Editorial of the Special Issue "Molecular Medicine Applications in Infectious Diseases: Latest Innovations".

The integration of molecular approaches in medicine allows for a more precise understanding of the mechanisms underlying infectious diseases, paving the way for targeted therapies, personalized medicine, and the development of new diagnostic tools [...].

Molecular Mechanisms of Flavonoids against Tumor Gamma-Herpesviruses and Their Correlated Cancers-A Focus on EBV and KSHV Life Cycles and Carcinogenesis.

Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) are cancer-causing viruses that belong to human gamma-herpesviruses. They are DNA viruses known to establish lifelong infections in humans, with the ability to develop various types of cancer. Drug resistance remains the main barrier to achieving effective therapies for viral infections and cancer. Thus, new medications with dual antiviral and anticancer actions are highly needed. Flavonoids are secondary metabolites biosynthesized by plants with diverse therapeutic effects on human health. In this review, we feature the potential role of flavonoids (flavones, protoflavones, isoflavones, flavanones, flavonols, dihydroflavonols, catechins, chalcones, anthocyanins, and other flavonoid-type compounds) in controlling gamma-herpesvirus-associated cancers by blocking EBV and KSHV infections and inhibiting the formation and growth of the correlated tumors, such as nasopharyngeal carcinoma, Burkitt's lymphoma, gastric cancer, extranodal NK/T-cell lymphoma, squamous cell carcinoma, Kaposi sarcoma, and primary effusion lymphoma. The underlying mechanisms via targeting EBV and KSHV life cycles and carcinogenesis are highlighted. Moreover, the effective concentrations or doses are emphasized.

Insights into Antiviral Properties and Molecular Mechanisms of Non-Flavonoid Polyphenols against Human Herpesviruses.

Herpesviruses are one of the most contagious DNA viruses that threaten human health, causing severe diseases, including, but not limited to, certain types of cancer and neurological complications. The overuse and misuse of anti-herpesvirus drugs are key factors leading to drug resistance. Therefore, targeting human herpesviruses with natural products is an attractive form of therapy, as it might improve treatment efficacy in therapy-resistant herpesviruses. Plant polyphenols are major players in the health arena as they possess diverse bioactivities. Hence, in this article, we comprehensively summarize the recent advances that have been attained in employing plant non-flavonoid polyphenols, such as phenolic acids, tannins and their derivatives, stilbenes and their derivatives, lignans, neolignans, xanthones, anthraquinones and their derivatives, curcuminoids, coumarins, furanocoumarins, and other polyphenols (phloroglucinol) as promising anti-herpesvirus drugs against various types of herpesvirus such as alpha-herpesviruses (herpes simplex virus type 1 and 2 and varicella-zoster virus), beta-herpesviruses (human cytomegalovirus), and gamma-herpesviruses (Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus). The molecular mechanisms of non-flavonoid polyphenols against the reviewed herpesviruses are also documented.

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.

A constructivist approach to teach neuroanatomy lab: Students' perceptions of an active learning environment.

BACKGROUND: A recent trend in medical education is developing a more dynamic and integrated curriculum. Team-based learning (TBL) increases students' engagement and the active construction of anatomical knowledge. This initial study aimed to empirically observe medical students' perceptions of their achievement of learning outcomes and the construction of their neuroanatomy knowledge, critical thinking, and problem-solving using an interactive whiteboard (IWB) as a teaching strategy. METHODS: An independent neuroanatomy lab survey collected students' perceptions and comments about their learning experiences using the IWB on a questionnaire using a 5-point Likert scale. RESULTS: Student participants felt that using the IWB has facilitated their learning experience. 94.2% of student participants endorsed feelings that new technology has helped them achieve their learning outcomes, helped them integrate both their basic science and clinical science/skills knowledge (90.4%), enhanced their problem-solving skills (92.3%), facilitated their interaction with the neuroanatomy faculty (96.2%) and increase their critical thinking (88.4%). CONCLUSION: Collecting such empirical data about students' perceptions and their learning environment should help neurosciences faculty in medical schools better outline their activities to faculty at other medical institutions. Applying these methods may enhance the learning process, save time during neuroanatomy lab, and it could also help overcome the shortage of qualified neuroanatomy educators.

Anatomic all-epiphyseal ACL reconstruction with "inside-out" femoral tunnel placement in immature patients yields high return to sport rates and functional outcome scores a minimum of 24 months after reconstruction.

PURPOSE: To understand if anatomic physeal-sparing ACL reconstruction in the immature host preserves range of motion, permits a return to sports, and avoids limb length discrepancy and accelerated intra-articular degeneration with a cross-sectional radiographic, physical examination and patient-reported outcomes analysis. METHODS: A cross-sectional recall study included 38 patients aged 7-15 who underwent all-epiphyseal ACL reconstruction with hamstring allograft performed by a single surgeon at a large academic medical center. All-epiphyseal reconstructions were performed using a modified Anderson physeal-sparing technique, with the femoral tunnel placed using an "inside-out" technique. Assessments consisted of a physical exam, long leg cassette radiographs, KT-1000 measurements, subjective patient metrics, and magnetic resonance imaging. RESULTS: Thirty-eight (56.7%) of 66 eligible patients returned for in-person clinical and radiographic exams. Patients were 11.4 ± 1.8 years at the time of surgery. Five patients were females (13.2%). Mean follow-up was 5.5 ± 2.4 years. ACL re-injuries occurred in four patients (10.5%), all of whom underwent revision reconstructions. Thirty-three of the remaining 34 (97.1%) patients returned to sports following their reconstruction, and 24 (70.6%) returned to their baseline level of competition. Mean limb length discrepancy (LLD) was 0.2 ± 1.4 cm. Nine patients had an LLD of > 1 cm (26.5%), which occurred at an equivalent age as those with < 1 cm LLD (10.8 ± 2.0 vs. 11.7 ± 1.7, n.s.). Pre-operative Marx scores (13.1 ± 3.5) were not significantly different from post-operative values (12.3 ± 5.1, n.s.). Patients who required ACL revisions had significantly lower Marx scores than those with intact primary grafts (8.3 ± 7.1 vs. 13.4 ± 4.5, p = 0.047). Cohort mean International Knee Documentation Committee (IKDC) score was 89.7 ± 12.7. CONCLUSION: Anatomic all-epiphyseal anatomic ACL reconstruction appears to be useful in patients with significant projected remaining growth, with good return-to-sport outcomes and minimal risk of clinically significant physeal complications. However, given the limited patient recall possible in the present study, further large sample size, high-quality works are necessary to validate our findings. LEVEL OF EVIDENCE: Level IV.

Protective Effects of Flavonoids Against Mitochondriopathies and Associated Pathologies: Focus on the Predictive Approach and Personalized Prevention.

Multi-factorial mitochondrial damage exhibits a "vicious circle" that leads to a progression of mitochondrial dysfunction and multi-organ adverse effects. Mitochondrial impairments (mitochondriopathies) are associated with severe pathologies including but not restricted to cancers, cardiovascular diseases, and neurodegeneration. However, the type and level of cascading pathologies are highly individual. Consequently, patient stratification, risk assessment, and mitigating measures are instrumental for cost-effective individualized protection. Therefore, the paradigm shift from reactive to predictive, preventive, and personalized medicine (3PM) is unavoidable in advanced healthcare. Flavonoids demonstrate evident antioxidant and scavenging activity are of great therapeutic utility against mitochondrial damage and cascading pathologies. In the context of 3PM, this review focuses on preclinical and clinical research data evaluating the efficacy of flavonoids as a potent protector against mitochondriopathies and associated pathologies.

Bioactive peptides and proteins as alternative antiplatelet drugs.

Antiplatelet drugs reduce the risks associated with atherothrombotic events and show various applications in diverse cardiovascular diseases including myocardial infarctions. Efficacy of the current antiplatelet medicines including aspirin, clopidogrel, prasugrel and ticagrelor, and the glycoprotein IIb/IIIa antagonists, are limited due to their increased risks of bleeding, and antiplatelet drug resistance. Hence, it is important to develop new effective antiplatelet drugs, with fewer side-effects. The vast repertoire of natural peptides can be explored towards this goal. Proteins and peptides derived from snake venoms and plants represent exciting candidates for the development of novel and potent antiplatelet agents. Consequently, this review discusses multiple peptides that have displayed antiplatelet aggregation activity in preclinical drug development stages. This review also describes the antiplatelet mechanisms of the peptides, emphasizing the signaling pathways intervened by them. Also, the hurdles encountered during the development of peptides into antiplatelet drugs have been listed. Finally, hitherto unexplored peptides with the potential to prevent platelet aggregation are explored.

MicroRNA targeting by quercetin in cancer treatment and chemoprotection.

A growing number of evidences from clinical and preclinical studies have shown that dysregulation of microRNA (miRNA) function contributes to the progression of cancer and thus miRNA can be an effective target in therapy. Dietary phytochemicals, such as quercetin, are natural products that have potential anti-cancer properties due to their proven antioxidant, anti-inflammatory, and anti-proliferative effects. Available experimental studies indicate that quercetin could modulate multiple cancer-relevant miRNAs including let-7, miR-21, miR-146a and miR-155, thereby inhibiting cancer initiation and development. This paper reviews the data supporting the use of quercetin for miRNA-mediated chemopreventive and therapeutic strategies in various cancers, with the aim to comprehensively understand its health-promoting benefits and pharmacological potential. Integration of technology platforms for miRNAs biomarker and drug discovery is also presented.

Preconditioning with atorvastatin against renal ischemia-reperfusion injury in nondiabetic versus diabetic rats.

Acute renal failure complicates renal ischemia-reperfusion (I/R) owing to reactive oxygen species production. Atorvastatin (ATO) has anti-inflammatory and antioxidant properties. The current study investigated whether ATO alleviated damage induced by renal I/R injury in nondiabetic versus diabetic rat models. Thirty-six rats were equally divided into 6 groups: group A1 (nondiabetic sham), group A2 (nondiabetic I/R), group A3 (nondiabetic ATO + I/R), group B1 (diabetic sham), group B2 (diabetic I/R), and group B3 (diabetic ATO + I/R). All groups experienced 45 min of bilateral renal ischemia followed by 24 h of reperfusion. Groups A3 and B3 were treated with single intraperitoneal doses of ATO (10 mg/kg) 30 min before ischemia. Histological analysis of kidney tissues, kidney function tests, and analyses of caspase-3 and CD44 expression and oxidative stress markers were performed to assess tubular injury. Histological analysis revealed marked tubular damage in groups A2 and B2 but improvement in groups A3 and B3. Improvements were also found in groups A3 and B3 for caspase-3 and CD44 expression, kidney function tests, and oxidative stress markers. Our results suggest ATO may ameliorate renal I/R injury differently between nondiabetic and diabetic rats.

A Microbiological, Toxicological, and Biochemical Study of the Effects of Fucoxanthin, a Marine Carotenoid, on Mycobacterium tuberculosis and the Enzymes Implicated in Its Cell Wall: A Link Between Mycobacterial Infection and Autoimmune Diseases.

This study explored the antitubercular properties of fucoxanthin, a marine carotenoid, against clinical isolates of Mycobacterium tuberculosis (Mtb). Two vital enzymes involved in Mtb cell wall biosynthesis, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), were selected as drug targets to reveal the mechanism underlying the antitubercular effect of fucoxanthin. The obtained results showed that fucoxanthin showed a clear bacteriostatic action against the all Mtb strains tested, with minimum inhibitory concentrations (MIC) ranging from 2.8 to 4.1 µM, along with a good degree of selectivity index (ranging from 6.1 to 8.9) based on cellular toxicity evaluation compared with standard drug isoniazid (INH). The potent inhibitory actions of fucoxanthin and standard uridine-5'-diphosphate against UGM were recorded to be 98.2% and 99.2%, respectively. TBNAT was potently inactivated by fucoxanthin (half maximal inhibitory concentration (IC50) = 4.8 µM; 99.1% inhibition) as compared to INH (IC50 = 5.9 µM; 97.4% inhibition). Further, molecular docking approaches were achieved to endorse and rationalize the biological findings along with envisaging structure-activity relationships. Since the clinical evidence of the last decade has confirmed the correlation between bacterial infections and autoimmune diseases, in this study we have discussed the linkage between infection with Mtb and autoimmune diseases based on previous clinical observations and animal studies. In conclusion, we propose that fucoxanthin could demonstrate great therapeutic value for the treatment of tuberculosis by acting on multiple targets through a bacteriostatic effect as well as by inhibiting UGM and TBNAT. Such outcomes may lead to avoiding or decreasing the susceptibility to autoimmune diseases associated with Mtb infection in a genetically susceptible host.

Psoromic Acid, a Lichen-Derived Molecule, Inhibits the Replication of HSV-1 and HSV-2, and Inactivates HSV-1 DNA Polymerase: Shedding Light on Antiherpetic Properties.

Psoromic acid (PA), a bioactive lichen-derived compound, was investigated for its inhibitory properties against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), along with the inhibitory effect on HSV-1 DNA polymerase, which is a key enzyme that plays an essential role in HSV-1 replication cycle. PA was found to notably inhibit HSV-1 replication (50% inhibitory concentration (IC50): 1.9 µM; selectivity index (SI): 163.2) compared with the standard drug acyclovir (ACV) (IC50: 2.6 µM; SI: 119.2). The combination of PA with ACV has led to potent inhibitory activity against HSV-1 replication (IC50: 1.1 µM; SI: 281.8) compared with that of ACV. Moreover, PA displayed equivalent inhibitory action against HSV-2 replication (50% effective concentration (EC50): 2.7 µM; SI: 114.8) compared with that of ACV (EC50: 2.8 µM; SI: 110.7). The inhibition potency of PA in combination with ACV against HSV-2 replication was also detected (EC50: 1.8 µM; SI: 172.2). Further, PA was observed to effectively inhibit HSV-1 DNA polymerase (as a non-nucleoside inhibitor) with respect to dTTP incorporation in a competitive inhibition mode (half maximal inhibitory concentration (IC50): 0.7 µM; inhibition constant (Ki): 0.3 µM) compared with reference drugs aphidicolin (IC50: 0.8 µM; Ki: 0.4 µM) and ACV triphosphate (ACV-TP) (IC50: 0.9 µM; Ki: 0.5 µM). It is noteworthy that the mechanism by which PA-induced anti-HSV-1 activity was related to its inhibitory action against HSV-1 DNA polymerase. Furthermore, the outcomes of in vitro experiments were authenticated using molecular docking analyses, as the molecular interactions of PA with the active sites of HSV-1 DNA polymerase and HSV-2 protease (an essential enzyme required for HSV-2 replication) were revealed. Since this is a first report on the above-mentioned properties, we can conclude that PA might be a future drug for the treatment of HSV infections as well as a promising lead molecule for further anti-HSV drug design.

Synergistic actions of vitamin D and metformin on skeletal muscles and insulin resistance of type 2 diabetic rats.

Diabetes Mellitus is a chronic generalized disorder due to insulin insufficiency or resistance. Skeletal muscles represent one of the most important target organs that is affected by insulin signaling. The aim of the current work was to investigate the effect of metformin versus vitamin D (and also simultaneous administration) therapy in type 2 diabetic (T2D) rats on the state of the muscle and insulin sensitivity. Thirty six male rats constituted the animal model and have been divided into five groups: control, Diabetic, Diabetic + Metformin, Diabetic + Vitamin D, Diabetic + Metformin + Vitamin D. Blood samples were taken for biochemical measurements of serum calcium, interleukin-6 (IL-6), Triglycerides (TG), glucose, insulin, and calculation of HOMA-IR, and then rats were sacrificed, dissected for removal of gastrocnemius muscle that is used for both biochemical, histopathological and electron microscopy examination. Oral administration of vitamin D alone or in combination with metformin improved insulin sensitivity in skeletal muscles, and sustained the metabolic complications along with muscle atrophy and inflammation in T2D rats. We demonstrated super-beneficial action on insulin resistance of additional vitamin D therapy in T2DM rats that were insufficiently controlled by metformin alone.

Does posttreatment thymoquinone reverse high-dose atorvastatin-induced hepatic oxidative injury in rats?

Atorvastatin (ATO) was commonly used to lower blood cholesterol, but it caused harmful effects to organs, including the liver. Thymoquinone (TQ), a prominent constituent of Nigella sativa, has antioxidant, antiinflammatory, antiapoptotic, antimicrobial, and anticancer activity. The current study investigated the mechanism of ATO-induced hepatotoxicity, whether posttreatment TQ could reverse ATO-induced hepatic injury, and the mechanism of action of TQ as a hepatoprotective agent. Forty adult male Sprague Dawley rats were divided into four equal groups: control, TQ-treated, ATO-treated, and combined ATO/TQ-treated. Rats were treated for 8 weeks and 10 days and euthanized by cervical dislocation 3 days after the last treatment. Blood samples and livers were tested for liver enzymes, oxidative stress, and apoptosis markers and used for histopathological and ultrastructural examination. The ATO-treated group showed an increase in liver enzymes, decreases in reduced glutathione and catalase, and increases in the malondialdehyde lipid peroxidation marker, protein carbonylation, and caspase 3 activity. Posttreatment TQ in the ATO/TQ-treated group seemed to reverse these changes. Histopathological and ultrastructural examination supported these data. Results from the current study suggested that posttreatment TQ may reverse oxidative stress injury in rat liver produced by ATO, suggesting a potential clinical application of using TQ to prevent ATO-induced hepatic injury.

Curriculum mapping as a tool to facilitate curriculum development: a new School of Medicine experience.

BACKGROUND: Every curriculum needs to be reviewed, implemented and evaluated; it must also comply with the regulatory standards. This report demonstrates the value of curriculum mapping (CM), which shows the spatial relationships of a curriculum, in developing and managing an integrated medical curriculum. METHODS: A new medical school developed a clinical presentation driven integrated curriculum that incorporates the active-learning pedagogical practices of many educational institutions worldwide while adhering to the mandated requirements of the accreditation bodies. A centralized CM process was run in parallel as the curriculum was being developed. A searchable database, created after the CM data was uploaded into an electronic curriculum management system, was used to ensure placing, integrating, evaluating and revising the curricular content appropriately. RESULTS: CM facilitated in a) appraising the content integration, b) identifying gaps and redundancies, c) linking learning outcomes across all educational levels (i.e. session to course to program), c) organizing the teaching schedules, instruction methods, and assessment tools and d) documenting compliance with accreditation standards. CONCLUSIONS: CM is an essential tool to develop, review, improve and refine any integrated curriculum however complex. Our experience, with appropriate modifications, should help other medical schools efficiently manage their curricula and fulfill the accreditation requirements at the same time.

Possible protective role of silybin against polymyxin E-induced toxic effect in rat kidneys: A biochemical approach.

AIMS: Polymyxin E was used for treating gram-negative bacterial infections but not recently for fear of its nephrotoxicity. Silybin has potential to counteract nephrotoxicity; however, few studies have investigated its protective effect on the kidney in an animal model. The purpose of the present study was to assess whether silybin could decrease elevated urine and serum renal biochemical markers induced by polymyxin E in rat kidney. METHODS: Forty rats were divided randomly into four groups of 10 rats: control (I), vehicle (II), treatment (III, using polymyxin E), and protection (IV, using silybin and polymyxin E). Urine was collected daily for 7 days to test for N-acetyl-beta-D-glucosaminidase (NAG). Serum was collected after euthanizing the rats on day 7 to test kidney functions. RESULTS Group III had significant increases in NAG (all P < 0.001) compared with the other groups, but no differences were found between the other groups. Significant differences in kidney functions were found between Group III and Groups I and II, and between Group IV and Groups I and II (all P < 0.001). No differences were found between Groups III and IV. CONCLUSIONS: Group III results suggested an affection of the renal glomeruli and tubules, and Group IV results suggested a possible protective effect of silybin against polymyxin E-induced nephrotoxicity. Additional studies are recommended that use different doses of silybin for Groups III and IV to test for statistical differences for kidney functions and that test the protective effect of silybin against nephrotoxicity induced by polymyxin E in humans.

Does silybin protect against toxicity induced by polymyxin E in rat kidney?

AIMS: Although once a common antibiotic, polymyxin E fell out of favor after reports of its nephrotoxicity. However, recent concerns with gram-negative bacteria, which are resistant to multiple antibiotics, have resulted in increased interest in polymyxin E. Silybin is a known antihepatotoxic drug and may have potential for protecting the kidney from polymyxin E. Therefore, the aim of the current study was to evaluate whether silybin affected the damages produced by polymyxin E on the rat kidney. METHODS: Four groups of rats with 10 rats per group were included in the study: control (no treatment, group I), vehicle (control vehicle treatment, group II), polymyxin E treatment (group III), and polymyxin E and silybin treatment (group IV). Groups II-IV received intravenous treatment twice a day for 7 days. All rats were euthanized after 7 days. Histological, ultrastructural, and morphometric analyses were performed on the rats' kidney tissues. RESULTS: Analysis of tissues from group III showed differences from groups I and II, such as glomerular and tubular affection and changes in morphometric measures. Results for group IV were more similar to those of groups I and II than those of group III. CONCLUSIONS: Our results suggested that administering silybin with polymyxin E alleviated polymyxin E-induced nephrotoxicity in the rat kidney. Future biochemical studies should investigate whether silybin could ameliorate the nephrotoxicity caused by polymyxin E in rats and whether concomitant administration of silybin could be an effective clinical pharmacological strategy to protect against polymyxin E-induced insult in human kidneys.

Hepatoprotective effect of blocking N-methyl-d-aspartate receptors in male albino rats exposed to acute and repeated restraint stress.

Stress affects many organs in addition to the brain, including the liver. We assessed the effects on the liver of blocking N-methyl-d-aspartate (NMDA) glutamate receptors with memantine in acute and repeated restraint stress. Forty-two male albino rats were divided into 7 groups; control, acute restraint stress (ARS), ARS + memantine, repeated restraint stress, repeated restraint + memantine, and positive control groups. We measured serum iron, zinc, alanine transferase and aspartame transferase, hepatic malondialdehyde, tumor necrosis factor-α (TNF-α), glutathione peroxidase, superoxide dismutase, metallothionein content, zinc transporter ZRT/IRT-like protein 14 mRNA expression, and hepcidin expression. We conducted a histopathological evaluation via histological staining and immunostaining for glial fibrillary acidic protein and synaptophysin expression, both of which are markers of hepatic stellate cell (HSC) activation. Both ARS and repeated stress increased markers of hepatic cell injury, oxidative stress, and HSC activation. Blocking NMDA with memantine provided a hepatoprotective effect in acute and repeated restraint stress and decreased hepatic cell injury, oxidative stress, and HSC activation.

Biological Evaluation and Molecular Docking of Protocatechuic Acid from Hibiscus sabdariffa L. as a Potent Urease Inhibitor by an ESI-MS Based Method.

Studies on enzyme inhibition remain a crucial area in drug discovery since these studies have led to the discoveries of new lead compounds useful in the treatment of several diseases. In this study, protocatechuic acid (PCA), an active compound from Hibiscus sabdariffa L. has been evaluated for its inhibitory properties against jack bean urease (JBU) as well as its possible toxic effect on human gastric epithelial cells (GES-1). Anti-urease activity was evaluated by an Electrospray Ionization-Mass Spectrometry (ESI-MS) based method, while cytotoxicity was assayed by the MTT method. PCA exerted notable anti-JBU activity compared with that of acetohydroxamic acid (AHA), with IC50 values of 1.7 and 3.2 µM, respectively. PCA did not show any significant cytotoxic effect on (GES-1) cells at concentrations ranging from 1.12 to 3.12 µM. Molecular docking study revealed high spontaneous binding ability of PCA to the active site of urease. Additionally, the anti-urease activity was found to be related to the presence of hydroxyl moieties of PCA. This study presents PCA as a natural urease inhibitor, which could be used safely in the treatment of diseases caused by urease-producing bacteria.

Hibiscus sabdariffa L. and Its Bioactive Constituents Exhibit Antiviral Activity against HSV-2 and Anti-enzymatic Properties against Urease by an ESI-MS Based Assay.

For decades, Hibiscus sabdariffa L. and its phytochemicals have been shown to possess a wide range of pharmacologic properties. In this study, aqueous extract of Hibiscus sabdariffa (AEHS) and its bioactive constituent protocatechuic acid (PCA), have been evaluated in vitro for their antiviral activity against HSV-2 clinical isolates and anti-enzymatic activity against urease. Antiherpetic activity was evaluated by the titer reduction assay in infected Vero cells, and cytotoxicity was evaluated by the neutral red dye-uptake method. Anti-urease activity was determined by a developed Electrospray Ionization-Mass Spectrometry (ESI-MS)-based assay. PCA showed potent anti-HSV-2 activity compared with that of acyclovir, with EC50 values of 0.92 and 1.43 µg∙mL-1, respectively, and selectivity indices > 217 and > 140, respectively. For the first time, AEHS was shown to exert anti-urease inhibition activity, with an IC50 value of 82.4 µg∙mL-1. This, combined with its safety, could facilitate its use in practical applications as a natural urease inhibitor. Our results present Hibiscus sabdariffa L. and its bioactive compound PCA as potential therapeutic agents in the treatment of HSV-2 infection and the treatment of diseases caused by urease-producing bacteria.