Curcumin-loaded self-emulsifying drug delivery system (cu-SEDDS): a promising approach for the control of primary pathogen and secondary bacterial infections in cutaneous leishmaniasis
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Authors: Khan, Momin; Ali, Muhammad; Shah, Walayat; Shah, Akram; Yasinzai, Muhammad Masoom
Abstract
Cutaneous leishmaniasis being a neglected tropical disease (NTD) faces several challenges in chemotherapy. If infected with secondary bacterial infections, the treatment regime of cutaneous ulcers in cutaneous leishmaniasis is further complicated which usually require two or more than two chemotherapeutic agents for healing. In the current study, seven curcumin-loaded self-emulsifying drug delivery system (cu-SEDDS) formulations (namely F1-F7) were prepared by mixing different excipients (oils, surfactants, and co-solvents) through stirring (vortex) and sonication. The formulations were characterized regarding their droplet size, polydispersity index (PDI), and zeta potential by zeta sizer. The cu-SEDDS formulations displayed different sizes ranging from 32.4 up to 80.0 nm. The zeta potential of the formulations ranged from - 1.56 up to - 4.8. The antileishmanial activities of the cu-SEDDS formulations in terms of IC50 against Leishmania tropica ranged from 0.19 up to 0.37 mu g/ml. The minimum inhibitory concentrations (MICs) of these formulations against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were in the range of 48-62 mu g/ml. The hemolysis caused by formulations was 1-2%. The spreading potential of the formulations (F1 and F5) over damaged skin model was remarkable. These results suggest that cu-SEDDS further enhanced the broad spectrum antileishmanial and antibacterial profile of curcumin and could be used for the treatment of cutaneous leishmaniasis and its associated secondary infections.
alpha-Glucosidase Inhibitory Activity of the Extracts and Major Phytochemical Components of Smilax glabra Roxb
NATURAL PRODUCTS JOURNAL
Authors: Phuong T. M. Nguyen; Quang V. Ngo; Minh T. H. Nguyen; Maccarone, Alan T.; Pyne, Stephen G.
Abstract
Background: A therapeutic approach to treat diabetes is to decrease postprandial hyperglycemia. alpha-Glucosidase inhibitors from plant sources offer an attractive strategy for the control of hyperglycemia. Smilax glabra Roxb is a medicinal plant found in Asia, including Vietnam, which is used in the treatment of chronic diseases. However, the antidiabetic activity and the identification of alpha-glucosidase inhibitors from this plant have not been intensively investigated. This research was carried out to determine the alpha-glucosidase inhibitory activity of the extracts and that of the major phytochemical components of Smilax glabra Roxb. This could lead to further studies on the role of these compounds in hyperglycemia control, as well as identify their potential future applications. Methods: Column chromatography combined with crystallization procedures were used to isolate active fractions and two major compounds. The chemical structures of these compounds were determined by analysis of their NMR spectroscopic data, as well as MS data and comparisons made with the literature data. The a-glucosidase inhibitory activity was determined spectrophotometrically using p-nitrophenyl alpha-D-glucopyranoside as a substrate. The in vitro cytotoxicity of the isolated compounds and fractions was determined using the MTT assay. Results: The two major compounds, astilbin and 5-O-caffeoylshikimic acid together with two very active fractions, F7 and F8, were isolated from the rhizome. The two major compounds had alpha-glucosidase inhibitory activities with IC50 values of ca. 125 mu g/mL and 38 mu g/mL, respectively which are about 4 and 13 folds higher activity than the reference compound acarbose (IC50 of ca. 525 mu g/mL). Fractions F7 and F8 showed very promising inhibitory activities towards alpha-glucosidase with IC50 values of 5.5 and 5.8 mu g/mL, respectively. Cytotoxicity data on mouse fibroblast NIH3T3 cells indicated that the active compounds and fractions were not toxic at concentrations that are greater than their respective IC50 values. The alpha-glucosidase inhibitory activity of 5-Ocaffeoylshikimic acid and that of the two active fractions are reported here for the first time. Conclusion: The two major isolated compounds and fractions, F7 and F8, significantly contribute to the alpha-glucosidase inhibitory activity of S. glabra Roxb extract. Further work is needed to clarify their modes of action and potential application.