Efficacy of myo-inositol in improving pregnancy rate and regulation of menstrual cycle for patients with polycystic ovarian syndrome: A systematic review and meta-analysis

Background@#Polycystic ovarian syndrome (PCOS) is a common, reproductive endocrinopathy associated with ovarian dysfunction, cardiovascular disorders, obesity, and infertility. Myo-inositol is a novel treatment for women with PCOS that claimed to have improved fertility rate in this population. This systematic review and meta-analysis examined the effect of myo-inositol on pregnancy rate, menstrual cycle, and adverse effects from randomized controlled trials (RCTs). @*Methods@#RCTs that evaluated the efficacy of myo-inositol in improving pregnancy rate and regulation of menstrual cycle in women with PCOS. Electronic databases were searched and studies published up to October 24, 2021 were included in the systematic review and meta-analysis. Study selection and assessment of quality were conducted independently by two review authors. @*Results@#Seven studies with 729 patients treated with myo-inositol and 677 patients treated with placebo and/or metformin were included in the analysis. The research groups did not diverge significantly in terms of basic characteristics, such as age, adnexal or uterine pathology, body mass index, and duration of infertility. In the myo-inositol group, regulation of the normal menstrual cycle is at 20%, significantly higher than the metformin group at 12%, (p<0.001). However, there is no significant difference in the pregnancy rate between myoinositol and placebo (p=0.42) and/or metformin (p=0.17). @*Conclusion@#This systematic review and meta-analysis showed that myo-inositol can be an alternative treatment for PCOS in terms of regulation of menses and may improve the success of spontaneous pregnancies. However, additional randomized, double-blind controlled trials with larger sample sizes, low heterogeneity, and uniform inclusion criteria are recommended to establish the effects of myo-inositol on PCOS treatment and pregnancy rate.

Expression of 1L-myo-Inositol -1-Phosphate Synthase (EC 5.5.1.4) is Deregulated in the Cerebellum of Curly Tail Mutant Mice

Previous research, defining spatial control of inositol phosphate biosynthesis in the developing brain of CBA (normal) and CT [curly tail (ct-CT) and straight tail (st-CT)] mutant mice implicated a role for 1l-myo-inositol 1-phosphate synthase (MIP) in normal functioning of the central nervous system. Biochemical research indicated that MIP enzymatic activity, conversion of glucose 6-phosphate into inositol phosphate, is highest in the cerebellum of ct-CT and lowest in st-CT, when compared to that of CBA mice.Here, we utilized microscopic and biochemical investigations to analyze and extend previous findings of MIP expression in the cerebellum. Results of this research indicated that MIP expression correlates, well, with its enzymatic activity in the cerebellum of CBA and CT mutantmice. Statistical analyses of fluorescent micrographs detected a significant difference in fluorescence intensity between MIP from ct-CT, st-CT, and CBA mice.These data support vitallinks between inositol phosphate biosynthesis, MIP expression, and normal functioning of the cerebellum. Moreover, published data, identifying significant behavioral differences in the CT mutant, as well as data linking motor and non-motor cerebellar functions to abnormal levels of inositol, support the conclusion that aspects of normal cerebellar functions require temporal and spatial control of inositol phosphate biosynthesis, MIP expression.

A comparative study of combination of Myo-inositol and D-chiro-inositol versus Metformin in the management of polycystic ovary syndrome in obese women with infertility

Background: Polycystic ovary syndrome (PCOS) is a symptom complex associated with increased amounts of circulating androgens in females, increased insulin resistance and obesity. The drugs, Myo-inositol, D-chiro-inositol and Metformin, which are insulin sensitizers, are very helpful in taking care of one of the key components of PCOS that is insulin resistance. This study was done to compare the effects of combination of Myo-inositol and D-chiro-inositol with the use of metformin on clinical and biochemical profile in PCOS.Methods: A prospective, randomized, comparative study was conducted on 200 patients. The patients were randomly assigned into the two groups of 100 each. Group A receiving Tab. Myoinositol 550mg twice daily and Tab. D-chiro-inositol 13.8mg twice daily and Group B receiving Tab. Metformin 500mg thrice daily. The patients were assessed by menstrual cycle regulation, hirsutism score (Ferriman Gallwey), fasting and post prandial glucose and insulin levels, serum DHEA levels, serum free testosterone levels and fasting day 3 serum LH and FSH ratio.Results: In both the groups there was significant improvement in all the above mentioned parameters, however the group with Combination of Myo-inositol and D-chiro-inositol had statistically significant improvement over the Metformin group.Conclusions: Combination of Myo-inositol and D-chiro-inositol and use of metformin, significantly improved insulin sensitivity in PCOS women. But combination of Myo-inositol and D-chiro-inositol was effective in controlling the hormonal profiles (LH/FSH ration and free testosterone) when compared to Metformin.

Risk Assessment of "Other Substances" – Inositol

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements and energy drinks sold in Norway. VKM has assessed the risk of doses given by NFSA. These risk assessments will provide NFSA with the scientific basis while regulating the addition of “other substances” to food supplements and other foods. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/ or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. In this series of risk assessments of "other substances", VKM has not evaluated any potential beneficial effects from these substances, only possible adverse effects. The present risk assessment is based on previous risk assessments of inositol and articles retrieved from a literature search. According to information from NFSA, inositol is an ingredient in energy drinks sold in Norway. NFSA has requested a risk assessment of 10 mg/100 ml inositol in energy drinks. Drinking patterns reflecting a high acute intake, a mean chronic intake and a high chronic intake were assessed. Inositol (CAS no. 6917-35-7) is a sugar alcohol. Among the nine possible stereoisomers, myo inositol (CAS no. 87-89-8) is the most abundant. The name inositol is frequently used as a synonym for myo -inositol. Inositol occurs naturally in all organisms including humans, and is an important component in all human cells. Inositol-containing lipids and phosphates are required for various structural and functional processes, including membrane formation, signalling, membrane trafficking and osmoregulation. Endogenous production of inositol in humans amounts to about 4 g/day (about 57 mg/kg bw per day in a 70 kg adult) (EFSA, 2014). The total dietary intake of inositol in adults is estimated to range between 500 to 1000 mg/day (about 7-14 mg/kg bw per day). Inositol added to energy drinks in Norway denotes the compound myo -inositol, according to information from NFSA. M yo -inositol is a water-soluble compound naturally occurring in the cells of all living organisms including humans, animals, plants and microorganisms. Certain plant (fruits and vegetables) and foods from animals contain inositol, and seeds of cereals and legumes show high levels of the inositol storage form, phytic acid (inositol hexaphosphate). With regard to hazard identification and characterisation of inositol, most of the adverse effects observed in several human studies were related to gastrointestinal symptoms such as nausea, flatulence, loose stools and diarrhoea. Drinking patterns reflecting a high acute intake, a mean chronic intake and a high chronic intake were assessed for energy drinks containing 10 mg inositol per 100 ml, for the age groups children (3 to <10 years and 10 to <14 years), adolescents (14 to <18 years) and adults (≥18 years). For the high acute drinking pattern, the intake was estimated to be 1000, 1500, 2000 and 2000 ml/day for children (3 to <10 years), children (10 to <14 years), adolescents (14 to <18 years) and adults (>18 years), respectively. For the mean chronic drinking pattern, the intake was estimated to be 58, 65, 64 and 71 ml/day for children (3 to <10 years), children (10 to <14 years), adolescents (14 to <18 years) and adults (≥18 years), respectively. For the high chronic drinking pattern, the intake was estimated to be 163, 180, 210 and 320 ml/day for children (3 to <10 years), children (10 to <14 years), adolescents (14 to <18 years) and adults (≥18 years), respectively. The data on toxicity of inositol was very limited. The human study with the longest exposure at highest doses (3 months treatment at maximum tolerated dose) that was available for risk assessment was a clinical study of 40-74 year old smokers with bronchial dysplasia, from which a NOAEL of 18 g/day of myo -inositol was established (Lam et al. 2006). VKM estimated the margins of exposure (MOE) based on the NOAEL established in this study. The MOE is the ratio of the NOAEL value to the exposure. An acceptable MOE value for a NOAEL-based assessment of inositol based on a human study is ≥10, taking into account a factor 10 for the interindividual variation between humans in toxicokinetics and toxicodynamics. Due to the uncertainty regarding the relevance of the study by Lam et al. (2006) for the general healthy population, an additional safety factor of 3 was used. Therefore, an acceptable MOE value was 30. For all age groups, the MOE values were in the range of 857 to 2570 for mean chronic intake and in the range of 367 to 857 for high chronic intake of energy drinks, respectively, i.e. far above the acceptable MOE value of 30. Since neither the sub-optimal human study by Lam et al. (2006) or the animal studies in rodent models of chronic diseases available were on healthy subjects, as a supplement to the MOE values calculated from the human study, comparisons with endogenous production and amounts in food of inositol were also performed. No studies specifically on children (3 to <10 years and 10 to <14 years) and adolescents (14 to <18 years) were identified. Based on the included literature there was no evidence indicating that age affects tolerance or endogenous production of inositol. Therefore, in this risk characterisation a tolerance and an endogenous production of inositol as for adults, based on body weight, was assumed for these age groups. For the high acute drinking pattern, and for the mean chronic and the high chronic drinking patterns all estimated intakes of inositol from energy drinks containing 10 mg/100 ml were far below the endogenous production (57 mg/kg bw per day), and also below the dietary intake (7-14 mg/kg bw per day). VKM concludes that it is unlikely that the exposure to inositol from the high acute, the mean chronic or the high chronic drinking patterns causes adverse health effects in children (3 to <10 years and 10 to <14 years), adolescents (14 to <18 years) and adults (≥18 years).

Pre-treatment effect of myo-inositol and l-5, methyltetrahydrofolate in ovulation induction oocyte quality and pregnancy outcome in clomiphene resistance polycystic ovarian disease

Background: This study was designed to assess the treatment effect of myo-inositol and l-5, methyltetrahydrofolate in oocyte quality, pregnancy outcome in clomiphene citrate resistance PCOS cases.Methods: Authors conducted prospective open label, randomized, parallel group study in SIMS Hapur, U.P. Eligible patients full filling inclusion criteria were randomized into two groups having 25 patients in each group using myo-inositol 580mg and l-5, methyltetrahydrofolate 800mcg in treatment group and tab folic acid 400mcg in placebo group for 12 weeks. The follow-up visits are on weeks 4, 8 and 12.Results: 12 weeks later, 21 patients in treatment group restored one spontaneous menstrual cycle and 19 patients maintained the normal ovulatory activity in follow up cycle. Ovulation induction done in 18 patients with clomiphene citrate at the dose of 50mg during treatment out of which 10 conceive, as compared with only 9 women out of the 25 women (36 percent) in the placebo group ovulate (P>0.001) out of which 4 conceived. There was significant decrease in Sr. testosterone, DHEA and AMH level and estradiol level, while statically significant increase in Sr. SHBG and FSH level seen in treatment group(p<0.001).Conclusions: In the study, more number of studied patients get back to normal menstrual cyclicity, insulin-lowering activity and its intracellular role in oocyte maturation. Significant Dec seen in serum estradiol level at the day of HCG administration.

Increased cryo-survival rate in ejaculated human sperm from infertile men following pre-freeze in vitro myo-inositol supplementation / 대한생식의학회지

OBJECTIVE: To investigate the effects of in vitro myo-inositol (Myo-Ins) supplementation of cryopreserved human semen on the cryo-survival rate (CSR). METHODS: Semen samples were obtained from 41 infertile men. Following routine semen analysis, each sample was divided into two equal aliquots (0.5 mL each). One aliquot was treated with 1 mg of Myo-Ins dissolved in 10 µL of sperm preparation medium. The second aliquot was treated with 10 µL of the same medium (control). Both aliquots were incubated for 20 minutes prior to freezing to slow the freezing process. The frozen samples were examined for post-thaw percentages of total motility (TM), progressive motility (PM), and the CSR, defined as the percentage of post-thaw TM divided by the percentage of pre-freeze TM and multiplied in 100. The results were expressed as median and interquartile range (25th and 75th percentiles). RESULTS: The pre-freeze TM (50% [30%–50%]) and PM (35% [20%–35%]) were significantly higher than the post-thaw TM and PM in the Myo-Ins group (15% [10%–35%] and 10% [5%–20%]; p < 0.001 and p < 0.001, respectively) and the control group (10% [6%–30%] and 5% [3%–15%]; p < 0.001 and p < 0.001, respectively). The CSR of the 41 semen aliquots supplemented with Myo-Ins (40% [25%–70%]) was significantly higher than that of the control samples (30% [13%–58%], p=0.041). The CSR of the 26 abnormal semen samples that were supplemented with Myo-Ins (38% [20%–50%]) was significantly higher than that of the control samples (23% [12%–30%], p=0.031). CONCLUSION: In vitro Myo-Ins supplementation of ejaculated human sperm from infertile men resulted in a significant increase in the CSR in samples with abnormal pre-freeze sperm parameters.

Construction of a glucaric acid biosensor for screening myo-inositol oxygenase variants / 生物工程学报

Glucaric acid (GA), a top value-added chemical from biomass, has been widely used for prevention and control of diseases and the production of polymer materials. In GA biosynthesis pathway, the conversion of inositol to glucuronic acid that catalyzed by myo-inositol oxygenase is the limiting step. It is necessary to improve MIOX activity. In the present study, we constructed a high-throughput screening system through combing the concentration of GA with the green fluorescent protein fluorescence intensity. By applying this screening system, three positive variants (K59V/R60A, R171S and D276A) screened from the mutant library. In comparison, the recombinant strain Escherichia coli BL21(DE3)/MU-R171S accumulated more GA, 136.5% of that of the parent strain.

Combined treatment with myo-inositol and luteolin selectively suppresses growth of human lung cancer A549 cells possibly by suppressing activation of PDK1 and Akt / 南方医科大学学报

OBJECTIVE@#To study the effects of myo-inositol and luteolin on human lung cancer A549 cells and explore the possible mechanisms.@*METHODS@#A549 cells were treated with different concentrations of myo-inositol and luteolin, either alone or in combination, and the cell viability was examined using MTT assay. A549 cells and human bronchial epithelial Beas-2B cells were treated for 48 h with 10 mmol/L myo-inositol and 20 μmol/L luteolin, alone or in combination, and the cell proliferation was detected using MTT assay; the colony formation and migration of the cells were examined with colony formation assay and wound healing assay, respectively. The protein expression levels in A549 cells were detected using Western blotting.@*RESULTS@#Both myo-inositol and luteolin could dose-dependently inhibit the viability of A549 cells. Treatments with 10 mmol/L myo-inositol, 20 μmol/L luteolin, and both for 48 h caused significant reduction in the cell viability (92%, 83% and 70% of the control level, respectively) and colony number (79%, 73% and 43%, respectively), and significantly lowered the wound closure rate (24.61%, 13.08% and 8.65%, respectively, as compared with 29.99% in the control group). Similar treatments with myoinositol and luteolin alone or in combination produced no significant inhibitory effect on the growth, colony formation or migration of Beas-2B cells. The expressions of p-PDK1 and p-Akt in myo-inositol-treated A549 cells and the expression of pPDK1 in luteolin-treated cells were significantly decreased ( < 0.05), and the decrements were more obvious in the combined treatment group ( < 0.05).@*CONCLUSIONS@#Luteolin combined with myo-inositol can selectively inhibit the proliferation and migration of A549 cells, and these effects are probably mediated, at least in part, by suppressing the activation of PDK1 and Akt.

Metabolic engineering of Saccharomyces cerevisiae for production of glucaric acid / 生物工程学报

Glucaric acid, a high value-added organic acid, is widely used in food, pharmaceutical and chemical industries. For microbial production of glucaric acid in Saccharomyces cerevisiae, we constructed a synthetic glucaric acid biosynthetic pathway by coexpressing the genes encoding myo-inositol oxygenase from mice and uronate dehydrogenase from Pseudomonas putida. Moreover, myo-inositol-1-phosphate synthase was identified as a rate-limiting enzyme in glucaric acid pathway and was upregulated, resulting in the production of glucaric acid of (107.51±10.87) mg/L, a 2.8-fold increase compared to the parent strain. Then, by repressing the activity of phosphofructokinase, the concentration of glucaric acid further increased to (230.22±10.75) mg/L. The strategy could be further used to construct cell factories for glucaric acid production.

Modulation of Melanin Synthesis by Amaranthus spp. L Seed Extract in Melan-a Cells

Anti-melanogenic effects of amaranth (AT), one of the key source of squalene, were investigated in melanocytes. Amaranth seed powder was extracted with water and melan-a cells were treated with various concentrations of AT. By using HPLC, content of myo-inositol, one of potential active components, was measured in the crude extract of AT.AT reduced the melanin content in melan-a melanocytes and down-regulated melanogenic enzyme activity such as tyrosinase, TRP-1 and TRP-2. By regulating melanogenic enzyme activity, AT may be a potential natural source for whitening agent. Myo-inositol was detected in AT by HPLC and may be one of the active compounds from AT involved in the regulation of anti-melanogenesis. In this study, we demonstrated that AT has anti-melanogenesis properties. This new function of amaranth may be useful in the development of new skin-whitening products and its value as food.

TonEBP and SMIT expression in human placenta / 대한해부학회지

Tonicity-responsive enhancer binding protein (TonEBP) is a signal transcription factor of transporters such as sodium-myo-inositol cotransporter (SMIT), aldose reductase. TonEBP has a variety of functions such as control of intracellular osmolytes and immunomodulating. It is known that TonEBP is abundant in the placenta, but location and function aren't known. The aim of this study is to describe the localization of TonEBP in the placenta. We assayed the immunohistochemistry of TonEBP and performed in situ hybridization of SMIT in normal human full term placenta. In normal human full term placenta, TonEBP was in villous trophoblasts, extravillous trophoblasts and some endothelial cells. The result of the in situ hybridization of SMIT was similar to that of immunohistochemistry of TonEBP. Neither TonEBP nor SMIT was present in TonEBP knockout mouse placenta. This shows TonEBP is a key factor in SMIT transcription. TonEBP may play an important role in transporting of inositol to fetus in placenta.

Chemical constituents from fruits of Dimocarpus longan / 中草药

Objective: To investigate the chemical constituents of the fruits of Dimocarpus longan. Methods: The chemical constituents were isolated from 95% alcohol-extract on seeds of longan by silica gel, polyamide, as well as Sephadex LH-20 column chromatography. Their structures were identified on the basis of physical and chemical properties and spectral analysis. Results: Twelve compounds were isolated and identified as: β-sitosterol (1), 2-phenylethanol (2), 2-methyl-1,10-undecanediol (3) (24R)-6β-hydroxy-24- ethyl-cholest-4-en-3-one (4), oleanolic acid (5), pinoresinol (6), nicotinic acid (7), 4-hydroxybenzoic acid (8), β-daucosterol (9), 1-O-methyl-D-myo-inositol (10), uracil (11), and adenosine (12). Conclusion: Compounds 2-8 and 10 are reported from the pericarp of longan (the fruits of D. longan) for the first time, and compound 3 is a new compound named longandiol.

Proton magnetic resonance spectroscopy of brain in obstructive sleep apnoea in north Indian Asian subjects.

Background & objectives: Repeated apnoeic/hypoapnoeic episodes during sleep may produce cerebral damage in patients with obstructive sleep apnoea (OSA). The aim of this study was to determine the absolute concentration of cerebral metabolites in apnoeic and non-apnoeic subjects from different regions of the brain to monitor the regional variation of cerebral metabolites. Methods: Absolute concentration of cerebral metabolites was determined by using early morning proton magnetic resonance spectroscopy (1H MRS) in 18 apnoeic patients with OSA (apnoeics) having apnoea/hypopnoea index (AHI) >5/h, while 32 were non-apnoeic subjects with AHI< 5/h. Results: The absolute concentration of tNAA [(N-acetylaspartate (NAA)+N-acetylaspartylglutamate (NAAG)] was observed to be statistically significantly lower (P<0.05) in apnoeics in the left temporal and left frontal gray regions compared to non-apnoeics. The Glx (glutamine, Gln + glutamate, Glu) resonance showed higher concentration (but not statistically significant) in the left temporal and left frontal regions of the brain in apnoeics compared to non-apnoeics. The absolute concentration of myo-inositol (mI) was significantly high (P<0.03) in apnoeics in the occipital region compared to non-apnoeics. Interpretation & conclusions: Reduction in the absolute concentration of tNAA in apnoeics is suggestive of neuronal damage, probably caused by repeated apnoeic episodes in these patients. NAA showed negative correlation with AHI in the left frontal region, while Cho and mI were positively correlated in the occipital region and Glx showed positive correlation in the left temporal region of the brain. Overall, our results demonstrate that the variation in metabolites concentrations is not uniform across various regions of the brain studied in patients with OSA. Further studies with a large cohort of patients to substantiate these observations are required.

Numerical Design of Double Quantum Coherence Filter for the Detection of Myo-Inositol In vivo

PURPOSE: A numerical method of designing a multiple quantum filter (MQF) is presented for the optimum detection of myo-inositol (mI), an important brain metabolite, by using in vivo proton nuclear magnetic resonance spectroscopy ((1)HMRS). MATERIALS AND METHODS: Starting from the characterization of the metabolite, the filter design includes the optimization of the sequence parameters such as the two echo times (TEs), the mixing time (TM), and the flip angle and offset frequency of the 3rd 90 degrees pulse which converts multiple quantum coherences (MQCs) back into single quantum coherences (SQCs). The optimized filter was then tested both in phantom and in human brains. RESULTS: The results demonstrate that the proposed MQF can improve the signal-tobackground ratio of the target metabolite by a factor of more than three by effectively suppressing the signal from the background metabolites. CONCLUSION: By incorporating a numerical method into the design of MQFs in 1HMRS the spectral integrity of a target metabolite, in particular, with a complicated spin system can be substantially enhanced.

Production of D-myo-inositol(1,2,4,5,6)pentakisphosphate using alginate-entrapped recombinant Pantoea agglomerans glucose-1-phosphatase

The glucose-1-phosphatase encoding gene (agp) of Pantoea agglomerans was sequenced and heterologously expressed in Escherichia coli. The enzyme showed very high homology to periplasmatic glucose-1-phosphatases of other members of the Enterobacteriaceae family. It was isolated from transformed Escherichia coli cells in a single step in high yields (32.3 ± 1.2 mg per litre of culture) by Ni-NT agarose affinity chromatography to >95 percent purity as calculated from specific activity determinations. The purified glucose-1-phosphatase was entrapped in alginate beads with an entrapment efficiency of >80 percent. Temperature stability was enhanced as a consequence of entrapment, whereas pH dependence of enzyme activity was not affected. Maximum catalytic activity of entrapped glucose-1-phosphatase was found at 70°C, whereas the free enzyme exhibited maximal activity at 60°C. A single pH optimum at pH 4.5 was determined for the free and the entrapped enzyme. Kinetic parameters for the hydrolysis of sodium phytate were found to be affected by entrapment. They were determined to be K M = 0.84 mmol l-1 and k cat = 8 s-1 at pH 4.5 and 37°C for the entrapped glucose-1-phosphatase and K M = 0.35 mmol l-1 and k cat = 20.5 s-1 for the free enzyme. Complete conversion of phytate into one single myo-inositol pentakisphosphate isomer, identified as D-myo-inositol(1,2,4,5,6)pentakis-phosphate, was shown to be feasible by using the enzyme-loaded alginate beads in batch operations. The entrapped enzyme showed a high operational stability by retaining almost full activity even after ten uses.

Apoptotic effect of IP6 was not enhanced by co-treatment with myo-inositol in prostate carcinoma PC3 cells

Inositol hexaphosphate (IP6) is a major constituent of most cereals, legumes, nuts, oil seeds and soybean. Previous studies reported the anticancer effect of IP6 and suggested that co-treatment of IP6 with inositol may enhance anticancer effect of IP6. Although the anticancer effect of IP6 has been intensively studied, the combinational effect of IP6 and inositol and involved mechanisms are not well understood so far. In the present study, we investigated the effect of IP6 and myo-inositol (MI) on cell cycle regulation and apoptosis using PC3 prostate cancer cell lines. When cells were co-treated with IP6 and MI, the extent of cell growth inhibition was significantly increased than that by IP6 alone. To identify the effect of IP6 and MI on apoptosis, the activity of caspase-3 was measured. The caspase-3 activity was significantly increased when cells were treated with either IP6 alone or both IP6 and MI, with no significant enhancement by co-treatment. To investigate the effect of IP6 and MI of cell cycle arrest, we measured p21 mRNA expression in PC3 cells and observed significant increase in p21 mRNA by IP6. But synergistic regulation by co-treatment with IP6 and MI was not observed. In addition, there was no significant effect by co-treatment compared to IP6 treatment on the regulation of cell cycle progression although IP6 significantly changed cell cycle distribution in the presence of MI or not. Therefore, these findings support that IP6 has anticancer function by induction of apoptosis and regulation of cell cycle. However, synergistic effect by MI on cell cycle regulation and apoptosis was not observed in PC3 prostate cancer cells.

Determination of Urinary Myo-/Chiro-Inositol Ratios from Korean Diabetes Patients

Of two major forms (myo- and chiro-inositol) of inositols, only chiro-inositol enhances the activity of proteins involved in intracellular glucose metabolism. This study aims to determine the urinary myo-/chiro-inositol ratio in type 1 and type 2 diabetes patients and compare its ratio with the normal control group. The 24-hour urinary myo- and chiro-inositols in 71 Korean diabetes patients and 39 control subjects have been quantified using high-performance liquid chromatography, and their ratios have been evaluated as indices of insulin resistance. The level of 24-hour urinary myo-inositol was significantly higher in both type 1 and type 2 diabetes than with the control group, whereas the urinary chiro-inositol in type 1 or type 2 diabetes was lower than that in normal subjects. The myo-/chiro-inositol ratio in diabetes patients was higher than that in the control group. Twenty four-hour urinary myo-/ chiro-inositol ratios were significantly elevated in type 1 and type 2 diabetes patients compared to the control group, suggesting that a high ratio of urinary myo-/chiro- inositol in type 2 diabetes patients might be used for an index of insulin resistance.

Human Genne Myo-Inositol Monophosphatase 2 Gene and Clinical Disease / 实用儿科临床杂志

Human genne myo-inositol monophosphatase 2(IMPA2) was recently a novel and promising gen that was associated with disease,especially in mental and neuro diseases.Its locus is in chromosome 18p11 2,about 15 kb.It encodes IMPA2 enzyme.IMPA2 enzyme as a mainly and catalytic inositol plays an important role in cell signaling system.The mechanism of action of IMPA2 gene is still unclear.But in basic research on genetic structure and IMPA2 product,the biochemical functions and crystal structure have gradually been recognized;In the clinical application,the association with disease has been detected in manic depression,schizophrenia and febrile seizuers.IMPA2 even has been a susceptible gene to certain diseases.IMPA2 has increasingly been the hotspot in gene research.

Specific staining of myo-inositol-1-phosphatase on polyacrylamide gels after electrophoresis.

A sensitive staining method was developed to localise the activity of myoinositol- 1-phosphatase on Polyacrylamide gels after electrophoresis. The method can also be used for non-specific phosphatases as well as for those specific phosphatases acting upon inositol polyphosphates which are prime cellular second messengers. One or two nmol of phosphate is sufficient and less than 3 μg of purified protein will facilitate the localisation of phosphatase. If more phosphatases are present in the enzyme preparation, a combination of inhibitors can be used to suppress the activities of unwanted phosphatases and the use of specific substrates will facilitate the localisation of enzyme of interest.

Fructose-1, 6-bisphosphatase in human fetal brain and liver during development.

Activity of fructose-1,6-bisphosphatase (EC 3.1.3.11), one of the key gluconeogenic enzymes, was measured in human fetal brain and liver during development. Fructose-1,6- bisphosphatase was distributed throughout the different regions of the brain. In contrast to the partially purified enzyme from the brain, the liver enzyme was dependent on Mg2+ for maximal activity, EDTA, citrate, oleate and linoleate were stimulatory, whereas 5'-AMP inhibited the activity of the liver enzyme.