Involvement of heme oxygenase-1 in the anti-inflammatory activity of Chrysanthemum boreale Makino extracts on the expression of inducible nitric oxide synthase in RAW264.7 macrophages

Aim of the study

This study is to elucidate the involvement of anti-inflammatory heme oxygenase-1 (HO-1) in the inhibitory activity of a Chrysanthemum boreale Makino (CB) extract on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.

Materials and methods

Cell viability and NO assay were performed. In addition, iNOS expression was detected by Western blotting and real-time PCR. HO-1 expression was also evaluated by Western blotting, and blocking HO-1 activity on NO production was performed.

Results

The CB extract at the highest concentration (100 μg/ml) significantly inhibited NO production by approximately 90% and suppressed iNOS protein expression by approximately 84.8% compared to LPS-stimulated cells. Furthermore, the CB extract (100 μg/ml) inhibited iNOS mRNA expression in a concentration-dependant manner and suppressed iNOS mRNA expression by 94.8%. The CB extract induced the expression of HO-1 in a dose-dependent manner, and blocking HO-1 activity abolished the inhibitory effects of the CB extract. Moreover, the addition of carbon monoxide such as tricarbonyl dichlororuthenium (II) dimmer (RuCO), a byproduct derived from heme degradation, mimicked the inhibitory action of low concentrations of CB extract.

Conclusion

These results suggest that a CB extract has potent anti-inflammatory activity in RAW264.7 macrophages involving the induction of HO-1.     

Suppressive effect of inducible nitric oxide synthase (iNOS) expression by the methanol extract of Actinodaphne lancifolia

Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has played a crucial role in various pathophysiological processes including inflammation and carcinogenesis. Therefore, the inhibitors of NO synthesis or iNOS gene expression have been considered as potential anti-inflammatory and cancer chemopreventive agents. In our continuous search for iNOS inhibitors from natural products we have evaluated indigenous Korean plant extracts using an assay for inhibition of nitric oxide formation on lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells. As a result, the methanolic stem extract of Actinodaphne lancifolia showed an inhibitory activity of NO production in a dose-dependent manner (IC50 = 2.5 microg/ml). Additional study demonstrated that the extract of Actinodaphne lancifolia significantly suppressed the iNOS protein and gene expression in a dose-dependent manner. These results suggest that Actinodaphne lancifolia could be a potential candidate for developing an iNOS inhibitor from natural products. Further elucidation of active principles for development of new cancer chemopreventive and/or anti-inflammatory agents could be warranted.     

Ethanol extract of propolis inhibits nitric oxide synthase gene expression and enzyme activity

Propolis obtained from honeybee hives has been used in Oriental folk medicine as an anti-inflammatory, anti-carcinogenic, or immunomodulatory agent. However, the molecular basis for anti-inflammatory properties of propolis has not yet been established. Since nitric oxide (NO) synthesized by inducible nitric oxide synthase (iNOS) has been known to be involved in inflammatory and autoimmune-mediated tissue destruction, modulation of NO synthesis or action represents a new approach to the treatment of inflammatory and autoimmune diseases. The present study, therefore, examined effects of ethanol extract of propolis (EEP) on iNOS expression and activity of iNOS enzyme itself. Treatment of RAW 264.7 cells with EEP significantly inhibited NO production and iNOS protein expression induced by lipopolysaccharide (LPS) plus interferon-gamma (IFN-γ). EEP also inhibited iNOS mRNA expression and nuclear factor-kappa B (NF-κB) binding activity in a concentration-dependent manner. Furthermore, transfection of RAW 264.7 cells with iNOS promoter linked to a chloramphenicol acetyltransferase (CAT) reporter gene, revealed that EEP inhibited the iNOS promoter activity induced by LPS plus IFN-γ through the NF-κB sites of the iNOS promoter. In addition, EEP directly interfered with the catalytic activity of murine recombinant iNOS enzyme. These results suggest that EEP may exert its anti-inflammatory effect by inhibiting the iNOS gene expression via action on the NF-κB sites in the iNOS promoter and by directly inhibiting the catalytic activity of iNOS.     

Suppressive effects of methoxyflavonoids isolated from Kaempferia parviflora on inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells

Ethnopharmacological relevance

The rhizomes of Kaempferia parviflora Wall. ex Baker have been traditionally used in Thailand to treat abscesses, gout, and peptic ulcers.

Aim

Previously, we reported that the chloroform fraction of a Kaempferia parviflora extract had an inhibitory effect on rat paw-edema. In the present study, we isolated the constituents of this fraction and investigated the anti-inflammatory mechanism against nitric oxide (NO) production, tumor necrosis factor-α (TNF-α) and the expression of inducible nitric oxide synthase (iNOS) as well as phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated c-Jun N-terminal kinase (p-JNK). In addition, effects of trimethylapigenin (4) on the enzyme activities of protein kinases possibly leading to iNOS expression were examined to clarify the targets.

Materials and methods

The chloroform fraction was isolated using silica gel column chromatography and HPLC. Isolated compounds were tested against NO and TNF-α using RAW264.7 cells. Cytotoxicity and iNOS, p-ERK and p-JNK expression were also examined.

Results

Three active components, 5,7-dimethoxyflavone (2), trimethylapigenin (4), and tetramethylluteolin (5), markedly inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW264.7 cells. Compounds 2, 4, and 5 moderately inhibited production of TNF-α. Compounds 2, 4, and 5 strongly inhibited expression of iNOS mRNA and iNOS protein in a dose-dependent manner, but did not inhibit p-ERK or p-JNK protein expression. The most active compound, 4, did not inhibit the enzyme activity of inhibitor of κB kinases or mitogen-activated protein kinases, but inhibited that of spleen tyrosine kinase (SYK).

Conclusion

The mechanism responsible for the anti-inflammatory activity of methoxyflavonoids from the chloroform fraction of the rhizomes of Kaempferia parviflora is mainly the inhibition of iNOS expression, and the inhibition of SYK by 4 may be involved in the suppression of LPS-induced signaling in macrophages.     

Bioassay-guided isolation of anti-inflammatory components from the root of Rehmannia glutinosa and its underlying mechanism via inhibition of iNOS pathway

Ethnopharmacological relevance

The root of Rehmannia glutinosa (RR) is commonly used to reduce inflammation in various traditional Chinese herbal formulae; however, little is known regarding its active component(s).Aim of study: The objective of the present study was to examine the active component(s) responsible for the anti-inflammatory activity of RR via anti-nitric oxide production assay-guided fractionation; and the underlying anti-inflammatory mechanism of action of such component(s) was further investigated.

Materials and methods

Anti-nitric oxide (NO) activities with lipopolysaccharides (LPS)-stimulated RAW264.7 murine macrophages was used as screening platform. Gene, protein and inflammatory mediators' expression were also studied using real-time PCR, western blotting and ELISA, respectively.

Results

Using anti-NO assay-guided fractionation, sub-fraction C3 (from 31.25 to 62.5 μg/ml, p=0.001 to 0.01) possessed 100-fold more potent anti-inflammatory effect than that of the aqueous extract of RR. Characterization of C3 showed that the anti-inflammatory effect could be partly due to the presence of rehmapicrogenin, which could significantly inhibit NO production (p<0.001). C3 was further demonstrated in blocking inflammation by inhibiting gene (p<0.001) and protein expression of inducible NO synthase (iNOS) dose-dependently. Besides, C3 also significantly inhibited the production of prostaglandin E₂ (p<0.001 to 0.01), IL-6 (p<0.001 to 0.05) and COX-2 (p<0.05).

Conclusions

Rehmapicrogenin was, for the first time, shown to possess nitric oxide inhibitory activities. Bioassay-guided fractionation demonstrated that rehmapicrogenin-containing subfraction C3 exhibited potent anti-inflammatory effect by inhibiting iNOS, COX-2 and IL-6, while rehmapicrogenin was only partially responsible for the anti-inflammatory effect of RR.     

Echinacea increases arginase activity and has anti-inflammatory properties in RAW 264.7 macrophage cells,indicative of alternative macrophage activation

Ethnopharmacological relevance

The genus Echinacea is a popular herbal immunomodulator. Recent reports indicate that Echinacea products inhibit nitric oxide (NO) production in activated macrophages.

Aim of the study

In the present study we determined the inhibitory effects of alcohol extracts and individual fractions of alcohol extracts of Echinacea on NO production, and explored the mechanism underlying the pharmacological anti-inflammatory activity.

Materials and methods

Alcohol extracts of three medicinal Echinacea species, Echinacea angustifolia, Echinacea pallida and Echinacea purpurea, were prepared using Soxhlet apparatus and fractionated using HPLC. NO production by LPS activated RAW 264.7 macrophage cells was measured using a Griess reagent and iNOS detected using immunoblotting. In addition, effects on arginase activity were measured in RAW 264.7 cells stimulated with 8-bromo-cAMP +/− LPS.

Results

Alcohol extracts of all three Echinacea species significantly inhibited NO production by lipopolysaccharide (LPS)-activated the RAW 264.7 macrophage cell line; among them Echinacea pallida was the most active. The Echinacea-mediated decrease in NO production was unlikely due to a direct scavenging of NO because the extracts did not directly inhibit NO released from an NO donor, sodium nitroprusside. An immunoblotting assay demonstrated that the extract of Echinacea pallida inhibited inducible nitric oxide synthase (iNOS) protein expression in LPS-treated macrophages. The enzymes iNOS and arginase metabolize a common substrate, l-arginine, but produce distinct biological effects. While iNOS is involved in inflammatory response and host defense, arginase participates actively in anti-inflammatory activation. Arginase activity of RAW 264.7 cells stimulated with 8-bromo-cAMP was significantly increased by alcohol extracts of all three Echinacea species. The polar fraction containing caffeic acid derivatives enhanced arginase activity, while the lipophilic fraction containing alkamides exhibited a potential of inhibiting NO production and iNOS expression.

Conclusions

These results suggest that the anti-inflammatory activity of Echinacea might be due to multiple active metabolites, which work together to switch macrophage activation from classical activation towards alternative activation.     

Tetramethylpyrazine inhibits production of nitric oxide and inducible nitric oxide synthase in lipopolysaccharide-induced N9 microglial cells through blockade of MAPK and PI3K/Akt signaling pathways,and suppression of intracellular reactive oxygen species

Aim of the study

To determine the inhibitory effect of tetramethylpyrazine (TMP) on lipopolysaccharide (LPS)-induced over-production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in N9 microglial cells.

Materials and methods

N9 cells were pretreated with vehicle or TMP and then exposed to LPS for the time indicated. Cell viability was determined by methylthiazoyltetrazolium (MTT) assay. Nitrite assay was performed by Griess reaction. Expression of iNOS mRNA was examined by RT-PCR. Protein levels of iNOS, p38 mitogen-activated protein kinase (MAPK), ERK1/2, JNK, phosphatidylinositol 3-kinase (PI3K) and Akt were determined by western blot analysis. Formation of reactive oxygen species (ROS) was evaluated by fluorescence image system.

Results

TMP inhibited LPS-induced over-production of NO and iNOS in N9 cells. TMP also inhibited the NF-κB translocation from cytoplasm into nucleus of N9 cells. In addition, TMP showed blocking effect on the phosphorylation of p38 MAPK, ERK1/2, JNK and Akt, but not PI3K. Further, TMP suppressed the formation of intracellular ROS in LPS-induced N9 cells.

Conclusions

TMP inhibited production of NO and iNOS in LPS-induced N9 cells through blocking MAPK and PI3K/Akt activation and suppressing ROS production.     

Molecular mechanism of anti-inflammatory activity of Pluchea indica leaves in macrophages RAW 264.7 and its action in animal models ofinflammation

Ethnopharmacological relevance: Pluchea indica Less.

(Asteraceae) is a Thai medicinal plant used in traditional medicine for the treatment of hemorrhoids, lumbago, leucorrhoea and inflammation. This study investigated the molecular mechanism of anti-inflammatory activity of Pluchea indica leaf extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and also determined its action in acute inflammation animal models.

Materials and methods

The inhibitory effect of Pluchea indica leaf extract on LPS-induced nitric oxide (NO) production was evaluated by Griess reaction. Protein and mRNA expressions were determined by real time RT-PCR and Western blotting analysis, respectively. Inducible nitric oxide synthase (iNOS) promoter activity was evaluated by iNOS promoter based reporter gene assay. In vivo anti-inflammatory effect was examined in ethylphenylpropiolate (EPP)-induced ear edema and carrageenan-induced paw edema in rat models.

Results

Ethyl acetate fraction of ethanol extract of Pluchea indica leaves (EFPI) exhibited the potent inhibitory effect on NO production in LPS-induced macrophages and also inhibited PGE₂ release. EFPI reduced iNOS mRNA and protein expression through suppressed iNOS promoter activity and nuclear translocation of subunit p65 of nuclear factor-κB, but did not inhibit phosphorylation of the mitogen-activated protein kinases (MAPKs). Moreover, EFPI possessed anti-inflammatory activities on acute phase of inflammation as seen in EPP-induced ear edema and carrageenan-induced paw edema inrats.

Conclusions

These data support the pharmacological basis of Pluchea indica plant as a traditional herbal medicine for treatment of inflammation.     

川芎嗪对急性百草枯中毒大鼠一氧化氮和诱导型一氧化氮合酶的影响及其治疗作用

目的 观察百草枯(PQ)急性中毒大鼠所致肺损伤(ALI)时一氧化氮(NO)和诱导型一氧化氮合酶(iNOS)的变化,探讨川芎嗪对急性百草枯中毒所致肺损伤的保护作用.方法 将50只SD大鼠随机分成5组,空白组、阴性对照组、阳性对照组、川芎嗪低剂量组和川芎嗪高剂量组.观察大体标本,组织病理以及生物学标志:肺湿/干重比、肺泡灌洗液中性粒细胞比和蛋白含量.同时测定肺组织NO含量和iNOS活性.结果 与阴性对照组相比,川芎嗪低剂量组肺组织病理显示肺淤血、肺水肿明显减轻.其生物学标志均降低(P＜0.05或P＜0.01),NO和iNOS也降低(P<0.01).结论 NO及iNOS在百草枯所致大鼠肺损伤中起重要作用,川芎嗪能降低NO及iNOS水平,减轻百草枯中毒大鼠肺组织损伤.     

Cissus quadrangularis ethanol extract upregulates superoxide dismutase, glutathione peroxidase and endothelial nitric oxide synthase expression in hydrogen peroxide-injured human ECV304 cells

Ethnopharmacological relevance

Cissus quadrangularis has been widely used in traditional medicine for the treatment of hemorrhoid. However, the detailed mechanism of antioxidant defense of C. quadrangularis in endothelial cells under oxidative stress remains unclear.

Aim of the study

The present study aims to elucidate the protective role of ethanol extract of C. quadrangularis (CQE) including its constituents, quercetin and resveratrol, on hydrogen peroxide (H₂O₂)-injured human umbilical vein endothelial ECV304 cells.

Materials and methods

Viability, genotoxicity and protein expression of ECV304 cells were analyzed by MTT, alkaline comet and Western blot, respectively. Production of intracellular reactive oxygen species (ROS) was determined using dichlorofluorescein fluorescence dye.

Results

After exposing cells to CQE containing quercetin and resveratrol, DNA damage was not observed. CQE including quercetin and resveratrol significantly attenuated ROS in H₂O₂-injured ECV304 cells in a concentration-dependent manner. The protein expression of superoxide dismutase (Cu/Zn-SOD, Mn-SOD), glutathione peroxidase (GPx) and endothelial nitric oxide synthase (eNOS) increased in the cells treated with CQE, quercetin or resveratrol prior to H₂O₂ exposure, as compared with control.

Conclusions

The results provide a molecular mechanism of C. quadrangularis, which could be partially related to quercetin and resveratrol, in restoring ROS in endothelial cells through the upregulation of Cu/Zn-SOD, Mn-SOD, GPx and eNOS.     

蜈蚣对心肌缺血性损伤小鼠NO及iNOS的影响

目的 :探讨中药蜈蚣对心肌缺血性损伤小鼠一氧化氮 (NO)及一氧化氮合酶 (i NOS)的影响。方法 :采用脑垂体后叶素造成小鼠心肌缺血性损伤模型。将健康小鼠分为四组 ,分别是空白组、模型组、蜈蚣小剂量组(2 .5 g/ kg)、蜈蚣大剂量组 (5 .0 g/ kg)。缺血 2 0 m in后取血观察乳酸脱氢酶 (L DH ) ,检测心肌组织一氧化氮 (NO) ,免疫组化法检测心肌一氧化氮合酶 (i NOS)。结果 :蜈蚣治疗后 L DH降低 ,NO、i NOS明显升高。结论 :蜈蚣可显著提高 NO及 i NOS的表达 ,这可能与蜈蚣保护血管内皮细胞功能有关。     

二苯乙烯苷对动脉硬化大鼠一氧化氮合酶及其基因的调节作用

目的:探讨二苯乙烯苷(TSG)对动脉粥样硬化(AS)大鼠一氧化氮合酶(NOS)及其基因的调节作用与抗AS机制。方法:采用高脂饲料喂饲+维生素D3复制大鼠动脉粥样硬化模型,雄性SD大鼠60只,随机分为6组:正常组、模型组、辛伐他汀阳性对照组、TSG高、中、低剂量组(120,60,30 mg.kg^-1.d^-1)。造模12周后抽样检测大鼠主动脉,以大鼠动脉粥样硬化斑块形成为造模指标。经治疗给药6周后,检测大鼠血清和主动脉组织中NOS水平,RT-PCR检测大鼠主动脉eNOS和iNOS mRNA表达。结果:与模型组相比,辛伐他汀组和TSG高、中剂量组均能显著增加血清和主动脉组织NOS的活性、主动脉组织eNOS mRNA的表达及降低主动脉组织iNOS mRNA的表达。结论:TSG能上调AS大鼠动脉壁eNOS mRNA的表达,抑制AS大鼠动脉壁iNOS mRNA的表达,这可能是TSG抗AS的机制之一。     

Aqueous extract of Astragali Radix ameliorates proteinuria in adriamycin nephropathy rats through inhibition of oxidative stress and endothelial nitric oxide synthase

Aim of the study

To investigate the effects of aqueous extract of Astragali Radix (ARE) on the oxidative stress status and endothelial nitric oxide synthase level in adriamycin (ADR) nephropathy rats.

Materials and methods

ADR nephropathy rats were randomly treated with ARE (2.5 g/kg/d, n = 6, ARE group), or benazepril (10 mg/kg/d, n = 6, angiotensin-converting enzyme inhibitor (ACEI) group) for ten weeks. Serum urea nitrogen, creatinine, albumin, total protein, cholesterol and 24-h urinary protein concentration were determined. Renal cortex catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA) activities, and 24-h urinary NO₃⁻/NO₂⁻ excretion were determined by chromatometry. Renal cortex cyclic guanosine monophosphate (cGMP) level was measured by enzyme immunoassay and eNOS expression was determined by immunohistochemistry.

Results

ARE and ACEI treatments could remarkably reduce more 24 h urinary protein excretion than that in ADR group (88.32 ± 9.96 mg, 81.78 ± 16.28 mg vs. 153.91 ± 28.63 mg, P < 0.01), and there was no difference between ARE and ACEI group. Renal cortex CAT, GSH-Px activities in ARE and ACEI group were significantly higher than ADR group, and renal cortex SOD activity in ARE group was higher than ADR group. Renal cortex MDA activity, cGMP level, and glomerular and tubular eNOS expression in ARE and ACEI group were lower than that in ADR group, and 24-h urinary NO₃⁻/NO₂⁻ excretion in ARE group was lower than ADR group. Renal cortex MDA content (r = 0.895, P < 0.01), cGMP content (r = 0.666, P < 0.01) and eNOS expression in glomerulus (r = 0.910, P < 0.01) were strongly positively associated with 24 h urinary protein excretion. And renal cortex SOD content was negatively associated with 24 h urinary protein excretion (r = −0.861, P < 0.01).

Conclusions

ARE may ameliorate the proteinuria by suppressing the over expression of eNOS, and inhibiting the oxidative injury in ADR nephropathy rats.     

Analgesic effects and anti-inflammatory properties of the crude methanolic extract of Schwenckia americana Linn (Solanaceae)

Aim of the study

To evaluate analgesic effect and anti-inflammatory properties of Schwenckia americana (Solanaceae), a medicinal plant used for treating rheumatic pains and swelling in North-western Nigeria.

Materials and methods

Three doses (25 mg/kg, 50 mg/kg and 100 mg/kg) of the crude methanolic extract of Schwenkia americana were evaluated for analgesic and anti-inflammatory activities using acetic acid induced writhing test, formalin induced nociception, and formalin induced hind paw oedema in rats.

Results

All doses (25, 50, 100 mg/kg) of the extract tested were effective. The extract at the tested doses produced a percentage inhibition of the acetic acid induced abdominal constriction of (53.3, 58.0 and 86.7%), respectively. A percentage inhibition of the formalin induced nociception of 44.00, 56.04, and 56.04% (early phase) and 33.00, 36.63 and 59.71% (late phase) was also produced. The inhibition of oedema formation increased with increasing dosage from 25 to 100 mg/kg. The crude extract produced a statistically significant analgesic and anti-inflammatory activity comparable to the effect of standard drug (10 mg/kg Piroxicam).

Conclusion

This study demonstrated the potential analgesic and anti-inflammatory properties of crude methanolic extract of Schwenkia americana thus justifying its traditional usage.     

In vitro anti-inflammatory effects of arctigenin,a lignan from Arctium lappa L., through inhibition on iNOS pathway

Ethnopharmacological relevance

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet.

Aim of the study

To investigate the anti-inflammatory mechanism of arctigenin.

Materials and methods

Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2.

Results

Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-α and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin.

Conclusions

These results indicated that potent inhibition on NO, TNF-α and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.     

Appetite suppressive effects of yeast hydrolysate on nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in hypothalamus

To investigate the effects of yeast hydrolysate on appetite regulation mechanisms in the central nervous system, nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in the paraventricular nucleus (PVN) and ventromedial hypothalamic nucleus (VMH) of the hypothalamus were examined. Male Sprague-Dawley (SD) rats were assigned to five groups: control (normal diet), BY-1 and BY-2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate <10 kDa/kg body weight, respectively), AY-1 and AY-2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate 10-30 kDa/kg body weight, respectively). The body weight gain in the BY groups was less than that in the control. In particular, the weight gain of the BY-2 group (133.0 +/- 5.1 g) was significantly lower (p < 0.05) than that of the control group (150.1 +/- 3.7 g). Among the test groups, the BY-2 group was shown to have significantly lower triacylglycerol (TG) levels (p < 0.05) than the other groups. The staining intensities and optical densities of NOS neurons in the PVN of the AY group were significantly higher (p < 0.05) than in the control and BY groups. The staining intensities and optical densities of VIP immunoreactivity in the PVN and VMH of the BY groups were higher than those of the AY groups and the control. In conclusion, these results indicated that yeast hydrolysate of <10 kDa reduced the body weight gain and body fat in normal diet-fed rats and increased the lipid energy metabolism by altering the expression of NOS and VIP in neurons.