Artepillin C derived from propolis induces neurite outgrowth in PC12m3 cells via ERK and p38 MAPK pathways.

We investigated whether artepillin C, a major component of Brazilian propolis, acts as a neurotrophic-like factor in rat PC12m3 cells, in which nerve growth factor (NGF)-induced neurite outgrowth is impaired. When cultures of PC12m3 cells were treated with artepillin C at a concentration of 20 microM, the frequency of neurite outgrowth induced by artepillin C was approximately 7-fold greater than that induced by NGF alone. Artepillin C induced-neurite outgrowth of PC12m3 cells was inhibited by the ERK inhibitor U0126 and by the p38 MAPK inhibitor SB203580.

[Effect of propolis on insulin resistance in fructose-drinking rats].

Propolis, a honeybee product, contains a variety of biologically active substances. The present study was designed to investigate the effects of propolis on insulin resistance induced by fructose-drinking rats (FDR; type 2 diabetic animal model). Male Wistar rats (6 weeks old) received 15% fructose solution in drinking water for 8 weeks.

[Effect of long-term treatment with royal jelly on insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats].

Royal jelly (RJ) is known to have abundant nutritional properties and a variety of biological activities. To investigate the effects of RJ on insulin resistance, 10-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a type 2 diabetic model, were treated for 4 weeks with RJ (10, 30, and 300 mg/kg, p.o.

Strong antihyperglycemic effects of water-soluble fraction of Brazilian propolis and its bioactive constituent, 3,4,5-tri-O-caffeoylquinic acid.

To clarify the suppression of postprandial blood glucose rise via alpha-glucosidase (AGH) inhibitory action by natural compounds, propolis was examined in this study. A single oral administration of propolis extract (50% methanol fraction on XAD-2 column chromatography) in Sprague-Dawley rats demonstrated a potent antihyperglycemic effect with the significant AUC(0-120 min) reduction of 38% at a dose of 20 mg/kg compared to that of controls. Among the active compounds isolated from the fraction, 3,4,5-tri-caffeoylquinic acid was found to be a prominent candidate that exerts the effect and shows a strong maltase-specific inhibition with an IC(50) value of 24 microM.

Cyclodextrin-enclosed substances of Brazilian propolis.

By using beta-cyclodextrin-inclusion as a unique technique, an efficient separation of pharmacologically active phenolic compounds from Brazilian propolis was achieved to provide one new compound, 3-(3-hydroxy-3-methyl-butyl)-5-prenyl-4-hydroxycinnamic acid, together with two common cinnamic acid derivatives, artepillin C and capillartemisin A, and two known flavanols, aromadendrin and 3,5,7-trihydroxy-4'-methoxyflavanol.

Two novel long-chain alkanoic acid esters of lupeol from alecrim-propolis.

Two new long-chain alkanoic acid esters of lupeol were isolated together with known triterpenoids, alpha-amyrin, beta-amyrin, cycloartenol, lanosta-7,24-diene-3beta-ol and lupeol from Alecrim-propolis collected in Brazil. The structures were characterized by spectroscopic means.

Gastrointestinal enzyme production of bioactive peptides from royal jelly protein and their antihypertensive ability in SHR.

In order to clarify the potential physiological function of royal jelly (RJ), we report here the gastrointestinal enzyme production of antihypertensive peptides from RJ. Intact RJ and its protein fraction did not retard the action of angiotensin I-converting enzyme (ACE) activity at all. However, development of ACE inhibition power of RJ was newly observed by pepsin hydrolysis (IC(50)=0.