HYPOTHESIS/PURPOSE: We hypothesized that LPva extracts can modulate the lipid profiles and serum antioxidant status of hypercholesterolemic rats. In the present study, we investigated the effects of aqueous and 80% ethanol extracts of LPva on atherogenic and serum antioxidant parameters as well as changes in abdominal aorta of high-cholesterol diet rats.
METHODS: The major components of the extracts, gallic acid, flavonoids and alkyl resorcinols were analyzed by using a validated reversed phase HPLC method. The rats were induced to hypercholesterolemic status with daily intake of 2% cholesterol for a duration of 8 weeks. Three different doses (100, 200 and 400mg/kg) of the extracts were administered daily on the 4th week onwards. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugation for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination.
RESULTS: The serum of LPva treated rats showed significant reduction in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels and the abdominal aorta showed a significant decrease of atheroma lesions in treated rats. Serum lipid profiles of treated rats showed a decrease in total cholesterol, total triglycerides and low-density lipoprotein (LDL) levels as compared to control group. The atherogenic indices in treated rats were significantly improved along with an increasing level of serum high-density lipoprotein (HDL). The extracts also exhibited significant increase of antioxidant enzymes and decrease of MDA as a product of lipid peroxidation.
CONCLUSION: LPva extracts can reduce the risk of dyslipidemia by improving the serum lipid profiles and modulating serum antioxidants.
METHODS: Two parameters were measured (i) rate of glucose uptake by 3T3-L1 adipocyte cells in-vitro (ii) degree of pancreatic destruction in streptozotocin-nicotinamide induced male diabetic rats receiving M. pumilum aqueous extract (M.P) (250 and 500mg/kg/day) as reflected by levels of pancreatic oxidative stress, inflammation and apoptosis. In the meantime, phyto-chemical compounds in M.P were also identified by using LC-MS.
RESULTS: M.P was found able to enhance glucose uptake by 3T3-L1 adipocyte cells in-vitro while its administration to the male diabetic rats causes decreased in the fasting blood glucose (FBG), glycated haemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) levels but causes increased in insulin and high-density lipoprotein (HDL) levels, to near normal. Levels of oxidative stress in the pancreas as reflected by levels of lipid peroxidation product (LPO) decreased while levels of anti-oxidantive enzymes (SOD, CAT and GPx) in pancreas increased. Additionally, levels of inflammation as reflected by NF-κB p65, Ikkβ and TNF-α levels decreased while apoptosis levels as reflected by caspase-9 and Bax levels decreased. Anti-apoptosis marker, Bcl-2 levels in pancreas increased.
CONCLUSIONS: The ability of M.P to enhance glucose uptake and reduces pancreatic complications could account for its beneficial effects in treating DM.
PURPOSE: The present study investigated the effects of oral treatment with M. pumilum var. alata (MPA) extracts on the estrogen receptor, metabolic characteristics and insulin signaling pathway in pancreas and liver of ovariectomised nicotidamide streptozotocin-induced diabetes in female rats.
MATERIALS AND METHODS: Ovariectomised diabetic (OVXS) Sprague-Dawley rats were orally administered with either aqueous leaf extract and ethanol (50%) stem-root extract of MPA (50 or 100 mg/kg) respectively for 28 days. Metabolic parameters were evaluated by measuring fasting blood glucose, serum insulin, oral glucose and insulin tolerance test. Distribution and expression level of insulin, oxidative stress and inflammatory marker in the pancreatic islets and liver were evaluated by immunohistochemistry and western blot, respectively.
RESULTS: Oral treatment with aqueous leaf and ethanol (50%) stem-root extracts of MPA (100 mg/kg) significantly reversed the elevated fasting blood glucose, impaired glucose and insulin tolerance. The protein expression of insulin, glucose transporter (GLUT-2 and GLUT-4) increased in the pancreatic islets and liver. Furthermore, marked improvement in the tissue morphology following treatment with MPA was observed. Similarly, the western blots analysis denotes improved insulin signaling in the liver and decreased reactive oxygen species producing enzymes, inflammatory and pro-apoptotic molecules with MPA treatment.
CONCLUSIONS: Taken together, this work demonstrate that 100 mg/kg of aqueous leaf extract and ethanol (50%) stem-root extract of MPA improves β-cell function and insulin signaling in postmenopausal diabetes through attenuation of oxidative stress and partially mediated by oestrogen receptor stimulation.
METHODS: Thirty-two female Wistar rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LPva) and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via daily oral gavages at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized and the gene expressions of BMP-2, OPG, RANKL and MCSF in the femoral bones were measured using a branch - DNA technique.
RESULTS: The RANKL gene expression was increased while the OPG and BMP-2 gene expressions were reduced in the OVXC group compared to the SHAM group. There were no significant changes in the MCSF gene expressions among the groups. Treatment with either LPva or ERT was able to prevent these ovariectomy-induced changes in the gene expressions in ovariectomized rats with similar efficacy.
CONCLUSION: LPva may protect bone against estrogen deficiency-induced changes by regulating the RANKL, OPG and BMP-2 gene expressions.