In Sik Hwang

Effects of Steaming Time and Frequency for Manufactured Red Liriope platyphylla on the Insulin Secretion Ability and Insulin Receptor Signaling Pathway.

In oriental medicine, Liriope platyphylla (LP) has long been regarded as a curative herb useful for the treatment of diabetes, asthma, and neurodegenerative disorders. The principal objective of this study was to assess the effects of steaming time and frequency for manufactured Red LP (RLP) on insulin secretion ability and insulin receptor signaling pathway. To achieve our goal, several types of LPs manufactured under different conditions were applied to INS cells and streptozotocin (STZ)-induced diabetic ICR mice, after which alterations in insulin concentrations were detected in the culture supernatants and sera. The optimal concentration for the investigation of insulin secretion ability was found to be 50 ug/mL of LP. At this concentration, maximum insulin secretion was observed in the INS cells treated with LP extract steamed for 3 h (3-SLP) with two repeated steps (3 h steaming and 24 h air-dried) carried out 9 times (9-SALP); no significant changes in viability were detected in any of the treated cells. Additionally, the expression and phosphorylation levels of most components in the insulin receptor signaling pathway were increased significantly in the majority of cells treated with steaming-processed LP as compared to the cells treated with LP prepared without steaming. With regard to glucose transporter (GLUT) expression, alterations of steaming time induced similar responses on the expression levels of GLUT-2 and GLUT-3. However, differences in steaming frequency were also shown to induce dose-dependent responses in the expression level of GLUT-2 only; no significant differences in GLUT-3 expression were detected under these conditions. Furthermore, these responses observed in vitro were similarly detected in STZ-induced diabetic mice. 24-SLP and 9-SALP treatment applied for 14 days induced the down-regulation of glucose concentration and upregulation of insulin concentration. Therefore, these results indicated that the steaming processed LP may contribute to the relief of diabetes symptoms and should be regarded as an excellent candidate for a diabetes treatment.

Protective effects of gomisin A isolated from Schisandra chinensis against CCl4-induced hepatic and renal injury

The aim of the present study was to investigate the protective effects of gomisin A, a lignan compound isolated from Schisandra chinensis, against liver and kidney damage induced by CCl(4) exposure. We assessed alterations in organ weights, levels of serum biochemical indicators, and activation of the caspase-3 and MAPK signaling pathways and carried out histological analysis of liver and kidney tissue in rats pretreated with gomisin A for four days. In the gomisin A/CCl(4)-treated group, only the liver experienced a significant increase in weight, whereas the other organs did not undergo any changes. Five biochemical indicators in serum indicated that liver and kidney toxicity dramatically decreased upon gomisin A pretreatment, although the decrease in ratios varied. Upon histological analysis, the gomisin A/CCl(4)-treated group showed less hepatocellular necrosis, a poorly dilated central vein in the liver section, decreased diameter of the glomerulus, a lower number of capillaries, and a convoluted tubule in the kidney section. Furthermore, the formation of active caspase-3 was inhibited by gomisin A pretreatment in the gomisin A/CCl(4)-treated group, whereas the expression level of Bax protein was slightly increased. Western blot analysis revealed that there were differences between the liver and kidney in terms of activation of the MAPK signaling pathway. In the liver, gomisin A pretreatment increased phosphorylation of three members of the MAPK pathway when compared to that in the vehicle pretreatment group. However, in the kidney, only the phosphorylation level of p38 was elevated upon gomisin A pretreatment, whereas levels of the other two members were decreased. These results suggest that gomisin A induces marked protective effects against hepatic and renal injury induced by CCl(4) exposure through differential regulation of the MAPK signal transduction pathway.

Quantitative evaluation of therapeutic effect of Liriope platyphylla on phthalic anhydride-induced atopic dermatitis in IL-4/Luc/CNS-1 Tg mice.

ETHNOPHARMACOLOGICAL RELEVANCE A variety of previous pharmacological studies have suggested that Liriope platyphylla may exert beneficial biological effects on inflammation, diabetes, neurodegenerative disorder, obesity, and atopic dermatitis (AD). AIM OF THE STUDY The therapeutic effect of aqueous extract of Liriope platyphylla (AEtLP) on AD was quantified using the luciferase report system in IL-4/Luc/CNS-1 transgenic (Tg) mice. MATERIALS AND METHODS Alteration of the luciferase signal was quantified in IL-4/Luc/CNS-1 Tg mice co-treated with phthalic anhydride (PA) and AEtLP for 2 weeks using the IVIS imaging system. Phenotypes of AD were assessed by ear thickness analysis, measurement of immune-related organ weights, ELISA, and histological and pathological analysis in Tg mice. RESULTS A strong luciferase signal was detected in the abdominal region of IL-4/Luc/CNS-1 Tg mice treated with only PA. However, this signal was significantly reduced in IL-4/Luc/CNS-1 Tg mice co-treated with PA+AEtLP in an AEtLP concentration-dependent manner. Especially, three organs, the thymus, pancreas, and submandibular lymph node (SL), showed a high signal response to PA treatment. Furthermore, to verify whether or not alteration of the luciferase signal is associated with AD, these disease response phenotypes were measured in the same group of mice. Common allergenic responses including increases in ear thickness, lymph node weight, IgE concentration, and infiltrated mast cells were detected in IL-4/Luc/CNS-1 Tg mice treated with PA. However, these responses were dramatically decreased by AEtLP treatment for 2 weeks. CONCLUSION These results indicate that the luciferase signal may successfully reflect the therapeutic effects of AEtLP in IL-4/Luc/CNS-1 Tg mice. Further, we suggest additional evidence that Liriope platyphylla may be considered as an effective therapeutic drug for the treatment of AD.

UV radiation-induced skin aging in hairless mice is effectively prevented by oral intake of sea buckthorn (Hippophae rhamnoides L.) fruit blend for 6 weeks through MMP suppression and increase of SOD activity

Oxidative stress and oxidative photodamage induced by UV radiation can cause serious skin damage that is characterized by wrinkling, roughness, laxity and pigmentation. The effects of a sea buckthorn (Hippophae rhamnoides L.) fruit blend (SFB) containing sea buckthorn fruit extract, blueberry extract and collagen on UV-induced skin aging were examined by treating hairless mice for 6 weeks with UV irradiation and SFB administered orally. The effects of SFB were measured in the skin of these mice by phenotypical and histological analysis and western blotting. According to wrinkle formation analysis, the oral intake of SFB induced a decrease in wrinkle formation in the damaged skin of UV-irradiated mice. The thickness of the epidermis and dermis in the vitamin extracts (Vit)- and SFB-treated group was lower than that in the vehicle-treated group, but the group treated with SFB50 was the most effective group. The mice treated with the Vit- or SFB solution maintained a normal moisture content through the inhibition of transdermal water loss (TEWL) and an increase in skin moisture content. Furthermore, the levels of matrix metalloproteinase (MMP) and collagen protein expression were assessed in five groups to examine the mechanisms underlying the effects of SFB oral intake. The application of SFB induced a decrease in MMP-1 and -9 expression to the levels observed in the vehicle-treated group, but MMP-9 expression showed a much larger decrease than MMP-1. Furthermore, the expression of collagen-1 in the skin corresponded to MMP expression except for the SFB30-treated group, whereas the superoxide dismutase (SOD) activity was increased dramatically in the SFB50-treated group. These results suggest that SFB has potential as a protective and therapeutic drug candidate against skin aging that functions by regulating the moisture content, MMP expression levels and SOD activity.

Differential effects of the steaming time and frequency for manufactured red Liriope platyphylla on nerve growth factor secretion ability, nerve growth factor receptor signaling pathway and regulation of calcium concentration

The herb Liriope platyphylla (LP) has been considered to have curative properties for diabetes, asthma and neurodegenerative disorders. To examine the effects of steaming time and frequency of manufactured red LP (RLP) on the nerve growth factor (NGF) secretion ability and NGF receptor signaling pathway, the NGF concentration, cell differentiation, NGF signaling pathway and calcium concentration were analyzed in neuronal cells treated with several types of LPs manufactured under different conditions. The maximum NGF secretion was observed in B35 cells treated with 50 µg/ml LP extract steamed for 9 h (9-SLP) and with two repeated steps (3 h steaming and 24 h air-dried) carried out 7 times (7-SALP). No significant changes in viability were detected in any of the cells treated with the various LPs, with the exception of 0-SLP and 0-SALP. In addition, PC12 cell differentiation was induced by treatment with the NGF-containing conditional medium (CM) collected from the RLP-treated cells. The levels of TrkA and extracellular signal-regulated kinase (ERK) phosphorylation in the high affinity NGF receptor signaling pathway were significantly higher in the cells treated with 3-SLP or 1-SALP/3-SALP CM compared with those treated with the vehicle CM. In the low affinity NGF receptor pathway, the expression levels of most components were higher in the 9-, 15- and 24-SALP CM-treated cells compared with the vehicle CM-treated cells. However, this level was significantly altered in cells treated with 3-SALP CM. Furthermore, an examination of the RLP function on calcium regulation revealed that only the LP- or RLP-treated cells exhibited changes in intracellular and extracellular calcium levels. RLP induced a significant decrease in the intracellular calcium levels and an increase in the extracellular calcium levels. These results suggest the possibility that steaming-processed LP may aid in the relief of neurodegenerative diseases through the NGF secretion ability and NGF signaling pathway.

Red Liriope platyphylla contains a large amount of polyphenolic compounds which stimulate insulin secretion and suppress fatty liver formation through the regulation of fatty acid oxidation in OLETF rats

Red Liriope platyphylla (RLP) manufactured by two repeated steps (steaming and drying) stimulates the insulin secretion ability and glucose receptor signaling pathway in an animal model for type I diabetes. This study examined the levels of glucose and lipid metabolism-related factors in a useful animal model for type II diabetes with obesity following RLP treatment for 3 weeks to determine if RLP treatment affects the glucose concentration, insulin secretion and fatty acid oxidation. The following results were obtained: i) RLP contained a large amount of polyphenolic compounds; ii) insulin secretion was induced in RLP-treated OLETF rats, although there were no significant differences in body weight, glucose tolerance test and glucose concentration; iii) the RLP-treated OLETF rats showed a significant increase in adiponectin concentration but the concentration of triglyceride and LDL decreased compared to the vehicle-treated rats; iv) although the abdominal fat mass and adipocyte size did not change with RLP treatment, expression of the adipocyte marker genes and β-oxidation genes in fat tissue was recovered to the level of the LETO rats; v) fatty liver formation was reduced dramatically in the liver of the RLP-treated group compared to the vehicle-treated group; vi) the expression of adipocyte marker genes and the β-oxidation gene in the liver tissue were generally similar to those of the abdominal fat but PPAR-γ showed a reverse pattern in the RLP- and vehicle-treated OLETF rats. These results suggest that RLP may stimulate insulin secretion and a decrease in lipid in serum, and may also suppress fatty liver formation through the regulation of fatty acid oxidation. The data presented here highlight the possibility that RLP can be considered a candidate for the prevention or alleviation of obesity-related diseases.

Alzheimer's phenotypes induced by overexpression of human presenilin 2 mutant proteins stimulate significant changes in key factors of glucose metabolism.

Alzheimers disease (AD) is closely associated with significant defects in glucose metabolism. To investigate whether AD pathology induced by overexpression of human mutant presenilin 2 (PS2) protein induces changes in glucose metabolism, glucose‑related factors were analyzed in the brain of 12‑month‑old neuron‑specific enolase (NSE)/hPS2m transgenic (Tg) mice. NSE/hPS2m Tg mice used in this study showed AD‑like phenotypes such as the accumulation of Aβ‑42, the increase of γ‑secretase activity and Tau hyperphosphorylation. A significant increase of glucose levels accompanied by a decrease of insulin levels was detected in NSE/hPS2m Tg mice, while the expression levels of insulin receptors were significantly decreased in NSE/hPS2m Tg mice compared to the non‑Tg littermates without affecting the insulin‑like growth factor (IGF) receptor. Moreover, the levels of AKT phosphorylation involved in the downregulation of the insulin receptor signaling pathway were reduced in the brain of NSE/hPS2m Tg mice compared with non‑Tg littermate, although the levels of glycogen synthase kinase 3 (GSK‑3) β phosphorylation were higher in the NSE/hPS2m Tg mice compared to non-Tg littermates. Furthermore, the levels of the expression of Glut‑1 and ‑3 were significantly reduced in the NSE/hPS2m Tg mice compared to those of control mice without affecting the Glut‑4 protein expression between the two groups of mice. In particular, the levels of the Aβ‑42 peptide in the brain of insulin‑treated NSE/hPS2m Tg mice were found to be slightly lower compared with those of the Aβ‑42 peptide in the non‑treated PS2 transgenic mice. Thus, the data presented in this study provide strong evidence that key factors of glucose metabolism are closely associated with the AD pathology induced by the hPS2m protein, and that insulin can serve as a potential therapeutic for AD patients.

LP9M80-H Isolated from Liriope platyphylla Could Help Alleviate Diabetic Symptoms via the Regulation of Glucose and Lipid Concentration

It was reported that the novel compounds (LP9M80-H) of Liriope platyphylla regulate glucose transporter (Glut) biosynthesis by activating the insulin-signaling pathway in the liver and brain of ICR mice. To investigate the therapeutic effects of LP9M80-H on the pathology of diabetes and obesity, alterations of key factors related to symptoms were analyzed in the Otsuka Long Evans Tokushima Fatty (OLETF) rats treated with LP9M80-H for 2 weeks. The abdominal fat masses in the LP9M80-H-treated group were lower than the vehicle-treated group, although there was no difference in body weight between the two groups. Additionally, when compared to the vehicle-treated group, LP9M80-H treatment induced a significant decrease in glucose levels and an increase in the insulin concentration in the blood of OLETF rats. A high level of insulin protein was also detected in pancreatic β cells of LP9M80-H-treated OLETF rats. A significant reduction in the concentration of lipids and adiponectin was detected only in LP9M80-H-treated OLETF rats. Furthermore, the expression of insulin receptor β and the insulin receptor substrate (IRS) was dramatically decreased in LP9M80-H-treated OLETF rats compared to the vehicle-treated group. Of the glucose transporters located downstream of the insulin-signaling pathway, glucose transporters (Glut) -2 and -3 were significantly decreased in LP9M80-H-treated OLETF rats, while the level of Glut-4 was maintained under all conditions. Therefore, these results suggest that LP9M80-H may contribute to relieving symptoms of diabetes and obesity through glucose homeostasis and regulation of lipid concentration.

Peroxiredoxin I regulates the component expression of γ-secretase complex causing the Alzheimer’s disease

Peroxiredoxin I (Prx I) is a member of the peroxiredoxins (Prxs) family, which are antioxidant enzymes that regulate various cellular process via intracellular oxidative signal pathways. In order to investigate the correlation between Prx I and the γ-secretase complex, which causes Alzheimers disease (AD), the expression level of Prx I was firstly evaluated in an animal model for AD. NSE/hPen-2 transgenic (Tg) mice, which were used as animal model in this study, showed a high level of Pen-2 expression and accumulation of Aβ-42 peptides in the hippocampus of brain. The expression level of Prx I was significantly higher on the mRNA and protein level in the brain of this model, while not change in Prx VI expression was observed. Furthermore, to verify the effect of Prx I on the γ-secretase components in vitro, the expression level of these components was analyzed in the Prx I transfectants. Of the components of the γ-secretase complex, the expression of PS-2 and Pen-2 was lower in the transfectants overexpressing Prx I compared to the vector transfectants. However, the expression of APP, NCT and APH-1 did not change in Prx I transfectants. Therefore, these results suggested that the expression of Prx I may be induced by the accumulation of Aβ-42 peptides and the overexpression of Prx I in neuroblastoma cells may regulate the expression of γ-secretase components.

LP-M, a Novel Butanol-Extracts Isolated from Liriope platyphylla, could Induce the Neuronal Cell Survival and Neuritic Outgrowth in Hippocampus of Mice through Akt/ERK Activation on NGF Signal Pathway

Liriope platyphylla has been used in oriental medicine as an effective medical plant to improve symptoms of cough, sputum production, neurodegenerative disorders, obesity and diabetes for long time. In order to investigate the effects of novel extracts on nerve growth factors (NGF)-stimulated neuritic outgrowth, the alteration of NGF expression and NGF receptor signaling pathway were detected in neuroblastoma cells and C57BL/6 mice. Of a total of 13 novel extracts, 4 extracts (LP-E, LP-M, LP-M50, LP2E17PJ) showed high viability on MTT assay. Also, all of these extracts induced NGF secretion and NGF mRNA expression in neuroblastoma cells. However, the NGF-induced neuritic outgrowth from PC12 cells was only stimulated by LP-E, LP-M and LP-M50. Furthermore, we selected LP-M as a best candidate, based on method and amounts of extraction, in order to verify its effect in mice. C57BL/6 mice were treated with 50 mg/kg of LP-M for 2 weeks and the effects on NGF regulation were analyzed with various methods. The expression of NGF mRNA was significantly increased in LP-M treated mice compared to vehicle treated mice. Also, the signaling pathway of p75NTR was inhibited in the cortex by LP-M treatment, with no change in the hippocampus of brain. However, the signaling pathway of TrkA was dramatically activated in only hippocampus via LP-M treatment. Therefore, these results suggest that the novel four extracts of L. platyphylla may contribute to the regulation of NGF expression and secretion in neuronal cells. LP-M was especially considered to be an excellent candidate for a neurodegenerative disease-therapeutic drug.