Anti-herpes simplex virus activities of monogalactosyl diglyceride and digalactosyl diglyceride from Clinacanthus nutans, a traditional Thai herbal medicine

Objective: To evaluate the monogalactosyl diglyceride(MGDG) and digalactosyl diglyceride(DGDG) from Clinacanthus nutans(C. nutans) for their in vitro antiviral activities against herpes simplex virus type 1(HSV-1) and type 2(HSV-2) by plaque reduction assay.Methods: MGDG and DGDG were extracted with chloroform from C. nutans leaves.MGDG and DGDG were separated from chloroform crude extract using column chromatography, characterized by thin layer chromatography and quantified by high performance liquid chromatography. The anti HSV-1 and 2 activity against pre-treatment and posttreatment of the compounds was evaluated using plaque reduction assay. The cytotoxicity of the extract and the compounds on Vero cells were performed by MTT assay.Results: MGDG and DGDG obtained by column chromatography showed identical profiles as standard MGDG and standard DGDG using thin layer chromatography and high performance liquid chromatography. MGDG and DGDG from C. nutans showed 100%inhibition of HSV-1 replication at the post step of infection at noncytotoxic concentration with IC50 values of 36.00 and 40.00 mg/m L, and HSV-2 at 41.00 and 43.20 mg/mL,respectively. Moreover, MGDG and DGDG from C. nutans were demonstrated to have antiherpes simplex activity at the same level as standard synthetic compounds. In contrast, pretreatment of Vero cells with MGDG and DGDG before HSV-1 and HSV-2 infection did not show inhibitory effect against these viruses. MGDG and DGDG exhibited antiviral activity against HSV-1 with selectivity index of 26.00 and 23.00 and HSV-2 of 23.30 and 21.30.Conclusions: MGDG and DGDG from C. nutans, a traditional Thai herbal medicine illustrated inhibitory activity against HSV-1 and HSV-2, probably by inhibiting the late stage of multiplication, suggesting their promising use as anti-HSV agents.

Quantitative determination of vitexin in Passiflora foetida Linn. leaves using HPTLC

Objective: To establish a simple, rapid, precise and accurate high performance thin layer chromatography(HPTLC) method with densitometric detection for the determination of vitexin in Passiflora foetida Linn.(P. foetida).Methods: Ethanolic extract of the plant leaf powder was used for the experimental work.Separation was performed on silica gel 60 F254 HPTLC plates with ethyl acetate:methanol: distilled water: formic acid in the proportion of 50:2:3:6(v/v), as the mobile phase. The determination was carried out using the densitometric absorbance mode at340 nm.Results: Vitexin response was linear over the range of 2.5–17.5 mg/m L with a correlation coefficient of 0.996. Intraday and interday precision studies showed the relative SD was< 3%. Accuracy of the method was determined and the average recovery was 100.3%.The limit of quantitation and limit of detection were 0.879 and 0.290 mg/m L, respectively.The contents of vitexin in P. foetida leaf extracts were within the range of 0.030%–0.310%.Conclusions: The method was evaluated for sensitivity, accuracy, precision and reproducibility. Each analysis by HPTLC is less expensive than current methods. This method is suitable for routine quality control of raw material of the leaves of P. foetida extract and its products.