The present study investigates the effect of oral administration of the aqueous extract of Gynura... more The present study investigates the effect of oral administration of the aqueous extract of Gynura procumbens on blood glucose levels in normal and streptozotocin (STZ) diabetic rats. However, the mechanism of its action is still not known. Hence, in vivo and in vitro studies were carried out to study the role of G. procumbens on blood glucose lowering effect. In in vivo studies, single administrations of aqueous extract 1g/kg b.w. to 16-h fasted streptozotocin (STZ)-induced diabetic rats reduced the mean blood glucose level at hour 2, 5, 6, 7 (P<0.05) but not in normal rats when administered by gastric intubation. The plasma insulin of STZ-induced diabetic rats was also measured using rat insulin ELISA kits. The result showed that plasma insulin has not elevated in these rats, which suggested that the hypoglycaemic activity was not due to an insulinotropic effect of G. procumbens. In glucose tolerance test where the rats were loaded with glucose (500mg/kg b.w.) intraperitoneally ...
Vernonia amygdalina simultaneously suppresses entiates glucose extract administration also caused... more Vernonia amygdalina simultaneously suppresses entiates glucose extract administration also caused a decrease in the expression of key enzymes of glycolysis namely hexokinase Atangwho et al. BMC Complementary and Alternative Medicine 2014, 14:426
Introduction: The study was done at the aim to assess the functionality and viability of the β ce... more Introduction: The study was done at the aim to assess the functionality and viability of the β cells of the streptozotocin-induced diabetic rats model following repetitive dosage of administration of ethanolic extracts of Andrographis paniculata. Materials and Methods: The diabetic rats were treated with the extracts for fourteen days and at the dose given was 500 mg/kg twice daily. The assessments were made on fasting blood glucose, insulin, and immunohistochemical aspect of β cells before and after treatment. Results: The results showed that there was a significant reduction on fasting blood glucose levels in metformin, 95% and 50% ethanolic plant extracts-treated groups but on insulin level only 95% and 50% ethanolic extracts-treated groups gave a significant reduction (p<0.05). Immunohistochemical assessments revealed that all extract groups and metformin-treated were significantly increased in the population of β cells (p<0.01). Conclusion: This study revealed that the plant...
Aim: The objective of the present study was to evaluate the in vitro effect of aqueous extract of... more Aim: The objective of the present study was to evaluate the in vitro effect of aqueous extract of Clinacanthus nutans leaves and the juice on the activity of UDP-glucuronosyltransferase (UGT), cytochrome P (CYP) 3A4, and CYP2E1 in human liver microsomes (HLMs). Materials and Methods: The herb-drug interactions of the leaf extracts and juice were determined by a specific enzyme activity of CYP isoforms with specific probe substrate using spectrophotometry. CYP3A4 activity was measured for aminopyrine-specific metabolite (formaldehyde) at 415 nm. CYP2E1 activity was determined using p-nitrophenol-specific metabolite (p-nitrocatechol) at 535 nm. UGT activity was quantified through the consumption of p-nitrophenol by UGT at 405 nm. Results: Results obtained showed that the juice and aqueous extract of C. nutans leaves exhibited significant inhibition (P < 0.05) in CYP3A4 and CYP2E1 activity in HLMs. The aqueous extract of C. nutans showed statistically significant (P < 0.05) activation on UGT activity at the concentration of 1000 ng/mL as compared to the negative control. Conclusion: There is a possibility that herb-drug interaction could occur with C. nutans through inhibitory effects on CYP3A4 and CYP2E1. The leaf preparation also activated UGT catalyzed metabolism which may result in a reduction of the potency of the drug metabolized by UGT pathway.
The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liv... more The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liver disease (NAFLD). We have recently reported that our standardized 50% methanolic extract (ME) of (50% ME of ) has alleviated NAFLD in Sprague⁻Dawley rats. This study aimed to assess the molecular mechanisms of action, and to further evaluate the antiangiogenic effect of this extract NAFLD was induced by eight weeks of high-fat diet, and treatment was applied for four weeks. Antiangiogenic activity was assessed by aortic ring assay and by in vitro tests. Our findings demonstrated that the therapeutic effects of 50% ME among NAFLD rats, were associated with a significant increase in serum adiponectin, reduction in the serum levels of RBP4, vaspin, progranulin, TNF-α, IL-6, and significant downregulation of the hepatic gene expression of PPARγ, SLC10A2, and Collα1. Concomitantly, 50% ME of has exhibited a potent antiangiogenic activity on ring assay, cell migration, vascular endothelial g...
Although Banxia Baizhu Tianma Tang (BBT) has been long administered for hypertensive treatment in... more Although Banxia Baizhu Tianma Tang (BBT) has been long administered for hypertensive treatment in Traditional Chinese Medicine (TCM), the ratio of the herbal components that makes up the formulation has not been optimized with respect to the anti-hypertensive effect that it inherently possesses. A newly amended BBT (ABBT) formulation was developed using the evidence-based approach of orthogonal stimulus-response compatibility model. The ABBT showed enhanced therapeutic effect while maintaining its traditional theoretical approach rooted in TCM. This study was designed to investigate the possible mechanism of actions involved in the vasodilatory activity of ABBT-50 by evaluating its vasodilative effect on isolated Sprague Dawley rats in the presence of absence of various antagonists. When pre-contracted with phenylephrine, relaxation was observed in endothelium intact (EC=0.027±0.003mg/ml, R=109.8±2.12%) and denuded aortic rings (EC=0.409±0.073mg/ml, R=63.15±1.78%), as well as in end...
The seeds of Swietenia macrophylla King (SM) (Meliaceae) are used as a folk medicine for the trea... more The seeds of Swietenia macrophylla King (SM) (Meliaceae) are used as a folk medicine for the treatment of hypertension in Malaysia. However, the antihypertensive and vasorelaxant effects of SM seeds are still not widely studied. Thus, this study was designed to investigate the in vivo antihypertensive effects and in vitro mechanism of vasorelaxation of a 50% ethanolic SM seed extract (SM50) and the fingerprint of SM50 was developed through tri-step Fourier transform infrared (FTIR) spectroscopy. The vasorelaxant activity and the underlying mechanisms of SM50 were evaluated on thoracic aortic rings isolated from Sprague-Dawley rats in the presence of antagonists. The pharmacological effect of SM50 was investigated by oral administration of spontaneously hypertensive rats (SHRs) with three different doses of SM50 (1000, 500, and 250 mg/kg/day) for 4 weeks and their systolic blood pressure (SBP) and diastolic blood pressure (DBP) values were measured weekly using tail-cuff method. The ...
Abstract Objective To decompose and reformulate Banxia Baizhu Tianma Decoction (BBT) in order to ... more Abstract Objective To decompose and reformulate Banxia Baizhu Tianma Decoction (BBT) in order to optimize its ratio for vasodilatory effect. The fingerprints of these six component herbs were also studied via Tri-step FTIR analysis. Methods The herbal components of BBT were extracted separately with different solvents, such as 95% ethanol, 50% ethanol, and distilled water. The vasodilatory effect of the extracts was studied using the in vitro pre-contracted aortic ring model. Among these extracts, the water extracts of Pinellia ternata [PT(W)] and Citri reticulatae [CR(W)], 50% ethanol extracts of Gastrodia elata [GE(50)] and Glycyrrhiza uralensis [GU(50)], and 95% ethanol extracts of Atractylodes macrocephala [AM(E)], and Poria cocos [PC(E)] were selected for the orthogonal stimulus-response compatibility group study due to their high effectiveness in vasodilation. Results The best combination ratio (G2) was GE(50), GU(50), AM(E), PC(E), CR(W), and PT(W) at EC 0 , EC 5 , EC 5 , EC 5 , EC 5 , and EC 5 , with EC 50 of (0.06 ± 0.01) mg/mL. Comparison between the vasodilatory effects of extracts derived from G2 and BBT were also studied. From the results, the 50% ethanol extract following G2 ratio was found to be most potent extract with the highest vasodilatory effect compared with other extracts derived from G2 or BBT, with EC 50 of (0.05 ± 0.005) mg/mL. Conclusion The optimum ratio and appropriate extraction method for the new BBT formulae are obtained. G2 is determined as the best formulae with the highest potency in producing the vasodilatory effect on isolated rat aortic rings. The results obtained suggest that 50% ethanol is found to be the best solvent to extract the vasoactive compounds of G2 in order to exhibit the highest efficacy of vasodilatory effect.
Hypertension, one of the famous "silent killers" that can attack people at any age, is ... more Hypertension, one of the famous "silent killers" that can attack people at any age, is a current hot topic among scientists due to multiple syndromic behavior and concomitant diseases. The new scientific-based Traditional Chinese Medicine (TCM) formulation approach was used in a previous study by combining five TCM herbs, including Gastrodia elata Bl., Uncaria rhynchophylla (Miq.) Miq. ex Havil., Pueraria thomsonii Benth., Panax notoginseng (Burk.) F.H. Chen, and Alisma orientalis (Sam.) Juzep in optimized ratio (named BPAid). The objective of the present study was to evaluate the mechanism pathways employed by BPAid for vasodilatory effect with the use of an in vitro isolated aortic rings assay. Interestingly, all the mechanisms investigated were involved in the BPAid's vasodilation activity in which the majority contributed through the nitric oxide/soluble guanylyl cyclase/cyclic guanosine monophosphate (NO/sGC/cGMP) pathways, followed by prostacyclin (PGI2), β2-adre...
Uncaria rhynchophylla is one of the major components included in Traditional Chinese Medicine pre... more Uncaria rhynchophylla is one of the major components included in Traditional Chinese Medicine prescriptions for hypertensive treatment. Previous studies have suggested that U. rhynchophylla might contain vasodilation-mediating active compounds, especially indole alkaloids. Hence, this study was carried out to determine the vasodilatory effects of U. rhynchophylla, which was extracted by different solvents. The most effective extract was then further studied for its signaling mechanism pathways. The authenticity of U. rhynchophylla was assured by using modernized tri-step Fourier transform infrared (FTIR), including conventional 1D FTIR, second derivative scanning combined with 2D-correlated IR spectroscopy. Results obtained proved that the fingerprint of U. rhynchophylla used was identical to the atlas. Isolated aortic rings from male Sprague-Dawley rats were preconstricted with phenylephrine (PE) followed by cumulative addition of U. rhynchophylla extracts. The signaling mechanism ...
Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia. Th... more Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia. This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint. Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01-2.55 mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists. The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC50 of 0.057 ± 0.006 and 0.430 ± 0.196 mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC50 0.971 ± 0.459 mg/mL), methylene blue (EC50 1.203 ± 0.426 mg/mL), indomethacin (EC50 2.128 ±...
An aqueous extract (AE) of vinegar made from Nypa fruticans Wurmb. can improve postprandial gluco... more An aqueous extract (AE) of vinegar made from Nypa fruticans Wurmb. can improve postprandial glucose levels in normoglycaemic rats. The aim of this study was to evaluate its antihyperglycaemic activity further using in vivo and in vitro approaches. AE was administered to streptozotocin (STZ)-induced diabetic rats twice daily at three doses (1000, 500, and 250 mg/kg b.w.) for 12 days p.o. Several biochemical analyses and a histological study of the pancreas and liver were performed, accompanied by a cell culture assay. As compared to diabetic control (DC), AE at the doses of 500 and 1000 mg/kg b.w. caused significant reduction (p < 0.05) of blood glucose, total cholesterol and triglycerides levels, with positive improvement of serum insulin levels. Interestingly, immunohistochemical staining of the pancreas suggested no β-cell regeneration, despite significant increase in insulin production. AE-treated groups, however, showed overall restoration of the hepatic histoarchitecture of ...
Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that ... more Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O. stamineus. The vasorelaxant activity and the underlying mechanisms of the chloroform fraction of the 50% methanolic extract of O. stamineus (CF) was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. CF caused relaxation of the aortic ring pre-contracted with phenylephrine in the presence and absence of endothelium, and pre-contracted with potassium chloride in endothelium-intact aortic ring. I...
Glycyrrhiza uralensis (G. uralensis) is one of the herbs used in traditional Chinese medicine (TC... more Glycyrrhiza uralensis (G. uralensis) is one of the herbs used in traditional Chinese medicine (TCM) and serves as an envoy medicinal. Since G. uralensis plays a major role in the anti-hypertensive TCM formulae, we believe that G. uralensis might possess vasorelaxation activity. This study is designed to investigate the vasorelaxation effect of G. uralensis from various extracts and to study its pharmacology effect. The vasorelaxation effect of G. uralensis extracts were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. Among these three extracts of G. uralensis, 50% ethanolic extract (EFG) showed the strongest vasorelaxation activity. EFG caused the relaxation of the aortic rings pre-contracted with phenylephrine either in the presence or absence of endothelium and pre-contracted with potassium chloride in endothelium-intact aortic ring. Nω-nitro-L-arginine methyl ester, methylene blue, or 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one inhibit the vasorelaxation eff...
Recently, a new syndromic disease combination theory of traditional Chinese medicine (TCM) for hy... more Recently, a new syndromic disease combination theory of traditional Chinese medicine (TCM) for hypertensive treatment has been introduced. In the wake of this new concept, a new science-based TCM formula that counteracts various syndromes is needed. The objective of this study was to develop such a formula. Five of the most clinically prescribed TCM herbs that work on different syndromes, namely Gastrodia elata, Uncaria rhynchophylla, Pueraria thomsonii, Panax notoginseng, and Alisma orientale, were selected for this study. The fingerprints of these five herbs were analyzed by tri-step Fourier transform infrared spectroscopy. Three different solvents, 95% ethanol, 50% ethanol, and distilled water, were used for the maceration of the herbs and their vasodilatory effects were studied using in vitro precontracted aortic ring model. Among these, the 50% ethanolic extracts of G. elata (GE50) and A. orientale (AO50), and 95% ethanolic extracts of U. rhynchophylla (UR95), P. thomsonii (PT9...
Previous studies demonstrated that eupatorin content in Orthosiphon stamineus fractions correlate... more Previous studies demonstrated that eupatorin content in Orthosiphon stamineus fractions correlated with their vasorelaxation activity. Even with previous studies, there is still very little information on the vasorelaxation effect of eupatorin, and not many scientific studies had been carried out. Therefore, the present study was designed to investigate the vasorelaxation activity and mechanism of action of eupatorin. The vasorelaxation activity and the underlying mechanisms of eupatorin was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. Eupatorin caused the relaxation of aortic rings pre-contracted with phenylephrine with and without endothelium (pD2=6.66±0.13, EMAX=99.72±6.39%; pD2=6.10±0.22, EMAX=65.78±8.01%), and also the relaxation of endothelium-intact aortic rings pre-contracted with potassium chloride (pD2=6.20±0.30, EMAX=71.89±12.25%). In the presence of Nω-nitro-l-arginine methyl ester (pD2&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.60, EMAX=24.91±6.39%), methylene blue (pD2=6.05±0.38, EMAX=66.79±9.69%), ODQ (pD25.84±0.32, EMAX=60.47±9.6%), indomethacin (pD2=6.27±0.21, EMAX=76.03±9.45%), tetraethylammonium (pD2=6.09±0.35, EMAX=69.35±11.31%), 4-aminopyridine (pD2=6.34±0.12, EMAX=76±6.1%), barium chloride (pD2=6.47±0.14, EMAX=79.61±10.02%), atropine (pD2=6.36±0.29, EMAX=86.47±12.95%) and propranolol (pD2=6.49±0.26, EMAX=83.2±12.01%), relaxation stimulated by eupatorin was significantly reduced. Eupatorin was also found to be active in reducing Ca(2+) release from sarcoplasmic reticulum and in blocking calcium channels. The present study demonstrates the vasorelaxation effect of eupatorin involving NO/sGC/cGMP and indomethacin pathways, calcium and potassium channels, and muscarinic and beta-adrenergic receptors.
The present study investigates the effect of oral administration of the aqueous extract of Gynura... more The present study investigates the effect of oral administration of the aqueous extract of Gynura procumbens on blood glucose levels in normal and streptozotocin (STZ) diabetic rats. However, the mechanism of its action is still not known. Hence, in vivo and in vitro studies were carried out to study the role of G. procumbens on blood glucose lowering effect. In in vivo studies, single administrations of aqueous extract 1g/kg b.w. to 16-h fasted streptozotocin (STZ)-induced diabetic rats reduced the mean blood glucose level at hour 2, 5, 6, 7 (P<0.05) but not in normal rats when administered by gastric intubation. The plasma insulin of STZ-induced diabetic rats was also measured using rat insulin ELISA kits. The result showed that plasma insulin has not elevated in these rats, which suggested that the hypoglycaemic activity was not due to an insulinotropic effect of G. procumbens. In glucose tolerance test where the rats were loaded with glucose (500mg/kg b.w.) intraperitoneally ...
Vernonia amygdalina simultaneously suppresses entiates glucose extract administration also caused... more Vernonia amygdalina simultaneously suppresses entiates glucose extract administration also caused a decrease in the expression of key enzymes of glycolysis namely hexokinase Atangwho et al. BMC Complementary and Alternative Medicine 2014, 14:426
Introduction: The study was done at the aim to assess the functionality and viability of the β ce... more Introduction: The study was done at the aim to assess the functionality and viability of the β cells of the streptozotocin-induced diabetic rats model following repetitive dosage of administration of ethanolic extracts of Andrographis paniculata. Materials and Methods: The diabetic rats were treated with the extracts for fourteen days and at the dose given was 500 mg/kg twice daily. The assessments were made on fasting blood glucose, insulin, and immunohistochemical aspect of β cells before and after treatment. Results: The results showed that there was a significant reduction on fasting blood glucose levels in metformin, 95% and 50% ethanolic plant extracts-treated groups but on insulin level only 95% and 50% ethanolic extracts-treated groups gave a significant reduction (p<0.05). Immunohistochemical assessments revealed that all extract groups and metformin-treated were significantly increased in the population of β cells (p<0.01). Conclusion: This study revealed that the plant...
Aim: The objective of the present study was to evaluate the in vitro effect of aqueous extract of... more Aim: The objective of the present study was to evaluate the in vitro effect of aqueous extract of Clinacanthus nutans leaves and the juice on the activity of UDP-glucuronosyltransferase (UGT), cytochrome P (CYP) 3A4, and CYP2E1 in human liver microsomes (HLMs). Materials and Methods: The herb-drug interactions of the leaf extracts and juice were determined by a specific enzyme activity of CYP isoforms with specific probe substrate using spectrophotometry. CYP3A4 activity was measured for aminopyrine-specific metabolite (formaldehyde) at 415 nm. CYP2E1 activity was determined using p-nitrophenol-specific metabolite (p-nitrocatechol) at 535 nm. UGT activity was quantified through the consumption of p-nitrophenol by UGT at 405 nm. Results: Results obtained showed that the juice and aqueous extract of C. nutans leaves exhibited significant inhibition (P < 0.05) in CYP3A4 and CYP2E1 activity in HLMs. The aqueous extract of C. nutans showed statistically significant (P < 0.05) activation on UGT activity at the concentration of 1000 ng/mL as compared to the negative control. Conclusion: There is a possibility that herb-drug interaction could occur with C. nutans through inhibitory effects on CYP3A4 and CYP2E1. The leaf preparation also activated UGT catalyzed metabolism which may result in a reduction of the potency of the drug metabolized by UGT pathway.
The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liv... more The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liver disease (NAFLD). We have recently reported that our standardized 50% methanolic extract (ME) of (50% ME of ) has alleviated NAFLD in Sprague⁻Dawley rats. This study aimed to assess the molecular mechanisms of action, and to further evaluate the antiangiogenic effect of this extract NAFLD was induced by eight weeks of high-fat diet, and treatment was applied for four weeks. Antiangiogenic activity was assessed by aortic ring assay and by in vitro tests. Our findings demonstrated that the therapeutic effects of 50% ME among NAFLD rats, were associated with a significant increase in serum adiponectin, reduction in the serum levels of RBP4, vaspin, progranulin, TNF-α, IL-6, and significant downregulation of the hepatic gene expression of PPARγ, SLC10A2, and Collα1. Concomitantly, 50% ME of has exhibited a potent antiangiogenic activity on ring assay, cell migration, vascular endothelial g...
Although Banxia Baizhu Tianma Tang (BBT) has been long administered for hypertensive treatment in... more Although Banxia Baizhu Tianma Tang (BBT) has been long administered for hypertensive treatment in Traditional Chinese Medicine (TCM), the ratio of the herbal components that makes up the formulation has not been optimized with respect to the anti-hypertensive effect that it inherently possesses. A newly amended BBT (ABBT) formulation was developed using the evidence-based approach of orthogonal stimulus-response compatibility model. The ABBT showed enhanced therapeutic effect while maintaining its traditional theoretical approach rooted in TCM. This study was designed to investigate the possible mechanism of actions involved in the vasodilatory activity of ABBT-50 by evaluating its vasodilative effect on isolated Sprague Dawley rats in the presence of absence of various antagonists. When pre-contracted with phenylephrine, relaxation was observed in endothelium intact (EC=0.027±0.003mg/ml, R=109.8±2.12%) and denuded aortic rings (EC=0.409±0.073mg/ml, R=63.15±1.78%), as well as in end...
The seeds of Swietenia macrophylla King (SM) (Meliaceae) are used as a folk medicine for the trea... more The seeds of Swietenia macrophylla King (SM) (Meliaceae) are used as a folk medicine for the treatment of hypertension in Malaysia. However, the antihypertensive and vasorelaxant effects of SM seeds are still not widely studied. Thus, this study was designed to investigate the in vivo antihypertensive effects and in vitro mechanism of vasorelaxation of a 50% ethanolic SM seed extract (SM50) and the fingerprint of SM50 was developed through tri-step Fourier transform infrared (FTIR) spectroscopy. The vasorelaxant activity and the underlying mechanisms of SM50 were evaluated on thoracic aortic rings isolated from Sprague-Dawley rats in the presence of antagonists. The pharmacological effect of SM50 was investigated by oral administration of spontaneously hypertensive rats (SHRs) with three different doses of SM50 (1000, 500, and 250 mg/kg/day) for 4 weeks and their systolic blood pressure (SBP) and diastolic blood pressure (DBP) values were measured weekly using tail-cuff method. The ...
Abstract Objective To decompose and reformulate Banxia Baizhu Tianma Decoction (BBT) in order to ... more Abstract Objective To decompose and reformulate Banxia Baizhu Tianma Decoction (BBT) in order to optimize its ratio for vasodilatory effect. The fingerprints of these six component herbs were also studied via Tri-step FTIR analysis. Methods The herbal components of BBT were extracted separately with different solvents, such as 95% ethanol, 50% ethanol, and distilled water. The vasodilatory effect of the extracts was studied using the in vitro pre-contracted aortic ring model. Among these extracts, the water extracts of Pinellia ternata [PT(W)] and Citri reticulatae [CR(W)], 50% ethanol extracts of Gastrodia elata [GE(50)] and Glycyrrhiza uralensis [GU(50)], and 95% ethanol extracts of Atractylodes macrocephala [AM(E)], and Poria cocos [PC(E)] were selected for the orthogonal stimulus-response compatibility group study due to their high effectiveness in vasodilation. Results The best combination ratio (G2) was GE(50), GU(50), AM(E), PC(E), CR(W), and PT(W) at EC 0 , EC 5 , EC 5 , EC 5 , EC 5 , and EC 5 , with EC 50 of (0.06 ± 0.01) mg/mL. Comparison between the vasodilatory effects of extracts derived from G2 and BBT were also studied. From the results, the 50% ethanol extract following G2 ratio was found to be most potent extract with the highest vasodilatory effect compared with other extracts derived from G2 or BBT, with EC 50 of (0.05 ± 0.005) mg/mL. Conclusion The optimum ratio and appropriate extraction method for the new BBT formulae are obtained. G2 is determined as the best formulae with the highest potency in producing the vasodilatory effect on isolated rat aortic rings. The results obtained suggest that 50% ethanol is found to be the best solvent to extract the vasoactive compounds of G2 in order to exhibit the highest efficacy of vasodilatory effect.
Hypertension, one of the famous "silent killers" that can attack people at any age, is ... more Hypertension, one of the famous "silent killers" that can attack people at any age, is a current hot topic among scientists due to multiple syndromic behavior and concomitant diseases. The new scientific-based Traditional Chinese Medicine (TCM) formulation approach was used in a previous study by combining five TCM herbs, including Gastrodia elata Bl., Uncaria rhynchophylla (Miq.) Miq. ex Havil., Pueraria thomsonii Benth., Panax notoginseng (Burk.) F.H. Chen, and Alisma orientalis (Sam.) Juzep in optimized ratio (named BPAid). The objective of the present study was to evaluate the mechanism pathways employed by BPAid for vasodilatory effect with the use of an in vitro isolated aortic rings assay. Interestingly, all the mechanisms investigated were involved in the BPAid's vasodilation activity in which the majority contributed through the nitric oxide/soluble guanylyl cyclase/cyclic guanosine monophosphate (NO/sGC/cGMP) pathways, followed by prostacyclin (PGI2), β2-adre...
Uncaria rhynchophylla is one of the major components included in Traditional Chinese Medicine pre... more Uncaria rhynchophylla is one of the major components included in Traditional Chinese Medicine prescriptions for hypertensive treatment. Previous studies have suggested that U. rhynchophylla might contain vasodilation-mediating active compounds, especially indole alkaloids. Hence, this study was carried out to determine the vasodilatory effects of U. rhynchophylla, which was extracted by different solvents. The most effective extract was then further studied for its signaling mechanism pathways. The authenticity of U. rhynchophylla was assured by using modernized tri-step Fourier transform infrared (FTIR), including conventional 1D FTIR, second derivative scanning combined with 2D-correlated IR spectroscopy. Results obtained proved that the fingerprint of U. rhynchophylla used was identical to the atlas. Isolated aortic rings from male Sprague-Dawley rats were preconstricted with phenylephrine (PE) followed by cumulative addition of U. rhynchophylla extracts. The signaling mechanism ...
Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia. Th... more Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia. This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint. Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01-2.55 mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists. The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC50 of 0.057 ± 0.006 and 0.430 ± 0.196 mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC50 0.971 ± 0.459 mg/mL), methylene blue (EC50 1.203 ± 0.426 mg/mL), indomethacin (EC50 2.128 ±...
An aqueous extract (AE) of vinegar made from Nypa fruticans Wurmb. can improve postprandial gluco... more An aqueous extract (AE) of vinegar made from Nypa fruticans Wurmb. can improve postprandial glucose levels in normoglycaemic rats. The aim of this study was to evaluate its antihyperglycaemic activity further using in vivo and in vitro approaches. AE was administered to streptozotocin (STZ)-induced diabetic rats twice daily at three doses (1000, 500, and 250 mg/kg b.w.) for 12 days p.o. Several biochemical analyses and a histological study of the pancreas and liver were performed, accompanied by a cell culture assay. As compared to diabetic control (DC), AE at the doses of 500 and 1000 mg/kg b.w. caused significant reduction (p < 0.05) of blood glucose, total cholesterol and triglycerides levels, with positive improvement of serum insulin levels. Interestingly, immunohistochemical staining of the pancreas suggested no β-cell regeneration, despite significant increase in insulin production. AE-treated groups, however, showed overall restoration of the hepatic histoarchitecture of ...
Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that ... more Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O. stamineus. The vasorelaxant activity and the underlying mechanisms of the chloroform fraction of the 50% methanolic extract of O. stamineus (CF) was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. CF caused relaxation of the aortic ring pre-contracted with phenylephrine in the presence and absence of endothelium, and pre-contracted with potassium chloride in endothelium-intact aortic ring. I...
Glycyrrhiza uralensis (G. uralensis) is one of the herbs used in traditional Chinese medicine (TC... more Glycyrrhiza uralensis (G. uralensis) is one of the herbs used in traditional Chinese medicine (TCM) and serves as an envoy medicinal. Since G. uralensis plays a major role in the anti-hypertensive TCM formulae, we believe that G. uralensis might possess vasorelaxation activity. This study is designed to investigate the vasorelaxation effect of G. uralensis from various extracts and to study its pharmacology effect. The vasorelaxation effect of G. uralensis extracts were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. Among these three extracts of G. uralensis, 50% ethanolic extract (EFG) showed the strongest vasorelaxation activity. EFG caused the relaxation of the aortic rings pre-contracted with phenylephrine either in the presence or absence of endothelium and pre-contracted with potassium chloride in endothelium-intact aortic ring. Nω-nitro-L-arginine methyl ester, methylene blue, or 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one inhibit the vasorelaxation eff...
Recently, a new syndromic disease combination theory of traditional Chinese medicine (TCM) for hy... more Recently, a new syndromic disease combination theory of traditional Chinese medicine (TCM) for hypertensive treatment has been introduced. In the wake of this new concept, a new science-based TCM formula that counteracts various syndromes is needed. The objective of this study was to develop such a formula. Five of the most clinically prescribed TCM herbs that work on different syndromes, namely Gastrodia elata, Uncaria rhynchophylla, Pueraria thomsonii, Panax notoginseng, and Alisma orientale, were selected for this study. The fingerprints of these five herbs were analyzed by tri-step Fourier transform infrared spectroscopy. Three different solvents, 95% ethanol, 50% ethanol, and distilled water, were used for the maceration of the herbs and their vasodilatory effects were studied using in vitro precontracted aortic ring model. Among these, the 50% ethanolic extracts of G. elata (GE50) and A. orientale (AO50), and 95% ethanolic extracts of U. rhynchophylla (UR95), P. thomsonii (PT9...
Previous studies demonstrated that eupatorin content in Orthosiphon stamineus fractions correlate... more Previous studies demonstrated that eupatorin content in Orthosiphon stamineus fractions correlated with their vasorelaxation activity. Even with previous studies, there is still very little information on the vasorelaxation effect of eupatorin, and not many scientific studies had been carried out. Therefore, the present study was designed to investigate the vasorelaxation activity and mechanism of action of eupatorin. The vasorelaxation activity and the underlying mechanisms of eupatorin was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. Eupatorin caused the relaxation of aortic rings pre-contracted with phenylephrine with and without endothelium (pD2=6.66±0.13, EMAX=99.72±6.39%; pD2=6.10±0.22, EMAX=65.78±8.01%), and also the relaxation of endothelium-intact aortic rings pre-contracted with potassium chloride (pD2=6.20±0.30, EMAX=71.89±12.25%). In the presence of Nω-nitro-l-arginine methyl ester (pD2&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.60, EMAX=24.91±6.39%), methylene blue (pD2=6.05±0.38, EMAX=66.79±9.69%), ODQ (pD25.84±0.32, EMAX=60.47±9.6%), indomethacin (pD2=6.27±0.21, EMAX=76.03±9.45%), tetraethylammonium (pD2=6.09±0.35, EMAX=69.35±11.31%), 4-aminopyridine (pD2=6.34±0.12, EMAX=76±6.1%), barium chloride (pD2=6.47±0.14, EMAX=79.61±10.02%), atropine (pD2=6.36±0.29, EMAX=86.47±12.95%) and propranolol (pD2=6.49±0.26, EMAX=83.2±12.01%), relaxation stimulated by eupatorin was significantly reduced. Eupatorin was also found to be active in reducing Ca(2+) release from sarcoplasmic reticulum and in blocking calcium channels. The present study demonstrates the vasorelaxation effect of eupatorin involving NO/sGC/cGMP and indomethacin pathways, calcium and potassium channels, and muscarinic and beta-adrenergic receptors.
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