Comparative study on the effects of micro- and nano-sized zinc oxide supplementation on zinc-deficient mice

Background@#Zinc (Zn) is an essential cofactor for physiological homeostasis in the body.Zn oxide (ZnO), an inorganic compound that supplies Zn, exists in various sizes, and its bioavailability may vary depending on the size in vivo. However, comparative studies on the nutritional effects of micro-sized ZnO (M-ZnO) and nano-sized ZnO (N-ZnO) supplementation on Zn deficiency (ZnD) animal models have not been reported. @*Objectives@#This study investigated the nutritional bioavailability of N-ZnO and M-ZnO particles in dietary-induced ZnD mice. @*Methods@#Animals were divided into six experimental groups: normal group, ZnD control group, and four ZnO treatment groups (Nano-Low, Nano-High, Micro-Low, and MicroHigh). After ZnD induction, N-ZnO or M-ZnO was administered orally every day for 4 weeks. @*Results@#ZnD-associated clinical signs almost disappeared 7 days after N-ZnO or M-ZnO administration. Serum Zn concentrations were higher in the Nano-High group than in the ZnD and M-ZnO groups on day 7 of ZnO treatment. In the liver and testis, Nano-Low and Nano-High groups showed significantly higher Zn concentrations than the other groups after 14-day treatment. ZnO supplementation increased Mt-1 mRNA expression in the liver and testis and Mt-2 mRNA expression in the liver. Based on hematoxylin-and-eosin staining results, N-ZnO supplementation alleviated histological damage induced by ZnD in the testis and liver. @*Conclusions@#This study suggested that N-ZnO can be utilized faster than M-ZnO for nutritional restoration at the early stage of ZnD condition and presented Mt-1 as an indicator of Zn status in the serum, liver, and testis.

Beta-carotene prevents the spermatogenic disorders induced by exogenous scrotal hyperthermia through modulations of oxidative stress, apoptosis, and androgen biosynthesis in mice / 대한수의학회지

We investigated whether β-carotene (β-CA) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of β-CA or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at 43℃ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and HIF-1α mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, NF-κB, and TGF-β1 mRNAs), and androgen biosynthesis (serological testosterone concentration and 3β-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by β-CA treatment, but only slightly improved by EA treatment. These findings indicate that β-CA, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

Beta-carotene prevents the spermatogenic disorders induced by exogenous scrotal hyperthermia through modulations of oxidative stress, apoptosis, and androgen biosynthesis in mice

We investigated whether β-carotene (β-CA) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of β-CA or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at 43℃ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and HIF-1α mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, NF-κB, and TGF-β1 mRNAs), and androgen biosynthesis (serological testosterone concentration and 3β-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by β-CA treatment, but only slightly improved by EA treatment. These findings indicate that β-CA, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

Long-circulating and target-specific distributions of cyanine 5.5-labeled hyaluronic acid nanoparticles in mouse organs during 28 days after a single administration / 대한수의학회지

Although hyaluronic acid (HA) has been developed as a nanoparticle (NP; 320–400 nm) for a drug delivery system, the tissue targeting efficacy and the pharmacokinetics of HA-NPs are not yet fully understood. After a dose of 5 mg/kg of cyanine 5.5-labeled HA-NPs or HA-polymers was intravenously administrated into mice, the fluorescence was measured from 0.5 h to 28 days. The HA-NPs fluorescence was generally stronger than that of HA-polymers, which was maintained at a high level over 7 days in vivo, after which it gradually decreased. Upon ex vivo imaging, liver, spleen, kidney, lung, testis and sublingual gland fluorescences were much higher than that of other organs. The fluorescence of HA-NPs in the liver, spleen and kidney was highest at 30 min, where it was generally maintained until 4 h, while it drastically decreased at 1 day. However, the fluorescence in the liver and spleen increased sharply at 7 days relative to 3 days, then decreased drastically at 14 days. Conversely, the fluorescence of HA-polymers in the lymph node was higher than that of HA-NPs. The results presented herein may have important clinical implications regarding the safety of as self-assembled HA-NPs, which can be widely used in biomedical applications.

Withdrawal: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

The reason why the author withdraw the paper is a controversy on intellectual property rights between JIBiopharm Inc. and Hoseo University.

Erratum: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

In the Materials and Methods section, material supply source is incorrectly cited and has been changed upon request of authors.

Long-circulating and target-specific distributions of cyanine 5.5-labeled hyaluronic acid nanoparticles in mouse organs during 28 days after a single administration

Although hyaluronic acid (HA) has been developed as a nanoparticle (NP; 320–400 nm) for a drug delivery system, the tissue targeting efficacy and the pharmacokinetics of HA-NPs are not yet fully understood. After a dose of 5 mg/kg of cyanine 5.5-labeled HA-NPs or HA-polymers was intravenously administrated into mice, the fluorescence was measured from 0.5 h to 28 days. The HA-NPs fluorescence was generally stronger than that of HA-polymers, which was maintained at a high level over 7 days in vivo, after which it gradually decreased. Upon ex vivo imaging, liver, spleen, kidney, lung, testis and sublingual gland fluorescences were much higher than that of other organs. The fluorescence of HA-NPs in the liver, spleen and kidney was highest at 30 min, where it was generally maintained until 4 h, while it drastically decreased at 1 day. However, the fluorescence in the liver and spleen increased sharply at 7 days relative to 3 days, then decreased drastically at 14 days. Conversely, the fluorescence of HA-polymers in the lymph node was higher than that of HA-NPs. The results presented herein may have important clinical implications regarding the safety of as self-assembled HA-NPs, which can be widely used in biomedical applications.

The effect of near-infrared fluorescence conjugation on the anti-cancer potential of cetuximab / 한국실험동물학회지

This study investigated the anti-cancer potential of a near-infrared fluorescence (NIRF) molecule conjugated with Cetuximab (Cetuximab-NIRF) in six-week-old female BALB/c athymic (nu+/nu+) nude mice. A431 cells were cultured and injected into the animals to induce solid tumors. Paclitaxel (30 mg/kg body weight (BW)), Cetuximab (1 mg/kg BW), and Cetuximab-NIRF (0.25, 0.5 and 1.0 mg/kg BW) were intraperitoneally injected twice a week into the A431 cell xenografts of the nude mice. Changes in BW, tumor volume and weight, fat and lean mass, and diameter of the peri-tumoral blood vessel were determined after two weeks. Tumor volumes and weights were significantly decreased in the Cetuximab-NIRF (1 mg/kg BW) group compared with the control group (P < 0.001). Lean mass and total body water content were also conspicuously reduced in the Cetuximab-NIRF (1 mg/kg BW) group compared with the vehicle control group. Peri-tumoral blood vessel diameters were very thin in the Cetuximab-NIRF groups compared with those of the paclitaxel group. These results indicate that the conjugation of Cetuximab with NIRF does not affect the anti-cancer potential of Cetuximab and NIRF can be used for molecular imaging in cancer treatments.

Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

This study was performed to investigate the effect of a concentrate of fermented wild ginseng root culture (HLJG0701) on memory improvement in the scopolamine (SPL)-induced memory-deficient mouse model. Eight-week-old male ICR mice were used to evaluate the protective effect of HLJG0701 against the SPL-induced memory loss animal model. The Morris water maze test, which measures hippocampus-dependent learning ability, and the Y-maze test, a short-term memory assessment test, were performed and related markers were analyzed. HLJG0701-treated groups displayed significantly reduced acetylcholinesterase activity and increased acetylcholine level compared with the SPL-administered group (SPL-G) (P < 0.05). In the Y-maze test, the spontaneous alternation in al HLJG0711-treated groups was significantly increased compared with that in SPL-G (P < 0.05). In the Morris water maze test, the escape latency and time spent in the target quadrant in all HLJG0701-treated groups were significantly decreased and increased, respectively, compared with those in SPL-G (P < 0.05). In addition, the brain-derived neurotrophic factor level in groups treated with HLJG0701 300 and 600 mg/kg body weight was significantly increased compared with that in SPL-G (P < 0.05). These results suggest that the HLJG0701 may protect against memory loss by inhibiting acetylcholinesterase activity and preventing acetylcholine deficiency.

Comparative in vivo biodistributions of nanoparticles and polymers of ¹⁷⁷lutetium-labeled hyaluronic acids in mice during 28 days

Hyaluronic acid (HA) has been investigated for biomedical and pharmaceutical applications. This study was conducted to determine the distributions of HA nanoparticles (NPs; size 350–400 nm) and larger HA polymers in mice at intervals after application. ¹⁷⁷Lutetium (Lu)-labeled HA-NPs or HA polymers were intravenously injected (5 mg/kg) into male ICR mice, and radioactivity levels in blood and target organs were measured from 0.25 h to 28 days post-injection. In blood, the radioactivities of HA-NPs and HA polymer peaked at 0.5 h after injection but were remarkably decreased at 2 h; subsequently, they maintained a constant level until 6 days post-injection. HA-NPs and HA polymers were observed in the liver, spleen, lung, kidney, and heart (in ascending order) but were seldom observed in other organs. After 3 days, both the HA-NP and HA polymer levels showed similar steady decreases in lung, kidney, and heart. However, in liver and spleen, the HA-NP levels tended to decrease gradually after 1 day and both were very low after 14 days, whereas the HA polymer level accumulated for 28 days. The results indicate that HA-NPs, with their faster clearance pattern, may act as a better drug delivery system than HA polymers, especially in the liver and spleen.

Temporal and subcellular distributions of Cy5.5-labeled hyaluronic acid nanoparticles in mouse organs during 28 days as a drug carrier

Temporal and subcellular distributions of hyaluronic acid (HA) as a degradable nanoparticle (NP) in animals were investigated to determine if HA-NP could be utilized as an appropriate drug delivery system. After mice were intravenously injected with 5 mg/kg of Cy5.5-labeled HA-NP sized 350–400 nm or larger HA-polymers, the fluorescence intensity was measured in all homogenized organs from 0.5 h to 28 days. HA-NP was greatly detected in spleen, liver and kidney until day 28, while it was maintained at low levels in other organs. HA-polymer was observed at low levels in all organs. HA-NP quantities in spleen and liver were reduced until day 3, but increased sharply between days 3 and 7, then decreased again, while their HA-polymers were maintained at low levels until day 28. In kidneys, both HA-NP and HA-polymer showed high levels after 0.5 h of administration, but steadily decreased until day 28. According to ultrastructural analyses, HA-NP was engulfed in Kupffer cells of liver and macrophages of spleen and kidney at day 1 and was accumulated in the cytoplasm of kidney tubular cells at day 7. Overall, these findings suggest that HA-NP could be considered a desirable drug carrier in the liver, kidney, or spleen.

Hair growth promoting effects of emodin in telogenic C57BL/6 mice

Emodin is an anthraquinone derivative from the roots of Rheum officinale Baill that possesses a variety of biological activities, including inhibition of 5α-reductase and prostaglandin D2. In this study, we investigated whether emodin promotes hair growth. After emodin was topically applied to the shaved dorsal skin of telogenic C57BL/6 N mice, the hair growth rate and morphological analysis were evaluated in dorsal skin for 15 days. After 13 days of treatment, minoxidil or emodin (0.01% or 0.1%)-treated groups showed remarkable regrowth of hairs relative to the vehicle control group. Scoring of the hair growth and rate of hair growth area for 15 days revealed that groups treated with minoxidil and 0.1% emodin were significantly higher than the vehicle control group. Histological examination revealed the emodin and minoxidil groups markedly recovered the number and morphology of hair follicles, including the subcutis depth, relative to the vehicle group. These results suggest that emodin has an excellent promoting effect in hair growth similar to that of minoxidil and might be useful for treatment of baldness or alopecia.

Comparison of teratogenecity induced by nano- and micro-sized particles of zinc oxide in cultured mouse embryos / 대한수의학회지

The increasing uses of zinc oxide nanoparticles (nZnO) in industrial and personal care products raise possible danger of using nZnO in human. To determine whether ZnO induces size-dependent anomalies during embryonic organogenesis, mouse embryos on embryonic day 8.5 were cultured for 2 days under 50, 100, and 150 microg of nZnO (< 100 nm) or micro-sized ZnO (mZnO; 80 +/- 25 microm), after which the morphological changes, cumulative quantity of Zn particles, and expressions of antioxidant and apoptotic genes were investigated. Although embryos exposed to 50 microg of ZnO exhibited no defects on organogenesis, embryos exposed to over 100 microg of ZnO showed increasing anomalies. Embryos treated with 150 microg of nZnO revealed significant changes in Zn absorption level and morphological parameters including yolk sac diameter, head length, flexion, hindbrain, forebrain, branchial bars, maxillary process, mandibular process, forelimb, and total score compared to the same dose of mZnO-treated embryos. Furthermore, CuZn-superoxide dismutase, cytoplasmic glutathione peroxidase (GPx) and phospholipid hydroperoxidase GPx mRNA levels were significantly decreased, but caspase-3 mRNA level was greatly increased in nZnO-treated embryos as compared to normal control embryos. These findings indicate that nZnO has severer teratogenic effects than mZnO in developing embryos.

Distribution and accumulation of 177Lu-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles in the tissues of ICR mice / 대한수의학회지

To investigate kinetics of free 177Lu and 177Lu-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION), suspensions were intravenously injected into the tail vein of mice at a dose of 5 microCi/mouse or 15 mg/kg body weight, respectively. Free 177Lu radioactivity levels were highest in kidney followed by liver and lung 1 day post-injection. 177Lu-labeled TCL-SPION radioactivity in liver and spleen was significantly higher compared to that of other organs throughout the experimental period (p < 0.05). Radioactivity in blood, brain, and epididymis rapidly declined until 28 days. Based on these results, TCL-SPION could be a safe carrier of therapeutics.

Evaluation of thermally cross-linked superparamagnetic iron oxide nanoparticles for the changes of concentration and toxicity on tissues of Sprague-Dawley rats / 대한수의학회지

This study was investigated the change of concentration and toxicity of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) on tissues of Sprague-Dawley rats. TCL-SPION at the dose of 15 mg/kg body weight was intravenously injected into the tail vein of the male Sprague-Dawley rats. The fate of TCL-SPION in serum, urine and tissues was observed during 28 days. Serum iron level was maximal at 0.25 h post-injection and gradually declined thereafter. In addition, the sinusoids of liver and the red pulp area of spleen were mainly accumulated iron from 0.5 h to 28-day post-injection. In kidney, iron deposition was detected in the tubular area until 0.5 h after injection. Malondialdehyde concentration in the liver slightly increased with time and was not different with that at zero time. In the liver and spleen, TNF-alpha and IL-6 levels of TS treated with TCL-SPION were not different with those of the control during the experimental period. From the results, TCL-SPION could stay fairly long-time in certain tissues after intravenous injection without toxicity. The results indicated that TCL-SPION might be useful and safe as a contrast for the diagnosis of cancer or a carrier of therapeutic reagents to treat diseases.

Distribution and accumulation of Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles in the tissues of ICR mice

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body.

Dietary zinc inhibits the formation of colonic preneoplastic lesion induced by azoxymethane and dextran sodium sulfate in mice / 대한수의학회지

Colorectal cancer (CRC) is one of the leading causes of cancer death in western countries or in the developed countries. Zinc intake has been associated with decreased risk of CRC. We investigated the effect of zinc on the formation of colonic aberrant crypt foci (ACF) induced by azoxymethane followed by dextran sodium sulfate in mice. Five-week old ICR mice were fed with the different zinc levels (0.01, 0.1, 1 ppm) for 12 weeks. The numbers of ACF were measured in the colonic mucosa. The ACF number of HZn group was significantly low compared with LZn group or MZn group. Cytosolic superoxide dismutase activity was the highest in HZn group, while thiobarbituric acid reactive substance level for lipid peroxidation was the highest in LZn group. There was no difference in number of PCNA-positive proliferative cells among the groups. TUNEL-positive apoptotic cells were increased in HZn group compared with LZn group. The HZn group exhibited a decrease of beta-catenin immunostaining areas compared with the LZn or MZn group. These findings indicate that dietary zinc might exert a protecting effect against colon carcinogenesis by inhibiting the development of ACF in the mice.

Suppressive Effect of Zinc on the Formation of Colonic Preneoplastic Lesions in the Mouse Fed High Levels of Dietary Iron

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Six-week old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of beta-catenin was also performed on the mucous membrane of colon. The number of large ACF (> or = 4 AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

Effects of Selenium on Colon Carcinogenesis Induced by Azoxymethane and Dextran Sodium Sulfate in Mouse Model with High-Iron Diet / 한국실험동물학회지

Selenium (Se) is known to prevent several cancers while the relationship between high iron and the risk of colorectal cancer is controversial. To investigate the effects of Se in colon carcinogenesis, we subjected three different levels of Se and high-iron diet to a mouse model of colon cancer in which animals were treated with three azoxymethane (AOM) injections followed by dextran sodium sulfate (DSS) administration. There were five experimental groups including vehicle group [normal-Fe (NFe, 45 ppm)+medium-Se (MSe, 0.1 ppm)], positive control group (AOM/DSS+NFe+MSe), AOM/DSS+high-Fe (HFe, 450 ppm)+low-Se (LSe, 0.02 ppm), AOM/DSS+HFe+MSe, and AOM/DSS+HFe+high-Se (HSe, 0.5 ppm). The animals were fed on the three different Se diets for 24 weeks. The incidence of colon tumor in the high-Se diet group (AOM/DSS+HFe+HSe) showed 19.4% lower than positive control group, 5.9% lower than AOM/DSS+HFe+MSe diet group, and 11.1% lower than AOM/DSS+HFe+LSe group. The tumor multiplicity was significantly higher in the low-Se diet group (AOM/DSS+HFe+LSe) compare to all other AOM/DSS treated groups. In the high-Se diet group, the activity of hepatic GPx was comparable to that of positive control group, and significantly higher than those of low-Se or medium-Se diet groups. Expression level of hepatic GPx-1 showed similar results. Hepatic malondialdehyde (MDA) level (indicator of oxidative stress) in the low-Se diet group showed the highest compared to the other groups, and it was significantly higher than positive control group. In the high-Se diet group the level of MDA in the liver was significantly lower than all other AOM/DSS treated groups. High-Se diet group showed significantly lower proliferative index than low-Se and medium-Se groups. The apoptotic indices in low-Se group and medium-Se group were significantly lower than positive control group. However, apoptotic index of high-Se diet group was significantly higher than all other AOM/DSS treated groups. These findings suggest that dietary Se supplement may have protective effect against colon cancer by decreasing proliferation, increasing apoptosis of tumor cells, and reducing oxidative stress in mice with high iron diet.

Effect of Sodium Silicate on Hair Growth in C57BL/6 Mice / 한국실험동물학회지

A promoting effect of Na2SiO3 on hair regrowth was investigated using an animal model of C57BL/6 mice. There were four experimental groups including distilled water (DW, a negative control), 5% minoxidil (MXD, a positive control), 50% Na2SiO3, and 100% Na2SiO3 solution. The animals were shaved with an electric clipper and then test solutions applied daily with a volume of 0.2 ml per to the dorsal skin of mice for 3 weeks. Body weight and food and water consumption were measured weekly. Photographs of hair regrowth were taken at experimental day 0, 4, 7, 10, 14, 17, and 21. Activities of alkaline phosphatase and gamma-glutamyl transpeptidase as well as expressions of growth factors were also determined in the dorsal skin of mice. The animal body weight were not significantly changed among the experimental groups. The MXD and Na2SiO3 accelerated hair regrowth compared with DW. The elongation of hair follicles were evidently observed in MXD and 50 or 100% Na2SiO3 groups. MXD significantly increased gamma-glutamyl transpeptidase at day 14, compared with DW (P<0.05). But the activities of alkaline phosphatase and gamma-glutamyl transpeptidase were not significantly increased in Na2SiO3 groups, compared with DW. The expression of epidermal growth factor was significantly increased in MXD and Na2SiO3 groups, compared with DW (P<0.05). The expression of vascular endothelial growth factor was not significantly changed by MXD or Na2SiO3 treatments. The expression of transforming growth factor (TGF)-beta1 was clearly decreased in MXD and Na2SiO3 groups, compared with DW. These results indicate that Na2SiO3 may have a hair growth-promoting activity and it can be used for treatment of alopecia or boldness in humans.