Graphical abstract

A chitosan-alginate nanoparticle system encapsulating doxorubicin (DOX) was prepared by a novel ionic gelation method using alginate as the crosslinker. These nanoparticles were around 100 nm in size and more stable with higher positive zeta potential and had higher % encapsulation efficiency (95%) than DOX loaded chitosan nanoparticles (DOX Csn NP) crosslinked with sodium tripolyphosphate (STPP). FTIR spectroscopy and thermogravimetric analysis revealed successful loading of DOX.In vitrodrug release showed an initial release phase followed by slow release phase with higher cumulative release obtained with DOX loaded chitosan-alginate nanoparticles (DOX Csn-Alg NP). Thein vitrocytotoxicity of DOX released from the two nanoparticle systems showed a notable difference on comparison with that of free DOX on the MCF-7 cell line. The SRB assay, AO/EB staining, and fluorescence uptake study indicated that free DOX only showed dose dependent cytotoxicity, whereas both dose and time dependency were exhibited by the two sets of NPs. While both systems show sustained release of DOX, from the cell viability plots, DOX Csn-Alg NPs showed their superiority over DOX Csn NPs. The results obtained are useful for developing DOX Csn-Alg NPs as a sustained release carrier system for DOX.

BackgroundTea is the most consumed beverage in the world which is second only to water. Tea contains a broad spectrum of active ingredients which are responsible for its health benefits. The composition of constituents extracted to the tea brew depends on the method of preparation for its consumption. The objective of this study was to investigate the extraction kinetics of phenolic compounds, gallic acid, caffeine and catechins and the variation of antioxidant activity with time after tea brew is made.MethodsCTC (Crush, Tear, Curl) tea manufactured in Sri Lanka was used in this study. Tea brew was prepared according to the traditional method by adding boiling water to tea leaves. The samples were collected at different time intervals. Total phenolic and flavonoid contents were determined using Folin ciocalteu and aluminium chloride methods respectively. Gallic acid, caffeine, epicatechin, epigallocatechin gallate were quantified by HPLC/UV method. Antioxidant activity was evaluated by DPPH radical scavenging and Ferric Reducing Antioxidant Power (FRAP) assays.ResultsGallic acid, caffeine and catechins were extracted within a very short period. The maximum extractable polyphenols and flavanoids were achieved at 6–8 min after the tea brew is prepared. Polyphenols, flavanoids and epigallocatechin gallate showed a significant correlation (p < 0.001) with the antioxidant activity of tea.ConclusionThe optimum time needed to release tea constituents from CTC tea leaves is 2–8 min after tea is made.

Visceral leishmaniasis (VL) is considered as a major health threat in the Indian subcontinent. Leishmania donovani, a usually visceralizing species, causes cutaneous leishmaniasis (CL) in Sri Lanka. However, visceralizing potential of the local L. donovani is not yet fully understood. This project studied the seroprevalence of local CL by using an in-house ELISA. An IgG-based ELISA using crude Leishmania antigen (Ag) was developed and validated. A total of 50 laboratory confirmed cases of locally acquired CL were examined using the newly developed ELISA. According to the optimized ELISA, seroprevalence of anti-Leishmania IgG antibodies in the study group was 34.0% (n = 17/50). Majority of seropositive individuals were males (n = 13/17), representing 76%. Nearly half of the seropositive individuals were young adults (20–40 years, n = 9/17, 53%). Higher proportions of single lesions, large lesions, and nodular lesions were associated with a seroconversion. A proportion of local L. donovani infections leading to CL have the ability to raise an antibody response in the host. This may indicate early systemic involvement as one possibility. Study of a large number of patients with adequate follow-up would be useful.

Background Human leishmaniasis is one of the major parasitic diseases with worldwide distribution. Sri Lanka is a recently established focus of leishmaniasis caused by a variant Leishmania donovani . Early case detection and management is a main approach identified for L. donovani control in the regional leishmaniasis elimination drive. Usefulness of light microscopy and in-vitro culture are limited in chronic, atypical or treated lesions though timely and accurate detection of all light microscopy/in-vitro culture negative cases of all forms of leishmaniasis is necessary for treatment. Timely treatment is important to minimize risk for death in visceral disease and undesired sequelae of long standing infection and illness on both patients and community. We described a 100% sensitive, Leishmania spp. specific modified version of a nested PCR (Mo-STNPCR) that also minimizes carry over and cross contaminations while facilitate investigation of light microscopy and in-vitro culture negative clinically suggestive cases of leishmaniasis. Methods Leishmania DNA was amplified using previously published P221: 5′-GGTTCCTTTCCTGATTTACG-3′ and P332: 5′-GGCCGGTAAAGGCCGAATAG-3’outer primers followed by a nested reaction using P223: 5′-TCCCATCGCAACCTCGGTT-3′ and P333: 5′-AAGCGGGCGCGGTGCTG-3′ inner primers that by passes the requirement of tube handling between the two steps of the conventional nested PCR. Leishmania DNA was detected in a range of infected tissue material. Infected material from patients with cutaneous leishmaniasis ( n = 30), visceral leishmaniasis ( n = 10) and from a control group including patients with non-leishmanial skin diseases ( n = 10), other systemic diseases ( n = 10) and healthy individuals ( n = 10) were examined with Mo-STNPCR. Results were further compared with those of light microscopy and in-vitro culture. Results Mo-STNPCR method was 100% sensitive and 100% specific for diagnosis of leishmaniasis. Light microscopy and in-vitro culture were positive in 75.0% ( n = 30/40) and 72.5% ( n = 29/40) samples respectively where combined results of them gave 87.5% ( n = 35/40) sensitivity. Mo-STNPCR did not cross react with control samples. Furthermore, Mo-STNPCR reduces the risk of cross-contaminations and carry over contaminations since the full reaction is carried out without opening the tubes. Per patient cost was calculated as 22 USD while the same was 3 and 6 USD for light microscopy and in-vitro culture respectively. Conclusion Mo-STNPCR method is a useful tool in detecting leishmaniasis in minority of cases that go undetected by first line investigations. ...

Background:A decoction prepared with barks of Adenanthera pavonina and Thespesia populnea is a herbal formulation which has been prescribed in Sri Lanka in the treatment of cancer patients for many years. This study was designed to investigate its phytochemical and antioxidant properties.Materials and Methods:The total phenolics and flavonoids were determined using Folin–Ciocalteau and aluminum chloride colorimetric methods, respectively. Gallic acid content in the decoction was determined using high-performance liquid chromatography. The antioxidant properties were evaluated by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, nitric oxide scavenging assay, deoxyribose method, and the reducing power of the decoction.Results:The concentration of total phenols, flavonoids, and gallic acid of the decoction were 34.13 ± 3.54 w/w % gallic acid equivalents, 41.37 ± 0.57 w/w % of (-)-Epigallocatechin gallate equivalents, and 0.58 ± 0.24 mg/g, respectively. The EC50 for DPPH, nitric oxide scavenging, and deoxyribose assays were 7.24 ± 0.50, 14.02 ± 0.66, and 53.21 ± 2.82 μg/ml, respectively. Reducing power of the decoction increased with the concentration.Conclusion:These investigations suggested that the decoction prepared with A. pavonina and T. populnea can be a potential source of nutraceuticals with antioxidant activity.

BackgroundDecoction prepared from leaves of Atalantia ceylanica is used in traditional medicine in Sri Lanka for the treatment of various liver ailments since ancient times. Lyophilized powder of the water extract of A. ceylanica leaves was investigated for its phytochemical constituents, antioxidant and hepatoprotective activity in-vitro.MethodsThe total phenolic and flavonoid contents were determined using Folin Ciocalteu method and aluminium chloride colorimetric assay respectively. The antioxidant activities of the decoction were investigated using 1,1-Diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical, nitric oxide scavenging assays and ferric ion reducing power assay. Hepatotoxicity was induced on porcine liver slices with ethanol to study hepatoprotective activity. Porcine liver slices were incubated at 37°C with different concentrations of the water extract of A. ceylanica in the presence of ethanol for 2 hours. The hepatoprotective effects were quantified by the leakage of alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH) to the medium. Thiobarbituric acid reactive substances (TBARS) assay was performed to examine the anti-lipid peroxidation activity caused by the plant extract.ResultsThe mean ± SD (n =9) for the levels of total phenolics and flavonoids were 4.87 ± 0.89 w/w% of gallic acid equivalents and 16.48 ± 0.63 w/w% of (-)-Epigallocatechin gallate equivalents respectively. The decoction demonstrated high antioxidant activity. The mean ± SD values of EC50 were 131.2 ± 36.1, 48.4 ± 12.1, 263.5 ± 28.3 and 87.70 ± 6.06 μg/ml for DPPH, hydroxyl radical, nitric oxide scavenging assays and ferric ion reducing power assay respectively.A significant decrease (p <0.05) was observed in ALT, AST and LDH release from porcine liver slices treated with A. ceylanica extract at a concentration of 2 mg/ml in the presence of ethanol (5 M) compared to that of ethanol (5 M) treated slices. Furthermore, a reduction in lipid peroxidation was also observed in liver slices treated with the leaf extract of A. ceylanica (2 mg/ml) compared to that of ethanol induced liver toxicity (p <0.05).ConclusionsThe results suggest that aqueous extract of A. ceylanica exerts hepatoprotective activity against ethanol induced liver toxicity of porcine liver slices which can be attributed to the antioxidant properties possessed by the plant material.Electronic supplementary materialThe online version of this article (doi:10.1186/1472-6882-14-395) contains supplementary material, which is available to authorized users.

Uric acid and hypoxanthine are produced in the catabolism of purine. Abnormal urinary levels of these products are associated with many diseases and therefore it is necessary to have a simple and rapid method to detect them. Hence, we report a simple reverse phase high performance liquid chromatography (HPLC/UV) technique, developed and validated for simultaneous analysis of uric acid, hypoxanthine, and creatinine in human urine. Urine was diluted appropriately and eluted with C-18 column 100 mm × 4.6 mm with a C-18 precolumn 25 mm × 4.6 mm in series. Potassium phosphate buffer (20 mM, pH 7.25) at a flow rate of 0.40 mL/min was employed as the solvent and peaks were detected at 235 nm. Tyrosine was used as the internal standard. The experimental conditions offered a good separation of analytes without interference of endogenous substances. The calibration curves were linear for all test compounds with a regression coefficient, r2 > 0.99. Uric acid, creatinine, tyrosine, and hypoxanthine were eluted at 5.2, 6.1, 7.2, and 8.3 min, respectively. Intraday and interday variability were less than 4.6% for all the analytes investigated and the recovery ranged from 98 to 102%. The proposed HPLC procedure is a simple, rapid, and low cost method with high accuracy with minimum use of organic solvents. This method was successfully applied for the determination of creatinine, hypoxanthine, and uric acid in human urine.