Evidence-based Potential Therapeutic Applications of Cannabinoids in Wound Management.

BACKGROUND: Although wound management is a major component of all domains of healthcare, conventional therapeutics have numerous limitations. The endocannabinoid system of the skin, one of the major endogenous systems, has recently been connected to wound healing. Cannabinoids and their interactions with the endogenous chemical signaling system may be a promising therapeutic option because they address some of the fundamental pathways for physiologic derangement that underpin chronic integumentary wounds. RECENT ADVANCES: The therapeutic applications of cannabinoids are increasing because of their legalization and resulting market expansion. Recently, their immunosuppressive and anti-inflammatory properties have been explored for the treatment of wounds that are not effectively managed by conventional medicines. CRITICAL ISSUES: Failure to manage wounds effectively is associated with reduced quality of life, disability, mortality, and increased healthcare expenditures. Therapeutic options that can manage wounds effectively and efficiently are needed. In this review, the authors summarize recent advances on the use of cannabinoids to treat skin disorders with an emphasis on wound management. FUTURE DIRECTIONS: Effective wound management requires medicines with good therapeutic outcomes and minimal adverse effects. Despite the promising results of cannabinoids in wound management, further controlled clinical studies are required to establish the definitive role of these compounds in the pathophysiology of wounds and their usefulness in the clinical setting.

CB2 cannabinoid receptor is a novel target for third-generation selective estrogen receptor modulators bazedoxifene and lasofoxifene.

The purpose of the current study was to investigate the ability of the third-generation selective estrogen receptor modulators (SERMs) bazedoxifene and lasofoxifene to bind and act on CB2 cannabinoid receptor. We have identified, for the first time, that CB2 is a novel target for bazedoxifene and lasofoxifene. Our results showed that bazedoxifene and lasofoxifene were able to compete for specific [(3)H]CP-55,940 binding to CB2 in a concentration-dependent manner. Our data also demonstrated that by acting on CB2, bazedoxifene and lasofoxifene concentration-dependently enhanced forskolin-stimulated cAMP accumulation. Furthermore, bazedoxifene and lasofoxifene caused parallel, rightward shifts of the CP-55,940, HU-210, and WIN55,212-2 concentration-response curves without altering the efficacy of these cannabinoid agonists on CB2, which indicates that bazedoxifene- and lasofoxifene-induced CB2 antagonism is most likely competitive in nature. Our discovery that CB2 is a novel target for bazedoxifene and lasofoxifene suggests that these third-generation SERMs can potentially be repurposed for novel therapeutic indications for which CB2 is a target. In addition, identifying bazedoxifene and lasofoxifene as CB2 inverse agonists also provides important novel mechanisms of actions to explain the known therapeutic effects of these SERMs.

Identification of raloxifene as a novel CB2 inverse agonist.

The purpose of the current study was to apply a high throughput assay to systematically screen a library of food and drug administration (FDA)-approved drugs as potential ligands for the cannabinoid receptor 2 (CB2). A cell-based, homogenous time resolved fluorescence (HTRF) method for measuring changes in intracellular cAMP levels was validated and found to be suitable for testing ligands that may act on CB2. Among the 640 FDA-approved drugs screened, raloxifene, a drug used to treat/prevent post-menopausal osteoporosis, was identified for the first time to be a novel CB2 inverse agonist. Our results demonstrated that by acting on CB2, raloxifene enhances forskolin-stimulated cAMP accumulation in a concentration-dependant manner. Furthermore, our data showed that raloxifene competes concentration-dependently for specific [(3)H]CP-55,940 binding to CB2. In addition, raloxifene pretreatment caused a rightward shift of the concentration-response curves of the cannabinoid agonists CP-55,940, HU-210, and WIN55,212-2. Raloxifene antagonism is most likely competitive in nature, as these rightward shifts were parallel and were not associated with any changes in the efficacy of cannabinoid agonists on CB2. Our discovery that raloxfiene is an inverse agonist for CB2 suggests that it might be possible to repurpose this FDA-approved drug for novel therapeutic indications for which CB2 is a target. Furthermore, identifying raloxifene as a CB2 inverse agonist also provides important novel mechanisms of actions to explain the known therapeutic effects of raloxifene.

Involvement of a non-CB1/CB2 cannabinoid receptor in the aqueous humor outflow-enhancing effects of abnormal-cannabidiol.

The purpose of this study was to investigate the effects of abnormal-cannabidiol (abn-cbd), a non-psychoactive cannabinoid agonist, on aqueous humor outflow via the trabecular meshwork (TM) of porcine eye, and to examine the involvement of a non-CB1/CB2 cannabinoid receptor and the p42/44 mitogen-activated protein kinase (p42/44 MAPK) pathway. The effects of abn-cbd on aqueous humor outflow were measured using a porcine anterior segment perfused organ culture model. The activation of p42/44 MAPK by abn-cbd was determined in cultured TM cells with western blot analysis using an anti-phospho-p42/44 MAPK antibody. Administration of abn-cbd caused a concentration-dependent enhancement of aqueous humor outflow facility with a maximum effect (155.0 ± 11.7% of basal outflow facility) after administration of 30 nM abn-cbd. Pretreatment with 1 µM of O-1918, a cannabidiol analog that acts as a selective antagonist at the non-CB1/CB2 receptor, produced a full antagonism of 30 nM abn-cbd induced increase of aqueous humor outflow facility. Pretreatment with 1 µM of CB1 antagonist SR141716A partially blocked, whereas pretreatment with either 1 µM of CB1 antagonist AM251 or 1 µM of CB2 antagonist SR144528 had no effect on abn-cbd induced enhancement of outflow facility. Treatment of TM cells with 30 nM of abn-cbd activated p42/44 MAPK, which was blocked completely by pretreatment with O-1918, and partially by pretreatment with SR141716A, but not by either AM251 or SR144528. In addition, PD98059, an inhibitor of p42/44 MAPK pathway, blocked completely the abn-cbd induced p42/44 MAPK activation and blocked partially the abn-cbd induced enhancement of outflow facility. In conclusion, the results from this study demonstrate that abn-cbd increases aqueous humor outflow through the TM pathway of the eye, and this effect is mediated by a non-CB1/CB2 cannabinoid receptor, with an involvement of p42/44 MAPK signaling pathway.

Negative pressure wound therapy in grade 1 and 2 diabetic foot ulcers: A randomized controlled study.

BACKGROUND AND AIMS: Foot ulcers are one of the major causes of morbidity and mortality among diabetics in India. Early diagnosis and timely management is vital in preventing the progression of the disease which may require amputation. Conventional methods take a long time for healing. This study aims to compare negative pressure wound therapy (NPWT) and conventional saline dressings in diabetic foot ulcer (DFU) healing. METHODS: This prospective randomized study was conducted in 45 patients with grade 1 and 2 DFUs. 22 patients in group A received NPWT and 23 patients in group B received saline dressings. The formation of granulation tissue, reduction in ulcer size, duration of hospital stay and time for complete healing of wounds were assessed. RESULTS: The formation of granulation tissue (91.14 vs 52.61%, p < 0.001) and reduction in ulcer size (40.78 vs 21.18%, p = 0.008) at 14 days was significantly more in group A. The duration of hospital stay (15.68 vs 29.00 days, p < 0.001) and time for 100% coverage of the wound with granulation tissue (14.82 ± 7.30 vs 44.57 ± 7.11 days, p < 0.001) was significantly less in group A. Complete healing of wounds at 3 months was observed in 20 patients (90.9%) in group A and 6 patients (26.1%) in group B (p = 0.006). CONCLUSION: In our study NPWT led to early reduction in ulcer size, more granulation tissue formation, shorter hospital stay and complete wound healing. In lower and middle income countries like India with high prevalence of DFUs, early recovery is a boon to the patients to resume their daily activities.

A potential role for cannabichromene in modulating TRP channels during acute respiratory distress syndrome.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a life-threatening clinical syndrome whose potential to become one of the most grievous challenges of the healthcare system evidenced by the COVID-19 pandemic. Considering the lack of target-specific treatment for ARDS, it is absolutely exigent to have an effective therapeutic modality to reduce hospitalization and mortality rate as well as to improve quality of life and outcomes for ARDS patients. ARDS is a systemic inflammatory disease starting with the pulmonary system and involves all other organs in a morbid bidirectional fashion. Mounting evidence including our findings supporting the notion that cannabinoids have potential to be targeted as regulatory therapeutic modalities in the treatment of inflammatory diseases. Therefore, it is plausible to test their capabilities as alternative therapies in the treatment of ARDS. In this study, we investigated the potential protective effects of cannabichromene (CBC) in an experimental model of ARDS. METHODS: We used, for the first time, an inhalant CBC treatment as a potential therapeutic target in a murine model of ARDS-like symptoms. ARDS was induced by intranasal administration of Poly(I:C), a synthetic mismatched double-stranded RNA, into the C57BL/6 mice (6-10 male mice/group, including sham, placebo, and CBC treated), three once-daily doses followed by a daily dose of inhalant CBC or placebo for the period of 8 days starting the first dose 2 h after the second Poly(I:C) treatment. We employed histologic, immunohistochemistry, and flow cytometry methods to assess the findings. Statistical analysis was performed by using one way analysis of variance (ANOVA) followed by Newman-Keuls post hoc test to determine the differences among the means of all experimental groups and to establish significance (p < 0.05) among all groups. RESULTS: Our data showed that CBC was able to reverse the hypoxia (increasing blood O2 saturation by 8%), ameliorate the symptoms of ARDS (reducing the pro-inflammatory cytokines by 50% in lung and blood), and protect the lung tissues from further destruction. Further analysis showed that CBC may wield its protective effects through transient receptor potential (TRP) cation channels, TRPA1 and TRPV1, increasing their expression by 5-folds in lung tissues compared to sham and untreated mice, re-establishing the homeostasis and immune balance. CONCLUSION: Our findings suggest that inhalant CBC may be an effective alternative therapeutic target in the treatment of ARDS. In addition, Increased expression of TRPs cation channels after CBC treatment proposes a novel role for TRPs (TRPA1 and TRPV2) as new potential mechanism to interpret the beneficial effects of CBC as well as other cannabinoids in the treatment of ARDS as well as other inflammatory diseases. Importantly, delivering CBC through an inhaler device is a translational model supporting the feasibility of trial with human subjects, authorizing further research.

Cystic Lymphangioma of the Greater Omentum: A Case of Partial Spontaneous Regression and Review of the Literature.

Introduction. Omental cysts are a part of cystic lymphangiomas and are benign proliferations of ectopic lymphatics without a communication with the normal lymphatic system. They commonly involve the neck in the pediatric population and are uncommon at other sites and occur rarely in adults. Case Presentation. A 42-year-old female with complaints of vague lower abdominal pain for 8 months presented with a soft, nontender swelling of size 22 × 18 cm in the hypogastrium and umbilical region. Computerized tomography (CT) of the abdomen showed a peripherally enhancing hypodense cystic lesion of size 19 × 14 × 12 cm perhaps arising from the mesentery. The cyst had spontaneously reduced in size by about 70% over the next 4 months. During surgery, the cyst of size 10 × 9 × 8 cm was present in the greater omentum. Excision was done, and histopathology was suggestive of cystic lymphangioma. Discussion. Cystic lymphangiomas have an incidence of 1/20000 at infancy and 1/100000 to 1/250000 of hospital admissions in adults, and the female-to-male ratio is 2 : 1. In adults, they are found in the age group between 40 and 70 years. Spontaneous regression of omental cysts is very rare and presumably from increased pressure in cysts overcoming incomplete obstructions or by establishment of alternative routes of drainage. CONCLUSION: As the disease is essentially benign and if there are no significant pressure symptoms, the cysts of short duration can be watched further for regression. Long-standing, symptomatic cysts, nonregression, and diagnostic uncertainty will warrant surgery to confirm the diagnosis and relieve the symptoms.

Isolated primary cold abscess of the sternum: a case report.

BACKGROUND: Musculoskeletal tuberculosis forms 10-25% of extrapulmonary tuberculosis which mainly involves the spine or weight-bearing joints. Tuberculous involvement of the sternum is a rare clinical entity even in countries where tuberculosis has high prevalence. Primary tuberculous sternal osteomyelitis accounts for approximately 0.3% of all types of tubercular osteomyelitis and the probable source appears to be extension from paratracheal or hilar lymph nodes. Despite tuberculosis being a common disease in endemic countries and worldwide, a thorough literature search of the PubMed database for keywords "primary tuberculosis of sternum" and "primary tuberculous osteomyelitis of sternum" yielded 30 and 22 articles, respectively. CASE PRESENTATION: We present an unusual case of a large dumb-bell-shaped cold abscess arising due to infection of the sternum. A 23-year-old immunocompetent Asian woman presented with a gradually progressing painless swelling on anterior chest wall for the last 5 months. She had a large visible swelling on anterior chest wall which was 12.5 cm in diameter, soft, non-tender, temperature was not raised, and fluctuant. Magnetic resonance imaging showed a large dumb-bell-shaped hyperintense collection in upper anterior chest wall with marrow edema and cortical irregularity in left side of manubrium. Pus was positive for nucleic acid testing (cartridge-based nucleic acid amplification test) for Mycobacterium tuberculosis and later culture was also positive. She was started on anti-tubercular therapy and aspirated twice. Currently, she has completed 6 months of therapy and the swelling has now disappeared. DISCUSSION: Swelling, pain localized to sternum, or ulceration of the skin with discharging sinus along with or without constitutional symptoms are the usual presentation. A high element of suspicion is needed for early diagnosis and treatment to prevent its complications. Sternal mycobacterial infections are categorized as primary, secondary, and/or acquired postoperatively. Although radiological investigations aid in diagnosis, the diagnosis is established by positive culture or histopathological examination. Anti-tubercular therapy is the mainstay of treatment with standard four-drug regimen for 6-9 months. Surgical drainage of the abscess should be considered only if it does not resolve by aspiration and anti-tubercular therapy.

Structure-activity relationships of fatty acid amide ligands in activating and desensitizing G protein-coupled receptor 119.

The purpose of the current study was to apply a high throughput assay to investigate the structure-activity relationships of fatty acid amides for activating and desensitizing G protein-coupled receptor 119, a promising therapeutic target for both type 2 diabetes and obesity. A cell-based, homogenous time resolved fluorescence (HTRF) method for measuring G protein-coupled receptor 119-mediated increase of cyclic adenosine monophosphate (cAMP) levels was validated and applied in this study. Using novel fatty acid amides and detailed potency and efficacy analyses, we have demonstrated that degree of saturation in acyl chain and charged head groups of fatty acid amides have profound effects on the ability of these compounds to activate G protein-coupled receptor 119. In addition, we have demonstrated for the first time that pretreatments with G protein-coupled receptor 119 agonists desensitize the receptor and the degrees of desensitization caused by fatty acid amides correlate well with their structure-activity relationships in activating the receptor.

A categorical structure-activity relationship analysis of GPR119 ligands.

The categorical structure-activity relationship (cat-SAR) expert system has been successfully used in the analysis of chemical compounds that cause toxicity. Herein we describe the use of this fragment-based approach to model ligands for the G protein-coupled receptor 119 (GPR119). Using compounds that are known GPR119 agonists and compounds that we have confirmed experimentally that are not GPR119 agonists, four distinct cat-SAR models were developed. Using a leave-one-out validation routine, the best GPR119 model had an overall concordance of 99%, a sensitivity of 99%, and a specificity of 100%. Our findings from the in-depth fragment analysis of several known GPR119 agonists were consistent with previously reported GPR119 structure-activity relationship (SAR) analyses. Overall, while our results indicate that we have developed a highly predictive cat-SAR model that can be potentially used to rapidly screen for prospective GPR119 ligands, the applicability domain must be taken into consideration. Moreover, our study demonstrates for the first time that the cat-SAR expert system can be used to model G protein-coupled receptor ligands, many of which are important therapeutic agents.

The importance of hydrogen bonding and aromatic stacking to the affinity and efficacy of cannabinoid receptor CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528).

Despite the therapeutic promise of the subnanomolar affinity cannabinoid CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528, 1), little is known about its binding site interactions and no primary interaction site for 1 at CB2 has been identified. We report here the results of Glide docking studies in our cannabinoid CB2 inactive state model that were then tested via compound synthesis, binding, and functional assays. Our results show that the amide functional group of 1 is critical to its CB2 affinity and efficacy and that aromatic stacking interactions in the TMH5/6 aromatic cluster of CB2 are also important. Molecular modifications that increased the positive electrostatic potential in the region between the fenchyl and aromatic rings led to more efficacious compounds. This result is consistent with the EC-3 loop negatively charged amino acid, D275 (identified via Glide docking studies) acting as the primary interaction site for 1 and its analogues.

Effects of palmitoylethanolamide on aqueous humor outflow.

PURPOSE: To study the effects of palmitoylethanolamide (PEA), a fatty acid ethanolamide, on aqueous humor outflow facility. METHODS: The effects of PEA on outflow facility were measured using a porcine anterior segment-perfused organ culture model. The involvements of different receptors in PEA-induced changes were investigated using receptor antagonists and adenovirus delivered small hairpin RNAs (shRNAs). PEA-induced activation of p42/44 mitogen-activated protein kinase (MAPK) was determined by Western blot analysis using an antiphospho p42/44 MAPK antibody. RESULTS: PEA caused a concentration-dependent enhancement of outflow facility, with the maximum effect (151.08 ± 11.12% of basal outflow facility) achieved at 30 nM of PEA. Pretreatment of anterior segments with 1 µM cannabinoid receptor 2 antagonist SR144528 and 1 µM PPARα antagonist GW6471, but not 1 µM cannabinoid receptor 1 antagonist SR141716A, produced a partial antagonism on the PEA-induced increase of outflow facility. Treatment of TM cells with PEA for 10 minutes activated phosphorylation of p42/44 MAPK, which was blocked by pretreatment with SR1444528 and GW6471, but not SR141716A. Knocking down the expression of either GPR55 or PPARα receptors with specific shRNAs for these receptors partially blocked PEA-induced increase in outflow facility and abolished PEA-induced phosphorylation of p42/44 MAPK. PD98059, an inhibitor of the p42/44 MAPK pathway, blocked both PEA-induced enhancement of aqueous humor outflow facility and PEA-induced phosphorylation of p42/44 MAPK. CONCLUSIONS: Our results demonstrate that PEA increases aqueous humor outflow through the TM pathway and these effects are mediated by GPR55 and PPARα receptors through activation of p42/44 MAPK.