Asian Pacific Journal of Tropical Biomedicine

315-322

Authors: Manal Kamel, Faten Salah, Zeinab Demerdash, Sara Maher, Shimaa Atta, Abeer Badr, Ahmed Afifi, Hanan El Baz

Objective: To develop a new sandwich based lateral flow immunochromatographic strip for rapid detection of circulating Schistosoma mansoni antigen in serum and urine samples of patients with active schistosomiasis. Methods: This lateral flow immunochromatographic strip was prepared by using anti-Schistosoma mansoni soluble egg antigen monoclonal antibody conjugated gold nanoparticles (MAb-AuNPs) as antigen-detecting antibody, while crystalline material (MCM)-41-MAb bioconjugate was immobilized at the test line as antigen-capturing antibody. Both antigen capturing and detecting antibodies formed sandwich complexes with circulating Schistosoma mansoni antigen in the positive samples. Sandwich complexes immobilized at the test line gave distinct red color. The assay reliability was examined by using urine and serum samples of 60 Schistosoma mansoni infected patients, 20 patients infected with parasites other than Schistosoma, and 20 healthy individuals as negative controls. Results were compared with those obtained via sandwich enzyme linked immunosorbent assay (ELISA). Results: The detection limit of circulating Schistosoma mansoni antigen by lateral flow immunochromatographic strip was lower (3 ng/mL) than the detection limit by ELISA (30 ng/mL). The sensitivity and specificity of lateral flow immunochromatographic strip in urine samples were 98.3% and 97.5%, respectively compared to 93.5% and 90.0% by ELISA. In serum samples, they were 100.0% and 97.5%, respectively compared to 97.0% and 95.0% by ELISA. The strip test took approximately 10 min to complete. Conclusions: This new lateral flow immunochromatographic strip offers a sensitive, rapid, and field applicable technique for diagnosis of active schistosomiasis.

333-338

Authors: Sumaya Farooq, Amit Sehgal

Objective: To evaluate the antioxidant interactions between aqueous infusions of green tea and Ocimum gratissimum at different ratios. Methods: Antioxidant activities of aqueous infusion of green tea and Ocimum gratissimum (leaves) alone or in combination at various proportions (3:1, 2:1, 1:1, 1:2, 1:3) were determined by DPPH, ABTS, NO and ex-vivo assays including lipid peroxidation and haemolysis. Total phenolic content and flavonoid content was calculated by Folin-Ciocalteu reagent and aluminum chloride colorimetry method, respectively. A correlation study was also conducted between the antioxidant activity and total phenolic/flavonoid content of various infusions. The interactions were analyzed by combination index applying CompuSyn software. Results: Green tea exhibited high radical scavenging ability as compared to Ocimum gratissimum infusion. Combination of green tea and Ocimum gratissimum exhibited moderate antagonism to strong synergistic interaction at various ratios. A strong correlation was found between total phenolic content/total flavonoid content and antioxidant activities of individual infusions (green tea and Ocimum gratissimum). For binary mixture at different ratios, a weak to strong correlation was observed between total phenolic content and antioxidant activity and almost no correlation between total flavonoid content and antioxidant potential. Conclusions: Overall, green tea and Ocimum gratissimum combination (1:1) displayed the highest antioxidant potential and maximum synergism.

346-352

Authors: Piyanoot Thongsri, Khanit Sa-ngiamsuntorn, Pongtip Sithisarn, Mullika T Chomnawang, Krit Thirapanmethee

Objective: To evaluate the potential anti-hepatitis C virus (HCV) activities of Cladogynos orientalis Zipp. ex Span and to investigate the molecular mode of action. Methods: Ethanolic and water extracts from various parts of Cladogynos orientalis were examined for cytotoxicity by MTT assay. Sub-cytotoxic concentrations of the extracts were used for further determining anti-HCV activity using cell culture-derived HCV genotype 2a propagated in HepaRG cell line. Immunofluorescence assay was performed to observe the effect on viruses at the pre-entry step. Mode of action at the post-entry step was investigated for the viral RNA and protein expressions by real time RT-PCR and Western blotting assays, respectively. Results: Although Cladogynos orientalis water extracts exhibited lower cytotoxicity than ethanolic extracts, all ethanolic extracts from roots, stems, and leaves of Cladogynos orientalis exhibited higher anti-HCV activities than water extracts. The highest anti-HCV activity was observed in infected cells treated with the extracts 5 h after absorption. No extracts showed pre-viral entry effect. At the post-viral entry step, only leaf ethanolic extracts inhibited NS5B expression, while all extracts did not inhibit HCV NS3 expression. Conclusions: Cladogynos orientalis ethanolic extracts could be further studied and the major active compound needs to be identified as a promising source for anti-HCV agents.