Intra-articular injection of stigmasterol-loaded nanoparticles reduce pain and inhibit the inflammation and joint destruction in osteoarthritis rat model: A pilot study.

Stigmasterol, a plant-derived sterol, sharing structural similarity with cholesterol, has demonstrated anti-osteoarthritis (OA) properties, attributed to its antioxidant and anti-inflammatory capabilities. Given that OA often arises in weight bearing or overused joints, prolonged localized treatment effectively targets inflammatory aspects of the disease. This research explored the impact of stigmasterol-loaded nanoparticles delivered via intra-articular injections in an OA rat model. Employing mesoporous silica nanomaterials (MSNs) combined with ß-cyclodextrin (ß-CD) as a vehicle, stigmasterol was loaded in conjunction with tannic acid, forming stigmasterol/ß-CD-MSNs to facilitate a sustained stigmasterol release. The study employed RAW 264.7 cells to examine the in vitro cytotoxicity and anti-inflammatory effect of stigmasterol/ß-CD-MSNs. For in vivo experimentation, we used healthy control rats and monosodium iodoacetate (MIA)-induced OA rats, separated into five groups, varying the injection substances. In vitro findings indicated that stigmasterol/ß-CD-MSNs suppressed the mRNA expression of key pro-inflammatory mediators such as interleukin-6, tumor necrosis factor-α, and matrix metalloproteinase-3 in a dose-dependent manner. In vivo experiments revealed a substantial decrease in the mRNA levels of pro-inflammatory factors in the stigmasterol(50 µg)/ß-CD-MSN group compared to the others. Macroscopic, radiographic, and histological evaluations established that intra-articular injections of stigmasterol/ß-CD-MSNs inhibited cartilage degeneration and subchondral bone deterioration. Therefore, in a chemically induced OA rat model, intra-articular stigmasterol delivery was associated with reduction in both local and systemic inflammatory responses, alongside a slowdown in joint degradation and arthritic progression.

Investigation of the anti-inflammatory effects of stigmasterol in mice: insight into its mechanism of action.

Stigmasterol is a phytosterol that presents pharmacologic properties. However, its anti-inflammatory mechanism and antinociceptive effect are not yet elucidated. Thus, the present study aimed to investigate the anti-inflammatory and antinociceptive activities of stigmasterol and its mechanism of action in mice. The antinociceptive activity was assessed by the acetic acid-induced writhing test, formalin test, and hot plate test. The anti-inflammatory activity was investigated by carrageenan-induced peritonitis and paw edema induced by arachidonic acid. The involvement of glucocorticoid receptors in the mechanism of stigmasterol anti-inflammatory action was investigated by molecular docking, also by pretreating mice with RU-486 (glucocorticoid receptor antagonist) in the acetic acid-induced writhing test. Mice motor coordination was evaluated by the rota-rod test and the locomotor activity by the open field test. The lowest effective dose of stigmasterol was standardized at 10 mg/kg (p.o.). It prevented abdominal writhes and paw licking, but it did not increase the latency time in the hot plate test, suggesting that stigmasterol does not show an antinociceptive effect in response to a thermal stimulus. Stigmasterol decreased leukocyte infiltration in peritonitis assay and reduced paw edema elicited by arachidonic acid. Molecular docking suggested that stigmasterol interacts with the glucocorticoid receptor. Also, RU-486 prevented the effect of stigmasterol in the acetic-acid abdominal writhing test, which might indicate the contribution of glucocorticoid receptors in the mechanism of stigmasterol action. Stigmasterol reduced the number of crossings but did not impair mice's motor coordination. Our results show that stigmasterol presents anti-inflammatory effects probably mediated by glucocorticoid receptors.

Synergistic Dose Permutation of Isolated Alkaloid and Sterol for Anticancer Effect on Young Swiss Albino Mice.

INTRODUCTION: Synergy is defined as an interaction of some substances that cooperate to give rise to the combined effect greater than the sum of their individual effects. It is a natural strategy that has evolved by nature to more efficacy with low cost. METHODS: This study is designed to evaluate the chemopreventive effect of a combined drug sample which is prepared by mixing an equal portion of stigmasterol and palmatine isolated from Azadirachta indica and Tinospora cordifolia respectively at a concentration of 100 mg/kg and 200 mg/kg body weight during the whole concentration. RESULTS: At the end of the study, it was found that this combined drug sample decreased the number of tumors and their size. This drug significantly reduced the serum level of glutamate pyruvate transaminase, alkaline phosphatase, glutamate oxalate transaminase, and bilirubin and enhanced the level of oxidative enzyme level of glutathione, superoxide dismutase, and catalase, and inhibit the level of lipid peroxides. DISCUSSION: The result suggests that combined drug samples exhibit a chemopreventive effect which is better than the effect of individual drugs (stigmasterol and palmatine).

Beneficial effects of secretome derived from mesenchymal stem cells with stigmasterol to negate IL-1ß-induced inflammation in-vitro using rat chondrocytes-OA management.

Osteoarthritis (OA) is the most prevalent joint disease predominantly characterized by inflammation which drives cartilage destruction. Mesenchymal stem cells-condition medium (MSC-CM) or the secretome is enriched with bioactive factors and possesses anti-inflammatory and regenerative effects. The present study aimed at evaluating the effects of combining MSC-conditioned medium with stigmasterol compared with the individual treatments in alleviating interleukin-1 beta (IL-1ß)-induced inflammation in rat chondrocytes. Stigmasterol is a phytosterol exhibiting anti-inflammatory effects. IL-1ß (10 ng/ml) was used to induce inflammation and mimic OA in-vitro in primary rat articular chondrocytes. The IL-1ß-stimulated chondrocytes were treated with MSC-CM, stigmasterol, and a combination of MSC-CM and stigmasterol for 24 h. Cell viability was measured using MTT assay. Protein expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), collagen II (COL2A1) and matrix metalloproteinase (MMP)-13 were evaluated by immunofluorescence. Gene expression levels of MMP-3, MMP-13 and A Disintegrin-like and Metalloproteinases with Thrombospondin Motifs (ADAMTS)-5 were measured using qRT-PCR. NF-κB signaling pathway was studied using western blotting. A significant reduction in the expression of iNOS, IL-6, MMP-3, MMP-13 and ADAMTS-5, and a significant increase in COL2A1 expression was observed in the rat chondrocytes across all the treatment groups. However, the combination treatment of MSC-CM and stigmasterol remarkably reversed the IL-1ß-induced pro-inflammatory/pro-catabolic responses to near normal levels comparable to the control group. The combination treatment (MSC-CM + stigmasterol) elicited a superior anti-inflammatory/anti-catabolic effect by inhibiting the IL-1ß-induced NF-κB activation evidenced by the negligible phosphorylation of p65 and IκBα subunits, thereby emphasizing the benefit of the combination therapy over the individual treatments.

Stigmasterol promotes neuronal migration via reelin signaling in neurosphere migration assays.

Stigmasterol (ST) is a multifunctional phytosterol and is found in diverse food. In our previous transcriptomics study, we found ST upregulated migration-related genes. In the present study, we carried out in vitro neurosphere migration assays to investigate the effects of ST on neuronal migration. For this purpose, neurospheres were produced by culturing rat (Sprague-Dawley) E14 cortical neurons. The addition of ST (75 µM) to culture medium increased not only the numbers of migratory neurons by 15% but the distance of movement up to 120 µm from the centers of neurospheres as compared to vehicle cultures. Immunocytochemistry and immunoblotting showed ST upregulated the expressions of Reelin (Reln) and its downstream signaling molecules like phospho-JNK (c-Jun N-terminal kinase), doublecortin (DCX) and dynein heavy chain (DHC) in migratory neurons. Furthermore, in silico molecular docking simulation indicated that ST interacts with Relin receptor ApoER2 by forming a hydrogen bond with Lys2467 and other van der Waals interactions. Taken together, our study shows that ST upregulates Reln signaling and promotes neuronal migration and suggests that ST supplementation is considered as a potential means of treating migration-related CNS disorders.

Intake of stigmasterol and ß-sitosterol alters lipid metabolism and alleviates NAFLD in mice fed a high-fat western-style diet.

OBJECTIVE: To investigate and compare the effects of two common dietary phytosterols, stigmasterol and ß-sitosterol, in altering lipid metabolism and attenuating nonalcoholic fatty liver disease (NAFLD). METHODS: Stigmasterol and ß-sitosterol were administered to mice at 0.4% in a high-fat western-style diet (HFWD) for 17 weeks. RESULTS: Stigmasterol and ß-sitosterol significantly ameliorated HFWD-induced fatty liver and metabolic abnormalities, including elevated levels of hepatic total lipids, triacylglycerols, cholesterol and liver histopathology. Both phytosterols decreased the levels of intestinal bile acids, accompanied by markedly increased fecal lipid levels. In addition, they altered the expression of genes involved in lipid metabolism. ß-Sitosterol was less effective in affecting most of these parameters. Lipidomic analysis of liver and serum samples showed that stigmasterol prevented the HFWD-induced elevation of some di- and triacylglycerol species and lowering of some phospholipid species. Stigmasterol also decreased serum levels of ceramides. CONCLUSION: Stigmasterol and ß-sitosterol, at a dose corresponding to that suggested for humans by the FDA for lowering cholesterol levels, are shown to alleviate HFWD-induced NAFLD. Stigmasterol was more effective than ß-sitosterol, possibly because of its suppression of hepatic lipogenic gene expression and modulation of circulating ceramide levels.

Effects of Stigmasterol and ß-Sitosterol on Nonalcoholic Fatty Liver Disease in a Mouse Model: A Lipidomic Analysis.

To study the effects of stigmasterol and ß-sitosterol on high-fat Western diet (HFWD)-induced nonalcoholic fatty liver disease (NAFLD), lipidomic analyses were conducted in liver samples collected after 33 weeks of the treatment. Principal component analysis showed these phytosterols were effective in protecting against HFWD-induced NAFLD. Orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and S-plots showed that triacylglycerols (TGs), phosphatidylcholines, cholesteryl esters, diacylglycerols, and free fatty acids (FFAs) were the major lipid species contributing to these discriminations. The alleviation of NAFLD is mainly associated with decreases in hepatic cholesterol, TGs with polyunsaturated fatty acids, and alterations of free hepatic FFA. In conclusion, phytosterols, at a dose comparable to that suggested for humans by the FDA for the reduction of plasma cholesterol levels, are shown to protect against NAFLD in this long-term (33-week) study.

ß-Sitosterol and stigmasterol ameliorate dextran sulfate sodium-induced colitis in mice fed a high fat Western-style diet.

Phytosterols, the plant analogues of cholesterol, widely occur in the human diet. In this study, we investigated and compared the effects of stigmasterol and ß-sitosterol (both with purities ≥95%) on dextran sulfate sodium (DSS)-induced colitis in C57BL/6J male mice fed a high fat Western-style diet. Mice treated with DSS developed severe mucosal colitis, with a marked distortion and crypt loss of colonic surface epithelium. Both ß-sitosterol and stigmasterol significantly inhibited colon shortening, lowered fecal hemoglobin content, and reduced the severity of colitis in the middle and distal colon (p < 0.05). These phytosterols also significantly suppressed the activation of nuclear factor-kappa B. They also significantly decreased colony stimulating factor-1 and the nuclear translocation of inflammatory master regulator nuclear factor-kappa B. Stigmasterol significantly lowered the colonic inflammation score and the expression of cyclooxygenase-2 and colony stimulating factor-1, while ß-sitosterol was less or not effective. These results suggest that dietary intake of stigmasterol and ß-sitosterol ameliorates colitis. Such activities of stigmasterol and ß-sitosterol in humans remain to be investigated.

α-Spinasterol: a COX inhibitor and a transient receptor potential vanilloid 1 antagonist presents an antinociceptive effect in clinically relevant models of pain in mice.

BACKGROUND AND PURPOSE: Postoperative pain is one of the most common manifestations of acute pain and is an important problem faced by patients after surgery. Moreover, neuronal trauma or chemotherapeutic treatment often causes neuropathic pain, which induces disabling and distressing symptoms. At present, treatments of both painful conditions are inadequate. α-Spinasterol, which is well characterized as a transient receptor potential vanilloid 1 antagonist, has anti-inflammatory, antioxidant and antinociceptive effects. Therefore, we investigated its antinociceptive potential on postoperative and neuropathic pain, as well as its effect on COX-1 and COX-2 activities. EXPERIMENTAL APPROACH: Nociceptive responses in a postoperative pain model (surgical incision-induced) or different neuropathic pain models (trauma or chemotherapy-induced) were investigated in mice. KEY RESULTS: Oral administration of α-spinasterol reduced postoperative pain, when given as a pre- (0.5 h before incision) or post-treatment (0.5 h after incision), and reduced cell infiltration in the injured tissue. α-Spinasterol also reduced the mechanical allodynia induced by partial sciatic nerve ligation and the mechanical and cold allodynia induced by paclitaxel. Moreover, α-spinasterol inhibited COX-1 and COX-2 enzyme activities without altering the body temperature of animals. Importantly, α-spinasterol did not alter spontaneous or forced locomotor activity. Furthermore, it did not cause gastric damage or liver and kidney changes, nor did it alter cell viability in the cerebral cortex and spinal cord slices of mice. CONCLUSION AND IMPLICATIONS: α-Spinasterol is an effective and safe COX inhibitor with antinociceptive effects in postoperative and neuropathic pain models. Therefore, it is an interesting prototype for the development of novel analgesic drugs.

Buddleja thyrsoides Lam. crude extract presents antinociceptive effect on an arthritic pain model in mice.

Arthritis is a chronic inflammatory disease which reduces the life quality of affected individuals. Therapeutic tools used for treating inflammatory pain are associated with several undesirable effects. Buddleja thyrsoides Lam., known as 'Barbasco' or 'Cambara', is mostly used in several disorders and possesses antirheumatic, anti-inflammatory, and analgesic properties. Here, we investigated the antinociceptive and anti-inflammatory effects of the B. thyrsoides crude extract applied orally and topically in acute pain models and an arthritic pain model induced by complete Freund's adjuvant (CFA) paw injection in male mice (25-30 g). The high-performance liquid chromatography (HPLC) of the B. thyrsoides extract crude revealed the presence of the lupeol, stigmasterol, and ß-sitosterol. The stability study of the B. thyrsoides gel did not show relevant changes at low temperatures. The oral treatment with the B. thrysoides extract prevented the capsaicin-induced spontaneous nociception and the acetic acid-induced abdominal writhing, but did not alter the thermal threshold in the tail immersion test. The B. thyrsoides antinociceptive effect was not reversed by naloxone in the capsaicin test. The B. thyrsoides oral or topical treatment reversed the CFA-induced mechanical allodynia and thermal hyperalgesia with maximum inhibition (Imax) of 69 ± 6 and 68 ± 5% as well as 78 ± 15 and 87 ± 12%, respectively. Moreover, the topical but not oral treatment inhibited the CFA-induced cell infiltration, but did not reduce the paw edema significantly. The oral treatment with B. thyrsoides did not cause adverse effects. These findings suggest that the oral or topical treatment with B. thyrsoides presents antinociceptive actions in an arthritic pain model without causing adverse effects.

Preclinical Assessment of Cardiovascular Alterations Induced by Birch Polypore Mushroom, Piptoporus betulinus (Agaricomycetes).

Piptoporus betulinus has been used in folk medicine for millennia. However, no data currently exist regarding its potential cardiovascular activity. In this work, the crude ethanolic extract and fractions (hexane, ethyl acetate, and water) with increased polarity from the partitioning process, as well as stigmasterol (the major metabolite isolated from P. betulinus), were administered orally at different doses to normotensive male Wistar rats an hour before recording mean arterial pressure, heart rate, renal blood flow, renal vascular conductance, arterial blood flow, and arterial vascular conductance. The acute oral administration of crude ethanolic extract and all fractions did not alter mean arterial pressure when compared with the control group, which received a vehicle. In addition, subchronic (14 days) oral administration of crude ethanolic extract, fractions, and stigmasterol did not alter cardiovascular parameters. In conclusion, our findings demonstrate that oral administration of organic extracts of P. betulinus did not induce cardiovascular alterations.

The effect of a plant extract enriched in stigmasterol and ß-sitosterol on glycaemic status and glucose metabolism in alloxan-induced diabetic rats.

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana pseudostem, is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. The present study was aimed at elucidating the mechanism of antihyperglycaemia exerted by the ethanol extract of banana pseudostem (EE) and its isolated compounds viz., stigmasterol (C1) and ß-sitosterol (C2), in an alloxan-induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EE (100 and 200 mg per kg b. wt.) for 4 weeks showed reduced levels of fasting blood glucose and reversal of abnormalities in serum/urine protein, urea and creatinine in diabetic rats compared to the diabetic control group of rats. Diabetic symptoms such as polyphagia, polydipsia, polyuria, urine glucose and reduced body weight were ameliorated in the diabetic group of rats fed with EE, C1 and C2 (100 mg per kg b. wt., once daily) for 28 days. The levels of insulin and Hb were also increased, while the HbA1c level was reduced. The altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase and lactate dehydrogenase) and pyruvate kinase were significantly reverted to normal levels by the administration of EE, C1 and C2. In addition, increased levels of hepatic glycogen and glycogen synthase and the corresponding decrease of glycogen phosphorylase activity in diabetic rats illustrated the antihyperglycaemic potential of EE and its components. The histological observations revealed a marked regeneration of the ß-cells in the drug treated diabetic rats. These findings suggest that EE might exert its antidiabetic potential in the presence of C1 and C2, attributable to the enhanced glycolytic activity, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant ß-cells.

Evaluation of the antidepressant- and anxiolytic-like activity of α-spinasterol, a plant derivative with TRPV1 antagonistic effects, in mice.

The transient receptor potential vanilloid 1 (TRPV1) receptor has recently gained attention as a new molecular target in the treatment of mental disorders such as depression and anxiety. α-Spinasterol is a plant steroid that acts as a TRPV1 antagonist. The present study was undertaken to evaluate the antidepressant- and anxiolytic-like properties of α-spinasterol in mice. The obtained results showed that α-spinasterol (at doses of 1 and 2mg/kg) exerted anti-immobility effect in mice subjected to the forced swim test. Furthermore, co-administration of an ineffective dose of α-spinasterol (0.5mg/kg) with an ineffective dose of another TRPV1 antagonist - capsazepine (50 µg/mouse) produced a synergistic effect in the forced swim test. This compound was, however, devoid of anxiolytic-like effects in the elevated plus maze (at doses of 0.5-2mg/kg) and the light/dark box test (at a dose of 2mg/kg) in mice. Of note, α-spinasterol did not produce significant changes in body temperature and did not alter spontaneous locomotor activity in mice. The present study adds further support to the thesis that antagonism of the TRPV1 receptors may produce antidepressant effects. α-Spinasterol may represent a new therapeutic approach towards the development of novel antidepressant therapy. However, further detailed studies on the antidepressant potential of α-spinasterol are warranted.

Bioaccessibility study of plant sterol-enriched fermented milks.

The bioaccessibility (BA) of total and individual plant sterols (PS) of four commercial PS-enriched fermented milk beverages (designated as A to D) was evaluated using in vitro gastrointestinal digestion including the formation of mixed micelles. The fat content of the samples ranged from 1.1 to 2.2% (w/w), and PS enrichment was between 1.5 and 2.9% (w/w). ß-Sitosterol, contained in all samples, was higher in samples A and B (around 80% of total PS). The campesterol content was C (22%) > A (7%) > B (5%). Sitostanol was the most abundant in sample D (85%). Stigmasterol was only present in sample C (33%). The greatest BA percentage for total PS corresponded to samples A and B (16-17%), followed by sample D (11%) and sample C (9%). The total BA was not related to the protein, lipid or PS content of the beverages, whereas samples with higher carbohydrates and fiber contents showed lower BA. The BA of the individual PS differed according to the sample considered, and was not related to the PS profile of the sample, thus indicating strong dependency upon the matrix (PS ingredient and other components). Although in vivo studies should be carried out to better assess the functionality of PS in functional foods such as enriched fermented milk beverages, our in vitro study is a useful preliminary contribution to evaluation of the efficacy of these products.

Isolation and evaluation of anticancer efficacy of stigmasterol in a mouse model of DMBA-induced skin carcinoma.

Stigmasterol (99.9% pure) was isolated from Azadirachta indica and its chemopreventive effect on 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer was investigated in Swiss albino mice. Skin tumors were induced by topical application of DMBA and promoted by croton oil. To assess the chemopreventive potential of stigmasterol, it was orally administered at a concentration of 200 mg/kg and 400 mg/kg three times weekly for 16 weeks. Reduction in tumor size and cumulative number of papillomas were seen as a result of treatment with stigmasterol. The average latency period was significantly increased as compared with the carcinogen-treated control. Stigmasterol induced a significant decrease in the activity of serum enzymes, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and bilirubin as compared with the control. Stigmasterol significantly increased glutathione, superoxide dismutase, and catalase as compared with the control. Elevated levels of lipid peroxide and DNA damage in the control group were significantly inhibited by administration of stigmasterol. From the present study, it can be inferred that stigmasterol has chemopreventive activity in an experimental model of cancer. This chemopreventive activity may be linked to the oxidative stress of stigmasterol. The antigenotoxic properties of stigmasterol are also likely to contribute to its chemopreventive action.

Comparing different sterol containing solid lipid nanoparticles for targeted delivery of quercetin in hepatocellular carcinoma.

Quercetin (QT) is a potential chemotherapeutic drug with low solubility that seriously limits its clinical use. The aim of this study was enhancing cellular penetration of QT by sterol containing solid lipid nanoparticles (SLNs) which make bilayers fluent for targeting hepatocellular carcinoma cells. Three variables including sterol type (cholesterol, stigmasterol and stigmastanol), drug and sterol content were studied in a surface response D-optimal design for preparation of QT-SLNs by emulsification solvent evaporation method. The studied responses included particle size, zeta potential, drug loading capacity and 24 h release efficiency (RE24%). Scanning electron and atomic force microscopy were used to study the morphology of QT-SLNs and their thermal behavior was studied by DSC analysis. Cytotoxicity of QT-SLNs was determined by MTT assay on HepG-2 cells and cellular uptake by fluorescence microscopy method. Optimized QT-SLNs obtained from cholesterol and QT with the ratio of 2:1 that showed particle size of 78.0 ± 7.0 nm, zeta potential of -22.7 ± 1.3 mV, drug loading efficiency of 99.9 ± 0.5% and RE24 of 56.3 ± 3.4%. IC50 of QT in cholesterol SLNs was about six and two times less than free QT and phytosterol SLNs, respectively, and caused more accumulation of QT in HepG2 cells. Blank phytosterol SLNs were toxic on cells.

Common sources and composition of phytosterols and their estimated intake by the population in the city of São Paulo, Brazil.

OBJECTIVE: Phytosterols have been used alone, or combined with lipid-altering drugs, to reduce cholesterol levels and the burden of cardiovascular disease. Considerable variation in the composition of phytosterols exists and its consumption, in a regular diet, by the Brazilian population is still unknown. Thus, the aim of the present study was to determine the phytosterols content of the most consumed plant foods and to estimate the phytosterols intake by this population. METHODS: Intake of plant foods of a representative population of the city of São Paulo (n = 1609), randomly selected on the basis of the Brazilian Institute for Geography and Statistics census data (2010), was obtained by a food frequency questionnaire (FFQ). Foods were chosen on the basis of the Consume Expenditure Survey (2002-2003) and from answers to the FFQ. Phytosterols composition of most consumed greens, legumes, cereals, and seeds, fruits, and vegetable oils was determined by gas chromatography (flame ionization detection). Daily phytosterols intake was estimated in terms of mg per 100 g (mg/100 g(-1)) of edible portion. Underreporters and overreporters were excluded. RESULTS: Mean (SE) daily phytosterols intake in the diet of the study population was 100.6 (1.2) mg, with ß-sitosterol as the largest sterol component (65.4%), followed by campesterol (23.2%), and stigmasterol (10%). No significant changes in daily phytosterols intake were observed after exclusion of underreporters and overreporters. Considerable variation was observed in phytosterols content among the most consumed plant foods. CONCLUSIONS: Analysis of phytosterols composition in most consumed plant foods has shown that phytosterols content varied among food groups. Dietary intake of phytosterols in a large population of the city of São Paulo is in the same range of some countries.

Stigmasterol blocks cartilage degradation in rabbit model of osteoarthritis.

Stigmasterol has been shown exhibit anti-osteoarthritic properties in vitro studies. However, the in vivo effects of stigmasterol on cartilage are still unclear. This study investigated the anti-osteoarthritic properties of stigmasterol on cartilage degradation in a rabbit model of osteoarthritis (OA). Twenty rabbits underwent bilateral anterior cruciate ligament transection (ACLT) to induce OA. Five rabbits were used as normal control. Two weeks after operation, the rabbits were randomly divided into two groups. Each group of 10 rabbits received intra-articular injection with 0.3 ml of stigmasterol in left knees and vehicle in right knees, once weekly. Group 1 was killed 6 weeks after ACLT and 2 were sacrificed 9 weeks after ACLT. The knee joints were assessed by gross morphology, histology and gene expression analysis. We found that expression of genes encoding matrix metalloproteinases (MMPs) was significantly higher while tissue inhibitors of metalloproteinase (TIMP)-1 was significantly lower in the both joints of the two OA groups compared to normal controls. Stigmasterol reduced the cartilage degradation as assessed by histological analysis and markedly suppressed MMPs expression both in group 1 and group 2. Our results suggest that stigmasterol may be considered as a possible therapeutical agent in the treatment of OA.

Dietary intake of plant sterols stably increases plant sterol levels in the murine brain.

Plant sterols such as sitosterol and campesterol are frequently administered as cholesterol-lowering supplements in food. Recently, it has been shown in mice that, in contrast to the structurally related cholesterol, circulating plant sterols can enter the brain. We questioned whether the accumulation of plant sterols in murine brain is reversible. After being fed a plant sterol ester-enriched diet for 6 weeks, C57BL/6NCrl mice displayed significantly increased concentrations of plant sterols in serum, liver, and brain by 2- to 3-fold. Blocking intestinal sterol uptake for the next 6 months while feeding the mice with a plant stanol ester-enriched diet resulted in strongly decreased plant sterol levels in serum and liver, without affecting brain plant sterol levels. Relative to plasma concentrations, brain levels of campesterol were higher than sitosterol, suggesting that campesterol traverses the blood-brain barrier more efficiently. In vitro experiments with brain endothelial cell cultures showed that campesterol crossed the blood-brain barrier more efficiently than sitosterol. We conclude that, over a 6-month period, plant sterol accumulation in murine brain is virtually irreversible.

Antioxidant activity of Heterotheca inuloides extracts and of some of its metabolites.

Arnica (Heterotheca inuloides) is a widely used medicinal plant in México; it has been recognized as anti-inflammatory, analgesic, cytotoxic, scavenger of superoxide anion and also as a preventive of lipid peroxidation. In vivo studies have demonstrated a hepatoprotective action of the methanolic extract of this plant as well as of quercetin, one of its main components, and the evidence obtained pointed out to an antioxidant mechanism. In this work, we focused on the free radical scavenging capacity of acetonic and methanolic extracts of H. inuloides in comparison with reference compounds. The two extracts were 2-12 times more effective (IC50, microg/mL) than the reference compounds to cope with the following radicals or molecules tested: 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)), 2,2-diphenyl-1-picrylhydrazyl (DPPH), peroxynitrite (ONOO(-)), superoxide (O2(-)), singlet oxygen ((1)O(2)), hypochlorous acid (HOCl), hydrogen peroxide (H2O2), hydroxyl (OH). Additionally, five secondary metabolites isolated from the methanolic extract displayed potent concentration-dependent antioxidant effects against reactive oxygen species produced in vitro (IC50 values in the range of 0.018-4.31mg/mL). d-Chiro-inositol showed the higher antioxidant effect against O2(-), H2O2 and OH while spinasterol and quercetin were the most active against (1)O(2) and ONOO(-), respectively. The antioxidant properties of the extracts and metabolites tested partially support the wide use of this plant in traditional medicine.