Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by caffeic acid phenethyl ester, a major component of Chinese propolis.

OBJECTIVES: We evaluated the immune-modulatory effects of Chinese propolis (CP) and its major constituent, caffeic acid phenethyl ester (CAPE), on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. METHODS: Mouse spleen cells stimulated by anti-CD3 monoclonal antibody were co-cultured with CP, CAPE, and HC030031, a specific antagonist of the TRPA1 Ca2+-permeable cation channel. Cytokine production was assayed by enzyme-linked immunosorbent assay. Interleukin (IL)-2 mRNA expression was examined by reverse transcription-quantitative polymerase chain reaction. RESULTS: In stimulated spleen cells treated with 1/16,000 CP diluent, IL-2 production was markedly enhanced, while IL-4 and IL-10 productions were not significantly affected. In contrast, interferon (IFN)-γ, IL-6, and IL-17 productions were markedly reduced. These effects of CP were reproduced by the CAPE treatment. A time-course observation demonstrated that, compared to control cells, IL-2 mRNA expression and production were significantly enhanced in the spleen cells stimulated by CAPE; however, IL-2 production was markedly delayed compared to that in the untreated control cells. The enhancement of IL-2 production by CAPE was scarcely alleviated by the addition of HC030031. These effects of CAPE upon IL-2 mRNA production were abolished in spleen cells without anti-CD3 antibody stimulation. CONCLUSIONS: CAPE is an important regulator of CP for cytokine regulation in anti-CD3 antibody-stimulated spleen cells. The agent specifically reduced IFN-γ, IL-6, and IL-17 and slightly enhanced Th2 cytokine production while significantly enhancing IL-2 production at the transcriptional level.

Amelioration of Osteoarthritis Development by Daily Oral Supplementation of Royal Jelly.

Royal jelly (RJ), an essential food for the queen honeybee, has a variety of biological activities. Although RJ exerts preventive effects on various lifestyle-related diseases, such as osteoporosis and obesity, no study evaluated the effect of RJ on the development of osteoarthritis (OA), the most common degenerative joint disease. Here, we showed that daily oral administration of raw RJ significantly prevented OA development in vivo following surgically-induced knee joint instability in mice. Furthermore, in vitro experiments using chondrocytes, revealed that raw RJ significantly reduced the expression of inflammatory cytokines and enzymes critical for the degradation of the extracellular matrix (ECM). Similar results were observed after treatment with 10-hydroxy-2-decenoic acid, the most abundant and unique fatty acid in raw RJ. Our results suggest that oral supplementation with RJ would benefit the maintenance of joint health and prophylaxis against OA, possibly by suppressing the activity of inflammatory cytokines and ECM-degrading enzymes.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by artepillin C, a major component of Brazilian green propolis.

OBJECTIVES: In this report, we attempt to clarify the immune modulatory effects of Brazilian green propolis (BGP) and its major component, artepillin C, on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. We also estimate the physiological mechanism affecting artepillin C's upon the cells. METHODS: Male C3H/HeN mouse spleen cells stimulated by antiCD3 monoclonal antibody were co-cultured with BGP, artepillin C, and HC030031, a transient receptor potential ankyrin 1 (TRPA1) Ca2+ channel antagonist. The synthesis of interferon (IFN)-γ, interleukin (IL)-6, IL-17, IL-4, IL-10, and IL-2 was assayed by enzyme-linked immunoassay. The expression of IL-2 mRNA and the protein product were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. RESULTS: The production of IL-2 was markedly enhanced, while that of IL-4 and IL-10 was not significantly affected; by contrast, the production of IFN-γ, IL-6, and IL-17 was significantly reduced in the antibody-stimulated spleen cells treated with BGP at a non-cytostatic concentration. These effects were reproduced in the cells treated with artepillin C. The expression of IL-2 mRNA was unaffected; however, that of the protein was significantly enhanced in the artepillin C-treated cells compared to untreated control cells. The enhancement of protein expression and the production of IL-2 by artepillin C was significantly alleviated by adding HC030031. CONCLUSIONS: Artepillin C is an important regulator of cytokine synthesis from activated spleen cells. The agent specifically augmented the expression of IL-2 via the Ca2+-permeable cation channel, TRPA1, at least in part, at the translational or secretion levels.

Protective Effect of Repeatedly Preadministered Brazilian Propolis Ethanol Extract against Stress-Induced Gastric Mucosal Lesions in Rats.

The present study was conducted to clarify the protective effect of Brazilian propolis ethanol extract (BPEE) against stress-induced gastric mucosal lesions in rats. The protective effect of BPEE against gastric mucosal lesions in male Wistar rats exposed to water-immersion restraint stress (WIRS) for 6 h was compared between its repeated preadministration (50 mg/kg/day, 7 days) and its single preadministration (50 mg/kg). The repeated BPEE preadministration attenuated WIRS-induced gastric mucosal lesions and gastric mucosal oxidative stress more largely than the single BPEE preadministration. In addition, the repeated BPEE preadministration attenuated neutrophil infiltration in the gastric mucosa of rats exposed to WIRS. The protective effect of the repeated preadministration of BPEE against WIRS-induced gastric mucosal lesions was similar to that of a single preadministration of vitamin E (250 mg/kg) in terms of the extent and manner of protection. From these findings, it is concluded that BPEE preadministered in a repeated manner protects against gastric mucosal lesions in rats exposed to WIRS more effectively than BPEE preadministered in a single manner possibly through its antioxidant and anti-inflammatory actions.

Protective Effect of Brazilian Propolis against Liver Damage with Cholestasis in Rats Treated with α-Naphthylisothiocyanate.

We examined the protective effect of Brazilian propolis against liver damage with cholestasis in rats treated with α-naphthylisothiocyanate (ANIT) in comparison with that of vitamin E (VE). Rats orally received Brazilian propolis ethanol extract (BPEE) (25, 50, or 100 mg/kg), VE (250 mg/kg) or vehicle at 12 h after intraperitoneal injection of ANIT (75 mg/kg) and were killed 24 h after the injection. Vehicle-treated rats showed liver cell damage and cholestasis, judging from the levels of serum marker enzymes and components. The vehicle group had increased serum total cholesterol, triglyceride, phospholipid, and lipid peroxide levels, increased hepatic lipid peroxide, reduced glutathione, and ascorbic acid levels and myeloperoxidase activity, and decreased hepatic superoxide dismutase activity. BPEE (50 mg/kg) administered to ANIT-treated rats prevented liver cell damage and cholestasis and attenuated these serum and hepatic biochemical changes except hepatic ascorbic acid, although administered BPEE (25 or 100 mg/kg) was less effective. VE administered to ANIT-treated rats prevented liver cell damage, but not cholestasis, and attenuated increased serum lipid peroxide level, increased hepatic lipid peroxide level and myeloperoxidase activity, and decreased hepatic superoxide dismutase activity. These results indicate that BPEE protects against ANIT-induced liver damage with cholestasis in rats more effectively than VE.

Protective effect of Brazilian propolis against hepatic oxidative damage in rats with water-immersion restraint stress.

In the present study we examined the protective effect of Brazilian propolis against hepatic oxidative damage in rats with water-immersion restraint stress (WIRS) in comparison with that of vitamin E (VE). Fasted rats orally received Brazilian green propolis ethanol extract (BPEE; 10, 50 or 100 mg/kg), VE (250 mg/kg) or vehicle at 30 min before the onset of WIRS. Exposure of vehicle-treated rats to 6 h of WIRS caused liver cell damage, judging from the levels of serum alanine aminotransferase and aspartate aminotransferease, increased hepatic lipid peroxide, NO(x) contents and myeloperoxidase activity, and decreased hepatic non-protein SH, ascorbic acid contents and superoxide dismutase activity. Preadministration of BPEE (50 or 100 mg/kg) or VE to the stressed rats protected against the hepatic damage and attenuated the increased hepatic lipid peroxide and NO(x) contents and myeloperoxidase activity and the decreased hepatic non-protein SH and ascorbic acid contents and superoxide dismutase activity. These protective effects of BPEE (50 mg/kg) were greater than those of BPEE (100 mg/kg) and were almost equal to those of VE. These results indicate that BPEE protects against hepatic oxidative damage in rats exposed to WIRS possibly through its antioxidant and antiinflammatory properties such as VE.

Antidepressant-like activity of 10-hydroxy-trans-2-decenoic Acid, a unique unsaturated Fatty Acid of royal jelly, in stress-inducible depression-like mouse model.

Symptoms of depression and anxiety appeared in mice after they had been subjected to a combination of forced swimming for 15 min followed by being kept in cages that were sequentially subjected to leaning, drenching, and rotation within 1-2 days for a total of 3 weeks. The animals were then evaluated by the tail-suspension test, elevated plus-maze test, and open-field test at 1 day after the end of stress exposure. Using these experimental systems, we found that 10-hydroxy-trans-2-decenoic acid (HDEA), an unsaturated fatty acid unique to royal jelly (RJ), protected against the depression and anxiety when intraperitoneally administered once a day for 3 weeks simultaneously with the stress loading. Intraperitoneally administered RJ, a rich source of HDEA, was also protective against the depression, but RJ given by the oral route was less effective. Our present results demonstrate that HDEA and RJ, a natural source of it, were effective in ameliorating the stress-inducible symptoms of depression and anxiety.

Oral administration of royal jelly facilitates mRNA expression of glial cell line-derived neurotrophic factor and neurofilament H in the hippocampus of the adult mouse brain.

Royal jelly (RJ) is known to have a variety of biological activities toward various types of cells and tissues of animal models, but nothing is known about its effect on brain functions. Hence, we examined the effect of oral administration of RJ on the mRNA expression of various neurotrophic factors, their receptors, and neural cell markers in the mouse brain. Our results revealed that RJ selectively facilitates the mRNA expression of glial cell line-derived neurotrophic factor (GDNF), a potent neurotrophic factor acting in the brain, and neurofilament H, a specific marker predominantly found in neuronal axons, in the adult mouse hippocampus. These observations suggest that RJ shows neurotrophic effects on the mature brain via stimulation of GDNF production, and that enhanced expression of neurofilament H mRNA is involved in events subsequently caused by GDNF. RJ may play neurotrophic and/or neuroprotective roles in the adult brain through GDNF.