Platelet P2Y12 signalling pathway in the dysregulated immune response during sepsis.

Sepsis is a complicated pathological condition in response to severe infection. It is characterized by a strong systemic inflammatory response, where multiple components of the immune system are involved. Currently, there is no treatment for sepsis. Blood platelets are known for their role in haemostasis, but they also participate in inflammation through cell-cell interaction and the secretion of inflammatory mediators. Interestingly, an increase in platelet activation, secretion, and aggregation with other immune cells (such as monocytes, T-lymphocytes and neutrophils) has been detected in septic patients. Therefore, antiplatelet therapy in terms of P2Y12 antagonists has been evaluated as a possible treatment for sepis. It was found that blocking P2Y12 receptors decreased platelet marker expression and limited attachment to immune cells in some studies, but not in others. This review addresses the role of platelets in sepsis and discusses whether antagonizing P2Y12 signalling pathways can alter the disease outcome. Challenges in studying P2Y12 antagonists in sepsis also are discussed. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

A role for platelets in metabolic reprogramming of tumor-associated macrophages.

Cancer incidence and mortality are growing worldwide. With a lack of optimal treatments across many cancer types, there is an unmet need for the development of novel treatment strategies for cancer. One approach is to leverage the immune system for its ability to survey for cancer cells. However, cancer cells evolve to evade immune surveillance by establishing a tumor microenvironment (TME) that is marked by remarkable immune suppression. Macrophages are a predominant immune cell within the TME and have a major role in regulating tumor growth. In the TME, macrophages undergo metabolic reprogramming and differentiate into tumor-associated macrophages (TAM), which typically assume an immunosuppressive phenotype supportive of tumor growth. However, the plasticity of macrophage biology offers the possibility that macrophages may be promising therapeutic targets. Among the many determinants in the TME that may shape TAM biology, platelets can also contribute to cancer growth and to maintaining immune suppression. Platelets communicate with immune cells including macrophages through the secretion of immune mediators and cell-cell interaction. In other diseases, altering platelet secretion and cell-cell communication has been shown to reprogram macrophages and ameliorate inflammation. Thus, intervening on platelet-macrophage biology may be a novel therapeutic strategy for cancer. This review discusses our current understanding of the interaction between platelets and macrophages in the TME and details possible strategies for reprogramming macrophages into an anti-tumor phenotype for suppressing tumor growth.

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges.

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

Sex-related differences in the response of anti-platelet drug therapies targeting purinergic signaling pathways in sepsis.

Sepsis, a complex clinical syndrome resulting from a serious infection, is a major healthcare problem associated with high mortality. Sex-related differences in the immune response to sepsis have been proposed but the mechanism is still unknown. Purinergic signaling is a sex-specific regulatory mechanism in immune cell physiology. Our studies have shown that blocking the ADP-receptor P2Y12 but not P2Y1 receptor was protective in male mice during sepsis, but not female. We now hypothesize that there are sex-related differences in modulating P2Y12 or P2Y1 signaling pathways during sepsis. Male and female wild-type (WT), P2Y12 knock-out (KO), and P2Y1 KO mice underwent sham surgery or cecal ligation and puncture (CLP) to induce sepsis. The P2Y12 antagonist ticagrelor or the P2Y1 antagonist MRS2279 were administered intra-peritoneally after surgery to septic male and female mice. Blood, lungs and kidneys were collected 24 hours post-surgery. Sepsis-induced changes in platelet activation, secretion and platelet interaction with immune cells were measured by flow cytometry. Neutrophil infiltration in the lung and kidney was determined by a myeloperoxidase (MPO) colorimetric assay kit. Sepsis-induced platelet activation, secretion and aggregate formation were reduced in male CLP P2Y12 KO and in female CLP P2Y1 KO mice compared with their CLP WT counterpart. Sepsis-induced MPO activity was reduced in male CLP P2Y12 KO and CLP P2Y1 KO female mice. CLP males treated with ticagrelor or MRS2279 showed a decrease in sepsis-induced MPO levels in lung and kidneys, aggregate formation, and platelet activation as compared to untreated male CLP mice. There were no differences in platelet activation, aggregate formation, and neutrophil infiltration in lung and kidney between female CLP mice and female CLP mice treated with ticagrelor or MRS2279. In human T lymphocytes, blocking P2Y1 or P2Y12 alters cell growth and secretion in vitro in a sex-dependent manner, supporting the data obtained in mice. In conclusion, targeting purinergic signaling represents a promising therapy for sepsis but drug targeting purinergic signaling is sex-specific and needs to be investigated to determine sex-related targeted therapies in sepsis.

Pharmaceutical Assessment of Melia azedarach Gum as a Binder and Disintegrant in Immediate-Release Tablets.

Excipients are components other than active ingredients that are added to pharmaceutical formulations. Naturally sourced excipients are gradually gaining preeminence over synthetically sourced excipients due to local availability and continuous supply. This study aimed to investigate the binding and disintegrating characteristics of gum extracted from the bark of Melia azedarach tree. The bark of Melia azedarach was harvested from Kwahu Asasraka in Ghana. The gum was extracted with ethanol (96%), and the percentage yield, phytochemical constituents, and flow characteristics were assessed. As a disintegrant, the gum was utilized to formulate granules at varying concentrations of 5% w/w and 10% w/w using starch as the standard. The gum was also utilized to prepare granules at varying concentrations of 10% w/v and 20% w/v as a binder, with tragacanth gum serving as the reference. Eight batches of tablets were produced from the granules. The formulated tablets from each batch were then subjected to quality control testing, which included uniformity of weight, friability, disintegration, hardness, drug content, and dissolution tests, respectively. Tannins, saponins, alkaloids, and glycosides were identified in the Melia azedarach gum. The gum had a percentage yield of 67.75% and also exhibited good flow properties. All tablets passed the uniformity of weight, friability, disintegration, hardness, dissolution, and drug content tests, respectively. According to the findings of the study, Melia azedarach gum can be utilized as an excipient in place of tragacanth and starch as a binder and disintegrant, respectively, in immediate-release tablets.

Pharmaceutical Applications of Glucose Syrup from High Quality Cassava Flour in Oral Liquid Formulations.

Pharmaceutical oral solutions are preparations in which the active ingredients are dissolved in suitable liquid vehicles such as syrups. This study sought to determine the potential of glucose syrup produced from high quality cassava flour (HQCF) as a vehicle or sweetener in the preparation of paracetamol syrup and simple linctus. Four formulations (two paracetamol syrups (B1 and B2) and two simple linctus formulations (A1 and A2)) were prepared using glucose syrup from HQCF as vehicle or sweetener while two controls (B3 and A3) were prepared for each group using sucrose syrup as vehicle or sweetener. Two brands of paracetamol syrup and simple linctus were purchased from retail pharmacies to serve as standards. Physical and organoleptic parameters such as pH, taste and color, microbial load, and drug content of all formulations were determined. All formulations passed the microbial load and drug content tests as specified by the British Pharmacopoeia. The paracetamol syrups were all sweet with characteristic bitter aftertastes except formulation B2 which was sweetened with sucralose. All the simple linctus formulations were sweet except A2 (sweetened with sucralose) which was very sweet. The taste masking capacity of the glucose syrup produced from HQCF matched that of the sucrose syrup in the products formulated. Therefore, glucose syrup from HQCF could be a suitable alternative to sucrose syrup as a vehicle or sweetener in oral liquid formulations and can ultimately reduce the cost of these oral liquid formulations.

Utilization of Pectin from Okra as Binding Agent in Immediate Release Tablets.

Polymeric materials from plants continue to be of interest to pharmaceutical scientists as potential binders in immediate release tablets due to availability, sustainability, and constant supply to feed local pharmaceutical industries. Paracetamol tablet formulations were utilized in investigating the potential binding characteristics of pectin harnessed from various okra genotypes (PC1-PC5) in Ghana. The pectin yields from the different genotypes ranged from 6.12 to 18.84%w/w. The pH of extracted pectin ranged from 6.39 to 6.92, and it had good swelling indices and a low moisture content. Pectin extracted from all genotypes were evaluated as binders (10, 15, and 20%w/v) and compared to tragacanth BP. All formulated tablets (F1-F18) passed the weight uniformity, drug content, hardness, and friability tests. Based on their crushing strength, tablets prepared with pectin from the various genotypes were relatively harder (P ≤ 0.05) than tablets prepared with tragacanth BP. Tablets prepared with pectins as binders at 10%w/v and 15%w/v passed the disintegration and dissolution tests with the exception of PC4 at 15%w/v. Incorporation of pectin from all genotypes (excluding PC5) as a binder at concentrations above 15%w/v (F13, F16, F14, and F15) produced tablets which failed the disintegration test and showed poor dissolution profiles. Thus, pectin from these genotypes can be industrially commodified as binders in immediate release tablets using varying concentrations.

Health risk assessment of trace metals in selected food crops at Abuakwa South Municipal, Ghana.

Trace metals contamination has recently been a major issue due to its damaging effects on public health and environmental receptors. This study focussed on the health risk assessment of trace metals (As, Pb, Cr, and Ni) associated with the direct intake of some selected food crops (namely cocoyam and plantain) at Abuakwa South Municipal, Ghana. The food crops and soil samples were selected randomly from three reclaimed mined sites and one non-mining site in the study area. Results from the trace metal concentration analyses in the soil samples showed that As, Cr, and Ni were above the control. The daily intake of metals (DIM), target hazard quotient (THQ), and carcinogenic risk (CR) assessments of health risks accompanied by the continuous ingestion of the selected food crops polluted through these trace metals were evaluated. 0.23 mg/kg and 0.05 mg/kg, 0.11 mg/kg and 0.02 mg/kg, 0.78 mg/kg and 0.65 mg/kg, and 0.23 mg/kg and 0.09 mg/kg were recorded for As, Cr, Ni, and Pb in that order in the cocoyam and plantain, respectively. The As and Pb concentrations in the food crops were above the WHO recommended limits. This implies that individuals within the vicinity are exposed to high levels of As and Pb through food intake which could result in varying health implications. The DIM and THQ for the studied trace metals were below their permissible limits suggesting that there is a tolerable non-carcinogenic adverse health risk level for adults and children within the studied area. In addition, the lifetime probability of contracting cancer by ingesting Ni, Pb, and Cr in plantain grown in the study area is high. It is recommended that regular monitoring of these trace metals in food crops be carried out in preventing their excessive accumulation.

Wound Management Property of a Hydroethanolic Leaf Extract of Cnestis ferruginea DC.

OBJECTIVE: To establish the wound management property of a hydroethanolic Cnestis ferruginea leaf extract (CFHE). MATERIALS AND METHODS: The wound area was measured after excision at the dorsal part of the Albino rats, and after treatment with 5-15% w/w CFHE ointments for 14 days. Absorbances of platelet-rich plasma treated with 0.8-100 mg/mL CFHE and an aggregating agent were spectrophotometrically determined in an in vitro platelet aggregation test. Wound tissue histopathology of CFHE ointment-treated animals revealed angiogenesis, reepithelialization, deposition of collagen, and granular tissue formation in wound tissues. Reduction in thigh oedema and pain threshold, in 7-day-old chicks, were assessed by carrageenan-induced oedema and Randall-Sellito pressure models, respectively. By the Agar diffusion method, bacterial growth inhibition by a 15% w/w CFHE ointment was investigated on Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus. Aureus, and Streptococcus pyogenes. RESULTS: All concentrations of CFHE ointment significantly reduced (p < 0.0001) wound area by 29-41% posttreatment. CFHE (1.6-100 mg/ml) promoted platelet aggregation (p ≤ 0.0001) by 37-67% (IC50: 3.1-6.2 mg/ml). There were improved wound tissue reepithelization, fibroblast proliferation, angiogenesis, and collagen deposition with 15% CFHE ointment treatment. CFHE ointment significantly (p ≤ 0.0001) and dose-dependently reduced thigh oedema and showed a significant (p ≤ 0.05) analgesic effect. In vitro, 15% CFHE ointment caused >100% growth inhibition of selected bacteria. CONCLUSION: The hydroethanolic leaf extract of Cnestis ferruginea possesses wound healing, platelet aggregation, anti-inflammatory, analgesic, and antimicrobial properties and, hence, could be effective in the management of open and some closed wounds.

Pectin from Okra (Abelmoschus esculentus L.) Has Potential as a Drug Release Modifier in Matrix Tablets.

Natural polymers have become attractive to pharmaceutical researchers and manufacturers as excipients because of the advantages they possess relative to their semisynthetic and synthetic counterparts. Although pectin from some natural sources has been investigated for use in the pharmaceutical industry as excipients, pectin from okra, which is readily available and used as food in many parts of the world, has not been extensively investigated as a potential control-releasing agent in tablets. This study thus seeks to determine the drug release modifying properties of okra pectin from 6 different genotypes of okra cultivated and available in Ghana. Pectin was extracted from different genotypes of okra, physicochemical properties were characterized, and control release matrix tablets of metformin (F1-F6) were formulated using the wet granulation method with the okra pectin as the drug release modifier, respectively. The drug content, in vitro drug release, and mathematical kinetic modeling of drug release from the matrix tablets were studied. Drug release profiles of formulated matrix tablets were compared to an existing (innovator) brand of metformin sustained-release tablet on the market using the similarity and difference factors, respectively. The extracted pectin had percentage yields ranging from 6 to 20% w/w with swelling indexes and water-holding capacities between 300-500% and 9-10 mL/g, respectively, and pH within 6.20-6.90. All the formulated batches passed the drug content test (90-105%) and produced the optimal release of metformin (>80%) after 24 hours. Different batches of formulated tablets exhibited different mechanisms of drug release with batches F1, F2, F5, and F6 being similar (ƒ2 values being >50 and ƒ1 values <15) to the innovator brand. Pectin from the 6 different genotypes of okra studied has the potential for use as drug release modifiers in pharmaceutical manufacturing of control release matrix tablets and production of more affordable medicines.

Formulation and In Vitro Evaluation of Oral Capsules from Liquid Herbal Antimalarials Marketed in Ghana.

Malaria ranks amongst the major health challenges faced by many developing countries. In Sub-Saharan and tropical regions of Africa, malaria continues to claim the life of one out of every twenty children below the age of five years. In adults, mortality rates are lower, but frequent debilitating attacks reduce the quality of life for chronic sufferers. The patronage and usage of liquid herbal antimalarials in the management and treatment of malaria in Ghana have been on the ascendency over the past decade. This project seeks to transform five liquid herbal antimalarial preparations (Agbeve pevah, Time mixture, Givers mixture, Masada mixture, and Rooter mixture) produced locally and commonly used for the treatment of malaria fever into capsules. This will help eliminate the current limitations, such as lack of patient compliance due to the bitterness and bulky nature of packaged preparation. The amount of dry extract per dose of each herbal antimalarial preparation and the wavelength of maximum absorption (λ max) of aqueous solutions of Agbeve, Time, Givers, Masada, and Rooter extract were determined. The flow properties of formulated granules were determined and subsequently encapsulated. The formulated capsules were evaluated using basic pharmacopeial tests, such as uniformity of weight, disintegration, drug content, and dissolution. Difference, f1, and similarity, f2, factors were employed in analyzing the dissolution profiles of the formulated capsules. The formulated granules exhibited good flow properties and passed the weight uniformity, disintegration, and drug content tests. The capsules exhibited optimal release of extract at the 45th minute in 0.1 M HCL. All formulated capsules had ƒ2 values >50 and ƒ1 values <15, indicating the similarity of their drug release profiles with their respective liquid herbal antimalarials. Oral capsules of Agbeve, Time, Givers, Masada, and Rooter have been successfully formulated and can be used as a substitute for Agbeve pevah, Time mixture, Givers mixture, Masada mixture, and Rooter mixture, respectively, in the treatment of malaria.

The Role of the Patient Information Leaflet in Patients'Medication Therapy: A Case Study within the Kumasi Metropolis of Ghana.

One of the tools used in providing comprehensible medication information to patients on their medication use for improved adherence and subsequent optimal therapeutic effect is the Patient Information (PI) leaflet. In Ghana, the patient information leaflet is available through various sources including health-care professionals (HCPs) and electronic forms. The World Health Organization (WHO) estimates that more than 70% of patients, especially in the developing countries, who receive medications do not read the accompanying leaflet. This study assessed the role of the patient information leaflet in Patients' medication therapy in the Kumasi metropolis of Ghana. A random cross-sectional survey was conducted in various hospitals and pharmacies within selected districts in the Kumasi metropolis. The survey revealed that 96.9% of the sampled respondents (n = 300) were provided with PI leaflets on their medicines while only 3.1% of them indicated otherwise. Among the proportion of respondents who were provided with PI leaflets, 66.7% of them read the information on the drug leaflets whilst the remaining 33.3% did not. Ultimately, 62.4% of those who read the PI leaflets were influenced to discontinue their medication. In conclusion, reading of the drug information leaflet was higher than that found in previous studies in Ghana. Reading the leaflet did not increase adherence but aroused anxiety and decreased adherence in some patients. A large number of the patients who were given the PI leaflets indicated that it did not provide them with the needed information.