Tong Ho Kang

Publications of Tong Ho Kang

• Inhibitory effect of Aralia continentalis on the cariogenic properties of Streptococcus mutans.

  Authors: Da-Hong Lee, Bo-Ra Seo, Ha-Yeon Kim, Gi-Chun Gum, Hyeon-Hee Yu, Hyung-Keun You, Tong Ho Kang, Yong-Ouk You

  Journal of ethnopharmacology. 09/2011; 137(2):979-84.

  Aralia continentalis has been used in traditional Korean medicine for dental diseases such as toothache, dental caries, periodontal disease and gingivitis, and also has been used for neuralgia,Aralia continentalis has been used in traditional Korean medicine for dental diseases such as toothache, dental caries, periodontal disease and gingivitis, and also has been used for neuralgia, analgesia, sweating, and as an antirheumatic. The present study was designed to investigate the inhibitory effect of Aralia continentalis extract on cariogenic properties of Streptococcus mutans, which is one of the most important bacteria in the formation of dental caries and dental plaque. The inhibitory effects of Aralia continentalis extract on the growth, acid production, water-insoluble glucan synthesis, and adhesion were investigated in Streptococcus mutans. The biofilm formation of Streptococcus mutans was determined by scanning electron microscopy (SEM) and safranin staining. The ethanol extract of Aralia continentalis showed concentration dependent inhibitory activity on the growth of Streptococcus mutans and significant inhibition of acid production at the concentrations of 0.25, 0.5, 1, 2 and 4 mg/ml compared to the control group. The synthesis of water-insoluble glucan by glucosyltransferase (GTFase) was decreased in the presence of 0.5-4 mg/ml of the extract of Aralia continentalis. The extract markedly inhibited Streptococcus mutans adherence to saliva-coated hydroxyapatite beads (S-HAs). The extract of Aralia continentalis has an inhibitory effect on the formation of Streptococcus mutans biofilms at the concentrations higher than 2mg/ml. These results suggest that Aralia continentalis may inhibit cariogenic properties of Streptococcus mutans, and also may support the scientific rationale that native inhabitants used the extract for the treatment of dental diseases.

• Gami-Chunghyuldan ameliorates memory impairment and neurodegeneration induced by intrahippocampal Aβ 1-42 oligomer injection.

  Authors: Jin Gyu Choi, Minho Moon, Hyo Geun Kim, Inhee Mook-Jung, Sun Yong Chung, Tong Ho Kang, Sun Yeou Kim, Eunjoo H Lee, Myung Sook Oh

  Neurobiology of learning and memory. 06/2011; 96(2):306-14.

  Soluble oligomeric forms of amyloid beta (AβO) are regarded as a main cause of synaptic and cognitive dysfunction in Alzheimer's disease (AD) and have been a primary target in the development of drugSoluble oligomeric forms of amyloid beta (AβO) are regarded as a main cause of synaptic and cognitive dysfunction in Alzheimer's disease (AD) and have been a primary target in the development of drug treatments for AD. The present study utilized a mouse model of AD induced by intrahippocampal injection of AβO (10 μM) to investigate the effects of Gami-Chunghyuldan (GCD), a standardized multi-herbal medicinal formula, on the presentation of memory deficits and neurohistological pathogenesis. GCD (10 and 50mg/kg/day, 5 days, p.o.) improved AβO-induced memory impairment as well as reduced neuronal cell death, astrogliosis, and microgliosis in the hippocampus. In addition, GCD prevented AβO-triggered synaptic disruption and cholinergic fiber loss. These results suggest that GCD may be useful in the prevention and treatment of AD.

• Curculigo orchioides, natural compounds for the treatment of noise-induced hearing loss in mice.

  Authors: Bin Na Hong, Yong-Ouk You, Tong Ho Kang

  Archives of pharmacal research. 04/2011; 34(4):653-9.

  Noise exposure is one of the most common causes of hearing loss. Noise-induced hearing loss (NIHL) is thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical andNoise exposure is one of the most common causes of hearing loss. Noise-induced hearing loss (NIHL) is thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical and metabolic mechanisms. Curculigo orchioides Gaerten (C. orchioides) is considered to have immunostimulant, hepatoprotective, antioxidative, anticancer, and antidiabetic activities. But the effect of C. orchioides on NIHL is not yet reported, this study focused on examining the therapeutic effects of C. orchioides on NIHL in a mouse model. Oral treatment with the extract of C. orchioides began 24 h following an examination that determined a shift in hearing threshold induced by noise exposure. Hearing threshold shifts were assessed by analyzing auditory brainstem responses at 1, 5, and 7 days following noise exposure. Central auditory function was evaluated using auditory middle latency responses, and cochlear function was determined based on transient-evoked otoacoustic emissions. C. orchioides reduced hearing threshold shifts, central auditory function damage, and cochlear function deficits. Our results suggest that C. orchioides can be utilized as a potential therapeutic natural product for NIHL.

• Effects of optimized-SopungSunkiwon on memory impairment and enhancement.

  Authors: Jin Gyu Choi, Woong Mo Yang, Tong Ho Kang, Myung Sook Oh

  Neuroscience letters. 03/2011; 491(2):93-8.

  Optimized-SopungSunkiwon (OSS) is a multi-herbal formula that contains six medicinal herbs from SopungSunkiwon, a traditional medicine used for neurodegenerative disorders. In this study, weOptimized-SopungSunkiwon (OSS) is a multi-herbal formula that contains six medicinal herbs from SopungSunkiwon, a traditional medicine used for neurodegenerative disorders. In this study, we investigated the anti-amnesic effects of OSS in a dementia model. Acetylcholinesterase (AChE) inhibition assay was performed to investigate the cholinergic antagonistic effect of OSS. In addition, a step-through passive-avoidance test was performed with scopolamine-induced memory impairment in mice, and immunohistochemistry was analyzed to investigate synaptic formation with synaptic proteins. OSS inhibited AChE activity, resulting in significant improvement of memory functions. In the passive-avoidance test, the latency time of OSS-treated mice was significantly longer than that of either the control or scopolamine-treated group. In the immunohistochemical analysis, synaptic proteins such as synaptophysin and PSD-95 were significantly increased in OSS-treated mice. These results demonstrate that OSS may affect impairment and enhancement of memory and increase synaptophysin and PSD-95 facilitating acetylcholine release and synaptic growth.

• Diosgenin from Dioscorea nipponica ameliorates diabetic neuropathy by inducing nerve growth factor.

  Authors: Tong Ho Kang, Eunjung Moon, Bin Na Hong, Sang Zin Choi, Miwon Son, Ji-Ho Park, Sun Yeou Kim

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1493-8.

  Diabetic neuropathy is characterized by axonal degeneration, demyelination, and atrophy in association with failed axonal regeneration, remyelination, and synaptogenesis. Recent reports suggest thatDiabetic neuropathy is characterized by axonal degeneration, demyelination, and atrophy in association with failed axonal regeneration, remyelination, and synaptogenesis. Recent reports suggest that reduced levels of nerve growth factor (NGF) may play a significant role in the pathogenesis of diabetic polyneuropathy. In this study, we investigated the regulation of NGF by steroid diosgenin (DG) in a diabetic neuropathy rodent model. We found that DG, the primary spirostane-type steroid in several Dioscorea species, increased NGF levels in the sciatic nerve of diabetic rats. Additionally, DG increased neurite outgrowth in PC12 cells and enhanced nerve conduction velocities in the diabetic neuropathy mouse model. DG-treated diabetic mice showed reduced disarrangement of the myelin sheath and increased area of myelinated axons by electron microscope studies and exhibited improvement in the damaged axons. Our data further suggest that DG increased the nerve conduction velocity through induction of NGF. Thus, our findings indicate that DG, a major sapogenin obtained from Dioscorea nipponica, reverses functional and ultrastructural changes and induces neural regeneration in a diabetic neuropathy model.

• Post-exposure treatment with ginsenoside compound K ameliorates auditory functional injury associated with noise-induced hearing loss in mice.

  Authors: Bin Na Hong, Se Young Kim, Tae Hoo Yi, Tong Ho Kang

  Neuroscience letters. 10/2010; 487(2):217-22.

  Noise-induced hearing loss (NIHL) is thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical and metabolic mechanisms. Unfortunately, initial studies assessing theNoise-induced hearing loss (NIHL) is thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical and metabolic mechanisms. Unfortunately, initial studies assessing the effectiveness of post-exposure treatment after hearing loss have yielded largely disappointing results. This study explored the effects of oral treatment with Korean red ginseng (RG) and with two bioavailable ginsenoside metabolites, ginsenoside Rh1 and ginsenoside compound K (GCK), in response to NIHL in a murine model. Pharmacological treatments began 24h after noise exposure and were continued once daily for 7 days. Central auditory function was evaluated using auditory middle latency responses, and cochlear function was determined based on transient evoked otoacoustic emissions. Additionally, cochlear hair cell morphology was investigated after noise exposure. Both Korean red ginseng and compound K reduced threshold shifts, central auditory function damage, and cochlear functional and morphological deficits. In contrast, treatment with ginsenoside Rh1 did not result in recovery of NIHL in mice. These results suggest that consumption of Korean red ginseng may facilitate recovery from noise-induced hearing loss. Furthermore, one of the active constituents in ginseng is likely ginsenoside compound K.

• Inhibitory effects of 5-chloroacetyl-2-piperidino-1,3-selenazole, a novel selenium-containing compound, on skin melanin biosynthesis.

  Authors: Eunjoo H Lee, Yu-Ji Lim, Sang Keun Ha, Tong Ho Kang, Mamoru Koketsu, Chulhun Kang, Sun Yeou Kim, Ji-Ho Park

  The Journal of pharmacy and pharmacology. 03/2010; 62(3):352-9.

  Increased production and accumulation of melanin leads to many hyperpigmentation disorders such as melasma, freckles and geriatric pigment spots. Thus, there is a need for the development ofIncreased production and accumulation of melanin leads to many hyperpigmentation disorders such as melasma, freckles and geriatric pigment spots. Thus, there is a need for the development of depigmenting agents. Based on our previous reports, selenium derivatives as anti-melanogenic lead compounds could be very important. The aim of this study was to investigate the depigmenting effect of novel selenium-containing compounds. The inhibitory effects of 5-chloroacetyl-2-piperidino-1,3-selenazole (CS1), a novel selenium-containing compound, on melanogenesis were investigated in B16F10 melanoma cells and cultured brownish guinea pig skin tissue with alpha-melanocyte-stimulating hormone stimulation. We found that CS1 inhibited melanin production in B16F10 cells by suppressing tyrosinase activity and its protein expression. In addition, Western blotting analysis revealed that CS1 suppressed the expression of tyrosinase-related protein (TRP)-1 and TRP-2. Therefore, the depigmenting effect of CS1 might have been due to inhibition of tyrosinase activity and expression of melanogenic enzymes. Furthermore, CS1 had inhibitory effects on melanin biosynthesis of primary cultured skin of brownish guinea pig. The results suggested that CS1 could be a useful candidate for the treatment of skin hyperpigmentation.

• Effect of baicalein from Scutellaria baicalensis on prevention of noise-induced hearing loss.

  Authors: Tong Ho Kang, Bin Na Hong, Channy Park, Se-Young Kim, Raekil Park

  Neuroscience letters. 12/2009;

  Noise-induced hearing loss (NIHL) has been thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical and metabolic mechanisms. This study examined the effects ofNoise-induced hearing loss (NIHL) has been thought to primarily involve damage to the sensory hair cells of the cochlea via mechanical and metabolic mechanisms. This study examined the effects of baicalin, baicalein, and Scutellaria baicalensis (SB) extract against NIHL in a mouse model. Mice received oral treatment with SB, baicalin, baicalein beginning 30min prior to noise exposure and continuing once daily throughout the study. Hearing threshold shift was assessed by auditory brain stem responses for 35 days following noise exposure. Central auditory function was evaluated by auditory middle latency responses. Cochlear function was determined based on transient evoked otoacoustic emissions. SB significantly reduced threshold shift, central auditory function damage, and cochlear function deficits, suggesting that SB may protect auditory function in NIHL and that the active constituent may be a flavonoid, baicalein.

• Effects of red ginseng extract on UVB irradiation-induced skin aging in hairless mice.

  Authors: Tong Ho Kang, Hye Min Park, Yoon-Bum Kim, Hyunae Kim, Nami Kim, Jae-Ho Do, Chulhun Kang, Yunhi Cho, Sun Yeou Kim

  Journal of ethnopharmacology. 07/2009; 123(3):446-51.

  Panax ginseng C.A. Meyer, Korean herb medicine, has been widely used in China and Japan for fatigue and enhancement of resistance to many diseases. AIM OF THE STUDY: This study is aimed to assess thePanax ginseng C.A. Meyer, Korean herb medicine, has been widely used in China and Japan for fatigue and enhancement of resistance to many diseases. AIM OF THE STUDY: This study is aimed to assess the effects of Korean red ginseng extract on UVB irradiation induced skin aging in hairless mice. MATERIALS AND METHODS: Red ginseng extracts prepared with ethanol were used in this study. To standardize Korean red ginseng, it was analyzed by HPLC. And inhibitory effects of red ginseng extract on UVB irradiation-induced skin aging in hairless mice were determined by the measurement of wrinkle, expression of type I procollagen and MMP-1 and immunohistology. RESULTS: Based on the HPLC quantitative analysis, ginsenoside Rb1 content in Korean red ginseng was 43.5mg/g of extract. In the result of body weight gain and food efficiency rate, body weights of all groups were increased during experimental periods. In the wrinkle measurement and image analysis of skin replicas, the results showed that the dietary supply containing red ginseng extract significantly inhibited wrinkle formation caused by chronic UVB irradiation. In the changes of expression of procollagen type I and MMP-1 in the skin of UV irradiated hairless mice fed dietary supplement containing 2.5% red ginseng extract, level of mRNA of procollagen type I was decreased. But protein level of that was increased. And in terms of MMP-1, either mRNA or protein levels of MMP-1 were significantly decreased. These results showed anti-wrinkle effect of Korean red ginseng involved the inhibition of collagen degradation rather than increased collagen synthesis. CONCLUSION: It is shown that Korean red ginseng may be functional food candidate for skin photoaging.

• HPLC with pulsed amperometric detection for sorbitol as a biomarker for diabetic neuropathy.

  Authors: Hee-Jung Sim, Ji-Seon Jeong, Ha-Jeong Kwon, Tong Ho Kang, Hye Min Park, Yong-Moon Lee, Sun Yeou Kim, Seon-Pyo Hong

  Journal of chromatography. B, Analytical technologies in the biomedical and life sciences. 05/2009;

  This study describes the optimal analytical conditions for sorbitol analysis by a high-performance anion-exchange chromatography-pulsed amperometric detection method. Its clinical utility as aThis study describes the optimal analytical conditions for sorbitol analysis by a high-performance anion-exchange chromatography-pulsed amperometric detection method. Its clinical utility as a diagnostic tool was established by measuring sorbitol in the sciatic nerves or salivary glands of diabetes mellitus-induced mice. Sorbitol was completely separated from other monosaccharides on an anion-exchange column with 100mM NaOH as eluent. The limit of detection (S/N=3) and limit of quantification (S/N=10) were 0.03ng (3ng/g) and 0.10ng (10ng/g), respectively. The linear dynamic range was 0.01-50.0mug/g (r(2)=0.9997 and 0.9989 for sciatic nerves and salivary glands, respectively), and the mean recoveries for intra- or inter-day assays were in the range of 98.5-103.9%. This method easily identified diabetic and normal groups, making it a practical procedure for the rapid screening of diabetic neuropathy.

• High-dosage pyridoxine-induced auditory neuropathy and protection with coffee in mice.

  Authors: Bin Na Hong, Tae-Hoo Yi, Sun Yeou Kim, Tong Ho Kang

  Biological & pharmaceutical bulletin. 04/2009; 32(4):597-603.

  Auditory neuropathy (AN) is a hearing disorder characterized by an abnormal auditory brainstem response (ABR). This study examined experimental AN model induced in mice following increased dosages ofAuditory neuropathy (AN) is a hearing disorder characterized by an abnormal auditory brainstem response (ABR). This study examined experimental AN model induced in mice following increased dosages of pyridoxine. Induced AN was examined for </=10 weeks following the last pyridoxine treatment. To assess AN, we evaluated the ABR, auditory middle latency response (AMLR), otoacoustic emission (OAE), and histochemical morphology of the auditory nerve. Pyridoxine-treated mice exhibited an increase in the hearing threshold shift and delayed latency of both ABR and AMLR in proportion to pyridoxine dosage. Additionally, the extent of auditory nerve fiber loss increased in a dose-dependent manner following pyridoxine intoxication. Coffee or trigonelline treatment ameliorated the hearing threshold shift, delayed latency of the auditory evoked potential, and improved sensory fiber loss induced by pyridoxine intoxication. The present findings demonstrate that high-dose pyridoxine administration can be used to produce a new mouse model for AN, and coffee or trigonelline as a main active compound of coffee extract can potentially facilitate recovery from pyridoxine-induced auditory neuropathy.

• High dosage sildenafil induces hearing impairment in mice.

  Authors: Bin Na Hong, Tae-Hoo Yi, Sun Yeou Kim, Tong Ho Kang

  Biological & pharmaceutical bulletin. 11/2008; 31(10):1981-4.

  Sildenafil is widely administered for the treatment of erectile dysfunction. Recently, sensorineural hearing loss following the ingestion of sildenafil was reported in one male patient. We examinedSildenafil is widely administered for the treatment of erectile dysfunction. Recently, sensorineural hearing loss following the ingestion of sildenafil was reported in one male patient. We examined hearing in mice that were administered high doses of sildenafil for up to 105 d. To assess hearing impairment, we evaluated auditory brainstem responses, auditory middle latency responses, and otoacoustic emissions. At high doses, sildenafil increased the hearing threshold shift of auditory brainstem responses. High-dose sildenafil treatment also resulted in delayed latency of both auditory brainstem responses and auditory middle responses. Otoacoustic emissions differed between control and high-dose sildenafil groups with long-term treatment. Collectively, these data demonstrate that high-dose and long-term sildenafil administration can induce hearing impairment in mice.

• Coffee improves auditory neuropathy in diabetic mice.

  Authors: Bin Na Hong, Tae-Hoo Yi, Raekil Park, Sun Yeou Kim, Tong Ho Kang

  Neuroscience letters. 07/2008;

  Coffee is a widely consumed beverage and has recently received considerable attention for its possible beneficial effects. Auditory neuropathy is a hearing disorder characterized by an abnormalCoffee is a widely consumed beverage and has recently received considerable attention for its possible beneficial effects. Auditory neuropathy is a hearing disorder characterized by an abnormal auditory brainstem response. This study examined the auditory neuropathy induced by diabetes and investigated the action of coffee, trigonelline, and caffeine to determine whether they improved diabetic auditory neuropathy in mice. Auditory brainstem responses, auditory middle latency responses, and otoacoustic emissions were evaluated to assess auditory neuropathy. Coffee or trigonelline ameliorated the hearing threshold shift and delayed latency of the auditory evoked potential in diabetic neuropathy. These findings demonstrate that diabetes can produce a mouse model of auditory neuropathy and that coffee consumption potentially facilitates recovery from diabetes-induced auditory neuropathy. Furthermore, the active constituent in coffee may be trigonelline.

• Protective effect of apigenin on ovariectomy-induced bone loss in rats.

  Authors: Jeong A Park, Sang Keun Ha, Tong Ho Kang, Myung Sook Oh, Min Hyoung Cho, Soo Yeol Lee, Ji-Ho Park, Sun Yeou Kim

  Life sciences. 07/2008; 82(25-26):1217-23.

  Recent studies have shown that apigenin not only inhibits bone resorption by osteoclasts but also induces osteoclast apoptosis. However, the influence of apigenin on osteoporosis in animals isRecent studies have shown that apigenin not only inhibits bone resorption by osteoclasts but also induces osteoclast apoptosis. However, the influence of apigenin on osteoporosis in animals is relatively unknown. The purpose of this study was to examine the bone-protective effects of apigenin in estrogen-deficient ovariectomized rats. Three-month-old female Sprague-Dawley rats were either sham-operated or ovariectomized and fed AIN-93G diet for 7 weeks to induce bone loss. To confirm bone loss, we used a newly developed non-invasive technique involving zoom-in micro-computed tomography. Apigenin was administered at a dose of 10 mg/kg three times a week for 15 weeks. Our results indicate that apigenin not only increased the mineral content and density of the trabecular bone at the neck of the left femur, but also decreased body weight and dietary consumption. Moreover, our biochemical results indicate that apigenin has a positive effect on bone turnover. The present data suggest that apigenin should be considered for use in the treatment of osteoporosis.

• Auditory neuropathy in streptozotocin-induced diabetic mouse.

  Authors: Bin Na Hong, Tong Ho Kang

  Neuroscience letters. 03/2008; 431(3):268-72.

  An investigation of the mechanism of damage to the peripheral nervous system and central nervous system in diabetes mellitus (DM) is highly important in current neurological research. AuditoryAn investigation of the mechanism of damage to the peripheral nervous system and central nervous system in diabetes mellitus (DM) is highly important in current neurological research. Auditory neuropathy is a hearing disorder in which the auditory brainstem evoked potential is absent or severely abnormal. This study investigated auditory neuropathy caused by streptozotocin in mouse model. In order to assess diabetic auditory neuropathy, we evaluated auditory brainstem response (ABR) for the evaluation of sensorineural function in peripheral auditory nerve. Auditory middle latency response (AMLR) was employed to assess the middle response in the midbrain. STZ groups significantly increased the absolute latencies IV and the interpeak latencies I-III and I-IV of ABR compared with STZ 0 group. Pa latency of AMLR also significantly increased in proportion to STZ dosage. Taken together, our results demonstrate that STZ-induced DM may impair the auditory pathway from peripheral auditory nerve to midbrain in the mouse model. We suggest that the STZ-induced diabetic mouse model may be useful for the evaluation of auditory pathway impairment by using ABR and AMLR tests.

• Regulation of melanin synthesis by selenium-containing carbohydrates.

  Authors: Sang Joon Ahn, Mamoru Koketsu, Hideharu Ishihara, Soo Min Lee, Sang Keun Ha, Kun Ho Lee, Tong Ho Kang, Sun Yeou Kima

  Chemical & pharmaceutical bulletin. 04/2006; 54(3):281-6.

  This study reports depigmenting potency of selenium-containing carbohydrates, which would be based upon the finding of direct inhibition to mushroom tyrosinase. Two selenoglycosiede, SG-3This study reports depigmenting potency of selenium-containing carbohydrates, which would be based upon the finding of direct inhibition to mushroom tyrosinase. Two selenoglycosiede, SG-3 (bis(2,3,4-tri-O-acetyl-beta-D-arabinopyranosyl) selenide) and SG-8 (4'-methylbenzoyl 2,3,4,6-tetra-O-acetyl-D-selenomanopyranoside) among eleven selenium-containing compounds examined, were discovered to be effective depigmenting compounds on a mushroom tyrosinase inhibitory assay. SG-3 exhibited a competitive inhibition effect that was similar to kojic acid, well-known tyrosinase inhibitor. At 100 microM and 150 microM, SG-8 had an uncompetitive inhibitory effect that was higher than kojic acid. A study of a melan-a cell originated-tyrosinase inhibition assay showed that SG-8 had a lower inhibitory effect than kojic acid. SG-3 showed a similar inhibition effect to kojic acid on the melan-a cell-originated tyrosinase inhibitory assay. SG-8 showed dose-dependently cytotoxicity in a study of inhibition melanin synthesis by melan-a cells. Most melan-a cells did not survive after being treated with 20 microM of SG-8. At 10 microM, SG-3 inhibited melanin synthesis in the melan-a cells, and the effect was similar to phenylthiourea, which is a well-known inhibitor of melanin synthesis. Therefore, SG-3 is a new candidate for depigmenting reagents.

• Enhancement of neuroprotection of mulberry leaves (Morus alba L.) prepared by the anaerobic treatment against ischemic damage.

  Authors: Tong Ho Kang, Hye Rim Oh, Sun Moon Jung, Jong Hoon Ryu, Mee Won Park, Yong Kon Park, Sun Yeou Kim

  Biological & pharmaceutical bulletin. 03/2006; 29(2):270-4.

  Several neurological disorders such as Alzheimer's and Parkinson's diseases have been attributed to gamma-aminobutyric acid (GABA) depletion in the brain. In order to provide a pharmacological basisSeveral neurological disorders such as Alzheimer's and Parkinson's diseases have been attributed to gamma-aminobutyric acid (GABA) depletion in the brain. In order to provide a pharmacological basis for the neuroprotective actions of the enhanced accumulation of GABA in mulberry leaves (ML) against cerebral ischemia in vitro and in vivo, a process was developed to enhance the accumulation of GABA in mulberry leaves (GAML) as a result of the various anaerobic treatments. The GABA concentrations were changed by N(2) gas purging, the reaction temperature, reaction time, pH and the leaf size. GABA enhanced the potential of neuroprotection in the PC12 cells damaged by H(2)O(2)-induced oxidation. GAML reduced the cytotoxicity in the PC12 cells against oxygen glucose deprivation-induced cerebral ischemic condition. The neuroprotective effect of GAML was further demonstrated in vivo using middle cerebral artery occlusion brain injury model. GAML significantly decreased the infarct volume of the brain compared with than control group. Overall, these results suggest that the anaerobic treatment of ML makes GAML enhance the neuroprotection effect against in vivo cerebral ischemia such as in vitro.

• Neuroprotective effects of the cyanidin-3-O-beta-d-glucopyranoside isolated from mulberry fruit against cerebral ischemia.

  Authors: Tong Ho Kang, Jin Young Hur, Hyun Bok Kim, Jong Hoon Ryu, Sun Yeou Kim

  Neuroscience letters. 02/2006; 391(3):122-6.

  This study investigated the neuroprotective effects of cyanidin-3-O-beta-d-glucopyranoside (C3G) from the mulberry fruits on neuronal cell damage. A 1% HCl-MeOH mulberry fruit extract was shown toThis study investigated the neuroprotective effects of cyanidin-3-O-beta-d-glucopyranoside (C3G) from the mulberry fruits on neuronal cell damage. A 1% HCl-MeOH mulberry fruit extract was shown to have a cytoprotective effect on PC12 cells that had been exposed to hydrogen peroxide. The extract inhibited the cerebral ischemic damage caused by oxygen glucose deprivation (OGD) in PC12 cells. The neuroprotective effect of the mulberry fruit extract was further demonstrated in vivo using a mouse-brain-injury model with a transient middle cerebral artery occlusion (MCAO). C3G was isolated as a neuroprotective constituent from the mulberry fruit extract. Compared with the control group, C3G had neuroprotective effects on the PC12 cells exposed to hydrogen peroxide in vitro and on cerebral ischemic damage in vivo.

• Protective effect of apigenin on ovariectomy-induced bone loss in rats

  Authors: Jeong A Park, Sang Keun Ha, Tong Ho Kang, Myung Sook Oh, Min Hyoung Cho, Soo Yeol Lee, Ji-Ho Park, Sun Yeou Kim

  Life Sciences.

  Recent studies have shown that apigenin not only inhibits bone resorption by osteoclasts but also induces osteoclast apoptosis. However, the influence of apigenin on osteoporosis in animals isRecent studies have shown that apigenin not only inhibits bone resorption by osteoclasts but also induces osteoclast apoptosis. However, the influence of apigenin on osteoporosis in animals is relatively unknown. The purpose of this study was to examine the bone-protective effects of apigenin in estrogen-deficient ovariectomized rats.Three-month-old female Sprague–Dawley rats were either sham-operated or ovariectomized and fed AIN-93G diet for 7 weeks to induce bone loss. To confirm bone loss, we used a newly developed non-invasive technique involving zoom-in micro-computed tomography. Apigenin was administered at a dose of 10 mg/kg three times a week for 15 weeks. Our results indicate that apigenin not only increased the mineral content and density of the trabecular bone at the neck of the left femur, but also decreased body weight and dietary consumption. Moreover, our biochemical results indicate that apigenin has a positive effect on bone turnover. The present data suggest that apigenin should be considered for use in the treatment of osteoporosis.

• Coffee improves auditory neuropathy in diabetic mice

  Authors: Bin Na Hong, Tae Hoo Yi, Raekil Park, Sun Yeou Kim, Tong Ho Kang

  Neuroscience Letters.

  Coffee is a widely consumed beverage and has recently received considerable attention for its possible beneficial effects. Auditory neuropathy is a hearing disorder characterized by an abnormalCoffee is a widely consumed beverage and has recently received considerable attention for its possible beneficial effects. Auditory neuropathy is a hearing disorder characterized by an abnormal auditory brainstem response. This study examined the auditory neuropathy induced by diabetes and investigated the action of coffee, trigonelline, and caffeine to determine whether they improved diabetic auditory neuropathy in mice. Auditory brainstem responses, auditory middle latency responses, and otoacoustic emissions were evaluated to assess auditory neuropathy. Coffee or trigonelline ameliorated the hearing threshold shift and delayed latency of the auditory evoked potential in diabetic neuropathy. These findings demonstrate that diabetes can produce a mouse model of auditory neuropathy and that coffee consumption potentially facilitates recovery from diabetes-induced auditory neuropathy. Furthermore, the active constituent in coffee may be trigonelline.