Emerging bio-dispersant and bioremediation technologies as environmentally friendly management responses toward marine oil spill: A comprehensive review.

Marine oil spills emanating from wells, pipelines, freighters, tankers, and storage facilities draw public attention and necessitate quick and environmentally friendly response measures. It is sometimes feasible to contain the oil with booms and collect it with skimmers or burn it, but this is impracticable in many circumstances, and all that can be done without causing further environmental damage is adopting natural attenuation, particularly through microbial biodegradation. Biodegradation can be aided by carefully supplying biologically accessible nitrogen and phosphorus to alleviate some of the microbial growth constraints at the shoreline. This review discussed the characteristics of oil spills, origin, ecotoxicology, health impact of marine oils spills, and responses, including the variety of remedies and responses to oil spills using biological techniques. The different bioremediation and bio-dispersant treatment technologies are then described, with a focus on the use of green surfactants and their advances, benefits/drawbacks. These technologies were thoroughly explained, with a timeline of research and recent studies. Finally, the hurdles that persist as a result of spills are explored, as well as the measures that must be taken and the potential for the development of existing treatment technologies, all of which must be linked to the application of integrated procedures.

Purification and characterization of Se-enriched Grifola frondosa glycoprotein, and evaluating its amelioration effect on As3+ -induced immune toxicity.

BACKGROUND: Selenium (Se)-enriched glycoproteins have been a research highlight for the role of both Se and glycoproteins in immunoregulation. Arsenic (As) is a toxicant that is potentially toxic to the immune function and consequently to human health. Several reports suggested that Se could reduce the toxicity of heavy metals. Moreover, more and more nutrients in food had been applied to relieve As-induced toxicity. Hence glycoproteins were isolated and purified from Se-enriched Grifola frondosa, and their preliminary characteristics as well as amelioration effect and mechanism on As3+ -induced immune toxicity were evaluated. RESULTS: Four factions, namely Se-GPr11 (electrophoresis analysis exhibited one band: 14.32 kDa), Se-GPr22 (two bands: 20.57 and 31.12 kDa), Se-GPr33 (three bands: 15.08, 20.57 and 32.78 kDa) and Se-GPr44 (three bands: 16.73, 32.78 and 42.46 kDa), were obtained from Se-enriched G. frondosa via DEAE-52 and Sephacryl S-400 column. In addition, Se-GPr11 and Se-GPr44 are ideal proteins that contain high amounts of almost all essential amino acids. Thereafter, the RAW264.7 macrophage model was adopted to estimate the effect of Se-GPr11 and Se-GPr44 on As3+ -induced immune toxicity. The results showed that the pre-intervention method was the best consequent and the potential mechanisms were, first, by improving the oxidative stress state (enhancing the activity of superoxide dismutase and glutathione peroxidase, decreasing the levels of reactive oxygen species and malondialdehyde); secondly, through nuclear factor-κB and mitogen-activated protein kinase-mediated upregulation cytokines (interleukin-2 and interferon-γ) secretion induced by As3+ . CONCLUSION: The results suggested Se-enriched G. frondosa may be a feasible supplement to improve health level of the As3+ pollution population. © 2021 Society of Chemical Industry.

Influence of Chronic Toxicity, Lipid Metabolism, Learning and Memory Ability, and Related Enzyme in Sprague-Dawley Rats by Long-Term Chromium Malate Supplementation.

In our previous study, chromium malate is beneficial for type 2 diabetic rats in control glycometabolism and lipid metabolism. The present study was designed to observe the chronic toxicity, lipid metabolism, learning and memory ability, and related enzymes of chromium malate in rats during the year. The results showed that pathological, toxic, feces, and urine of chromium malate (at daily doses of 10.0, 15.0, and 20.0 µg Cr/kg bm) did not change measurably. Chromium malate (at daily doses of 15.0 and 20.0 µg Cr/kg bm) could significantly reduce the levels of total cholesterol (TC), LDL, and triglyceride (TG), and increase the level of HDL in male rats compared to control group and chromium picolinate group. Significant escalating trends of the escape latency and swimming speed (Morris water maze test), and the original platform quadrant stops, residence time, and swimming speed (Space exploration test) in male rats of chromium malate groups were obtained. The SOD, GSH-Px, and TChE activities of chromium malate (at daily doses of 15.0 and 20.0 µg Cr/kg bm) were enhanced significantly in male rats compared with those of the normal control group and chromium picolinate group. Glycometabolism and related enzymes had no significant changes compared to normal control group and chromium picolinate group. These results indicated that long-term chromium malate supplementation did not cause measurable toxicity at daily doses of 10.0, 15.0, and 20.0 µg Cr/kg bm and could improve dyslipidemia and learning and memory deficits.

Se-enriched G. frondosa polysaccharide protects against immunosuppression in cyclophosphamide-induced mice via MAPKs signal transduction pathway.

To assess the immunomodulatory and antioxidant activities of a Se-polysaccharide from Se-enriched G. frondosa (Se-GFP-22), immunosuppressed mice models were generated by cyclophosphamide (CTX) administration and then treated with Se-GFP-22. Results showed that Se-GFP-22 could increase thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes, DTH reaction, serum hemolysin formation and immunoglobulin (Ig G, Ig A and Ig M) levels in CTX-treated mice. Se-GFP-22 significantly enhanced the antioxidant activity in CTX-treated mice, as shown by the evaluation of GSH-Px, SOD and CAT activities, as well as MDA levels in serum, liver and kidney. Se-GFP-22 strongly stimulated inflammatory cytokines (IL-2 and IFN-γ) and NO productions by up-regulating mRNA expressions of IL-2, IFN-γ and iNOS. Se-GFP-22 possessed the immunomodulatory activity by up-regulating various transcription factors (JNK, ERK, and p38) in MAPKs signaling pathways. This study suggested that Se-GFP-22 may provide an alternative strategy in lessening chemotherapy-induced immunosuppression.

A novel Se-polysaccharide from Se-enriched G. frondosa protects against immunosuppression and low Se status in Se-deficient mice.

In this study, a Se-deficient mice model was successfully developed by feeding a Se-deficient diet (0.02 mg Se/kg diet) for 4 weeks, and Se supplementation by Se-polysaccharides (Se-GFP-22) was lasted for 4 weeks. The immunomodulatory activity and Se supplementation of Se-GFP-22 from Se-enriched G. frondosa was investigated. Results showed that Se-GFP-22 remarkably enhanced glutathione peroxidase (GSH-Px) and thioredoxin reductase (TrxR) activities in liver, kidney and plasma, and serum, liver, spleen and kidney Se levels of Se-deficient mice. Se-GFP-22 increased the thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes and DTH reaction. Se-GFP-22 caused significant increments in cytokine (IL-1ß, TNF-α and IFN-γ) levels and Ig G, Ig A, Ig M and Ig E levels. Se-GFP-22 exhibited superior immunomodulatory effects than GFP-22. These findings indicated that Se-GFP-22 promote the protective effects against Se deficiency-induced immunosuppression and could be a potential immunomodulatory agent and a dietary Se-supplement.

The synergism and attenuation effect of Selenium (Se)-enriched Grifola frondosa (Se)-polysaccharide on 5-Fluorouracil (5-Fu) in Heps-bearing mice.

Previous study revealed that Se-GP11 could exhibited its antitumor activity by improving the immune functions. 5-Fu, as a chemotherapeutic drugs, can kill many immune cells in addition to tumor cells. Accordingly, the enhanced antitumor and reduced toxicity of Se-GP11 on 5-Fu were estimated in this study. The results demonstrated that Se-GP11 could evidently increase the antitumor activity of 5-Fu. Furthermore, Se-GP11 could enhance the immune functions during the tumor inhibition process of 5-Fu for increasing the cytokines secretion (IL-2 and TNF-α) and immune organs weights. In addition, Se-GP11 could reduce the toxicity of 5-Fu on liver by improving the hematological and biochemical parameters and up-regulating the SOD activities and down-regulating the MDA levels. Taken together, the results indicated that Se-GP11 may develop as an auxiliary preparation to chemical antitumor drugs.

Structural elucidation and antioxidant activity a novel Se-polysaccharide from Se-enriched Grifola frondosa.

Se-GFP-22, a heteropolysaccharide, with a weight-average Mw of 4.13×106Da, was purified from the crude Se-polysaccharide (Se-GFP) isolated from fruit bodies of Se-enriched Grifola frondosa. Selenium was accumulated efficiently in Grifola frondosa during cultivation with Na2SeO3. The structure was investigated through FT-IR, GC, GC-MS, NMR, HPSEC-MALL-RI, particle size, Conge-red test, CD, AFM and SEM. Se-GFP-22 was deduced as a backbone chain of 1,4-α-d-Glcp units with a branched point at C6 of both 1,3,6-ß-d-Manp and 1,4,6-α-d-Galp units. A typical absorption for selenium ester was existed in Se-GFP-22. Se-GFP-22 adopted as a spherical conformation with random coils. A novel Se-polysaccharide of different monosaccharide constituents, molecular weight, linkage types and high content of selenium has been isolated from G. frondosa. The antioxidant effect of Se-GFP-22 was more potent than that of G. frondosa polysaccharide (GFP-22), which may be influenced by the co-effect of polysaccharide and Se, molecular weight, degree of branching and configuration.

Long-Term Supplementation with Chromium Malate Improves Short Chain Fatty Acid Content in Sprague-Dawley Rats.

Our previous study showed that chromium malate improved the composition of intestinal flora, glycometabolism, glycometabolism-related enzymes, and lipid metabolism in type 2 diabetes mellitus (T2DM) rats. The present study was designed to evaluate the effect of chromium malate with long-term supplementation on short chain fatty acid (SCFA) content in Sprague-Dawley rats. The samples were analyzed by gas chromatography with high linearity (R 2 ≥ 0.9995), low quantification limit (0.011-0.070 mM), and satisfactory recoveries. The method was simple and environmentally friendly. The acetic content in cecum of 3-month control group was significantly higher than that of 1-year control group. When compared with 1-year control group, chromium malate (at a dose of 20.0 µg Cr/kg bw) could significantly increase acetic, propionic, i-butyric butyric, butyric, i-valeric, valeric, and n-caproic levels. The acetic, propionic, i-butyric, valeric, and n-caproic contents of 1-year chromium malate group (at a dose of 20.0 µg Cr/kg bw) had a significant improvement when compared with 1-year chromium picolinate group. Acetic, propionic, and butyric contained approximately 91.65 % of the total SCFAs in 1-year group. The results indicated that the improvement of chromium malate on short chain fatty acid content change was better than that of chromium picolinate.

Anti-tumor and immunomodulatory activity of selenium (Se)-polysaccharide from Se-enriched Grifola frondosa.

A polysaccharide termed Se-GP11 was extracted and purified from Se-enriched Grifola frondosa in our previous study. This study investigated the characterization, anti-tumor and immunomodulatory activity of Se-GP11. The results showed that Se-GP11 was composed of mannose, glucose and galactose with a molar ratio of 1:4.91:2.41. The weight-average molecular weight (Mw) and weight-average mean square radius (Rw) of Se-GP11 in 0.1M sodium chloride solution were 3.3×10(4)Da and 32.8 nm. Se-GP11 existed as a globular conformation with random coil structure. Se-GP11 had no anti-tumor activity against HepG-2 cells in vitro, and it significantly inhibited the growth of Heps tumor in vivo. Se-GP11 increased the relatively thymus and spleen weights as well as serum necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) levels. In addition, Se-GP11 promoted the phagocytosis and NO production of RAW264.7 as compared with that of the normal control group. The results revealed that the Se-GP11 may exhibit the anti-tumor through improving immunologic function of the tumor bearing mice.

Type 2 diabetic rats on diet supplemented with chromium malate show improved glycometabolism, glycometabolism-related enzyme levels and lipid metabolism.

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism in type 2 diabetic rats. Our results showed that fasting blood glucose, serum insulin level, insulin resistance index and C-peptide level in the high dose group had a significant downward trend when compared with the model group, chromium picolinate group and chromium trichloride group. The hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, Glut4, phosphor-AMPKß1 and Akt levels in the high dose group were significantly higher than those of the model, chromium picolinate and chromium trichloride groups. Chromium malate in a high dose group can significantly increase high density lipoprotein cholesterol level while decreasing the total cholesterol, low density lipoprotein cholesterol and triglyceride levels when compared with chromium picolinate and chromium trichloride. The serum chromium content in chromium malate and chromium picolinate group is significantly higher than that of the chromium trichloride group. The results indicated that the curative effects of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism changes are better than those of chromium picolinate and chromium trichloride. Chromium malate contributes to glucose uptake and transport in order to improved glycometabolism and glycometabolism-related enzymes.

Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

Evaluation of the Reproductive Toxicity, Glycometabolism, Glycometabolism-Related Enzyme Levels and Lipid Metabolism of Chromium Malate Supplementation in Sprague-Dawley Rats.

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the reproductive toxicity of chromium malate in Sprague-Dawley rats and then inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, and lipid metabolism. The results showed that no pathological, toxic feces and urine changes were observed in clinical signs of parental and fetal rats in chromium malate groups. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of chromium malate groups have no significant change compared with control group and chromium picolinate group. The serum and organ contents of Cr in chromium malate groups have no significant change when compared with control group. No measurable damage on liver, brain, kidney, and testis/uterus of chromium malate groups was found. No significant change in body mass, absolute and relative organ weights, and hematological and biochemical changes of rats were observed compared with the control and chromium picolinate groups. The results indicated that supplements with chromium malate does not cause obvious damage and has no obvious effect on glycometabolism, glycometabolism-related enzyme, and lipid metabolism on female and male rats. The results of this study suggested that chromium malate is safe for human consumption and has the potential for application as a functional food ingredient and dietary supplement.

Purification, characterization, and antioxidant activities of selenium-containing proteins and polysaccharides in royal sun mushroom, Agaricus brasiliensis (Higher Basidiomycetes).

The Agaricus brasiliensis proves to be the main source of many minerals, especially selenium (Se). In this study, Se-containing polysaccharides and proteins were isolated, purified, and characterized. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activity of Se-containing proteins and polysaccharides were also studied. Selenium in A. brasiliensis is present mostly in organic forms, accounting for 81.57% of the total Se. The organic forms of selenium mainly present in Se proteins account for 73.53%, while 12.23% is in Se polysaccharides. Two Se-containing proteins (AB-SePA-22) and (AB-SePG-22) with Se contents of 4.935 µg/g and 6.083 µg/g were obtained. AB-SePA-22 appeared as four bands with molecular masses of 16.7, 21.7, 26.3, and 33.6 kDa, respectively. The Se content of the three Se-containing polysaccharides, namely AB-SeP-1, AB-SeP-2, and AB-SeP-3, were 1.911, 0.613, and 0.671 µg/g, respectively. AB-SeP-1 (3.1×103 Da) was composed of glucose and galactose in a 7.494:1 molar ratio, whereas AB-SeP-2 (2.1×104 Da and 3.5×104 Da) and AB-SeP-3 (1.1×105 Da) were composed of glucose, galactose, and mannose with molar ratios of 27.01:1.55:1 and 9.805:1:1.22, respectively. Moreover, crude Se polysaccharide and total soluble Se protein had good antioxidant activities on scavenging DPPH and hydroxyl radical, and further research is needed.

Isolation, characterization and antioxidant activity of polysaccharide from Schisandra sphenanthera.

A water-soluble polysaccharide (SSPP11) from Schisandra sphenanthera was purified by DEAE-cellulose and Sephadex G-100 columns. Structure of SSPP11 and its antioxidant activity was evaluated. Results showed that SSPP11 has a molecular weight of 5.3×10(3)Da and is composed of Man, Glu and Gal. A linkage analysis and NMR study revealed that SSPP11 has a backbone of →1)-d-Man-(6→, →1)-d-Manp-(2→, →1)-d-Glup(4→, →1)-d-Glup-(6→, →1)-d-Galp-(4→, →1)-d-Galp-(4,6→ and →1)-d-Manp-(3,6→, with Man, Glu and Gal, which are distributed in branched chains. The Congo red absorption test revealed that SSPP11 has a triple helix stereo-configuration. Moreover, antioxidant activity of SSPP11 was stronger than the polysaccharide from Schisandra chinensis (Turcz.) Baill. In sum, this study demonstrates that a moderate molecular weight, triple helix stereo-configuration and higher degree of branching are beneficial for exerting antioxidant activity.

Enhanced antitumor and reduced toxicity effect of Schisanreae polysaccharide in 5-Fu treated Heps-bearing mice.

Previous study indicated that the refined polysaccharide from Schisandra could improve the CTX-induced inhibition of T and B lymphocytes proliferation. Accordingly, the enhanced antitumor and reduced toxicity effects of a low molecular weight purified polysaccharide from Schisandra (SCPP11) were investigated in 5-fluorouracil (5-Fu) treated Heps-bearing mice. The results revealed that the SCPP11 (oral administration) exhibited a significant enhanced effect of antitumor activity when combined with 5-Fu. Moreover, a increased effect was also observed in boosting immunity functions when the Heps-bearing mice receiving SCPP11 combination with 5-Fu administration, including increased in thymus indexes and enhancing serum IL-2 and TNF-α secretion. In addition, SCPP11 could ameliorate the hematological and biochemical parameters changes induced by 5-Fu to normal level, and reduce the formation of MDA and enhance the activities of SOD in liver to against 5-Fu induced free radical damage. The above results suggested that the SCPP11 combined with 5-Fu presented enhanced effects on antitumor activity and the SCPP11 could attenuate the 5-Fu-induced toxicity effect. It could serve as a new and promising adjuvant for chemotherapy drugs.

Isolation, purification and characterisation of selenium-containing polysaccharides and proteins in selenium-enriched Radix puerariae.

BACKGROUND: Selenium (Se) is an essential dietary mineral and Radix puerariae (RP) (the dried root of Pueraria lobata Willd.) is a botanical supplement widely used as a nutraceutical. Food enriched with Se provides a feasible and economic approach for production of organic Se compounds. However, little is known about Se-enriched RP and the structure of Se-containing polysaccharides and proteins derived from Se-enriched RP. RESULTS: The organic form of Se accounted for 82.42% of total content. Purification by DEAE-52 and Sephadex G-100 column chromatography yielded three single fractions--RP-SeP-11, RP-SeP-22 and RP-SeP-33--with Se contents of 0.9562 × 10⁻³, 0.6113 × 10⁻³ and 0.3827 × 10⁻³ g kg⁻¹, respectively. RP-SeP-11 (3.5 kDa) was made of glucose, RP-SeP-22 (19.6 kDa) was composed of xylose and glucose, and RP-SeP-33 (97.9 kDa) was made up galactose, mannose and glucose. Two Se-containing proteins were obtained with Se content of 3.175 × 10⁻³ and 4.328 × 10⁻³ g kg⁻¹, respectively. One appeared as three subunits with molecular masses of 43.0, 29.0 and 17.8 kDa while the other appeared as two subunits with molecular masses of 43.0 and 26.3 kDa. CONCLUSION: The results provide a basis for promoting the utilisation of RP resources enriched with Se as a promising tool for the food industry and are significant for its contribution to Se biochemistry in plants.

Extraction, preliminary characterization and antioxidant activity of Se-enriched Maitake polysaccharide.

A Se-enriched Grifola frondosa polysaccharide (Se-GP) was obtained from G. frondosa enriched with Se by spraying an Na2SeO3 solution during fruit body growth using a Box-Behnken design and compared to G. frondosa polysaccharide (GP) for preliminary characterization and determination of the antioxidant activity. Under optimal conditions, polysaccharide yields and both the Se-GP and GP contents do not differ; however, the Se content of Se-GP (17.52 µg/g) was 48.7 times that of GP. Three homogenous Se-GPs (Se-GP11, Se-GP22 and Se-GP33) or GPs (GP11, GP22 and GP33) were obtained via DEAE-52 and Sephacryl S-400 purification. Their molecular weight and polysaccharide content of these compounds were not obviously different, whereas the Se content of Se-GP11, Se-GP22 and Se-GP33 was 9.41, 6.59 and 16.25 times that of GP11, GP22 and GP33, respectively. The antioxidant activity of Se-GP for the DPPH, ABTS and hydroxyl radicals was higher than that of GP and was highest for the hydroxyl radical.

Antitumor activity of hyaluronic acid-selenium nanoparticles in Heps tumor mice models.

In this study, hyaluronic acid-selenium (HA-Se) nanoparticles as novel complexes were synthesized and their antitumor activities in vivo were investigated. The mice inoculated with Heps tumor were orally administered with HA-Se nanoparticles at 86.45 mg/kg (H) and 4.32 mg/kg (L) body weights as high and low doses respectively (2.20% selenium content in the HA-Se nanoparticles samples by ICP-AES) for 10 days. The transmission electron microscopy (TEM) results indicated that the HA-Se nanoparticles were spherical with mean size of 50-70 nm. The HA-Se nanoparticles could significantly reduce tumor weights at the tumor inhibition ratios of 46.92% (H) and 49.12% (L) respectively. However, in the 5-fluorouracil positive group (25 mg/kg), the tumor inhibition ratio was 61.71%. From the study, the HA-Se nanoparticles (4.32 mg/kg) significantly increased thymus and spleen relative weights, enhanced the activities of superoxide dismutase (SOD), reduced the formation of malondialdehyde (MDA) and the activities of aspartate transaminase, alanine transaminase and crea in Heps tumor mice. The results of the study indicated that the HA-Se nanoparticles are potential antitumor candidate for cancer treatment.

Enhanced anti-diabetic activity of a combination of chromium(III) malate complex and propolis and its acute oral toxicity evaluation.

In order to obtain the additional benefit of anti-diabetic activity and protective effects of liver injury for diabetes, the anti-diabetic effect and acute oral toxicity of a combination of chromium(III) malate complex (Cr(2)(LMA)(3)) and propolis were assessed. The anti-diabetic activity of the combination of the Cr(2)LMA(3) and propolis was compared with Cr(2)(LMA)(3) and propolis alone in alloxan-induced diabetic mice by daily oral gavage for a period of 2 weeks. Acute oral toxicity of the combination of the Cr(2)LMA(3) and propolis was tested using ICR mice at the dose of 1.0-5.0 g/kg body mass by a single oral gavage and observed for a period of 2 weeks. The results of the anti-diabetic activity of the combination from the aspects of blood glucose level, liver glycogen level, and the activities of aspartate transaminase, alanine transaminase, and alkaline phosphatase indicated that the increased anti-diabetic activity and the protective efficacy of liver injury for diabetes were observed. In acute toxicity study, LD(50) (median lethal dose) value for the combination was greater than 5.0 g/kg body mass. The combination of Cr(2)LMA(3) and propolis might represent the nutritional supplement with potential therapeutic value to control blood glucose and exhibit protective efficacy of liver injury for diabetes and non-toxicity in acute toxicity.

Anti-diabetic properties of chromium citrate complex in alloxan-induced diabetic rats.

The chromium citrate complex [CrCIT] was synthesized and its structure was determined by infrared, UV-visible and atomic absorption spectroscopy, elemental and thermodynamic analysis. Anti-diabetic activity, oxidative DNA damage capacity and acute oral toxicity of [CrCIT] were investigated and compared with that of chromium trichloride hexahydrate. [CrCIT] was synthesized in a single step reaction by chelating chromium(III) with citric acid in aqueous solution. The molecular formula of [CrCIT] was inferred as CrC(6)H(5)O(7)·4H(2)O. The anti-diabetic activity of the complex [CrCIT] was assessed in alloxan-diabetic rats by daily oral gavage for 3 weeks. The biological activity results showed that the complex at the dose of 0.25-0.75 mg Cr/kg body weight could decrease the blood glucose level and increase liver glycogen level in alloxan-diabetic rats. [CrCIT] had more beneficial influences on the improvement of controlling blood glucose, serum lipid and liver glycogen levels compared with CrCl(3)·6H(2)O. Furthermore, [CrCIT] did not cause oxidative DNA damage under physiologically relevant conditions, and [CrCIT] did not produce any hazardous symptoms or deaths in acute oral toxicity test, showing the LD(50) value for female and male rats were higher than 15.1 g/kg body weight. The results suggested that [CrCIT] might represent a novel and proper chromium supplement with potential therapeutic value to control blood glucose in diabetes.