Cannabis as a Source of Approved Drugs: A New Look at an Old Problem.

Cannabis plants have been used in medicine since ancient times. They are well known for their anti-diabetic, anti-inflammatory, neuroprotective, anti-cancer, anti-oxidative, anti-microbial, anti-viral, and anti-fungal activities. A growing body of evidence indicates that targeting the endocannabinoid system and various other receptors with cannabinoid compounds holds great promise for addressing multiple medical conditions. There are two distinct avenues in the development of cannabinoid-based drugs. The first involves creating treatments directly based on the components of the cannabis plant. The second involves a singular molecule strategy, in which specific phytocannabinoids or newly discovered cannabinoids with therapeutic promise are pinpointed and synthesized for future pharmaceutical development and validation. Although the therapeutic potential of cannabis is enormous, few cannabis-related approved drugs exist, and this avenue warrants further investigation. With this in mind, we review here the medicinal properties of cannabis, its phytochemicals, approved drugs of natural and synthetic origin, pitfalls on the way to the widespread clinical use of cannabis, and additional applications of cannabis-related products.

Hybrid Hydrogels of FKF-Peptide Assemblies and Gelatin for Sustained Antimicrobial Activity.

The growing resistance of pathogenic bacteria to conventional antibiotics promotes the development of new antimicrobial agents, including peptides. Hydrogels composed of antimicrobial peptides (AMPs) may be applied as topical treatments for skin infection and wound regeneration. The unique antimicrobial and ultrashort-peptide FKF (Phe-Lys-Phe) was recently demonstrated to form bactericidal hydrogels. Here, we sought to improve the cyto-biocompatibility of FKF by combining FKF hydrogels with gelatin. Homogeneous hybrid hydrogels of FKF:gelatin were developed based on a series of self-assembly steps that involved mixing solutions of the two components with no covalent cross-linkers. The hydrogels were characterized for their structural features, dissolution, cyto-biocompatibility, and antibacterial properties. These hybrid hydrogels first release the antibacterial FKF assemblies, leaving the gelatinous fraction of the hydrogel to serve as a scaffold for tissue regeneration. Sponges of these hybrid hydrogels, obtained by lyophilization and rehydrated prior to application, exhibited enhanced antimicrobial activity compared to the hydrogels' formulations.

Prevalence and Characteristics of Carriage of Neisseria meningitidis Among Young Israeli Adults.

Background: No updated data currently exist regarding Neisseria meningitidis carriage and genomic epidemiology among young Israeli adults. Methods: Oropharyngeal swabs were collected from 1801 military recruits on the day of recruitment during 2019. Neisseria meningitidis was detected and identified by culture and quantitative polymerase chain reaction (qPCR). Confirmed isolates were serotyped by qPCR, and encapsulated strains underwent whole-genome sequencing. Risk factors for carriage were determined by analyzing focused questionnaires using uni- and multivariate models. Genomic typing was performed by means of core genome multilocus sequence typing. Results: Carriage rates overall and of encapsulated strains were 20.1% and 6.7%, respectively. Genogroups B (49.2%) and Y (26.7%) were the most commonly encapsulated strains. Genogroups C, W, and X were scarce, and genogroup A was absent. The most notable clonal complexes (CCs) were CC23 (n = 30), CC32 (n = 16), and CC44/41 (n = 9). Carriage was significantly associated with smoking (odds ratio [OR], 1.82; 95% CI, 1.43-2.33) and boarding school attendance before recruitment (OR, 1.49; 95% CI, 1.14-1.96). Conclusions: The prevalence of meningococcal carriage among young Israeli adults is high, compared with similar studies in other developed countries. This might be due to sociocultural characteristics including smoking and boarding school attendance during and after high school. The dominant genogroups and CCs found were compatible with those implicated in invasive disease in Israel.

The Effects of One Anastomosis Gastric Bypass Surgery on the Gastrointestinal Tract.

One anastomosis gastric bypass (OAGB) is an emerging bariatric procedure, yet data on its effect on the gastrointestinal tract are lacking. This study sought to evaluate the incidence of small-intestinal bacterial overgrowth (SIBO) following OAGB; explore its effect on nutritional, gastrointestinal, and weight outcomes; and assess post-OABG occurrence of pancreatic exocrine insufficiency (PEI) and altered gut microbiota composition. A prospective pilot cohort study of patients who underwent primary-OAGB surgery is here reported. The pre-surgical and 6-months-post-surgery measurements included anthropometrics, glucose breath-tests, biochemical tests, gastrointestinal symptoms, quality-of-life, dietary intake, and fecal sample collection. Thirty-two patients (50% females, 44.5 ± 12.3 years) participated in this study, and 29 attended the 6-month follow-up visit. The mean excess weight loss at 6 months post-OAGB was 67.8 ± 21.2%. The glucose breath-test was negative in all pre-surgery and positive in 37.0% at 6 months (p = 0.004). Positive glucose breath-test was associated with lower reported dietary intake and folate levels and higher vitamin A deficiency rates (p ≤ 0.036). Fecal elastase-1 test (FE1) was negative for all pre-surgery and positive in 26.1% at 6 months (p = 0.500). Both alpha and beta diversity decreased at 6 months post-surgery compared to pre-surgery (p ≤ 0.026). Relatively high incidences of SIBO and PEI were observed at 6 months post-OAGB, which may explain some gastrointestinal symptoms and nutritional deficiencies.

Comparing the Antimicrobial Effect of Silver Ion-Coated Silicone and Gentamicin-Irrigated Silicone Sheets from Breast Implant Material.

BACKGROUND: Post-operative infection is a significant complication of breast implant surgery that may require extensive use of antibiotics and surgical interventions. Here, we developed a biomaterial coating that is chemically bonded to silicone implants which delivers antimicrobial ions over time. METHODS: After coating the silicone implants with a "mediator" polymer (γ-PGA), the implants were impregnated with silver (Ag) ions. Antimicrobial effects of these implants were assayed with modified Kirby-Bauer disk diffusion method. The silicone disks were transferred to a plate with fresh bacteria. Control was intended to simulate an intra-operative wash. RESULTS: The Ag-γ-PGA coated silicone demonstrated antimicrobial effects against the most common etiological agents of breast implant infections, including Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Klebsiella pneumoniae. There was no effect of inhibition of bacterial growth around the control silicone or the silicone coated only with γ-PGA. The zone of inhibition was generally larger around the Ag-γ-PGA coated silicone as compared to the silicone irrigated with gentamicin, and continued antibacterial effect was also observed at 48 hours in the Ag-γ-PGA coated silicone for all bacteria groups with the exception of P. aeruginosa. Gentamicin-irrigated silicone did not inhibit bacterial growth at 48 hours. CONCLUSION: The observed antibacterial performance of the Ag-γ-PGA coating as compared to simulated intra-operative antibiotic wash is promising and should be further evaluated to develop the next generation of implants with diminished risk for post-operative implant infections.

Dimethyl fumarate and vitamin D derivatives cooperatively enhance VDR and Nrf2 signaling in differentiating AML cells in vitro and inhibit leukemia progression in a xenograft mouse model.

Acute myeloid leukemia (AML) is one of the deadliest hematological malignancies without effective treatment for most patients. Vitamin D derivatives (VDDs) - active metabolites 1α,25-dihydroxyvitamin D2 (1,25D2) and 1α,25-dihydroxyvitamin D3 (1,25D3) and their analogs - are differentiation-inducing agents which have potential for the therapy of AML. However, calcemic toxicity of VDDs limits their clinical use at doses effective against cancer cells in vivo. Here, we demonstrate that in AML cell cultures, moderate pro-differentiation effects of low concentrations of VDDs can be synergistically enhanced by structurally distinct compounds known to activate the transcription factor Nuclear Factor (Erythroid-derived 2)-Like 2 (NFE2L2 or Nrf2). Particularly, dimethyl fumarate (DMF), which is clinically approved for the treatment of multiple sclerosis and psoriasis, strongly cooperated with 1,25D3, PRI-5100 (19-nor-1,25D2; paricalcitol) and PRI-5202 (a double-point modified 19-nor analog of 1,25D2). The pro-differentiation synergy between VDDs (1,25D3 or PRI-5202) and Nrf2 activators (DMF, tert-butylhydroquinone or carnosic acid) was associated with a cooperative upregulation of the protein levels of the vitamin D receptor (VDR) and Nrf2 as well as increased mRNA expression of their respective target genes. These data support the notion that VDDs and Nrf2 activators synergize in inducing myeloid cell differentiation through the cooperative activation of the VDR and Nrf2/antioxidant response element signaling pathways. We have previously reported that PRI-5202 is more potent by approximately two orders of magnitude than 1,25D3 as a differentiation inducer in AML cell lines. In this study, we found that PRI-5202 was also at least 5-fold less calcemic in healthy mice compared to both its direct precursor PRI-1907 and 1,25D3. In addition, PRI-5202 was remarkably more resistant against degradation by the human 25-hydroxyvitamin D3-24-hydroxylase than both 1,25D2 and 1,25D3. Importantly, using a xenograft mouse model we demonstrated that co-administration of PRI-5202 and DMF resulted in a marked cooperative inhibition of human AML tumor growth without inducing treatment toxicity. Collectively, our findings provide a rationale for clinical testing of low-toxic VDD/DMF combinations as a novel approach for differentiation therapy of AML.

Recent Updates on the Phytochemistry and Pharmacological Properties of Phlomis viscosa Poiret.

Crude ethanolic extracts from Phlomis viscosa Poiret leaves from the Judea region (Israel) are renowned for their remarkable geroprotective properties: anti-inflammatory, anti-diabetic, and anti-cancer. A phytochemical investigation carried out in this study revealed that the tested plant might belong to a particular distinct chemotype because its phytochemicals are different from compounds that were mentioned in the literature. Among the compounds identified by us was diosmin, the synthetic derivatives of which were further obtained and investigated. In particular, activities of the isolated compounds and synthesized diosmin derivatives were assessed. Our results revealed that the following compounds significantly lessened secretion of some pro-inflammatory cytokines: diosmin, himachala-2-diene, and 5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl) chromen-4-one. In addition, diosmin, synthesized diosmin derivatives, and some identified terpenes were found to have anti-diabetic activities. A significant anti-cancer effect of the whole extract on U-87 (human glioblastoma carcinoma cells line) and MCF7 (human breast carcinoma cell line) was also demonstrated, and it was better than that of DOX (doxorubicin). Collectively, the results obtained in the in vitro models suggest a wide spectrum of beneficial bioactivities of the extract and its active compounds.

Serine protease inhibitors interact with IFN-γ through up-regulation of FasR; a novel therapeutic strategy against cancer.

Among the many immunomodulatory and anti-tumor activities, IFN-γ up-regulates tumor cell death mediated by Fas receptor (FasR). Our and several other studies have demonstrated the involvement of trypsin-like proteases (TLPs) in the mode of action of IFN-γ. In the present study, we tried to unravel the role of serine proteases in IFN-γ induced Fas-mediated cell death. Our present results show that both tosyl-l-Lysine chloromethylketone (TLCK), a trypsin like protease inhibitor and tosyl-l-phenylalanine chloromethylketone (TPCK) - a chymotrypsin like protease (CLP) inhibitor, sensitize HeLa cells to Fas-mediated cell death. The combined effect of these protease inhibitors with anti-Fas was stronger than additive. In contrast, elastase inhibitor III (EI), which also contains the chloromethyl ketone moiety, was not active. Furthermore, co-addition of TLCK or TPCK with IFN-γ markedly enhanced Fas-induced cell death. IFN-γ led to up-regulation of FasR on its own, which was further enhanced by the co-addition of TLCK or TPCK. This was evident both by increased expression of Fas receptor on cell surface and by elevated Fas mRNA level. This study may provide the basis for the design of a novel combinatory therapeutic strategy that could enhance the eradication of tumors.

Regulation of autophagy by α1-antitrypsin: "a foe of a foe is a friend".

Autophagy is involved in both the cell protective and the cell death process but its mechanism is largely unknown. The present work unravels a novel intracellular mechanism by which the serpin α1-antitrypsin (AAT) acts as a novel negative regulator of autophagic cell death. For the first time, the role of intracellularly synthesized AAT, other than in liver cells, is demonstrated. Autophagic cell death was induced by N-α-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and tamoxifen. By utilizing a fluorescently tagged TPCK analog, AAT was "fished out" (pulled out) as a TPCK intracellular protein target. The interaction was further verified by competition binding experiments. Both inducers caused downregulation of AAT expression associated with activation of trypsin-like proteases. Furthermore, silencing AAT by siRNA induced autophagic cell death. Moreover, AAT administration to cultured cells prevented autophagic cell death. This new mechanism could have implications in the treatment of diseases by the regulation of AAT levels in which autophagy has a detrimental function. Furthermore, the results imply that the high synthesis of endogenous AAT by cancer cells could provide a novel resistance mechanism of cancer against autophagic cell death.

Cardiolipin plays a role in KCN-induced necrosis.

Cardiolipin (CL) is a unique anionic, dimeric phospholipid found almost exclusively in the inner mitochondrial membrane and is essential for the function of numerous enzymes that are involved in mitochondrial energy metabolism. While the role of cardiolipin in apoptosis is well established, its involvement in necrosis is enigmatic. In the present study, KCN-induced necrosis in U937 cells was used as an experimental model to assess the role of CL in necrosis. KCN addition to U937 cells induced reactive oxygen species (ROS) formation, while the antioxidants inhibited necrosis, indicating that ROS play a role in KCN-induced cell death. Further, CL oxidation was confirmed by the monomer green fluorescence of 10-N-nonyl acridine orange (NAO) and by TLC. Utilizing the red fluorescence of the dimeric NAO, redistribution of CL in mitochondrial membrane during necrosis was revealed. We also showed that the catalytic activity of purified adenosine triphosphate (ATP) synthase complex, known to be modulated by cardiolipin, decreased following KCN treatment. All these events occurred at an early phase of the necrotic process prior to rupture of the cell membrane. Furthermore, CL-deficient HeLa cells were found to be resistant to KCN-induced necrosis as compared with the wild type cells. We suggest that KCN, an effective reversible inhibitor of cytochrome oxidase and thereby of the respiratory chain leads to ROS increase, which in turn oxidizes CL (amongst other membrane phospholipids) and leads to mitochondrial membrane lipid reorganization and loss of CL symmetry. Finally, the resistance of CL-deficient cells to necrosis further supports the notion that CL, which undergoes oxidation during necrotic cell death, is an integral part of the milieu of events taking place in mitochondria leading to membrane disorganization and mitochondrial dysfunction.