Multifunctional alginate/polydeoxyribonucleotide hydrogels for promoting diabetic wound healing.

A multifunctional alginate/PDRN hydrogel system by ionic crosslinking and the Schiff base reaction between oxidized alginate (OA) and PDRN was developed in the present study. Biocompatibility assessment of the PDRN-loaded OA hydrogels showed a significant enhancement in cell viability in human dermal fibroblast (HDF) cells. In addition, hydrogels showed migratory, anti-inflammatory, intracellular reactive oxygen species scavenging, and anti-apoptotic activities. In vivo studies using a streptozotocin-induced diabetic Wister rat model indicated that OA-4PDRN had the highest percentage of wound closure (96.1 ± 2.6 %) at day 14 compared to the control (79.0 ± 2.3 %) group. This was accompanied by up-regulation of vascular endothelial growth factor (VEGF), interleukin-10 (IL-10), and transforming growth factor-beta (TGF-ß) accompanied by down-regulation of pro-inflammatory markers (IL-6, IL-1ß). Following histopathological observations, PDRN-loaded OA hydrogel ensured tissue safety and induced wound healing with granular tissue formation, collagen deposition, re-epithelialization, and regeneration of blood vessels and hair follicles. The downregulation of inflammatory cytokines (CD68) and expression of angiogenesis-related cytokines (CD31) in wound sites revealed the suppression of inflammation and increased angiogenesis, ensuring skin tissue regeneration in diabetic wound healing. In conclusion, the findings suggest that PDRN-loaded OA hydrogel has enormous therapeutic potential as a diabetic wound dressing.

Development and characterization of polydeoxyribonucleotide (PDRN) loaded chitosan polyplex: In vitro and in vivo evaluation of wound healing activity.

Polydeoxyribonucleotide (PDRN) is an accelerated diabetic wound healing therapy with promising abilities to promote cell growth, angiogenesis, collagen synthesis, and reduce inflammation where its sustainable delivery and release behavior is critical to ensure effective wound healing properties. Therefore, a nanopolyplex was developed here, by encapsulating PDRN with chitosan to affirm its delivery systematically. The physicochemical characterization revealed its successful encapsulation which facilitates the gradual release of PDRN. In vitro studies of the polyplex demonstrated no cytotoxicity and enhanced cell proliferation and migration properties with high antimicrobial activities. In vivo, wound healing studies in Wistar rats dorsal skin defect model induced with diabetes mellitus affirm the highest wound healing activity and wound closure rate by chitosan/PDRN polyplex treatment. Considerably high histopathological changes such as epithelialization, collagen deposition, blood vessels, and hair follicle formation were observed under the polyplex treatment. The immunohistochemical analysis for platelet endothelial cell adhesion molecule (CD31) and cluster of differentiation (CD68) revealed the ability of polyplex to increase CD31 expression and decrease CD68 expression thereby promoting the wound healing process. Collectively, these results suggest that significantly accelerated, high-quality wound healing effects could be obtained by the developed chitosan/PDRN polyplex and thus it could be introduced as a potential therapeutic product for diabetic wound healing.

Barleria prionitis L. extracts ameliorate doxorubicin-induced acute kidney injury via modulation of oxidative stress, inflammation, and apoptosis.

Background and aim: Doxorubicin (DOX) is a chemotherapeutic drug with potential nephrotoxic effects on patients who are on cancer chemotherapy. An interest has been observed in using natural products to ameliorate the potential side effects of DOX. The present study is to investigate the cellular mechanisms underlying the protective effects of Barleria prionitis L. (BP) (Acanthaceae) extracts, DOX-induced acute kidney injury (AKI). Experimental procedure: Hexane (25 mg/kg/day), ethyl acetate (80 mg/kg/day), n-butanol (70 mg/kg/day), and water (120 mg/kg/day) extracts of BP, were administered to DOX-induced (5 mg/kg (2500 µL/kg), ip) Wistar rats for four consecutive weeks. At the end of the study, investigations were carried out for the assessment of biomarkers of nephrotoxicity, oxidative stress, inflammation, and apoptosis. Results: Treatments with BP extracts significantly reversed DOX-induced elevations in serum and urine biochemical markers of nephrotoxicity (serum creatinine; 21-33%, blood urea nitrogen; 26-58%, ß2-microglobulin; 19-22% and urine total protein; 47-67%). There was a reduction in the levels of tumor necrosis factor-α, interleukin-1ß, and malondialdehyde in kidney homogenates of rats treated with the n-butanol extract (by 43, 62, and 24%) and water extract (by 57%, 85%, and 26%) (p < 0.05). Immunohistochemical expression of the pro-apoptotic B-cell associated X protein was reduced while the anti-apoptotic B-cell lymphoma gene product 2 protein was increased in kidney tissues after the treatments with BP extracts. Conclusions: The selected BP extracts significantly ameliorated DOX-induced AKI. The findings would open new vistas for the development of a drug using the BP extracts to minimize DOX-induced AKI in cancer patients.

Asparagus falcatus L. (Asparagaceae) leaf extracts attenuate doxorubicin-induced renal toxicity via antioxidant, anti-inflammatory, and anti-apoptotic pathways.

The search for therapeutic agents that improve kidney function against doxorubicin-induced renal toxicity is important. Herein, the potential nephroprotective activity by Asparagus falcatus L. (AF, Asparagaceae) leaf extracts against doxorubicin-induced renal toxicity (5 mg/kg, ip) in Wistar rats (n = 6/group) after oral administration of hexane (55 mg/kg), ethyl acetate (35 mg/kg), butanol (75 mg/kg), and aqueous (200 mg/kg) extracts of AF for 28 consecutive days was investigated. It was noticed that the treatment with the selected extracts of AF significantly attenuated doxorubicin-induced elevations of serum creatinine, urea nitrogen, ß2-microglobulin, cystatin C, and proteinuria in experimental rats. The histology showed attenuation of the features of acute tubular injury. Treatment regimens significantly reversed the doxorubicin-induced reduction in total antioxidant status, glutathione peroxidase, and glutathione reductase activity in renal tissue homogenates. A suppression in lipid peroxidation was noted with hexane, ethyl acetate, and butanol extracts of AF. Moreover, a reduction in the concentration of the pro-inflammatory mediator TNF-α (p < 0.05), and immunohistochemical expression of COX-2 were observed. The immunohistochemical expression of pro-apoptotic Bax protein was decreased and the anti-apoptotic BCL-2 was increased in renal tissues following the treatments. In conclusion, it was revealed that, hexane, ethyl acetate, butanol, and aqueous extracts of AF attenuate doxorubicin-induced renal toxicity in Wistar rats through antioxidant, anti-inflammatory, and anti-apoptotic pathways. The plant, AF could be recommended as a promising therapeutic agent to minimize renal toxicity induced by doxorubicin in cancer patients, however, subsequent clinical trials are warranted.

Nephroprotective mechanisms of Ambrette (Abelmoschus moschatus Medik.) leaf extracts in adriamycin mediated acute kidney injury model of Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Ambrette (Abelmoschus moschatus Medik., Family: Malvaceae) is a common Ayurvedic herbal medicine used in the treatment of kidney-related diseases, in the forms of tea, medicated oil, medicated wine, etc., however, its nephroprotective mechanisms remain unexploited. AIM OF THE STUDY: To investigate the mechanisms by which the hexane (A-HE), ethyl acetate (A-EE), butanol (A-BE), and aqueous (A-WE) leaf extracts of Ambrette protect against the adriamycin-mediated acute kidney injury in Wistar rats. MATERIALS AND METHODS: A-HE, A-EE, A-BE, A-WE, and fosinopril sodium were administered at therapeutically effective doses (55, 75, 60, 140, 0.09 mg/kg) to adriamycin-induced (5 mg/kg, ip) Wistar rats for 28 consecutive days. RESULTS: Oral administration of the selected extracts of A. moschatus resulted in amelioration of kidney injury as observed by the significant changes of biomarkers of kidney function in serum and in urine, biochemical parameters of oxidative stress, and inflammation in kidney homogenates (p < 0.05). Furthermore, the administration of plant extracts caused a significant reduction in total kidney injury scores in H and E stained kidney sections (p < 0.05). The immunohistochemical expression of the inflammatory marker, COX-2, and the pro-apoptotic marker, Bax, were attenuated and the expression of the anti-apoptotic marker, BCL-2, was increased. A-HE exerted superior nephroprotective effects over the other three extracts and the drug reference standard. CONCLUSIONS: The findings revealed that Ambrette exerts promising protective effects against adriamycin-mediated acute kidney injury through antioxidant, anti-inflammatory, and anti-apoptosis pathways. A-HE might serve as a potential candidate for the development of therapeutic drug leads that will be beneficial in the treatment of acute kidney injury.

Standardized aqueous stem bark extract of Gmelina arborea roxb. possesses nephroprotection against adriamycin-induced nephrotoxicity in Wistar rats.

Nephrotoxicity is a major limitation of adriamycin (ADR) chemotherapy. We hypothesized that administration of standardized aqueous bark extract of Gmelina arborea Roxb. (GA) (Family; Verbenaceae), a traditional therapeutic agent, may reduce the nephrotoxicity caused by ADR in Wistar rats. The dose-dependent nephroprotective activity of the standardized GA extract was investigated in ADR-induced (20 mg/kg, ip) nephrotoxicity in male Wistar rats (n = 6/group). The lyophilized powder of the aqueous refluxed (4 h) GA extract was administered at 100, 300 and 500 mg/kg doses orally for three consecutive days. Fosinopril sodium (0.09 mg/kg) was used as the positive control. Assessment of biochemical parameters on serum, urine and histopathology on H and E stained kidney sections were done at the end of the intervention. The treatment with GA and fosinopril decreased the elevation of serum creatinine, blood urea nitrogen, cystatin C, ß2-microglobulin and loss of total protein in urine in nephrotoxic rats in a dose-dependent manner (p < 0.05). In contrast, serum concentrations of albumin and total protein were increased significantly (p < 0.05). H and E stained kidney sections showed an attenuation of renal parenchymal injury following the treatment. The aqueous extract of GA demonstrated antioxidant potential in vitro. Present findings conclude that the standardized aqueous extract of GA stem bark exerted a dose-dependent protection against ADR-induced nephrotoxicity in vivo and may be a promising adjunct in ADR chemotherapy.

Biochemical characterization of high fat diet fed and low dose streptozotocin induced diabetic Wistar rat model.

The development of a stable disease model with an adequate biochemical profile is crucial for the preclinical investigation of new antidiabetic agents. This study aimed at optimization and characterization of high fat diet (HFD) fed streptozotocin (STZ) induced type 2 diabetes mellitus (type 2 DM) Wistar rat model. Wistar rats fed with HFD for four weeks received STZ (30, 40, and 50 mg/kg, intraperitoneal). Diabetic rats were observed for four more weeks and sacrificed. Non- injected healthy Wistar rats and HFD-fed rats were used as control groups. The glucose status and the lipid profile of the model were assessed. STZ-induced rats showed significant dose-dependent alterations in fasting serum insulin and glucose, homeostatic model assessment- insulin resistance (HOMA-IR), HOMA- ß cell function (HOMA- ß), quantitative insulin sensitivity check index (QUICKI), total cholesterol (TC), triglycerides (TG) and atherogenic index (AI). STZ 50 mg/kg group rats showed significant increase in glycated hemoglobin (HbA1c), low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) levels compared to healthy rats. The atherogenic risk index (ARI), the Castelli risk index-I (CRII), and CRI-II were significantly (p < 0.05) high in the STZ 40 mg/kg and 50 mg/kg group rats. Results suggest that the Wistar rats fed with HFD rich in saturated fat for four weeks followed by a single intraperitoneal dose of 50 mg/kg of STZ would produce a stable diabetic model which closely mimic biochemical features of type 2 DM. Key messages: Wistar rats fed with HFD rich in saturated fat for four weeks followed by a single intraperitoneal dose of 50 mg/kg STZ would produce a stable diabetic model that closely mimics the biochemical characteristics of type 2 DM characterized by insulin resistance, relative insulin deficiency and impaired ß cell function.

Nephroprotective activity of Vetiveria zizanioides (L.) Nash supplement in doxorubicin-induced nephrotoxicity model of Wistar rats.

The nephroprotective effect of standardized aqueous root extract of Vetiveria zizanioides (L.) Nash (Family: Poaceae) was investigated in doxorubicin-induced (20 mg/kg, ip) experimental nephrotoxicity model of Wistar rats. The freeze-dried aqueous refluxed (4 hr) root extract of V. zizanioides (25, 50; equivalent human therapeutic dose and 100 mg/kg) was administered separately to nephrotoxic Wistar rats (n = 6/group). Supplement of V. zizanioides resulted a dose-dependent reduction in raised serum creatinine, ß2 -microglobulin, and blood urea nitrogen and a subsequent increase in serum total protein and albumin in nephrotoxic rats (p < .05). An attenuation of the doxorubicin-induced features of renal parenchymal injury was observed on H- and E-stained sections of the kidney tissues. Nootkatone, dehydroaromadendrene, isokhusenic acid, α-vetivone, and isolongifolene were identified in the methanol extract of V. zizanioides based on the GC-MS chromatogram analysis. The findings revealed that the supplement of standardized aqueous root extract of V. zizanioides had a significant dose-dependent nephroprotective activity against doxorubicin-induced experimental nephrotoxicity. PRACTICAL APPLICATIONS: Vetiveria zizanioides is a medicinal plant with a variety of therapeutic applications in kidney-related diseases. Apparently, it is used as a food ingredient due to its fresh and elegant scent and potential bioactivities. The aqueous root extract of V. zizanioides exerted relatively high antioxidant potential in vitro, substantiating the health effects of the plant pertaining to kidney diseases as a potential source of dietary antioxidant. The administration of the plant extract resulted in significant nephroprotection against doxorubicin-induced experimental nephrotoxicity revealing the significance of V. zizanioides as a promising dietary supplement in the management of kidney disease.

Undergraduate education in biochemistry and molecular biology: A parallel session at the IUBMB/PSBMB 2019 "Harnessing Interdisciplinary Education in Biochemistry and Molecular Biology" conference.

Although science education, including biochemistry and molecular biology education, starts before students commence university, for many students, undergraduate programs are their first real introduction to biochemistry and molecular biology. Students often report that biochemistry and molecular biology are relatively difficult topics hence the use of varied and well-thought-out approaches are critical to fully engage students. This session provided insights into undergraduate curriculum design.

Acute and 28-Day Repeated-Dose Oral Toxicity Assessment of Abelmoschus moschatus Medik. in Healthy Wistar Rats.

Abelmoschus moschatus Medik. (family: Malvaceae) has a long history of being used as a folk medicine in Sri Lanka. Despite the therapeutic use of this plant in traditional medicine, leaves of A. moschatus have not been subjected to scientific evaluation of toxicity/adverse effects in vivo. Thus, the present study was aimed to assess the acute and 28-day repeated-dose oral toxic effects of hexane (55 mg/kg), ethyl acetate (75 mg/kg), butanol (60 mg/kg), and aqueous (140 mg/kg) leaf extracts of A. moschatus in Wistar rats. Furthermore, identification of phytochemical constituents and determination of in vitro total antioxidant activity of the selected leaf extracts of A. moschatus were carried out. Repeated-dose oral administration of hexane and aqueous plant extracts produced no significant changes in the hematological profile and in selected biochemical parameters compared to the untreated healthy rats (p > 0.05). The administration of ethyl acetate and butanol extracts resulted in significant changes in some of the hematological parameters (p < 0.05), whereas biochemical parameters were not changed (p > 0.05). No significant changes in the relative organ weight of treated rats were observed (p > 0.05) except in the kidneys of Wistar rats treated with the ethyl acetate extract of A. moschatus (p < 0.05). Normal morphology with no signs of hemorrhages, necrosis, or inflammatory cell infiltrations was observed in the vital organs selected during the assessment of histopathology on H and E-stained tissue sections upon the treatment of selected extracts. Alkaloids were absent in the selected leaf extracts excluding the health risk for harmful alkaloids. The highest total antioxidant activity was reported in the butanol extract. In conclusion, the hexane and aqueous extracts of A. moschatus were completely nontoxic, whereas butanol and ethyl acetate extracts showed statistically significant changes in some hematological parameters and in relative organ weight of kidneys in healthy Wistar rats.

Protective effects of three selected standardized medicinal plant extracts used in Sri Lankan traditional medicine in adriamycin induced nephrotoxic Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abelmoschus moschatus Medik. (family: Malvaceae), Asparagus falcatus (family: Asparagaceae) and Barleria prionitis Linn. (family: Acanthaceae) have been used in the treatment of kidney diseases in Sri Lankan traditional medicine. Besides the traditional use, scientific scrutinization of safe therapeutic use of these medicinal plants in the management of kidney diseases has not been reported to date. AIM OF THE STUDY: The three selected doses of the aqueous extracts of the selected medicinal plants were studied for their protective effects against adriamycin (ADR) induced nephrotoxicity in Wistar rats. MATERIALS AND METHODS: Chemically standardized plant materials were used in the study. The nephroprotective activity of the lyophilized powder of the aqueous refluxed (4hr) leaf extracts of A. moschatus, A. falcatus and the whole plant extract of B. prionitis was investigated in adriamycin (20 mg/kg, ip) induced nephrotoxicity in Wistar rats (n = 6/group). The treatment regimens were initiated 24 h after the induction of nephrotoxicity and continued daily as a single dose for three consecutive days at three selected doses (200, 400 and 600 mg/kg). Fosinopril sodium (0.09 mg/kg) was used as the standard drug. Nephroprotective activity was assessed by estimating the selected biochemical parameters and by the assessment of histopathology on H and E stained sections of the kidney. RESULTS: The plant extracts at the three selected doses significantly attenuated the elevations in serum creatinine, blood urea nitrogen and the loss of urine total protein in a dose related manner in ADR induced nephrotoxic rats (p < 0.001). The serum concentration of albumin and total protein increased significantly (p < 0.001). Histopathological findings corroborated the biochemical evidence of nephroprotective activity. The aqueous extracts of the three selected medicinal plants exerted a relatively high antioxidant activity in vitro. CONCLUSIONS: Evaluation of the protective effects based on biochemical parameters and histopathology assessment revealed that the aqueous leaf extracts of A. moschatus, A. falcatus and the whole plant extract of B. prionitis possess significant nephroprotective activity against ADR induced acute nephrotoxicity. The secondary metabolites present in the plant extracts may attribute to the total antioxidant activities of the selected medicinal plant extracts thereby exerting protective effects against nephrotoxicity in Wistar rats.

Study of antihyperglycaemic activity of medicinal plant extracts in alloxan induced diabetic rats.

BACKGROUND: Diabetes mellitus, for a long time, has been treated with plant derived medicines in Sri Lanka. AIM: The aim of this study is to determine the efficacy and dose response of oral antihyperglycaemic activity of eight Sri Lankan medicinal plant extracts, which are used to treat diabetes in traditional medicine in diabetic rats. MATERIALS AND METHODS: Medicinal plants selected for the study on the basis of documented effectiveness and wide use among traditional Ayurveda physicians in the Southern region of Sri Lanka for the treatment of diabetes mellitus. The effect of different doses of aqueous stem bark extracts of Spondias pinnata (Anacardiaceae), Kokoona zeylanica (Celastraceae), Syzygium caryophyllatum (Myrtaceae), Gmelina arborea (Verbenaceae), aerial part extracts of Scoparia dulcis (Scrophulariaceae), Sida alnifolia (Malvaceae), leaf extract of Coccinia grandis (Cucurbitaceae) and root extract of Languas galanga (Zingiberaceae) on oral glucose tolerance test was evaluated. A single dose of 0.25, 0.50, 0.75, 1.00, 1.25, 2.00 g/kg of plant extract was administered orally to alloxan induced (150 mg/kg, ip) diabetic Wistar rats (n = 6). Glibenclamide (0.50 mg/kg) was used as the standard drug. The acute effect was evaluated over a 4 h period using area under the oral glucose tolerance curve. STATISTICAL ANALYSIS: The results were evaluated by analysis of variance followed by Dunnett's test. RESULTS: The eight plant extracts showed statistically significant dose dependent improvement on glucose tolerance (P < 0.05). The optimum effective dose on glucose tolerance for six extracts was found to be 1.00 g/kg in diabetic rats with the exception of C. grandis: 0.75 g/kg and L. galanga: 1.25 g/kg. CONCLUSION: The aqueous extract of G. arborea, S. pinnata, K. zeylanica, S. caryophyllatum, S. dulcis, S. alnifolia, L. galanga and C. grandis possess potent acute antihyperglycaemic activity in alloxan induced diabetic rats.