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Soybean [Glycine max L. (Merrill)] embryos accumulate sucrose, raffinose and stachyose during seed development and maturation. Raffinose and stachyose in soybean feed products are not digested by monogastric animals, resulting in flatulence and fewer nutrients for growth. Three lines of soybean selected for low-raffinose and low-stachyose (LRS) or low-raffinose, low-stachyose and low-phytin (LRSP1, LRSP2) concentrations in mature seed were compared to a CHECK line with normal concentrations of raffinose, stachyose and phytin. To determine if increasing the supply of free cyclitols to developing seed of these lines results in increased accumulation of galactosyl cyclitols, soybean stem-leaf-pod explants of each line were fed solutions containing 10mM d-chiro-inositol, 10mM myo-inositol, or 10mM d-pinitol, or a control solution without cyclitols for 7 days. Explants were air-dried for 14 days. Soluble carbohydrates were extracted from axis, cotyledon, and seed coat tissues of mature, dry seed and analyzed by high-resolution gas chromatography. Axis and cotyledons from mature seed of all modified lines had low concentrations of stachyose compared to the CHECK line when fed a control solution without cyclitols. Feeding d-chiro-inositol to explants increased fagopyritol B1 accumulation in mature seed from all lines. Feeding myo-inositol to explants increased stachyose accumulation in mature seed of LRSP1, but feeding d-pinitol to explants did not alter soluble carbohydrate composition of mature seed. These responses demonstrate that an increase in the supply of free d-chiro-inositol in maternal tissues can result in enhanced accumulation of fagopyritols in mature seed of low-raffinose and low-stachyose or low-raffinose, low-stachyose and low-phytin soybean.

▼ Oxidative stress plays a crucial role in the progression and development of diabetes and its complications due to chronic hyperglycemia. The present study was aimed to investigate the kidney tissue protective nature of d-pinitol, a cyclitol present in soybean, by assessing the key markers of hyperglycemia-mediated oxidative stress, proinflammatory cytokines and ultrastructural alterations in streptozotocin-induced diabetic rats. Oral administration of d-pinitol (50mg/kg body weight/day) for 30 days to diabetic group of rats showed a significant elevation in the level of total protein and significant decline in the levels of blood urea, serum uric acid, creatinine and advanced glycation endproducts (AGEs) and kidney proinflammatory cytokines such as TNF-α, IL-1β, IL-6, NF-κB p65 subunit and nitrite. Further, d-pinitol administration elicited a significant attenuation in the activities of kidney enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) and the levels of kidney non-enzymatic antioxidants such as vitamin E, vitamin C and reduced glutathione (GSH) in the diabetic group of rats, with a concomitant decline in the levels of kidney lipid peroxides, hydroperoxides and protein carbonyls. The histological and ultrastructural observations on the kidney tissues also confirmed the renoprotective nature of d-pinitol. Thus the present study demonstrated the renoprotective nature of d-pinitol by attenuating the hyperglycemia-mediated proinflammatory cytokines and antioxidant competence in kidney tissues of streptozotocin-induced diabetic rats.

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d-pinitol has been demonstrated to exert insulin-like and anti-inflammatory effects. However, the effects of the maturation and immunostimulatory functions of dendritic cells (DC) remain to be clearly elucidated. In this study, we have attempted to determine whether d-pinitol regulates surface molecule expression, cytokine production, endocytosis capacity, and underlying signaling pathways in murine bone marrow-derived DC. We also attempted to ascertain whether d-pinitol could influence Th1/Th2 immune response in vivo. The DC used in this study were derived from murine bone marrow cells, and were used as immature or LPS-stimulated mature DC. The DC were then assessed with regard to surface molecule expression, dextran-FITC uptake, cytokine production, capacity to induce T-cell differentiation, and underlying signaling pathways. d-pinitol was shown to significantly inhibit CD80, CD86, MHC class I, and MHC class II expression in the LPS-stimulated mature DC. The DC also evidenced impaired IL-12 expression and IFN-γ production. The d-pinitol-treated DC were found to be highly efficient in regards to Ag capture via mannose receptor-mediated endocytosis. d-pinitol was also demonstrated to inhibit LPS-induced MAPKs activation and NF-κB nuclear translocation. Moreover, the d-pinitol-treated DC manifested impaired induction of Th1 responses, and normal cell-mediated immune responses. These novel findings provide new insight into the immunopharmacological role of d-pinitol in terms of its effects on DC. These findings also broaden current perspectives concerning our understanding of the immunopharmacological functions of d-pinitol, and have ramifications for the development of therapeutic adjuvants for the treatment of DC-related acute and chronic diseases.

▼ Developing garden pea embryos are able to take up exogenously applied cyclitols: myo-inositol, which naturally occurs in pea, and two cyclitols absent in pea plants: d-chiro-inositol and d-pinitol. The competition in the uptake of cyclitols by pea embryo, insensitivity to glucose and sucrose, and susceptibility to inhibitor(s) of H^+-symporters (e.g. CCCP and antimycin A) suggest that a common cyclitol transporter is involved. Both d-chiro-inositol and d-pinitol can be translocated through the pea plant to developing embryos. During seed maturation drying, they are used for synthesis of mainly mono-galactosides, such as fagopyritol B1 and galactosyl pinitol A. Accumulation of d-chiro-inositol (and formation of fagopyritols), but not d-pinitol, strongly reduces accumulation of verbascose, the main raffinose oligosaccharide in pea seeds. The reasons for the observed changes are discussed.

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d-pinitol from Limeum pterocarpum. Successive treatments of an aqueous solution of Limeum pterocarpum extract have led to establish the existence of d-pinitol in this plant. To cite this article: A. Abdoulaye et al., C. R. Chimie 7 (2004).

▼ From the petrol extract of the aerial parts of Tribulus cistoides three steroid sapogenins and two N-acyltyramines were isolated, whereas the methanolic extract gave nine steroid saponins, among them the cardioac- tive cistocardin, saponin-3, saponin-4 and saponin-7. Furthermore, a furostanol diglycoside was isolated besides 5'-(hydroxysulphonyloxy) jasmonic acid, d-(+)-pinitol and sucrose. The structures were established by spectroscopic investigations of the isolated compounds and their hydrolysis products. 5'-(Hydroxysulphonyloxy) jasmonic acid has been prepared by partial synthesis.

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Oviposition by females of the pipevine swallowtail butterfly,Battus philenor, was stimulated by contact with alcoholic extracts of host foliage.d-(+)-Pinitol was isolated and identified from leaf material of one host species,Aristolochia macrophylla (Aristolochiaceae). In combination with chloroform-soluble components of host leaf material, this compound was comparable to the parent extract in stimulating oviposition.

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Aristolochia macrophylla (Lam.) is a major host of the pipevine swallowtail butterfly,Battus philenor (L.), in the eastern United States. The female butterflies use a synergistic mixture of inositols, acids and a lipid as oviposition cues in recognizing this plant on contact. The acids and lipid, all isolated from the Et₂O-CHCl₃ fraction of an alcoholic extract of fresh foliage, were identified as aristolochic acid I (1), aristolochic acid II (2) and 1,2-[di(9Z,12Z,15Z)-octadeca-9, 12, 15-trienoyl]-3-galactosyl-sn-glycerol (3). Identifications were facilitated by UV, MS (EI and FAB) and NMR (1D and 2D) spectral techniques and by analysis of the hydrolysis products of 3. The active inositols were identified as D-(+)-pinitol, reported previously, and sequoyitol. Though this is apparently the first report of oviposition responses to a diacyl glycerol glycoside by a phytophagous insect, responses to aristolochic acids and sequoyitol have been reported previously for anAristolochia-feeding swallowtail of a different genus in Japan. This indicates substantial evolutionary conservatism in chemical oviposition cues within the tribe Troidini.

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d-pinitol has been demonstrated to exert insulin-like and anti-inflammatory activities. However, its anti-allergic effect in the Th1/Th2 immune response is poorly understood. Recently, it was shown that T-bet and GATA-3 are master Th1 and Th2 regulatory transcription factors. In this study, we have attempted to determine whether d-pinitol regulates Th1/Th2 cytokine production, T-bet and GATA-3 gene expression in OVA-induced asthma model mice. We also examined to ascertain whether d-pinitol could influence eosinophil peroxidase (EPO) activity. After being sensitized and challenged with ovalbumin (OVA) showed typical asthmatic reactions. These reactions included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung tissue around blood vessels and airways, airway luminal narrowing, and the development of airway hyper-responsiveness (AHR). The administration of d-pinitol before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that d-pinitol plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of d-pinitol in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of d-pinitol.

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d-pinitol has been demonstrated to exert insulin-like and anti-inflammatory activities. However, its anti-allergic effect in the Th1/Th2 immune response is poorly understood. Recently, it was shown that T-bet and GATA-3 are master Th1 and Th2 regulatory transcription factors. In this study, we have attempted to determine whether d-pinitol regulates Th1/Th2 cytokine production, T-bet and GATA-3 gene expression in OVA-induced asthma model mice. We also examined to ascertain whether d-pinitol could influence eosinophil peroxidase (EPO) activity. After being sensitized and challenged with ovalbumin (OVA) showed typical asthmatic reactions. These reactions included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung tissue around blood vessels and airways, airway luminal narrowing, and the development of airway hyper-responsiveness (AHR). The administration of d-pinitol before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that d-pinitol plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of d-pinitol in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of d-pinitol.

▼ Compounds of dietary origin have always been considered as a paramount entity due to their popular belief of the absence of adverse side effects and also for their extraordinary efficacy against many diseases among which cancer is most important. The present investigation was aimed to evaluate the modulatory effect of d-Pinitol a compound from dietary origin, on the key mitochondrial tricarboxylic acid cycle, carbohydrate metabolizing enzymes and anti-apoptotic protein Bcl-2 against 7, 12-Dimethylbenz [a] anthracene (DMBA) induced mammary carcinoma in female Sprague Dawley rats. Breast caner was induced by intragastric administration of single dose of 20mg/kg body weight of DMBA. The results revealed that the levels of TCA cycle enzymes and carbohydrate metabolizing enzymes were drastically altered in both breast and liver tissues of cancer-bearing animals when compared to controls. Further, the anti-apoptotic protein Bcl-2 was found to be expressed during breast cancer. Interestingly, the oral administration of d-Pinitol at a dosage of 200mg/kg body weight for 45days to breast cancer-bearing rats were found to be significantly brought back the altered enzymes status to near normal range. This therapeutic activity may be due to the antioxidant property of d-Pinitol, which ultimately results in the mitochondrial compartment. Thus, our results clearly confirmed that d-Pinitol has some key modulatory property in mitochondrial and carbohydrate metabolizing enzymes through its antioxidant nature and also regulatory role in the proteins of anti-apoptotic cascade against the free radicals involved oxidative stress-mediated diseases, and which results in the consideration of the compound as safe and more effective in the treatment of mammary carcinoma in the near future.

▼ Chase experiments with ^1^4CO₂ and feeding experiments with labelled inositols showed that d-pinitol in leaves of Simmondsia chinensis arises via epimerization of d-ononitol. This finding represents an alternative pathway, since d-pinitol is formed in gymnosperms and other plants by epimerization of sequoyitol.

▼ Dietary compounds are reported to have the innate ability to interfere several diseases. D-Pinitol is one of the compounds from dietary origin, well documented for its excellent biological activities. We have reported the therapeutic efficiency of the D-Pinitol with reference to lipid peroxidation, antioxidants, drug metabolizing enzymes and expressions of proteins such as p53, Bcl-2, and caspase-3 during DMBA-induced mammary carcinogenesis. D-Pinitol at the dose of 200mg/kg body weight was administered orally to treat the breast cancer-bearing animals for consecutive 45 days. Interestingly, D-Pinitol significantly decreased the lipid peroxidation and increased the antioxidants and modulated the biotransformation enzymes to near normal level when compared to control. The western blotting and RT-PCR analysis also inevitably confirms that D-Pinitol treatment down regulated the expression of Bcl-2 and up regulated the p53 and caspase-3 proteins. The histological analysis of breast and liver tissues were well supported the protective role of D-Pinitol. Thus, the therapeutic property of D-Pinitol might be due to its strong antioxidant and remarkable induction in phase II and significant modulation in phase I drug metabolizing enzymes and prominent influence in the proteins of apoptotic, anti-apoptotic and tumor suppressors which ultimately end up with the consideration of D-Pinitol in the treatment of genotoxin mediated carcinogenesis.

▼ Dietary compounds are reported to have the innate ability to interfere several diseases. D-Pinitol is one of the compounds from dietary origin, well documented for its excellent biological activities. We have reported the therapeutic efficiency of the D-Pinitol with reference to lipid peroxidation, antioxidants, drug metabolizing enzymes and expressions of proteins such as p53, Bcl-2, and caspase-3 during DMBA-induced mammary carcinogenesis. D-Pinitol at the dose of 200mg/kg body weight was administered orally to treat the breast cancer-bearing animals for consecutive 45 days. Interestingly, D-Pinitol significantly decreased the lipid peroxidation and increased the antioxidants and modulated the biotransformation enzymes to near normal level when compared to control. The western blotting and RT-PCR analysis also inevitably confirms that D-Pinitol treatment down regulated the expression of Bcl-2 and up regulated the p53 and caspase-3 proteins. The histological analysis of breast and liver tissues were well supported the protective role of D-Pinitol. Thus, the therapeutic property of D-Pinitol might be due to its strong antioxidant and remarkable induction in phase II and significant modulation in phase I drug metabolizing enzymes and prominent influence in the proteins of apoptotic, anti-apoptotic and tumor suppressors which ultimately end up with the consideration of D-Pinitol in the treatment of genotoxin mediated carcinogenesis.

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From the methanolic extract of the roots of Tribulus cistoides the cardioactive saponin-3, which is known to occur in the leaves, was isolated along with tribulosin, a pregnane-type glycoside and eight new cholestane glycosides. d-(+)-Pinitol and sucrose were major constituents. The structures were established by spectroscopic studies of the isolated compounds, their acetylated derivatives and their hydrolysation products. Chemical conversions revealed the configurations at C-22 and C-25, respectively.

▼ Tracer studies with labelled inositols demonstrate that in contrast to earlier reports the formation of d-pinitol in Medicago sativa, Ononis spinosa and Trifolium incarnatum does not proceed by epimerization of sequoyitol but via d-ononitol. Hence, the novel pathway detected in Simmondsia chinensis occurs also in the Leguminous family and thus represents a major biosynthetic pathway for d-pinitol.

▼ Traditionally, dietary compounds have been practiced to eliminate toxins and to strengthen the defense system towards resistance to many disease. d-Pinitol is one of a natural dietary compound predominantly found in soy products. It has been reported to possess diverse biological properties and their therapeutic properties propel them to evaluate against various experimental diseases. We have reported here the protective role of d-Pinitol on renal and hepatic tissue against oxidative stress mediated experimental breast cancer model. DMBA, the polycyclic aromatic hydrocarbon, was used to induce breast cancer in female Sprague Dawley rats with single oral dose of 20mg/kg/body weight diluted in corn oil. The cancer-bearing rats were treated with the natural dietary compound d-Pinitol at the concentration of 200mg/kg/body weight orally for 45days. We observed that d-Pinitol significantly restored the elevated levels of marker enzymes such as ALT, AST and LDH and efficiently down regulates lipid per-oxidation and lysosomal enzymes. The antioxidants levels were found to be significantly enhanced and the carbohydrate key metabolizing enzymes were excellently modulated towards normal range. These biochemical alterations were well reflected in the histopathological studies of liver and kidney tissues of control and experimental groups. Thus, the hepatic and renal tissue protective property might be due to the antioxidant activity which might reduce the per-oxidation reaction that were induced by DMBA and also render protection to the membrane integrity through its firm antioxidant property and modulatory role with prominent intervention strategies in gluconeogenesis process and lysosomal enzymes.

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The mechanism preferentially regulating accumulation of raffinose family oligosaccharides (RFOs) or galactosyl cyclitols in legume seeds still remains unknown. The broad range of raffinose family oligosaccharides and galactosyl pinitols in the composition of seeds of Vicia genus gives researchers an exceptional opportunity for investigations on relationships in biosynthesis of both types of α-d-galactosides. Feeding explants of Vicia species radically different in the composition of RFOs and galactosyl pinitols with basic galactose acceptors, sucrose (for RFOs) or cyclitols (for galactosyl cyclitols) can be a helpful method for assessment of their regulatory role in accumulation of α-d-galactosides in seeds. Garden vetch (Vicia sativa L.) seeds, naturally accumulating RFOs, demonstrated an ability to take up and use exogenously applied d-pinitol and d-chiro-inositol for synthesis of their mono-, di- and tri-galactosides. Together with the accumulation of new galactosides, the concentration of RFOs decreased. In fine-leaved (Vicia tenuifolia Roth.) vetch seeds such a remarkably high concentration of galactosyl pinitols (GPs) was discovered that they nearly replaced RFOs, which is unique among legumes. If the accumulation of both types of galactosides is correlated with concentration of galactose acceptors, elevated levels of sucrose or myo-inositol should promote accumulation of RFOs, instead of GPs. Unexpectedly, feeding fine-leaved vetch raceme explants with myo-inositol or sucrose promoted accumulation of GPs, but not of RFOs. Our comparison of accumulation and biosynthesis of both types of galactosides (RFOs and GPs) throughout development and maturation of seeds from fine-leaved vetch has indicated that preferential accumulation of GPs is associated with the drying of seeds during maturation. Different patterns in activities of enzymes engaged in RFOs’ biosynthetic pathway and galactosyltransferases involved in biosynthesis of GPs indicated that distinct forms of enzymes can operate in both pathways. The feeding of explants with d-chiro-inositol causes accumulation of fagopyritols B1 in seeds of both Vicia species, which suggests presence of the same or a similar form of galactinol synthase. Accumulation of fagopyritols in fine-leaved vetch seeds did not affect accumulation of RFOs or galactosyl pinitols.

▼ The present study was aimed to investigate the possible pancreatic tissue protective nature of D-Pinitol, a cyclitol present in soybean, against free radical-mediated oxidative stress in streptozotocin-induced diabetic rats by assaying the activity of pancreatic enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione-S-transferase (GST) and the levels of plasma non-enzymatic antioxidants such as vitamin E, vitamin C, ceruloplasmin and reduced glutathione (GSH). To assess the extent of oxidative stress, the levels of lipid peroxidation (LPO) and hydroperoxides in both plasma and pancreatic tissues were also measured. A significant increase in the levels of both lipid peroxides and hydroperoxides with a concomitant decrease in antioxidant status was observed in the diabetic rats when compared to control rats. Oral administration of D-Pinitol (50mg/kg b.w./day for 30days), a major cyclitol present in soybean, ameliorates the free radical-mediated alterations to near normalcy. The pancreatic tissue protective nature of D-Pinitol was further evidenced by histological observations. The results were statistically comparable with glyclazide, a standard hypoglycemic drug. Thus, the results of the present study suggest that D-Pinitol protects the pancreatic tissue from free radical-mediated oxidative stress in addition to its antidiabetic property.

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Variability studies were carried out among different accessions of Argyrolobium roseum for 12 metric traits under natural and cultivated conditions. Almost all characters showed higher values in cultivated than natural population. Leaf breadth recorded highest CV (30.59%). Highest percentage of vitexin and D-pinitol (0.208 and 0.773% dwb) was observed in RAR-7 and RAR-6, respectively, under cultivated conditions. Phenotypic coefficient was higher than genotypic coefficient of variation. The association analysis revealed that root yield had positive significant correlation with 100 seed weight (r=0.839) biomass yield (r=0.601), where biomass yield had a positive significant correlation with leaf length, single pod weight. High heritability (97.4–99.8%) coupled with moderate genetic advance ranged between (49–67%) as a percent of mean was observed for leaf breadth, pod length, total foliage biomass yield and total root yield/plant. This suggests that direct selection for these traits is suitable for the improvement of this crop.

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A convenient strategy is reported for the synthesis of azole nucleoside analogues of d-pinitol (=3-O-methyl-d-chiro-inositol). The key intermediate 3-O-methyl-4,5-epoxy-d-chiro-inositol was obtained in excellent yield via an epoxidation from mono-methanesulfonate of d-pinitol. The process of opening of the epoxy ring by azole-bases appeared strongly regioselective in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene. All newly synthesized carbocyclic azole nucleosides were assayed against lung and bladder cancer in vitro. Only the triazole and benzotriazole nucleoside analogues inhibited the growth of human lung cancer cell lines (PG) with EC₅₀ of 11.3 and 22.6μM, respectively, and showed much less inhibitory activity against human bladder cell lines (T₂₄).

▼ Seedlings of two maritime pine populations from France ('Landes') and Morocco ('Tamjoute') were subjected to water stress. Aerial parts and roots of the seedlings were analysed for d-pinitol (3-O-methyl-d-inositol) and myo-inositol. In well-watered plants, pinitol concentration was two to three times higher in the Moroccan plants than in the French plants. Pinitol accumulated to the same relative degree in water-stressed seedlings of the two populations. Myo-inositol concentration seemed only to increase in roots of the Moroccan plants. The physiological function of pinitol is discussed.

▼ Sutherlandia frutescens (L.) R.Br. is extensively used in South Africa to treat a broad range of ailments such as the common cold and cancers and, recently, as adjunct therapy in HIV/AIDS. However, scientific studies focusing on the phytochemical profile and variation within and between populations of this ethnomedicinally important species are lacking. The amino acids GABA, L-canavanine, L-asparagine, and L-arginine and a glycan, D-pinitol, have been proposed as being responsible for the pharmacological activity ascribed to S. frutescens. Aerial parts of S. frutescens were collected from several natural populations and cultivation sites. All 20 naturally occurring amino acids together with GABA, L-canavanine and D-pinitol were quantified by LC-MS. Amino acids collectively constituted between 10% and 15% (w/w) of dried plant material. Proline, L-asparagine and alanine were the most abundant amino acids identified and collectively represent approximately 60% of total amino acid content; however, not all samples contained all the amino acids. The yields of the various compounds showed tremendous variation both within and between populations. For example, L-canavanine (a non-protein amino acid) ranged from 0.14 to 13.58mg/g. This is the first report on the variation of phytoconstituents claimed to contribute to the pharmacological properties of Cancer bush. This information could be of value to select specific chemotypes for cultivation and for developing guidelines for quality control purposes.

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Three new cycloartane-triterpene glycosides, astraverrucin IV, V and VI, were isolated from the aerial parts of Astragalus verrucosus. Based on spectroscopic analysis (IR, 1D and 2D-NMR, FABMS), the structures of the saponins were established to be cycloastragenol 3-O-[α-l-rhamnopyranosyl(1 → 4)-β-d-glucopyranoside], cycloastragenol 3-O-[α-l-rhamnopyranosyl(1 → 4)]-β-d-(3-O-acetyl)glucopyranoside and cycloastragenol 3-O-[α-l-rhamnopyranosyl (1 → 4)]-β-d-(6-O-acetyl)-glucopyranoside. d-pinitol and astraverrucin I were also obtained.

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D-pinitol (3-O-methyl-chiroinositol), an active principle of the traditional antidiabetic plant Bougainvillea spectabilis, is claimed to exert insulin-like effects. This study investigates the effect of D-pinitol on glucose homeostasis in animal models of diabetes, and on glucose transport by cultured muscle cells.

Plasma glucose concentrations were measured in normal, obese-diabetic ( ob/ ob) and streptozotocin (STZ)-diabetic mice after oral (p.o.) and intraperitoneal (i.p.) administration of D-pinitol. Glucose transport was measured in L6 rat muscle cells by 2-deoxyglucose (2DG) uptake.

In STZ-diabetic mice, 100 mg kg⁻¹ p.o. D-pinitol acutely decreased the hyperglycaemia (by 22% at 6 h). A similar decrease in plasma glucose (by 21%) was observed after 100 mg kg⁻¹ i.p. D-pinitol. Insulin concentrations and the rate of insulin-induced (1 unit kg⁻¹ actrapid i.p.) glucose disappearance were not altered by 100 mg kg⁻¹ p.o. D-pinitol. Chronic administration of D-pinitol (100 mg kg⁻¹ i.p. twice daily for 11 days) to STZ-diabetic mice maintained a reduction in plasma glucose concentrations from about 14 to 10 mmol l⁻¹.

In normal non-diabetic and severely insulin resistant ob/ ob mice, 100 mg kg⁻¹ p.o. D-pinitol did not significantly affect plasma glucose or insulin during acute studies.

Incubation of L6 muscle cells with D-pinitol (10⁻³  M) increased basal 2DG uptake by 41% after 10 min and by 34% after 4 h. The effect of D-pinitol was inhibited by the phosphatidylinositol 3-kinase inhibitor LY294002. D-pinitol did not increase insulin-stimulated 2DG uptake by L6 cells.

The data support the view that D-pinitol can exert an insulin-like effect to improve glycaemic control in hypoinsulinaemic STZ-diabetic mice. D-pinitol may act via a post-receptor pathway of insulin action affecting glucose uptake.

British Journal of Pharmacology (2000) 130, 1944–1948; doi:

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The bark extract of the medicinal plant Detarium microcarpum was analysed for its carbohydrate content by GLC-CIMS. Preparative HPLC of the benzoylated carbohydrate fraction led to the isolation of l-quino-1,5-lactone, d-(−)-bornesitol, d-pinitol, myo-inositol, sucrose, d-glucose, and d-fructose benzoates, which were characterised by NMR spectroscopy experiments.

▼ Numerous studies have indicated that inflammatory cytokines play a major role in osteoclastogenesis, leading to the bone resorption that is frequently associated with osteoporosis. d-pinitol, a 3-methoxy analogue of d-chiroinositol, was identified as an active principle in soy foods and legumes. Here we found that d-pinitol markedly inhibited the receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastic differentiation from bone marrow stromal cells and RAW264.7 macrophage cells. In addition, d-pinitol also reduced RANKL-induced p38 and JNK phosphorylation. Furthermore, RANKL-mediated increase of IKK, IκBα, and p65 phosphorylation and NF-κB-luciferase activity was inhibited by d-pinitol. However, d-pinitol did not affect the proliferation and differentiation of osteoblasts. In addition, d-pinitol also prevented the bone loss induced by ovariectomy in vivo. Our data suggest that d-pinitol inhibits osteoclastogenesis from bone marrow stromal cells and macrophage cells via attenuated RANKL-induced p38, JNK, and NF-κB activation, which in turn protect bone loss from ovariectomy.

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The synthesis of 3,5-di-O-benzyl-d-pinitol has been stereoselectively accomplished through intramolecular aldolization of 2,6-di-O-benzyl-4-O-methyl-l-lyxo-hexos-5-ulose followed by reduction with NaBH(OAc)₃. Computational analysis [DFT calculations at the B3LYP/6-31G(d) level] suggests that d-pinitol in water largely prefers the conformation corresponding to the ¹C₄ one of a α-l-rhamnopyranoside unit, being thus a good candidate for its mimicking.