In vitro anti-diabetic and anti-obesity activities of compounds from the Cuban medicinal plant, Allophylus cominia (L.) Sw

Based on ethnobotanical information collected from Cuban diabetic patients in Cuba, medicinal plants such as Allophylus cominia (L.) Sw. (A. cominia) was identified as a possible source of new drugs that could be used for the treatment of type 2 diabetes mellitus. Type 2 diabetes mellitus or non-insulin dependent diabetes mellitus (T2-DM) is a chronic disease, and when associated with obesity (a condition known as diabesity) leads to an increase in the risk of a number of comorbidities, e.g. cardiovascular, kidney and liver diseases. A. cominia is a Cuban plant used traditionally by diabetic patients for the treatment of their diabetes symptoms. Preliminary studies of its leaves (Veliz et al., 2003; Veliz et al., 2005 Sanchez et al., 2014) have shown potential anti-diabetic activity and it is therefore being further investigated in the search for a novel, nontoxic, and efficacious anti-diabetic agent. The present project investigated the in vitro hypo-glycaemic activity of A. cominia extracts. Chemical characterisation of the extracts was carried out using different phytochemical methods. Fatty acids, tannins, pheophytins (A and B), and a mixture of flavonoids were detected. The identified flavonoids (42.1 mg) were mearnsitrin, quercitrin, quercetin-3-alloside, and naringenin-7-glucoside. Some of these compounds have been reported in the literature as potent hypo-glycaemic agents. Separation of the mixture of quercitrin and mearnsitrin was carried out by high performance liquid chromatography using an amino column. Extracts from A. cominia were tested for their ability to inhibit the activity of four enzymes. DPPIV plays an essential role in glucose metabolism. PTP1B is important in inhibiting downstream signalling of the insulin and leptin receptors. Alpha-glucosidase is one of the enzymes responsible for the breakdown of carbohydrates into monosaccharides, and alpha-amylase breaks down large, insoluble starch molecules into soluble starches, producing successively smaller starches and ultimately, maltose. The flavonoids produced a concentration-dependent inhibition against DPPIV with a Ki value of 2.6 ± 0.2 μg/ml. The flavonoids fraction from A. cominia revealed a competitive inhibition using DPPIV substrate comparable to the inhibition by the commercial (P32/98) inhibitor. In addition, PTP1B enzyme was 100 ± 5% inhibited by the flavonoid mixture and 65 ± 2% inhibited by pheophytin A and 61 ± 1% inhibition by pheophytin B at 30 μg/ml respectively. The flavonoid mixture elicited a significant concentration-dependent inhibition against PTP1B with a Ki value of 3.2 ± 0.09 μg/ml, as well as with pheophytin A with a Ki value of 0.64 ± 0.05 μg/ml and pheophytin B with a Ki value of 0.88 ± 0.03 μg/ml; both were lower than that of TFMS inhibitor, with a Ki value of 1.1 ± 0.03 μg/ml. Both flavonoid and pheophytin A extracts from A. cominia revealed a competitive inhibition of PTP1B enzyme using DiFMUP as substrate. Competitive inhibition was also shown with TFMS inhibitor. On α-glucosidase enzyme, a 79 ± 1% inhibition was produced by the flavonoid mixture at 30 μg/ml. The flavonoid fraction from A. cominia showed a concentration-dependent pattern against α-glucosidase, with a Ki value of 1.7 ± 0.5 μg/ml that was lower than that of acarbose inhibitor (190 ± 0.5 μg/ml). These extracts have shown a competitive inhibition using 4-nitrophenyl-glucopyranoside as substrate. Acarbose also produced a competitive inhibition against α-glucosidase. No significant effect was found with any of the extracts from A. cominia at 30 μg/ml against α-amylase enzyme.;After separation of the flavonoids, mearnsitrin and quercitrin did not produce any effect (at 30 μg/ml) on any of the enzyme activities (DPPIV, PTP1B, α-glucosidase and α-amylase). Quercitrin and mearnsitrin were active only in synergy. On a glucose uptake assay using HepG2 cells, the crude methanolic extract from A. cominia enhanced insulin activity by increasing 2-NBDG uptake by two-fold (2-NBDG is a fluorescently-tagged glucose derivative). The 2-deoxy-D-glucose uptake by differentiated 3T3-L1 cell line showed an increase of the glucose uptake in the presence of 100 μg/ml of flavonoids by enhancing insulin activity (100 nM), whereas the uptake was increased in the presence of 100 μg/ml of pheophytin A without enhancing insulin activity. The effect of different compounds from A. cominia on 3T3-L1 cell differentiation was also confirmed by quantifying GLUT4 transporters in the pre-treated cells with flavonoids and pheophytin A. GLUT4 transporters in the pre-treated cells were similar to those of the differentiated normal 3T3-L1 adipocytes. 2-NBDG glucose uptake assay was also performed using L6 myotubes. The uptake was significantly increased by two-fold in the presence of 100 nM insulin, and by four-fold in the presence of both 100 nM insulin and 100 μg/ml flavonoids. A significant increase was also shown in the presence of 100 μg/ml pheophytin A and 100 nM insulin with a 10-fold increase (P<0.05) of glucose uptake by L6 cells. An increase of 2-NBDG uptake by L6 cells was shown in the presence of flavonoids and pheophytin A in addition to 100 nM insulin. Both flavonoid and pheophytin extracts (100 μg/ml) blocked the differentiation of 3T3-L1 fibroblasts into adipocytes by decreasing the fat accumulation by two-fold (more than the TNF-α inhibition at 10 ng/ml). A significant difference was shown (P<0.05) compared to the control. Troglitazone significantly enhanced 3T3-L1 differentiation by two-fold. Exposing 3T3-L1 cells to both extracts from the third day of the differentiation induction did not alter the adipogenesis. Exposing 3T3-L1 adipocytes to the extracts from A. cominia containing flavonoids and pheophytin A showed a significant decrease in the fat accumulation after five days of incubation with the extracts (P<0.05). However, no fat accumulation was observed after withdrawal of the extracts from the cell growth medium. These compounds may be responsible for the pharmacological effects observed in experimental diabetic models in Cuba. Therefore, all these results strongly suggest that this plant could be a new and promising candidate for treating diabesity with natural sources.Based on ethnobotanical information collected from Cuban diabetic patients in Cuba, medicinal plants such as Allophylus cominia (L.) Sw. (A. cominia) was identified as a possible source of new drugs that could be used for the treatment of type 2 diabetes mellitus. Type 2 diabetes mellitus or non-insulin dependent diabetes mellitus (T2-DM) is a chronic disease, and when associated with obesity (a condition known as diabesity) leads to an increase in the risk of a number of comorbidities, e.g. cardiovascular, kidney and liver diseases. A. cominia is a Cuban plant used traditionally by diabetic patients for the treatment of their diabetes symptoms. Preliminary studies of its leaves (Veliz et al., 2003; Veliz et al., 2005 Sanchez et al., 2014) have shown potential anti-diabetic activity and it is therefore being further investigated in the search for a novel, nontoxic, and efficacious anti-diabetic agent. The present project investigated the in vitro hypo-glycaemic activity of A. cominia extracts. Chemical characterisation of the extracts was carried out using different phytochemical methods. Fatty acids, tannins, pheophytins (A and B), and a mixture of flavonoids were detected. The identified flavonoids (42.1 mg) were mearnsitrin, quercitrin, quercetin-3-alloside, and naringenin-7-glucoside. Some of these compounds have been reported in the literature as potent hypo-glycaemic agents. Separation of the mixture of quercitrin and mearnsitrin was carried out by high performance liquid chromatography using an amino column. Extracts from A. cominia were tested for their ability to inhibit the activity of four enzymes. DPPIV plays an essential role in glucose metabolism. PTP1B is important in inhibiting downstream signalling of the insulin and leptin receptors. Alpha-glucosidase is one of the enzymes responsible for the breakdown of carbohydrates into monosaccharides, and alpha-amylase breaks down large, insoluble starch molecules into soluble starches, producing successively smaller starches and ultimately, maltose. The flavonoids produced a concentration-dependent inhibition against DPPIV with a Ki value of 2.6 ± 0.2 μg/ml. The flavonoids fraction from A. cominia revealed a competitive inhibition using DPPIV substrate comparable to the inhibition by the commercial (P32/98) inhibitor. In addition, PTP1B enzyme was 100 ± 5% inhibited by the flavonoid mixture and 65 ± 2% inhibited by pheophytin A and 61 ± 1% inhibition by pheophytin B at 30 μg/ml respectively. The flavonoid mixture elicited a significant concentration-dependent inhibition against PTP1B with a Ki value of 3.2 ± 0.09 μg/ml, as well as with pheophytin A with a Ki value of 0.64 ± 0.05 μg/ml and pheophytin B with a Ki value of 0.88 ± 0.03 μg/ml; both were lower than that of TFMS inhibitor, with a Ki value of 1.1 ± 0.03 μg/ml. Both flavonoid and pheophytin A extracts from A. cominia revealed a competitive inhibition of PTP1B enzyme using DiFMUP as substrate. Competitive inhibition was also shown with TFMS inhibitor. On α-glucosidase enzyme, a 79 ± 1% inhibition was produced by the flavonoid mixture at 30 μg/ml. The flavonoid fraction from A. cominia showed a concentration-dependent pattern against α-glucosidase, with a Ki value of 1.7 ± 0.5 μg/ml that was lower than that of acarbose inhibitor (190 ± 0.5 μg/ml). These extracts have shown a competitive inhibition using 4-nitrophenyl-glucopyranoside as substrate. Acarbose also produced a competitive inhibition against α-glucosidase. No significant effect was found with any of the extracts from A. cominia at 30 μg/ml against α-amylase enzyme.;After separation of the flavonoids, mearnsitrin and quercitrin did not produce any effect (at 30 μg/ml) on any of the enzyme activities (DPPIV, PTP1B, α-glucosidase and α-amylase). Quercitrin and mearnsitrin were active only in synergy. On a glucose uptake assay using HepG2 cells, the crude methanolic extract from A. cominia enhanced insulin activity by increasing 2-NBDG uptake by two-fold (2-NBDG is a fluorescently-tagged glucose derivative). The 2-deoxy-D-glucose uptake by differentiated 3T3-L1 cell line showed an increase of the glucose uptake in the presence of 100 μg/ml of flavonoids by enhancing insulin activity (100 nM), whereas the uptake was increased in the presence of 100 μg/ml of pheophytin A without enhancing insulin activity. The effect of different compounds from A. cominia on 3T3-L1 cell differentiation was also confirmed by quantifying GLUT4 transporters in the pre-treated cells with flavonoids and pheophytin A. GLUT4 transporters in the pre-treated cells were similar to those of the differentiated normal 3T3-L1 adipocytes. 2-NBDG glucose uptake assay was also performed using L6 myotubes. The uptake was significantly increased by two-fold in the presence of 100 nM insulin, and by four-fold in the presence of both 100 nM insulin and 100 μg/ml flavonoids. A significant increase was also shown in the presence of 100 μg/ml pheophytin A and 100 nM insulin with a 10-fold increase (P<0.05) of glucose uptake by L6 cells. An increase of 2-NBDG uptake by L6 cells was shown in the presence of flavonoids and pheophytin A in addition to 100 nM insulin. Both flavonoid and pheophytin extracts (100 μg/ml) blocked the differentiation of 3T3-L1 fibroblasts into adipocytes by decreasing the fat accumulation by two-fold (more than the TNF-α inhibition at 10 ng/ml). A significant difference was shown (P<0.05) compared to the control. Troglitazone significantly enhanced 3T3-L1 differentiation by two-fold. Exposing 3T3-L1 cells to both extracts from the third day of the differentiation induction did not alter the adipogenesis. Exposing 3T3-L1 adipocytes to the extracts from A. cominia containing flavonoids and pheophytin A showed a significant decrease in the fat accumulation after five days of incubation with the extracts (P<0.05). However, no fat accumulation was observed after withdrawal of the extracts from the cell growth medium. These compounds may be responsible for the pharmacological effects observed in experimental diabetic models in Cuba. Therefore, all these results strongly suggest that this plant could be a new and promising candidate for treating diabesity with natural sources

The Dapsone Hypersensitivity Syndrome revisited: a potentially fatal multisystem disorder with prominent hepatopulmonary manifestations

4,4'-Diaminodiphenylsulphone (Dapsone) is widely used for a variety of infectious, immune and hypersensitivity disorders, with indications ranging from Hansen's disease, inflammatory disease and insect bites, all of which may be seen as manifestations in certain occupational diseases. However, the use of dapsone may be associated with a plethora of adverse effects, some of which may involve the pulmonary parenchyma. Methemoglobinemia with resultant cyanosis, bone marrow aplasia and/or hemolytic anemia, peripheral neuropathy and the potentially fatal dapsone hypersensitivity syndrome (DHS), the focus of this review, may all occur individually or in combination. DHS typically presents with a triad of fever, skin eruption, and internal organ (lung, liver, neurological and other systems) involvement, occurring several weeks to as late as 6 months after the initial administration of the drug. In this sense, it may resemble a DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms). DHS must be promptly identified, as untreated, the disorder could be fatal. Moreover, the pulmonary/systemic manifestations may be mistaken for other disorders. Eosinophilic infiltrates, pneumonitis, pleural effusions and interstitial lung disease may be seen. This syndrome is best approached with the immediate discontinuation of the offending drug and prompt administration of oral or intravenous glucocorticoids. An immunological-inflammatory basis of the syndrome can be envisaged, based on the pathological picture and excellent response to antiinflammatory therapy. Since dapsone is used for various indications, physicians from all specialties may encounter DHS and need to familiarize themselves with the salient features about the syndrome and its management

Identification of a novel class of autotaxin inhibitors through cross-screening

Three novel series were generated in order to mimic the pharmacophoric features displayed by lead compound AM095, a Lysophosphatidic acid (LPA1) receptor antagonist. Biological evaluation of this array of putative LPA1 antagonists led us to the discovery of three novel series of inhibitors of the ecto-enzyme Autotaxin (ATX), responsible for LPA production in blood, with potencies in the range 1 – 4 μM accompanied with good (> 100 μg/mL) solubility

Structure-activity relationships of small molecule autotaxin inhibitors with a discrete binding mode

Autotaxin (ATX) is a secreted enzyme responsible for the hydrolysis of lysophosphatidylcholine (LPC) to the bioactive lysophosphatidic acid (LPA) and choline. The ATX-LPA signalling pathway is implicated in cell survival, migration, and proliferation; thus, the inhibition of ATX is a recognized therapeutic target for a number of diseases including fibrotic diseases, cancer, and inflammation, amongst others. Many of the developed synthetic inhibitors for ATX have resembled the lipid chemotype of the native ligand; however, a small number of inhibitors have been described that deviate from this common scaffold. Herein, we report the structure-activity relationships (SAR) of a previously reported small molecule ATX inhibitor. We show through enzyme kinetics studies that analogues of this chemotype are noncompetitive inhibitors, and using a crystal structure with ATX we confirm the discrete binding mode

Ascaris Lumbricoides: A Travel Joke?

Intestinal nematodes affect more than a billion people worldwide. They are commonly found in regions with poor fecal sanitation, such as developing countries. Although most of the nematode infections are non-fatal diseases, they contribute to significant morbidities such as loss of work capacity and malnutrition. We are presenting an 80-year-old male who was diagnosed with Ascaris Lumbricoides after a return from recent travel to Greece, with some clinical endoscopic images

Actinomycosis Esophagitis in a Patient With Persistent Dysphagia

Many causes of esophagitis exist in immunocompromised patients. Uncommon pathogens must be considered to facilitate timely and appropriate therapy. A limited number of cases of esophageal actinomycosis have been reported. This report describes an unusual case of esophageal actinomycosis in a patient with persistent dysphagia. The broad differential may have delayed definitive diagnosis in the case study patient. Biopsy and culture are essential for accurate diagnosis. Although actinomycosis is a rare disease, it should be included in the differential diagnosis of patients presenting with oral or esophageal complaints. It may also be considered as an opportunistic infection in immunocompromised patients. The treatment of choice is parenteral penicillin G, 18 to 24 million units for 2 to 6 weeks followed by oral therapy for 6-12 months