Prevalence of rheumatoid arthritis and diagnostic validity of a prediction score, in patients visiting orthropedic clinics in the Madinah region of Saudi Arabia: a retrospective cross-sectional study.

Introduction: In Saudi Arabia, the epidemiology of rheumatoid arthritis (RA) is not well studied and is marked by inconsistencies in clinical diagnosis. Therefore, in this study, we explored the prevalence, clinical characteristics, and diagnostic validity of a prediction score based upon disease markers in orthropedic clinics' patients in the Madinah region of Saudi Arabia. Method: The clinical data for this retrospective cross-sectional study were retrieved from the database registry of orthopedic clinics in selected hospitals of the Medinah province of Saudi Arabia. Sociodemographic features, disease markers and the clinical characteristics were collected for a period of 6 months, from December 1, 2020, to May 31, 2021. The prediction score was generated from the sum of disease markers, coded as dichotomous variables. Results: The total sample size of our study was 401. The prevalence of RA in the study subjects (n = 401) was 14.46% (n = 58). Among RA patients, the majority were females (60.3%). Painful joints (69%) and swollen joints (51.7%) were the most common clinical complaints among RA patients. RA patients suffered from arthritis (51.7%) and experienced fatigue (46.6%), weight loss (44.8%), and loss of appetite (41.4%). Diabetes (55.2%) was the most common comorbidity in the RA patients. The sensitivity and specificity of the prediction score at the criterion score of 2.5 were 67.3% and 63.0%, respectively. The area under the curve was 0.69 (95% CI [0.62-0.76]). Conclusion: There was a moderately high prevalence of RA in patients visiting the orthropedic clinics of the selected hospitals of Madinah region of Saudi Arabia. The diagnostic validity of the prediction score, though promising, was slightly lower than the acceptable range.

Chalcone Scaffolds, Bioprecursors of Flavonoids: Chemistry, Bioactivities, and Pharmacokinetics.

Chalcones are secondary metabolites belonging to the flavonoid (C6-C3-C6 system) family that are ubiquitous in edible and medicinal plants, and they are bioprecursors of plant flavonoids. Chalcones and their natural derivatives are important intermediates of the flavonoid biosynthetic pathway. Plants containing chalcones have been used in traditional medicines since antiquity. Chalcones are basically α,ß-unsaturated ketones that exert great diversity in pharmacological activities such as antioxidant, anticancer, antimicrobial, antiviral, antitubercular, antiplasmodial, antileishmanial, immunosuppressive, anti-inflammatory, and so on. This review provides an insight into the chemistry, biosynthesis, and occurrence of chalcones from natural sources, particularly dietary and medicinal plants. Furthermore, the pharmacological, pharmacokinetics, and toxicological aspects of naturally occurring chalcone derivatives are also discussed herein. In view of having tremendous pharmacological potential, chalcone scaffolds/chalcone derivatives and bioflavonoids after subtle chemical modification could serve as a reliable platform for natural products-based drug discovery toward promising drug lead molecules/drug candidates.

Hesperidin Targets Leishmania donovani Sterol C-24 Reductase to Fight against Leishmaniasis.

Hesperidin, a naturally occurring flavanoid, is present in citrus family of fruits. It was found effective against an array of pathogens including fungi, bacteria, viruses, and protozoa. Here, we evaluated its antileishmanial activity and possible mechanism of action through different in vitro and in silico experiments. It inhibited the growth and proliferation of the parasites significantly with a IC50 value of 1.019 ± 0.116 mM in vitro. It also reduced the growth of intra-macrophagic amastigotes with a IC50 value of 0.2858 ± 0.01398 mM. It induced the reactive oxygen species (ROS) in parasites in a dose-dependent manner. Through 2,7-dichloro dihydro fluorescein diacetate (H2DCFDA) staining, it was observed that around 96.9% parasites were ROS positive at 2.0 mM concentration of hesperidin. The ROS generated led to the apoptosis of parasites in a dose-dependent manner as observed by annexin/PI staining. Molecular docking with one of the very important and unique drug-targets of Leishmania donovani sterol C-24 reductase resulted in its significant inhibition. Here, we for the first time showed that hesperidin induced the antileishmanial response through the induction of apoptosis and inhibition of sterol C-24 reductase. Our study will be helpful in the development of a cost-effective antileishmanial lead with higher efficacy.

Antileishmanial Evaluation of Bark Methanolic Extract of Acacia nilotica: In Vitro and In Silico Studies.

Acacia nilotica (A. nilotica) is an important medicinal plant, found in Africa, the Middle East, and the Indian subcontinent. Every part of the plant possesses a wide array of biologically active and therapeutically important compounds. We reported the antileishmanial activity of A. nilotica bark methanolic extract through in vitro antileishmanial assays and dissected the mechanism of its action through in silico studies. Bark methanolic extract exhibited antipromastigote and antiamastigote potential in a time and dose-dependent manner with IC50 values of 19.6 ± 0.9037 and 77.52 ± 5.167 µg/mL, respectively. It showed cytotoxicity on THP-1-derived human macrophages at very high dose with a CC50 value of 432.7 ± 7.71 µg/mL. The major constituents identified by gas chromatography-mass spectrometry (GC-MS) analysis, 13-docosenoic acid, lupeol, 9,12-octadecadienoic acid, and 6-octadecanoic acid, showed effective binding with the potential drug targets of Leishmania donovani (L. donovani) including sterol 24-c-methyltransferase, trypanothione reductase, pteridine reductase, and adenine phosphoribosyltransferase, suggesting the possible mechanism of its antileishmanial action. Pharmacokinetic studies on major phytoconstituents analyzed by GC-MS supported their use as safe antileishmanial drug candidates. This study proved the antileishmanial potential of bark methanolic extract A. nilotica and its mechanism of action through the inhibition of potential drug targets of L. donovani.

Targeting sterol alpha-14 demethylase of Leishmania donovani to fight against leishmaniasis.

Leishmaniasis is a neglected tropical disease caused by the protozoan parasite Leishmania. It is endemic in more than 89 different countries worldwide. Sterol alpha-14 demethylase (LdSDM), a sterol biosynthetic pathway enzyme in Leishmania donovani, plays an essential role in parasite survival and proliferation. Here, we used a drug repurposing approach to virtually screen the library of the Food and Drug Administration (FDA)-approved drugs against LdSDM to identify the potential lead-drug against leishmaniasis. Zafirlukast and avodart showed the best binding with LdSDM. Zafirlukast was tested for in vitro antileishmanial assay, but no significant effect on L. donovani promastigotes was observed even at higher concentrations. On the other hand, avodart profoundly inhibited parasite growth at relatively lower concentrations. Further, avodart showed a significant decrease in the number of intra-macrophagic amastigotes. Avodart-induced reactive oxygen species (ROS) in the parasites in a dose-dependent manner. ROS induced by avodart led to the induction of apoptosis-like cell death in the parasites as observed through annexin V/PI staining. Here, for the first time, we reported the antileishmanial activity and its possible mechanism of action of FDA-approved drug, avodart, establishing a nice example of the drug-repurposing approach. Our study suggested the possible use of avodart as an effective antileishmanial agent after further detailed validations.

Repurposing of FDA-approved drugs as inhibitors of sterol C-24 methyltransferase of Leishmania donovani to fight against leishmaniasis.

Leishmaniasis is a vector-borne disease caused by around 20 species of Leishmania. The main clinical forms of leishmaniasis are cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). VL is caused by Leishmania infantum in Central and South America, Mediterranean Basin, Middle East, and by L. donovani in Asia and Africa. Sterol C-24 methyltransferase (LdSMT) of L. donovani is a transferase enzyme of the sterol biosynthesis pathway. This pathway is one of the major targets for drug developments in Leishmania. Due to insufficient evidence about the exact function of SMT inside the cell and the uniqueness of the SMT enzyme in the Leishmania parasites made it a significant target for an effective drug development approach. We performed virtual screening of the Food and Drug Administration (FDA)-approved drug library against LdSMT and found simeprevir, an antiviral drug on top in the binding score. It showed a significant binding affinity with LdSMT. The binding was supported by hydrogen bonds and several other interactions. Simeprevir inhibited L. donovani growth of promastigotes with 50% inhibitory concentration (IC50 ) of 51.49 ± 5.87 µM. Further studies showed that simeprevir induced ROS generation in 44.7% of parasites at 125-µM concentration. Here, we for the first time reported simeprevir as an antileishmanial lead molecule using a drug repurposing approach.

Cynaroside inhibits Leishmania donovani UDP-galactopyranose mutase and induces reactive oxygen species to exert antileishmanial response.

Cynaroside, a flavonoid, has been shown to have antibacterial, antifungal and anticancer activities. Here, we evaluated its antileishmanial properties and its mechanism of action through different in silico and in vitro assays. Cynaroside exhibited antileishmanial activity in time- and dose-dependent manner with 50% of inhibitory concentration (IC50) value of 49.49 ± 3.515 µM in vitro. It inhibited the growth of parasite significantly at only 20 µM concentration when used in combination with miltefosine, a standard drug which has very high toxicity. It also inhibited the intra-macrophagic parasite significantly at low doses when used in combination with miltefosine. It showed less toxicity than the existing antileishmanial drug, miltefosine at similar doses. Propidium iodide staining showed that cynaroside inhibited the parasites in G0/G1 phase of cell cycle. 2,7-dichloro dihydro fluorescein diacetate (H2DCFDA) staining showed cynaroside induced antileishmanial activity through reactive oxygen species (ROS) generation in parasites. Molecular-docking studies with key drug targets of Leishmania donovani showed significant inhibition. Out of these targets, cynaroside showed strongest affinity with uridine diphosphate (UDP)-galactopyranose mutase with -10.4 kcal/mol which was further validated by molecular dynamics (MD) simulation. The bioactivity, ADMET (absorption, distribution, metabolism, excretion and toxicity) properties, Organisation for Economic Co-operation and Development (OECD) chemical classification and toxicity risk prediction showed cynaroside as an enzyme inhibitor having sufficient solubility and non-toxic properties. In conclusion, cynaroside may be used alone or in combination with existing drug, miltefosine to control leishmaniasis with less cytotoxicity.

Evaluation of in vitro activities of extracellular enzymes from Aspergillus species isolated from corneal ulcer/keratitis.

Mycotic/fungal keratitis is a suppurative, generally ulcerative infection of the cornea. The filamentous fungi, Aspergillus spp. are the second leading cause of mycotic keratitis, particularly in India. Aspergillus spp. produce a range of extracellular enzymes that are used to break down complex molecules and used for growth and reproduction, also for survival on/in host organism. The current study was designed with an objective to screen in vitro extracellular enzyme activity of Fusarium and Aspergillus isolates from mycotic keratitis patients and to correlate the same as a putative virulence factor. Extracellular enzymes viz., deoxyribonuclease (DNase), protease, lipase, elastase, keratinase, etc., produced by Aspergillus have key role in keratomycosis and hence their (n = 85) in vitro activities were investigated. It was found that, the majority of the Aspergillus isolates produced protease (n = 75; 88% of 85) followed by lipase (n = 59; 69% of 85), DNase (n = 35; 41% of 85), elastase (n = 26; 31% of 85) and keratinase (n = 13; 15% of 85). The enzyme activity indices (EAI) for DNase, elastase, protease and lipase ranged between 1.01 and 1.98, whereas elastase EAI varied between 1.26 and 1.92. DNase, protease and lipase showed a maximum EAI of 1.98 and lowest EAI value of 1.01, respectively. Extracellular enzymes of Aspergillus spp. may have potential role in the onset and progression of keratitis.

Characterization of Aspergillus tamarii Strains From Human Keratomycoses: Molecular Identification, Antifungal Susceptibility Patterns and Cyclopiazonic Acid Producing Abilities.

Aspergillus tamarii appears to be an emerging aetiological agent of human keratomycoses in South India. The investigated strains were isolated from six suspected fungal keratitis patients attending a tertiary care eye hospital in Coimbatore (Tamil Nadu, India), and were initially identified by the microscopic examinations of the scrapings and the cultures. Our data suggest that A. tamarii could be easily overlooked when identification is carried out based on morphological characteristics alone, while the sequence analysis of the calmodulin gene can be used successfully to recognize this species accurately. According to the collected clinical data, ocular trauma is a common risk factor for the infection that gradually developed from mild to severe ulcers and could be healed with an appropriate combined antifungal therapy. Antifungal susceptibility testing revealed that A. tamarii strains are susceptible to the most commonly used topical or systemic antifungal agents (i.e., econazole, itraconazole and ketoconazole) except for natamycin. Moreover, natamycin proved to be similarly less effective than the azoles against A. tamarii in our drug interaction tests, as the predominance of indifferent interactions was revealed between natamycin and econazole and between natamycin and itraconazole as well. Four and five isolates of A. tamarii were confirmed to produce cyclopiazonic acid (CPA) in RPMI-1640 - which is designed to mimic the composition of human extracellular fluids - and in yeast extract sucrose (YES) medium, respectively, which is a widely used culture medium for testing mycotoxin production. Although a ten times lower mycelial biomass was recorded in RPMI-1640 than in YES medium, the toxin contents of the samples were of the same order of magnitude in both types of media. There might be a relationship between the outcome of infections and the toxigenic properties of the infecting fungal strains. However, this remains to be investigated in the future.

Repurposing Glyburide as Antileishmanial Agent to Fight Against Leishmaniasis.

BACKGROUND: Leishmaniasis is caused by a protozoan parasite, Leishmania. It is common in more than 98 countries throughout the world. Due to insufficient availability of antileishmanial chemotherapeutics, it is an urgent need to search for new molecules which have better efficacy, low toxicity and are available at low cost. OBJECTIVES: There is a high rate of diabetic cases throughout the world that is why we planned to test the antileishmanial activity of glyburide, an effective sugar lowering drug used for the treatment of diabetes. In this study, glyburide showed a significant decrease in the parasite growth and survival in vitro in a dose-dependent manner. METHODS: Anti-leishmanial activity of glyburide was checked by culturing Leishmania donovani promastigotes in the presence of glyburide in a dose and time dependent manner. Docking study against Leishmania donovani-Trypanothione synthetase (LdTrySyn) protein was performed using Autodock Vina tool. RESULTS: Growth reversibility assay shows that growth of treated parasite was not reversed when transferred to fresh culture media after 7 days. Moreover, docking studies show efficient interactions of glyburide with key residues in the catalytic site of Leishmania donovani- Trypanothione synthetase (LdTrySyn), a very important leishmanial enzyme involved in parasite's survival by detoxification of Nitric Oxide (NO) species, generated by the mammalian host as a defense molecule. Thus this study proves that the drug-repurposing is a beneficial strategy for identification of new and potent antileishmanial molecules. CONCLUSION: The results suggest that glyburide binds to LdTrySyn and inhibits its activity which further leads to the altered parasite morphology and inhibition of parasite growth. Glyburide may also be used in combination with other anti-leishmanial drugs to potentiate the response of the chemotherapy. Overall this study provides information about combination therapy as well as a single drug treatment for the infected patients suffering from diabetes. This study also provides raw information for further in vivo disease model studies to confirm the hypothesis.