Enrichment of linoleic acid from yellow horn seed oil through low temperature crystallization followed by urea complexation method and hypoglycemic activities

Yellow horn (Xanthoceras sorbifolia Bunge) contained abundant linoleic acid (LA), accounting for about 44% of its lipid. Here, LA was enriched by low temperature crystallization followed by urea complexation, and the optimal enrichment conditions were optimized with response surface methods (3:1 ratio of EtOH/FFA, crystallization at - 25 °C for 24.5 h; 2:1 ratio of urea/FFA1, 6.6:1 ratio of EtOH/urea, crystallization at - 10 °C for 22.4 h). Under these conditions, the final LA content and recovery were 97.10% and 62.09%, respectively. In vitro hypoglycemic studies suggested that the LA extract with stronger inhibition on α-glucosidase and lower one on α-amylase than acarbose exhibited a positive control for carbohydrate digestion with lower adverse effects. The enzyme kinetics and Lineweaver-Burk plots analyses revealed a reversible competitive inhibition on α-amylase and α-glucosidase. The findings of this research provided insights for the development of the LA extract as the functional component of health food.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01327-9.

Nutritional composition, health-promoting effects, bioavailability, and encapsulation of tree peony seed oil: a review

Tree peony is cultivated worldwide in large quantities due to its exceptional ornamental and medicinal value. In recent years, the edible value of tree peony seed oil (TPSO) has garnered significant attention for its high content of alpha-linolenic acid (ALA, >40%) and other beneficial minor components, including phytosterols, tocopherols, squalene, and phenolics. This review provides a systematic summary of the nutritional composition and health-promoting effects of TPSO, with a specific focus on its digestion, absorption, bioavailability, and encapsulation status. Additionally, information on techniques for extracting and identifying adulteration of TPSO, as well as its commercial applications and regulated policies, is included. Thanks to its unique nutrients, TPSO offers a wide range of health benefits, such as hypolipidemic, anti-obesity, cholesterol-lowering, antioxidant and hypoglycemic activities, and regulation of the intestinal microbiota. Consequently, TPSO shows promising potential in the food and cosmetic industries and should be cultivated in more countries. However, the application of TPSO is hindered by its low bioavailability, poor stability, and limited water dispersibility. Therefore, it is crucial to develop effective delivery strategies, such as microencapsulation and emulsion, to overcome these limitations. In conclusion, this review provides a comprehensive understanding of the nutritional value of TPSO and emphasizes the need for further research on its nutrition and product development.

Effect of Adsorption Deacidification on the Quality of Peony Seed Oil

To overcome the issues in the traditional deacidification processes of peony seed oil (PSO), such as losses of neutral oil and trace nutrients, waste discharge, and high energy consumption, adsorption deacidification was developed. The acid removal capacity of adsorbent-alkali microcrystalline cellulose was evaluated using the isothermal adsorption equilibrium and the pseudo-first-order rate equation. The optimized adsorption deacidification conditions included adsorbent-alkali microcrystalline cellulose at 3%, a heating temperature of 50 °C, and a holding time of 60 min. The physicochemical, bioactive properties, antioxidant capacities, and oxidative stabilities of PSO processed by alkali refining and oil-hexane miscella deacidification were compared under the same operating conditions. Fatty acid content was not significantly different across all three methods. The deacidification rates were 88.29%, 98.11%, and 97.76%, respectively, for adsorption deacidification, alkali refining, and oil-hexane miscella deacidification. Among the three deacidification samples, adsorption deacidification showed the highest retention of tocopherols (92.66%), phytosterols (91.96%), and polyphenols (70.64%). Additionally, the obtained extract preserved about 67.32% of the total antioxidant activity. The oil stability index was increased 1.35 times by adsorption deacidification. Overall, adsorption deacidification can be considered a promising extraction technology in terms of quality as compared to alkali refining and oil-hexane miscella deacidification.

Separation, identification, and design of α-glucosidase inhibitory peptides based on the molecular mechanism from Paeonia ostii 'Feng Dan' seed protein

Peptides are considered promising sources of nutraceuticals. In this study, a mixture of peptides was prepared from Paeonia ostii 'Feng Dan' seed meal protein by continuous enzymolysis. Successive separation and purification procedures, including ultrafiltration and reversed-phase high-performance liquid chromatography (RP-HPLC), were performed, and six novel peptides were identified by liquid chromatography-electrospray ionization source-mass spectrometry/mass spectrometry (LC-ESI-MS/MS). In an in vitro antidiabetic activity test, Tyr-Phe-Phe-Met exhibited stronger α-glucosidase inhibitory activity (48.17 ± 3.34% at 1 mg/mL) than the other peptides. Docking studies of this peptide into the active site of α-glucosidase showed that the formation of hydrogen bonds could be critical for the enzymatic trapping of inhibitory peptides. Furthermore, two novel peptides, Phe-Phe-Phe-Met (IC₅₀  = 245.46 ± 44.01 µM) and Tyr-Tyr-Phe-Met (IC₅₀  = 306.71 ± 48.17 µM), with improved α-glucosidase inhibitory activity, were designed based on molecular docking. Therefore, the seed meal of Paeonia ostii could be considered a functional food ingredient for the management of hyperglycemia, and three novel peptides were identified as α-glucosidase inhibitors.

Effects of Radio Frequency Pretreatment on Quality of Tree Peony Seed Oils: Process Optimization and Comparison with Microwave and Roasting

In this study, we explored the technical parameters of tree peony seeds oil (TPSO) after their treatment with radio frequency (RF) at 0 °C-140 °C, and compared the results with microwave (MW) and roasted (RT) pretreatment in terms of their physicochemical properties, bioactivity (fatty acid tocopherols and phytosterols), volatile compounds and antioxidant activity of TPSO. RF (140 °C) pretreatment can effectively destroy the cell structure, substantially increasing oil yield by 15.23%. Tocopherols and phytosterols were enhanced in oil to 51.45 mg/kg and 341.35 mg/kg, respectively. In addition, antioxidant activities for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) were significantly improved by 33.26 μmol TE/100 g and 65.84 μmol TE/100 g, respectively (p < 0.05). The induction period (IP) value increased by 4.04 times. These results are similar to those of the MW pretreatment. The contents of aromatic compounds were significantly increased, resulting in improved flavors and aromas (roasted, nutty), by RF, MW and RT pretreatments. The three pretreatments significantly enhanced the antioxidant capacities and oxidative stabilities (p < 0.05). The current findings reveal RF to be a potential pretreatment for application in the industrial production of TPSO.

Peony seed oil ameliorates neuroinflammation-mediated cognitive deficits by suppressing microglial activation through inhibition of NF-κB pathway in presenilin 1/2 conditional double knockout mice

Chronic neuroinflammation has been shown to exert adverse influences on the pathology of Alzheimer's disease (AD), associated with the release of abundant proinflammatory mediators by excessively activated microglia, causing synaptic dysfunction, neuronal degeneration, and memory deficits. Thus, the prevention of microglial activation-associated neuroinflammation is important target for deterring neurodegenerative disorders. Peony seed oil (PSO) is a new food resource, rich in α-linolenic acid, the precursor of long chain omega-3 polyunsaturated fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, which exhibit anti-inflammatory properties by altering cell membrane phospholipid fatty acid compositions, disrupting lipid rafts, and inhibiting the activation of the proinflammatory transcription factor NF-κB. However, few studies have examined the anti-neuroinflammatory effects of PSO in AD, and the relevant molecular mechanisms remain unclear. Presenilin1/2 conditional double knockout (PS cDKO) mice display obvious AD-like phenotypes, such as neuroinflammatory responses, synaptic dysfunction, and cognitive deficits. Here, we assessed the potential neuroprotective effects of PSO against neuroinflammation-mediated cognitive deficits in PS cDKO using behavioral tests and molecular biologic analyses. Our study demonstrated that PSO suppressed microglial activation and neuroinflammation through the down-regulation of proinflammatory mediators, such as inducible NOS, COX-2, IL-1β, and TNF-α, in the prefrontal cortex and hippocampus of PS cDKO mice. Further, PSO significantly lessened memory impairment by reversing hyperphosphorylated tau and synaptic proteins deficits in PS cDKO mice. Importantly, PSO's therapeutic effects on cognitive deficits were due to inhibiting neuroinflammatory responses mediated by NF-κB signaling pathway. Taken together, PSO may represent an effective dietary supplementation to restrain the neurodegenerative processes of AD.

Extraction and Characterization of the Polar Lipid Fraction of Blackberry and Passion Fruit Seeds Oils Using Supercritical Fluid Extraction

The study of the phytochemical composition of seed oils is of upmost importance for the food and cosmetic industries, mainly considering their associated biological properties. Extraction of seed oils using supercritical fluids (SFE) is an ecological and green alternative to conventional extraction processes since it is able to provide with potent bioactive extracts, avoiding degradation and transformation of the compounds present originally in the raw material. The objective of the present work was the extraction of pure fractions of polar lipids and their chemical characterization using chromatographic techniques such as GC-MS and LC-DAD-MS/MS of blackberry (Rubus glaucus) and passion fruit (Passiflora edulis) seed oils extracted by supercritical carbon dioxide. Oleamides derived from oleic acid were identified as the main compounds in both samples; in particular, 9-octadecenamide was the major identified oleamide. Besides, the extract obtained from passion fruit showed to be a source of linoleic acid, while the SFE extract from blackberry presented important concentrations of vanillin. The chemical composition of these seed oils can be of high interest for their further use in cosmetics and food industry.

Structural dependence of antidiabetic effect of steviol glycosides and their metabolites on streptozotocin-induced diabetic mice

BACKGROUND

Stevia has been proposed as a potential antidiabetic sweetener, mainly based on inconsistent results from stevioside or the plant extract, yet lacking relative experimental evidence from individual steviol glycosides (SGs) and their metabolites.

RESULTS

The results systematically revealed that the typical SGs and their final metabolite (steviol) presented an antidiabetic effect on streptozotocin (STZ) diabetic mice in all assayed antidiabetic aspects. In general, the performance strength of the samples followed the sequence steviol > steviol glucosyl ester > steviolbioside > rubusoside > stevioside > rebaudioside A, which is opposite to their sweetness strength order, and generally in accordance with the glucosyl group numbers in their molecules. This may imply that the antidiabetic effect of the SGs might be achieved through steviol, which presented antidiabetic performance similar to that of metformin with a dose of 1/20 that of metformin. Moreover, the ¹⁸ F-fluorodeoxyglucose traced micro-PET experiment revealed that stevioside and steviol could increase the uptake of glucose in the myocardium and brain of the diabetic mice within 60 min, and decrease the accumulation of glucose in the liver and kidney.

CONCLUSIONS

The SGs and steviol presented an antidiabetic effect on STZ diabetic mice in all assayed aspects, with an induction time to start the effect of the SGs. Stevioside and steviol could increase uptake of glucose in the myocardium and brain of the diabetic mice, and decrease accumulation of glucose in the liver and kidney. The performance strength of the SGs is generally in accordance with glucosyl group numbers in their molecules.

Integrated Profiling of Fatty Acids, Sterols and Phenolic Compounds in Tree and Herbaceous Peony Seed Oils: Marker Screening for New Resources of Vegetable Oil

Tree peonies (Paeonia ostii and Paeonia rockii) are popular ornamental plants. Moreover, these plants have become oil crops in recent years. However, there are limited compositional studies focused on fatty acids. Therefore, this work aims to reveal compositional characteristics, regarding fatty acids, sterols, γ-tocopherol and phenolic compounds, of tree peony seed oils from all major cultivation areas in China, and to compare with herbaceous peony seed oil. For that, an integrative analysis was performed by GC-FID, GC-MS and UHPLC-Q-TOF-MS technologies. The main fatty acid was α-linolenic acid (39.0–48.3%), while β-sitosterol (1802.5–2793.7 mg/kg) and fucosterol (682.2–1225.1 mg/kg) were the dominant phytosterols. Importantly, 34 phenolic compounds, including paeonol and “Paeonia glycosides” (36.62–103.17 μg/g), were characterized in vegetable oils for the first time. Conclusively, this work gives new insights into the phytochemical composition of peony seed oil and reveals the presence of bioactive compounds, including “Paeonia glycosides”.

Antidiabetic Stilbenes from Peony Seeds with PTP1B, α-Glucosidase, and DPPIV Inhibitory Activities

One unusual resveratrol tetramer, paeonilactiflorol (1), and 14 known compounds (2-15) were isolated from peony seeds ( Paeonia lactiflora) under the guidance of bioassay. Paeonilactiflorol (1) was determined by extensive HRESIMS, UV, IR, 1D and 2D NMR spectroscopic analyses. Most of the stilbenes showed obvious inhibition on PTP1B and α-glucosidase, superior to the monoterpene glycosides. Especially, the stilbene tetramer (1) and trimer (8) exhibited high activity inhibiting both PTP1B with IC₅₀ values of 27.23 and 27.81 μM and α-glucosidase with IC₅₀ values of 13.57 and 14.39 μM. Two trans-dimers (4 and 5) also showed dipeptidyl peptidase-4 (DPPIV) inhibitory activity (55.35% and 61.26%, 500 μM) in addition to PTP1B and α-glucosidase. Enzyme kinetic study indicated that the types of inhibition on PTP1B were noncompetitive for 3 and 5 and mixed for 8 and 10. Quantitative analysis suggested that the stilbene trimers 8 (23.17 ± 0.36 mg/g) and 10 (15.24 ± 0.25 mg/g) were the main contents in peony seeds and should be responsible for the antidiabetic effects. This investigation supports the therapeutic potential of peony seeds in the treatment of diabetes with stilbenes as the active constituents.

Oil biosynthesis and transcriptome profiles in developing endosperm and oil characteristic analyses in Paeonia ostii var. lishizhenii

Paeonia ostii var. lishizhenii, a well-known medicinal and horticultural plant, is indigenous to China. Recent studies have shown that its seed has a high oil content, and it was approved as a novel resource of edible oil with a high level of α-linolenic acid by the Chinese Government. This study measured the seed oil contents and fatty acid components of P. ostii var. lishizhenii and six other peonies, P. suffruticosa, P. ludlowii, P. decomposita, P. rockii, and P. lactiflora Pall. 'Heze' and 'Gansu'. The results show that P. ostii var. lishizhenii exhibits the average oil characteristics of tested peonies, with an oil content of 21.3%, α-linolenic acid 43.8%, and unsaturated fatty acids around 92.1%. Hygiene indicators for the seven peony seed oils met the Chinese national food standards. P. ostii var. lishizhenii seeds were used to analyze transcriptome gene regulation networks on endosperm development and oil biosynthesis. In total, 124,117 transcripts were obtained from six endosperm developing stages (S0-S5). The significant changes in differential expression genes (DEGs) clarify three peony endosperm developmental phases: the endosperm cell mitotic phase (S0-S1), the TAG biosynthesis phase (S1-S4), and the mature phase (S5). The DEGs in plant hormone signal transduction, DNA replication, cell division, differentiation, transcription factors, and seed dormancy pathways regulate the endosperm development process. Another 199 functional DEGs participate in glycolysis, pentose phosphate pathway, citrate cycle, FA biosynthesis, TAG assembly, and other pathways. A key transcription factor (WRI1) and some important target genes (ACCase, FATA, LPCAT, FADs, and DGAT etc.) were found in the comprehensive genetic networks of oil biosynthesis.

Simultaneous determination of paeonilactone A and paeonilactone B in rat plasma after oral administration of albiflorin by UPLC/TOF/MS following picolinoyl derivatization

A new highly sensitive analytical method was developed to investigate the in vivo metabolism of albiflorin, one of the most principal components in traditional Chinese medicine. After hydrolyzation with sulfatase, the main metabolites paeonilactone A and paeonilactone B of paeoniflorin in rat plasma were successfully detected for the first time by liquid chromatography mass spectrometry following picolinoyl derivatization. Borneol was used as the internal standard compound to quantify paeonilactone A and paeonilactone B in rat plasma. Paeonilactone A and paeonilactone B show different pharmacokinetic behaviors. The maximum plasma concentration of paeonilactone A reached 36.4±5.6ng/mL at about 8h after oral administration of albiflorin at a dose of 5mg/kg, while the maximum plasma concentration of paeonilactone B reached 12.4±3.4ng/mL at about 2h. The total metabolic pathway of albiflorin in rats was proposed. Albiflorin was found to be metabolized to the sulfate of paeonilactone A and paeonilactone B which may be responsible for the biological effect of albiflorin. The new analytical method may help to elucidate the clinical efficacy of traditional Chinese formula containing albiflorin.

The effects of process technology on the physicochemical properties of peony seed oil

Peony seed oils (PSOs) were prepared using supercritical CO2 (SC) and compared with soxhlet extraction (SE) and mechanical screw press extraction (SPE) methods. The fatty acid compositions of the oils were determined, and the physicochemical properties of the oils, including free radical-scavenging activity, α-amylase and α-glucosidase inhibition, thermal and rheological properties were evaluated. The unsaturated fatty acids in the SE oils were higher than SC and SPE oils due to the higher percentage of olefinic, allylic methylene and allylic methine protons in the SE oils. The SPE oils also displayed the highest DPPH and ABTS+ radical scavenging activity at the tested concentrations. However, the SE oils showed stronger inhibitory effects on α-amylase and α-glucosidase enzymes under in vitro conditions when compared with the other oil samples. The three oils had similar melting and crystalline point due to similar contents of fatty acids (FAs). The SC oils had a lower Ea than the others.

Punicic acid: A striking health substance to combat metabolic syndromes in humans

Punicic acid, a bioactive compound of pomegranate seed oil has gained wide attention for their therapeutic potential. Different studies conducted on animal and human models have revealed that punicic acid is very effective against various chronic diseases. Substantial laboratory works has been carried out to elaborate punicic acid effectiveness and mechanism of action in animals. The intention of this review article is to explore the facts about the clinical trials of punicic acid and to discuss different future strategies that can be employed to use it in human clinical trials. Although punicic acid may represent a novel therapeutic unconventional approach for some disorders, still further experimental studies are required to demonstrate its effects in human beings.

Inhibition of α-glucosidase and α-amylase by Spanish extra virgin olive oils: The involvement of bioactive compounds other than oleuropein and hydroxytyrosol

Despite the wide use of extra virgin olive oil (EVOO) to combat several diseases, the antidiabetic and anti-cholinesterase activity of Spanish EVOO have not been assessed. In order to evaluate which compounds are responsible for these activities of five Spanish EVOOs, in addition to flavonoids, we investigated for the first time the effect of the contents of carotenoids, fatty acids (FAs), and phytoprostanes (PhytoPs) on four enzymes: α-glucosidase, α-amylase, acetylcholinesterase, and butyrylcholinesterase. The extracts of these five Spanish EVOOs were found to contain three flavones, three carotenoids, six FAs, and seven classes of PhytoPs. The samples exhibited no in vitro anti-cholinesterase activity but presented strong antidiabetic activity, in the order: 'Arbequina'≈'Picual'≈'Cuquillo'>'Hojiblanca'>'Cornicabra'. The samples showed a higher in vitro hypoglycemic effect than individual or mixed standards, possibly due to interaction between multiple identified compounds and/or a very complex multivariate interaction between other factors.

Effect of traditional Chinese cooking methods on fatty acid profiles of vegetable oils

The effect of four frying processes (vegetable salad, stir frying, pan frying, and deep frying) on fatty acid composition of ten vegetable oils (peanut oil, soybean oil, rapeseed oil, corn oil, sunflower seed oil, rice bran oil, olive oil, sesame oil, linseed oil, and peony seed oil) was investigated using GC-MS. The result showed that trans-fatty acid (TFA) was produced during all processes. Rapeseed oil had the highest TFA content in vegetable salad oil with 2.88% of total fatty acid. The TFA content of sunflower seed oil was 0.00% in vegetable salad oil, however, after stir frying and pan frying, it increased to 1.53% and 1.29%, respectively. Peanut oil had the lowest TFA content after deep frying for 12h with 0.74mg/g. It was concluded that a healthy cooking process could be acquired by a scientific collocation.

The Hypoglycemic, Hypolipidemic, and Anti-Diabetic Nephritic Activities of Zeaxanthin in Diet-Streptozotocin-Induced Diabetic Sprague Dawley Rats

Zeaxanthin (ZA), an important compound found in Lycium barbarum, shows various pharmacodynamic effects. In our present study, a high-fat, high-sucrose diet and streptozotocin (STZ)-induced diabetic rat model was used to investigate the antidiabetic activities of ZA. After a 4-week administration of 200 and 400 mg/kg of ZA and 100 mg/kg of metformin hydrochloride, various blood biochemical indexes were detected. ZA strongly normalized the reduced bodyweight and enhanced fasting blood glucose in diabetic rats. The positive data obtained from the oral glucose tolerance test further confirmed its antidiabetic effects. ZA displayed significant hypolipidemic activities indicated by its modulation of serum levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and total cholesterol. The antidiabetic nephropathy of ZA was confirmed by its regulation of pathological kidney structures, urine levels of n-acetyl-β-d-glucosaminidase and albuminuria, and serum levels of urea nitrogen. ZA inhibited the serum levels of inflammatory factors including interleukin-2 (IL-2), IL-6, tumor necrosis factor-α, and nuclear factor kappa B, further confirming its renal protection. Moreover, the serum imbalances in superoxide dismutase, glutathione peroxidase, methane dicarboxylic aldehyde, and catalase were normalized by ZA, suggesting its antioxidant properties. Altogether, ZA produced hypoglycemic, hypolipidemic, and antidiabetic nephritic effects in a diet-STZ-induced diabetic rat model.

Conjugated fatty acid-rich oil from Gynostrmma pentaphyllum seed can ameliorate lipid and glucose metabolism in type 2 diabetes mellitus mice

Gynostrmma pentaphyllumseed oil (GPSO), extracted fromG. pentaphyllumseeds, is rich in conjugated linolenic acid, which is a special fatty acid consisting ofcis-9,trans-11,trans-13 isomers.

Enhancement of Exposure and Reduction of Elimination for Paeoniflorin or Albiflorin via Co-Administration with Total Peony Glucosides and Hypoxic Pharmacokinetics Comparison

There is evidence suggesting that herbal extracts demonstrate greater bioactivities than their isolated constituents at an equivalent dose. This phenomenon could be attributed to the absence of interacting substances present in the extracts. By measuring the pharmacokinetic parameters of paeoniflorin (PF) and albiflorin (AF) after being orally administered to rats in isolated form, in combination with each other and within total peony glucosides (TPG), respectively, the current study aimed to identify positive pharmacokinetic interactions between components of peony radix extracts. Moreover, the pharmacokinetic profiles of PF and AF under normoxia and hypoxia were also investigated and compared. In order to achieve these goals, a highly sensitive and reproducible ultra-peformance liquid chromatography-mass spectrometry (UPLC-MS) method was developed and validated for simultaneously quantitation of PF and AF in rat plasma. This study found that compared with that of single component (PF/AF), the exposure of PF in rat plasma after combination administration or TPG administration was significantly increased, meanwhile the elimination of PF/AF was remarkably reduced. It was also noticed that AUC and Cmax of PF in hypoxia rats were significantly decreased compared with that of normaxia rats, suggesting that there was a decreased exposure of PF in rats under hypoxia. The current study, for the first time, revealed the pharmacokinetic interactions between PF/AF and other constitutes in TGP and the pharmacokinetic profiles of PF and AF under hypoxia. In view of the current findings, it could be supposed that the clinical performance of total peony glucosides would be better than that of single constitute (PF/AF). The outcomes of this animal study are expected to serve as a basis for development of clinical guidelines on total peony glucosides usage.

Studies on the Antidiabetic and Antinephritic Activities of Paecilomyces hepiali Water Extract in Diet-Streptozotocin-Induced Diabetic Sprague Dawley Rats

Paecilomyces hepiali is a fungus widely used in Asian countries for various potential pharmacological activities. The present study aims to evaluate the antidiabetic and antinephritic effects of the Paecilomyces hepiali mycelium water extract (PHC) in diabetic rat, which is established by eight-week high-fat diet administration followed by one-week tail intravenous injection of 25 mg/kg streptozotocin (STZ). After four-week 0.12 g/kg metformin and PHC at doses of 0.08, 0.4, and 2.0 g/kg treatment, an increment of body weight, a decrement of plasma glucose, low levels of total cholesterol, and low density lipoprotein cholesterol in diabetic rats were observed. PHC promotes glucose metabolism by enhancing insulin, pyruvate kinase activity, and increasing the synthesis of glycogen. PHC normalized the disturbed levels of superoxide dismutase, methane dicarboxylic aldehyde, and glutathione peroxidase in kidney. The inhibitory effects on the levels of interleukin-2, interleukin-6, interleukin-10, and tumor necrosis factor-α in serum and kidney revealed the protection of PHC against diabetic nephropathy. Compared with nontreated diabetic rats, four-week PHC treatment resulted in a decrement on nuclear factor kappa B expression in kidney. These results show that Paecilomyces hepiali possesses antidiabetic and antinephritic effects which are related to the modulation of nuclear factor kappa B activity.