Shila Elizabeth Besra

Antiinflammatory effect of petroleum ether extract of leaves of Litchi chinensis Gaertn. (Sapindaceae)

Pharmacological studies were conducted with the petroleum ether extract of leaves of the plant Litchi chinensis Gaertn. (Sapindaceae) on experimental animals. The extract was found to possess antiinflammatory, analgesic and antipyretic activity. Acute toxicity studies revealed that the extract, up to a dose of 1 g/kg intraperitoneally, was nontoxic. The extract did not inhibit arachidonic acid-induced paw inflammation thus indicating that it may inhibit the cyclooxygenase pathway of arachidonic acid metabolism. The extract also enhanced peritoneal cell exudate along with macrophage significantly.

Induction of Apoptosis in Human Leukemic Cell Lines U937, K562 and HL-60 by Litchi chinensis Leaf Extract Via Activation of Mitochondria Mediated Caspase Cascades

The apoptogenic activity of Litchi chinensis leaf extract (LCLE) was investigated against three human leuke- mic cell lines-U937, K562 and HL-60. LCLE inhibited cell growth and metabolic activity of the leukemic cells and showed characteristic features of apoptosis. Flow cytometric analysis showed appreciable number of cells in early and late apoptotic stages. While U937 and K562 cell populations were arrested in the G2-M phase, the HL-60 cell population was arrested in the G1 phase of cell cycle. LCLE induced apoptosis is mediated through mitochondrial intrinsic pathway in- volving the release of cytochrome c into the cytosol and activation of caspase-9 and caspase-3.

Anti-leukemic activity of Wattakaka volubilis leaf extract against human myeloid leukemia cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE Wattakaka volubilis has been traditionally used in Ayurvedic medicine in India for treatment of several ailments such as bronchial asthma, inflammations, tumors, piles, leucoderma, application to boils, rat bite etc. AIM OF THE STUDY The present study was designed to investigate anti-leukemic activity of the crude aqueous methanolic extract and to identify active compounds from the leaves of Wattakaka volubilis. MATERIALS AND METHODS The leaves of Wattakaka volubilis were extracted with aqueous methanol. Liquid-liquid fractionation of the crude methanolic extract with different organic solvents was done and the fractions were screened for in vitro anti-leukemic activity using different leukemic cell lines. The active fractions were then subjected to chromatographic separation for isolation of bioactive compounds. Structure of isolated compound was elucidated by spectroscopic methods. The in vitro anti-leukemic activities of different extracts of the leaves and isolated compound WVP were studied in U-937, HL-60 and K-562 cell-lines by using cell count, MTT [(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] and DNA laddering assays, flow-cytometric and confocal microscopic techniques. RESULTS Kaempferol-3-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→6)-O]-β-d-glucopyranoside (WVP) was isolated from crude leaves extract of Wattakaka volubilis. Both the n-butanolic extract (WVB) of Wattakaka volubilis and its isolate WVP were found to be responsible for in vitro anti-leukemic activity. The IC(50) values of WVB were found be 120, 100 and 50(μg/ml) in U937, K562, and HL-60 cell lines, respectively. Whereas, the pure isolate WVP exhibited anti-leukemic activity with IC(50) values of 13.5, 10.8, and 13.2(μg/ml) in U937, K562, and HL-60 cell lines, respectively. The flow-cytometric analysis confirms that the cell cycle arrest occurs at G1 phase in case of U937 and K562 cell lines and G2/M phase in case of HL60 cell lines. Similarly both confocal microsocopic analysis and DNA laddering assay confirm the apoptosis and cell cycle arrests of leukemic cells. CONCLUSION The overall results provide evidence for the ethnopharmacological relevance for use of the plant Wattakaka volubilis in developing novel agents for the treatment of leukemia.

Influence of Lipid Core Material on Physicochemical Characteristics of an Ursolic Acid-Loaded Nanostructured Lipid Carrier: An Attempt To Enhance Anticancer Activity

The impact of saturation and unsaturation in the fatty acyl hydrocarbon chain on the physicochemical properties of nanostructured lipid carriers (NLCs) was investigated to develop novel delivery systems loaded with an anticancer drug, ursolic acid (UA). Aqueous NLC dispersions were prepared by a high-pressure homogenization-ultrasonication technique with Tween 80 as a stabilizer. Mutual miscibility of the components at the air-water interface was assessed by surface pressure-area measurements, where attractive interactions were recorded between the lipid mixtures and UA, irrespective of the extent of saturation or unsaturation in fatty acyl chains. NLCs were characterized by combined dynamic light scattering, transmission electron microscopy (TEM), atomic force microscopy (AFM), differential scanning calorimetry, drug encapsulation efficiency, drug payload, in vitro drug release, and in vitro cytotoxicity studies. The saturated lipid-based NLCs were larger than unsaturated lipids. TEM and AFM images revealed the spherical and smooth surface morphology of NLCs. The encapsulation efficiency and drug payload were higher for unsaturated lipid blends. In vitro release studies indicate that the nature of the lipid matrix affects both the rate and release pattern. All UA-loaded formulations exhibited superior anticancer activity compared to that of free UA against human leukemic cell line K562 and melanoma cell line B16.