Laxative effects of Liriope platyphylla are tightly correlated with suppression of endoplasmic reticulum stress in loperamide-induced constipation of SD rats / 한국실험동물학회지

A dysfunction of endoplasmic reticulum (ER) stress response can result in various diseases, including cancer, inflammation, diabetes and neurodegenerative disorders. To investigate whether ER stress response can play an essential role in the induction and treatment of chronic constipation, alterations in the key parameters for ER stress were measured in loperamide (Lop) induced constipation Sprague Dawley (SD) rats treated with aqueous extracts of Liriope platyphylla (AEtLP), which has been shown to have a laxative effect. Symptoms of chronic constipation including alteration of stool parameters and the transverse colon's structure were successfully induced by Lop treatment. Laxative effects such as enhancement of stools parameters, recovery of the mucosa thickness, increased muscle thickness and recovery of flat luminal surface were also observed in the Lop+AEtLP treated group. Furthermore, enhancement of eukaryotic initiation factor 2 alpha (eIF2α) phosphorylation and inositol-requiring enzyme 1 beta (IRE1β) expression, key indicators for ER stress, that were observed in the Lop+vehicle treated group were significantly recovered in the Lop+AEtLP treated group, although the phosphorylation level of c-Jun N-terminal protein kinase (JNK) remained constant. Moreover, alterations in the transcription level of the marker genes X-box binding protein 1 (XBP-1) and growth arrest and DNA damage-inducible protein (GADD34) were similar to those of eIF2α and IRE1β. However, their level was slightly or completely recovered after AEtLP treatment. Overall, this study provides the first evidence that ER stress response may be tightly correlated with chronic constipation induced by Lop treatment, as well as the laxative effects of AEtLP.

Beneficial effects of ethanol extracts of Red Liriope platyphylla on vascular dysfunction in the aorta of spontaneously hypertensive rats / 한국실험동물학회지

Some biological effects of Red Liriope platyphylla (RLP) on various chronic diseases including Alzheimer's disease, diabetes and obesity were suggested after a report of the production from Liriope platyphylla (L. platyphylla, LP) roots using a steaming process. To examine the beneficial effects of ethanol extracts RLP (EEtRLP) on the vascular dysfunction of hypertension, alterations in key factors related to vascular regulation and antioxidant conditions were investigated in spontaneously hypertensive rats (SHR) after EEtRLP treatment for 2 weeks. High levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were detected in 500 or 1,000 mg/mL EEtRLP. Although no significant improvement of systolic blood pressure or aortic wall thickness were observed in the EEtRLP treated group, the expression level of angiotensin converting enzyme (ACE) and ACE2 increased significantly after EEtRLP treatment. Moreover, the concentration of aldosterone and K ion in serum rapidly recovered in the EEtRLP treated group relative to the vehicle treated group. Furthermore, the endothelial nitric oxide synthase (eNOS) expression and superoxide dismutase (SOD) activity were significantly increased in the EEtRLP treated group relative to the vehicle treated group, while the level of malondialdehyde (MDA) and NOx in the serum of the same group were recovered to the level of Wistar Kyoto (WKY) rats. Overall, the results presented herein provide novel evidence that EEtRLP treatment may improve vascular dysfunction in the aorta of the SHR through up regulation of the antioxidant state and down regulation of aldosterone and K ion concentration. These results also suggest that EEtRLP may be a potential candidate for treatment of various chronic diseases showing vascular dysfunction.

Precautionary effects of Red Liriope platyphylla on NGF secretion and Abeta42 deposition under the preclinical stage of Alzheimer's disease in Tg2576 mice / 한국실험동물학회지

Red Liriope platyphylla (RLP) has been manufactured from Liriope platyphylla (L. platyphylla, LP) roots using steaming process and investigated as a curative agent for treatment of diabetes, obesity and neurodegenerative disorders. To examine the precautionary effects of aqueous extract RLP (AEtRLP) on the preclinical stages of Alzheimer's Disease (AD), alterations of the key factors influencing AD were investigated in Tg2576 mice after AEtRLP7 treatment for 4 months. Abeta-42 peptides level was significantly decreased in the brain of AEtRLP7-treated Tg2576 mice compared to vehicle-treated Tg2576 mice, although significant differences on improving behavioral defects were not observed in the same group. The concentration of nerve growth factor (NGF) in serum was also higher in AEtRLP7-treated Tg2576 mice than vehicle-treated Tg2576 mice. However, the phosphorylation of TrkA and Erk among the downstream effectors of the high affinity NGF receptor was significantly lower in AEtRLP7-treated Tg2576 mice. A similar pattern was observed in the expression level of downstream effectors within low affinity NGF receptor. Overall, these results suggest that AEtRLP7 can contribute to preventing the production and deposition of Abeta-42 peptides during the early progression stage of AD in the brain of Tg2576 mice through increased NGF secretion.

Red Liriope platyphylla stimulated the insulin secretion through the regulation of calcium concentration in rat insulinoma cells and animal models / 한국실험동물학회지

The aim of this study was to investigate the effects of Red L. platyphylla (RLP) on calcium and glucose levels during insulin secretion. To achieve this, alteration of insulin and calcium concentrations was measured in rat insulinoma-1 (INS-1) cells and animal models in response to RLP treatment. In INS-1 cells, maximum secretion of insulin was detected upon treatment with 200 microg/mL of RLP for 20 min. Nifedipine, an L-type calcium channel blocker, effectively inhibited insulin secretion from INS-1 cells. Regarding calcium levels, the maximum concentration of intracellular calcium in INS-1 cells was obtained by treatment with 100 microg/mL of RLP, whereas this level was reduced under conditions of 200 microg/mL of RLP. Further, RLP-treated INS-1 cells showed a higher level of intracellular calcium than that of L. platyphylla (LP), Korea White Ginseng (KWG), or Korea Red Ginseng (KRG)-treated cells. This RLP-induced increase in intracellular calcium was abrogated but not completely abolished upon treatment with 40 microM nifedipine in a dose-dependent manner. Furthermore, the insulin level was dramatically elevated upon co-treatment with high concentrations of glucose and RLP, whereas it was maintained at a low level in response to glucose and RLP co-treatment at low concentrations. In an animal experiment, the serum concentration of calcium increased or decreased upon RLP treatment according to glucose level compared to vehicle treatment. Therefore, these results suggest that insulin secretion induced by RLP treatment may be tightly correlated with calcium regulation, which suggests RLP is an excellent candidate for diabetes treatment.

Toxicity of red Liriope platyphylla manufactured by steaming process on liver and kidney organs of ICR mice / 한국실험동물학회지

Red Liriope platyphylla (RLP) produced by steaming process has been reported to enhance the secretion of insulin and nerve growth factor (NGF). However, there has been no report on the toxicity of RLP in the specific organs of mice. To investigate the toxic effect of RLP, we tried to observe a significant alteration on body weight, food/water intake, organ weight, liver pathology and kidney pathology in female ICR mice received 12.5, 25.0 and 50.0 mg/kg body weight/day of RLP via gavage for 10 days. Out of seven organs including brain, heart, lung, liver, kidney, spleen and ovary, two organs (heart and lung) showed significantly decreased weights in the medium dosage RLP-treated group, whereas weights of other organs were maintained at constant levels in all dosage groups. In the liver toxicity analysis, no significant increase of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate amino-transferase (AST) were detected in any RLP-treated group compared to vehicle-treated group. The specific pathological changes induced by most of toxic compounds were not observed in the liver in microscopic examination. Furthermore, in the kidney toxicological analysis, a significant enhancement of the blood urea nitrogen (BUN) concentration was detected in the high dosage RLP-treated group compared to the vehicle-treated group. However, the serum creatinine (CA) concentration on the serum biochemistry as well as the pathological changes in microscopic examination were not significantly different between the vehicle- and RLP-treated groups. Therefore, these results suggest that RLP does not induce any specific toxicity in liver or kidney tissues of mice, although the BUN level slightly increased in 50.0 mg/kg of RLP-treated group.

Aqueous extract of Liriope platyphylla, a traditional Chinese medicine, significantly inhibits abdominal fat accumulation and improves glucose regulation in OLETF type II diabetes model rats / 한국실험동물학회지

Liriope platyphylla is a medical herb that has long been used in Korea and China to treat cough, sputum, neurodegenerative disorders, obesity, and diabetes. The aims of this study were to determine the antidiabetic and antiobesity effects of aqueous extract of L. platyphylla (AEtLP) through glucose and lipid regulation in both pre-diabetes and obesity stage of type II diabetes model. Two concentrations of AEtLP were orally administrated to OLETF (Otsuka Long-Evans Tokushima Fatty) rats once a day for 2 weeks, after which changes in glucose metabolism and fat accumulation were measured. Abdominal fat mass dramatically decreased in AEtLP-treated OLETF rats, whereas glucose concentration slightly decreased in all AEtLP-treated rats. However, compared to vehicle-treated OLETF rats, only AEtLP10 (10% concentration)-treated OLETF rats displayed significant induction of insulin production, whereas AEtLP5 (5% concentration)-treated OLETF rats showed a lower level of insulin. Although serum adiponectin level increased in only AEtLP5-treated rats, significant alteration of lipid concentration was detected in AEtLP5-treated OLETF rats. Expression of Glut-1 decreased in all AEtLP-treated rats, whereas Akt phosphorylation increased only in AEtLP10-treated OLETF rats. Furthermore, the pattern of Glut-3 expression was very similar with that of Glut-1 expression, which roughly corresponded with the phosphorylation of c-Jun N-teminal kinase (JNK) and p38 in the mitogen-activated protein kinase pathway. Therefore, these findings suggest that AEtLP should be considered as a therapeutic candidate during pre-diabetes and obesity stage capable of inducing insulin secretion from pancreatic beta-cells, glucose uptake in liver cells, as well as a decrease in fat and lipid accumulation.

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

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.

The Symptoms of Atopic Dermatitis in NC/Nga Mice Were Significantly Relieved by the Water Extract of Liriope platyphylla / 한국실험동물학회지

Atopic dermatitis is an well-known skin disease showing inflammatory, chronically relapsing, non-contagious and pruritic symptoms. The aims of this study were to investigate the effects of Liriope platyphylla (LP) on atopic dermatitis of NC/Nga mice. To achieve this, NC/Nga mice were treated with four different conditions including vehicle, phthalic anhydride (PA), PA+5% LP and PA+10% LP, and the changes of immune-related factors were detected after 2 weeks. The pathological phenotypes of atopic dermatitis such as erythema, ear thickness, edema, scab and discharge were significantly decreased in PA+10% LP cotreated groups compare to PA treated group. Also, the weight of lymph node and thymus in immune organs were gradually decreased in LP treated groups, while the weight of spleen was slightly increased in same group. Furthermore, toluidine blue staining analysis, a method used to specifically identify the mast cell, showed that the decrease of master cell infiltration into the dermis were statistically observed in PA+5% LP and PA+10% LP5% cotreated groups. Especially, the decrease of IgE concentration was detected only PA+10% LP cotreated group, although this level was maintained in PA+5% LP cotreated group. Therefore, these results suggested that the water extracts of LP may contribute the relieve of atopic dermatitis symptoms and be considered as an excellent candidate for a atopic dermatitis-therapeutic drug.