Cocoa powder is rich in polyphenols, such as catechins and oligomeric procyanidins, and has a hypocholesterolemic effect in humans. This study evaluated the principal active components and potential mechanism(s) for the hypocholesterolemic effect of polyphenolic substances from cocoa powder in rats. Male Wistar rats were fed a 1% high-cholesterol diet (HC) or a high-cholesterol diet containing 1% polyphenol extract from cocoa powder (PE) or a mixture of 0.024% catechin and 0.058% epicatechin (CE) for 4 weeks. We also examined the effects of these polyphenolic substances on micellar cholesterol solubility in vitro. The PE group had significantly lower plasma cholesterol concentrations, and had significantly greater fecal cholesterol and total bile acids excretion than the HC group. The CE group diet did not influence plasma cholesterol concentrations, or fecal cholesterol or total bile acids excretion. Micellar solubility of cholesterol in vitro was significantly lower for procyanidin B2 (dimer), B5 (dimer), C1 (trimer) and A2 (tetramer), which are the main components of polyphenol extract from cocoa powder, compared to catechin and epicatechin. These results suggest that oligomeric procyanidins from cocoa powder are the principal active components responsible for the hypocholesterolemic effect, and inhibit the intestinal absorption of cholesterol and bile acids through the decrease in micellar cholesterol solubility.

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To identify a candidate compound for therapy of chronic viral hepatitis, we screened a series of oleanene-type triterpenoids for their ability to alleviate aflatoxin B 1 (AFB)-induced cytotoxicity, protect against actinomycin-tumor necrosis factor-induced apoptosis, and modulate the mixed lymphocyte reaction (MLR) in cultured cells. Glycyrrhizin at 200 lg/ml showed the strongest inhibitory effects on cytotoxicity without an immunomodulatory effect on MLR. In comparison, glycyrrhetic acid, the aglycone of glycyrrhizin, prevented apoptosis dose dependently and markedly decreased MLR with concomitant increases in concentration, but this compound failed to inhibit cytotoxicity. Among the compounds tested, soyasapogenol B at 100 lg/ml best alleviated cytotoxicity; it also protected against apoptosis at 50 lg/ml, and beginning at 1.0 lg/ml, this compound significantly increased MLR. At 25 lg/ml, soyasapogenol A, a group A saponin of soybean, showed maximum inhibition of cytotoxicity, but this inhibition rate tended to decrease with increasing dose rate. Uvaol markedly increased MLR with concomitant increases in concentration, and inhibited AFB-induced cytotoxicity, although it showed no protective effect on apoptosis. These screening data suggest that soyasapogenol B is a candidate therapeutic agent for chronic hepatitis because this compound can concomitantly (1) ameliorate cytotoxicity, (2) act as an antiapoptotic agent, and (3) increase MLR.

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The highly pathogenic avian protozoan Leucocytozoon caulleryi infects host chicken cells, and interference by the host genome results in difficulty in obtaining protozoal DNA for genetic analysis. We used flow cytometry analysis to separate expelled L. caulleryi gametocytes from infected chicken blood and to analyse cell populations and sorting by FACS efficiency. Infected blood cells stained with SYTO-24 showed a specific area on 2-dimensional scattergrams compared to uninfected blood. The specific area was sorted, and approximately 85% of the sorted cells were identified as L. caulleryi gametocytes by microscopic observation. DNA was also extracted from the sorted fraction, and a clear increase in polymerase chain reaction (PCR) amplification of protozoal DNA was observed compared to infected blood without sorting. Host-derived DNA was also detected by PCR; however, its amplification was decreased compared to that in unsorted infected blood. This is the first report of the separation of L. caulleryi gametocytes from infected host blood using flow cytometry. This method may be applied to further genetic analyses such as studies of the dynamics of stage-specific L. caulleryi gene expression.