care access difficulties and how they can be overcome. A qualitative study in France
International audienceAim: Our objective was to explore the difficulties experienced by transgender people in accessing primary health-care services and their expectations towards primary care providers to improve their health-care access. Background: Because transgender people are exposed to many discriminations, their health-care access is particularly poor. Guidelines recommend greater involvement of primary care providers in the processes because of the accessibility feature of primary care services. Methods: A qualitative study using semi-directed interviews was conducted among 27 transgender people (February 2018 - August 2018). These voluntary participants were recruited through different means: local trans or LGBTI (lesbian, gay, bisexual, trans, and/or intersex) associations, primary care providers, and social networks. The data analysis was based on reflexive thematic analysis in an inductive approach. Findings: Difficulties in accessing health-care occurred at all the levels of the primary health-care system: primary care providers - transgender people interaction, access to the primary care team facility (starting with the secretariat), access to secondary care specialists, and continuity of care. Transgender people report ill-adapted health-care services as a result of gender-based identification in health-care settings. Their main expectation was depsychiatrization and self-determination. They supported mixed health network comprising primary care providers and transgender people with a coordinating role for the general practitioner. These expectations should be priorities to consider in our primary health-care system to improve access to health-care for transgender people