Bioactivity-Guided Fractionation and Identification of Antidiabetic Compound of Syzygium polyanthum (Wight.)'s Leaf Extract in Streptozotocin-Induced Diabetic Rat Model.

(1) Background: An earlier study on the hypoglycemic activity of S. polyanthum (Wight.) leaf methanol extract identified squalene as the major chemical compound. The present study was conducted to assess the hypoglycemic effect of fractions and subfractions of the methanol extract of S. polyanthum compared to the squalene using a bioassay-guided in vivo study. (2) Methods: The methanol extract was fractionated using the liquid−liquid fractionation method. Streptozotocin-induced type 1 diabetic rat was used to study the hypoglycemic effect. (3) Results: The findings showed that chloroform fraction significantly (p < 0.05) lowered blood glucose levels of diabetic rats as compared to the control. Further fractionation of chloroform fraction yielded subfraction-1 and -2, whereby subfraction-1 exhibited a higher blood-glucose-lowering effect. The lipid profile test showed that the total cholesterol level of subfraction-1 and squalene-treated groups decreased significantly (p < 0.05). An immunohistochemistry study revealed that none of the treatments regenerated pancreatic ß-cells. Gas chromatography−mass spectrophotometer analysis identified the presence of squalene in the active methanol extract, chloroform fraction, and subfraction-1. In silico analysis revealed a higher affinity of squalene against protein receptors that control lipid metabolism than metformin. (4) Conclusions: Data obtained from the present work suggested the crude methanol extract exerted the highest hypoglycemic effect compared to fraction, subfraction, and squalene, confirming synergistic effect may be responsible for the hypoglycemic activity of S. polyanthum.

Moringa oleifera Lam. leaf extracts reverse metabolic syndrome in Sprague Dawley rats fed high-fructose high fat diet for 60-days.

Background: Moringa oleifera Lam. has been used traditionally for the treatment of different cardio-metabolic disorders. So, the aim was to assess its leaf extracts in metabolic syndrome rat model.Methods: Out of the total 36-rats, 6 rats were given normal matched diet (NMD) while the rest were provided high-fat diet and 20% fructose (HFD-20%F). Moringa oleifera leaf extracts were administered orally for 30 days. Body weight, blood glucose, BMI, blood pressure, lipids, insulin, insulin resistance, MCP-1, visceral fat and liver weight were evaluated.Results: Sixty-days feeding with HFD-20%F produced the metabolic syndrome features like hyperinsulinemia, insulin resistance, and increase in low-density lipoprotein (LDL), visceral fat, and liver weight significantly (p<.05) than the rats receiving (NMD). Moringa oleifera treatment for 30 days significantly provided the mitigation against metabolic syndrome features.Conclusion: Moringa oleifera Lam. leaf extract might be a good alternative herbal choice in the treatment of metabolic syndrome disease.

Blood pressure lowering effect and vascular activity of Phyllanthus niruri extract: The role of NO/cGMP signaling pathway and ß-adrenoceptor mediated relaxation of isolated aortic rings.

ETHNOPHARMACOLOGICAL RELEVANCE: Phyllanthus niruri have a long history of use in the traditional treatment of various ailments including hypertension. Literature reports have indicated that it is a potent antihypertensive herbal medication used traditionally. AIM OF THE STUDY: This study was carried out to investigate the antihypertensive and vasodilatory activity of four solvents extracts of P. niruri namely; petroleum ether (PEPN), chloroform (CLPN), methanol (MEPN) and water (WEPN), with the aim of elucidating the mechanism of action and identifying the phytochemical constituents. MATERIALS AND METHODS: Male Spontaneous Hypertensive Rats (SHRs) were given oral gavage of P. niruri extract daily for two weeks and the blood pressure was recorded in vivo. We also determine the vasodilation effect of the extracts on rings of isolated thoracic aorta pre-contracted with phenylephrine (PE, 1 µM). Endothelium-intact or endothelium-denuded aorta rings were pre-incubated with various antagonists like 1H-[1,2,4] oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ, 10 µM) and Methylene blue (MB 10 µM), sGC inhibitors; Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME, 10 µM) a nitric oxide synthase (NOS) inhibitor; atropine (10 µM), a cholinergic receptor blocker; indomethacin (10 µM), a cyclooxygenase inhibitor and various K+ channel blockers such as glibenclamide (10 µM) and tetraethyl ammonium (TEA 10 µM) for mechanism study. RESULTS: SHRs receiving P. niruri extracts showed a significant decrease in their blood pressure (BP) when compared to the baseline value, with PEPN being more potent. The extracts (0.125-4 mg/mL) also induced vasorelaxation on endothelium-intact aorta rings. PEPN elicited the most potent maximum relaxation effect (Rmax). Mechanism assessment of PEPN showed that its relaxation effect is significantly suppressed in endothelium-denuded aorta rings. Pre-incubation of aorta rings with atropine, L-NAME, ODQ, indomethacin, and propranolol also significantly attenuated its relaxation effect. Conversely, incubation with TEA and glibenclamide did not show a significant effect on PEPN-induced relaxation. CONCLUSION: This study indicates that the antihypertensive activity of P. niruri extract is mediated by vasoactive phytoconstituents that dilate the arterial wall via endothelium-dependent pathways and ß-adrenoceptor activity which, in turn, cause vasorelaxation and reduce blood pressure.

Mechanisms underlying the vascular relaxation activities of Zingiber officinale var. rubrum in thoracic aorta of spontaneously hypertensive rats.

OBJECTIVE: To evaluate vasorelaxant and vasoconstriction effects of Zingiber officinale var. rubrum (ZOVR) on live rats and isolated aortic rings of spontaneously hypertensive rats (SHRs). METHODS: Extracts of ZOVR were subjected to in-vivo antihypertensive screening using noninvasive blood pressures in SHRs. The most potent extract, ZOVR petroleum ether extract (ZOP) was then fractionated using n-hexane, chloroform and water. Isolated thoracic aortic rings were harvested and subjected to vascular relaxation studies of n-hexane fraction of ZOP (HFZOP) with incubation of different antagonists such as Nω-nitro-l-arginine methyl ester (L-NAME, 10 µmol/L), indomethacin (10 µmol/L), methylene blue (10 µmol/L), atropine (1 µmol/L), glibenclamide (10 µmol/L), prazosin (0.01 µmol/L), and propranolol (1 µmol/L). RESULTS: During the screening of various ZOVR extracts, ZOP produced the most reduction in blood pressures of SHRs and so did HFZOP. HFZOP significantly decreased phenylephrine-induced contraction and enhanced acetylcholine-induced relaxation. L-NAME, indomethacin, methylene blue, atropine, and glibenclamide significantly potentiated the vasorelaxant effects of HFZOP. Propranolol and prazosin did not alter the vasorelaxant effects of HFZOP. HFZOP significantly suppressed the Ca2+-dependent contraction and influenced the ratio of the responses to phenylephrine in Ca2+-free medium. CONCLUSION: This study demonstrates that ZOP may exert an antihypertensive effect in the SHR model. Its possible vascular relaxation mechanisms involve nitric oxide and prostacyclin release, activation of cGMP-KATP channels, stimulation of muscarinic receptors, and transmembrane calcium channel or Ca2+ release from intracellular stores. Possible active compounds that contribute to the vasorelaxant effects are 6-gingerol, 8-gingerol and 6-shogaol.

Safety assessment of the ethanolic extract of Gongronema latifolium Benth. leaves: a 90-day oral toxicity study in Sprague Dawley rats.

BACKGROUND: The leaves of Gongronema latifolium Benth. have long been recognized traditionally as a remedy for a variety of ailments in Africa. This study was conducted to evaluate the safety profile of the ethanolic extract of G. latifolium (GLES) leaves through a repeated dose 90-day oral toxicity study in male and female of Sprague Dawley rats. METHODS: GLES was orally administered at doses of 250, 500 and 1000 mg/kg/day consecutively for 90 days. RESULTS: No behavioral or physiological changes and mortality were observed. GLES did not have a marked impact on general hematological parameters and did not precipitate nephrotoxicity. However, compared to the control, serum triglycerides, total cholesterol and low-density lipoprotein levels were lower and white adipose tissue paired retroperitoneal fat depots were depleted in male rats treated with GLES3 by the end of the experiment. The liver was significantly enlarged in GLES-treated rats of both sexes. Negative gender-specific alterations were observed with the highest dose. Adverse risk was evident in the female rats mainly due to marked body weight gain and cerebrum weight reduction. CONCLUSION: Further research is needed to reach more specific conclusions about to the safety of ingesting high doses of GLES for long periods of time.

Cytostatic and Antiproliferative Activities of F5 Fraction of Crinum amabile Leaf Chloroform Extract Showed Its Potential as Cancer Chemotherapeutic Agent.

Medicinal plants have been considered as promising sources of drugs in treating various cancers. Crinum amabile (C. amabile), a plant species from the Amaryllidaceae family, is claimed to be a potential source for cancer chemotherapeutic compounds. Here, we aimed to investigate the potential of C. amabile as an anticancer agent. Dried leaves of C. amabile were serially extracted and our findings showed that chloroform extract (CE) was shown to exhibit cytotoxic effect against all cancer cell lines used. This active extract was further fractionated in which F5 fraction was shown to possess the highest cytotoxicity among all fractions. F5 fraction was then tested in-depth through Annexin V/FITC apoptosis and DNA fragmentation assays to determine its apoptotic effect on MCF-7 cells. Results revealed that F5 fraction only showed induction of cell apoptosis starting at 72-hour treatment while DNA fragmentation was not detected at any of the concentrations and treatment periods tested. Meanwhile, cell proliferation assay revealed that F5 fraction was able to inhibit normal cell proliferation as well as VEGF-induced cell proliferation of normal endothelial cell (HUVECs). In conclusion, F5 fraction from C. amabile leaf CE was able to exhibit cytostatic effect through antiproliferation activity rather than induction of cell apoptosis and therefore has the potential to be further investigated as an anticancer agent.

Vasorelaxant activities and the underlying pharmacological mechanisms of Gynura procumbens Merr. leaf extracts on rat thoracic aorta.

Previous studies have investigated the cardiovascular activity of Gynura procumbens Merr. single-solvent extracts. The objective of this study was to evaluate the in vitro vasorelaxant properties and the underlying pharmacological mechanisms of serial extracts and fractions of Gynura procumbens (GP). The leaves of GP were serially extracted with petroleum ether, chloroform, methanol and water using the maceration method. Suspended aortic ring preparations were pre-contracted with phenylephrine (PE 1 µM), followed by cumulative addition of GP extracts (0.25-3 mg/mL). The petroleum ether extract (GPPE) was the most potent among the four extracts. Pre-incubation of endothelium-intact aorta with atropine (1 µM), indomethacin (10 µM), methylene blue (10 µM), propranolol (1 µM) and potassium channel blockers such as TEA (1 µM), glibenclamide (10 µM), 4-aminopyridine (1 µM) and barium chloride (10 mM) had no effect on GPPE-induced vasorelaxation. The vasorelaxant effect of GPPE was partly diminished by pretreatment of aortic rings preparations with L-NAME (10 µM) and even more so in endothelium-denuded aortic rings, indicating a minimal involvement of endothelium-dependent pathway in GPPE-induced vasorelaxation. The calcium-induced vasocontractions were antagonized significantly and concentration-dependently by GPPE in calcium free and high potassium medium. These results illustrate that Ca2+ antagonizing actions of GPPE in rat isolated aorta are comparable to that of verapamil and may be mainly responsible for its vasodilation effect. The antioxidant activity of GPPE supports its vasorelaxant effect by attenuating the production of deleterious free radicals and reactive oxygen species in the vasculature.

Vasorelaxant and chemical fingerprint studies of Citrus reticulatae pericarpium extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: Citrus reticulatae Pericarpium (Chen pi) was widely used as an important ingredient in the prescription of TCM to treat phlegm fluid retention type hypertension. Since Chen pi is involved in treatment as antihypertensive TCM formula, we have reasonable expectation in believing that it might possess vasorelaxant activity. AIM OF THE STUDY: This study is designed to investigate the vasorelaxant effect of Chen pi and to study its pharmacology effects. MATERIALS AND METHODS: The vasorelaxant effect of water extract of Chen pi (CRW) were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. The fingerprint of Chen pi and the extracts were developed with quantification of hesperidin content by HPTLC. RESULTS: CRW exhibited the strongest vasorelaxant activity. CRW caused the relaxation of the phenylephrine pre-contracted aortic rings in the presence and absence of endothelium as well as in potassium chloride pre-contracted endothelium-intact aortic ring. The incubation of propranolol (ß-adrenergic receptor blocker), atropine (muscarinic receptor blocker), Nω-nitro-L-arginine methyl ester (NO synthase inhibitor), ODQ (sGC inhibitor), indomethacin (COX inhibitor), 4-aminopyridine (KV blocker), barium chloride (Kir blocker), and glibenclamide (KATP blocker) significantly reduced the vasorelaxant effects of CRW. CRW was also found to be active in reducing Ca2+ releases from the sarcoplasmic reticulum and suppressing the voltage-operated calcium channels. CONCLUSION: The vasorelaxant effect of CRW on rat aorta involves NO/sGC, calcium and potassium channels, muscarinic and ß-adrenergic receptors.

Correction to: Standardized extract of Ficus deltoidea stimulates insulin secretion and blocks hepatic glucose production by regulating the expression of glucose-metabolic genes in streptozitocin-induced diabetic rats.

After the publication of this article [1] it came to our attention that one author, Boon Yin Khoo, was erroneously omitted from the authorship list.

Adipocytokine Regulation and Antiangiogenic Activity Underlie the Molecular Mechanisms of Therapeutic Effects of Phyllanthus niruri against Non-Alcoholic Fatty Liver Disease.

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 Phyllanthus niruri (50% ME of P. niruri) 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 P. niruri has exhibited a potent antiangiogenic activity on ring assay, cell migration, vascular endothelial growth factor (VEGF), and tube formation, without any cytotoxic effect. Together, our findings revealed that the protective effects of P. niruri against NAFLD might be attributed to its antiangiogenic effect, as well as to the regulation of adipocytokines and reducing the expression of adipogenic genes.

Vasodilation and Antihypertensive Activities of Swietenia macrophylla (Mahogany) Seed Extract.

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 tri-step FTIR macro-fingerprint of SM50 showed that SM50 contains stachyose, flavonoids, limonoids, and ester, which may contribute to its vasorelaxant effect. The results showed that the vasorelaxant activity of SM50 was mostly attributed to channel-linked receptors pathways through the blockage of voltage-operated calcium channels (VOCC). SM50 also acts as both potassium channels opener and inositol triphosphate receptor (IP3R) inhibitor, followed by ß2-adrenergic pathway, and ultimately mediated through the nitric oxide/soluble guanylyl cyclase/cyclic 3',5'-guanosine monophosphate (NO/sGC/cGMP) signaling pathways. The treatment of SM50 also significantly decreased the SBP and DBP in SHRs. In conclusion, the antihypertensive mechanism of SM50 was mediated by VOCC, K+ channels, IP3R, G-protein-coupled ß2-adrenergic receptor, and followed by NO/sGC/cGMP signaling mechanism pathways in descending order. The data suggested that SM50 has the potential to be used as a herbal medicament to treat hypertension.

Anti-hypertensive and vasodilatory effects of amended Banxia Baizhu Tianma Tang.

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 (EC50=0.027±0.003mg/ml, Rmax=109.8±2.12%) and denuded aortic rings (EC50=0.409±0.073mg/ml, Rmax=63.15±1.78%), as well as in endothelium intact aortic rings pre-contracted with potassium chloride (EC50=32.7±12.16mg/ml, Rmax=34.02±3.82%). Significant decrease in the vasodilative effect of ABBT-50 was observed in the presence of Nω-nitro-l-arginine methyl ester (EC50=0.12±0.021mg/ml, Rmax=75.33±3.28%), 1H-[1,2,4] Oxadiazolo[4,3-a]quinoxalin-1-one (EC50=0.463±0.18mg/ml, Rmax=54.48±2.02%), methylene blue (EC50=0.19±0.037mg/ml, Rmax=83.69±3.19%), indomethacin (EC50=0.313±0.046mg/ml, Rmax=71.33±4.12%), atropine (EC50=0.146±0.013mg/ml, Rmax=77.2±3.41%), and 4-aminopyridine (EC50=0.045±0.008mg/ml, Rmax=95.55±2.36%). ABBT-50 was also suppressing Ca2+ release from sarcoplasmic reticulum and inhibiting calcium channels. Vasodilatory effects of ABBT-50 are mediated through NO/sGC/cGMP cascade and PGI2, followed by muscarinic pathways and calcium channels.

Mechanisms of Action of Uncaria rhynchophylla Ethanolic Extract for Its Vasodilatory Effects.

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 pathways were studied by incubation with different receptor antagonists before the PE precontraction. In conclusion, the 95% ethanolic U. rhynchophylla extract (GT100) was found to be most effective with an EC50 value of 0.028 ± 0.002 mg/mL and an Rmax value of 101.30% ± 2.82%. The signaling mechanism pathways employed for exerting its vasodilatory effects included nitric oxide/soluble guanylyl cylcase/cyclic guanosine monophosphate (NO/sGC/cGMP) and PGI2 (endothelium-derived relaxing factors), G protein-coupled M3- and ß2 receptors, regulation of membrane potential through voltage-operated calcium channel, intracellular Ca2+ released from inositol triphosphate receptor (IP3R), and all potassium channels except the Kca channel.

Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism.

CONTEXT: Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia. OBJECTIVE: This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint. MATERIALS AND METHODS: 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. RESULTS: 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 ± 1.218 mg/mL), atropine (EC50 0.470 ± 0.325 mg/mL), and propranolol (EC50 0.314 ± 0.032 mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC50 0.548 ± 0.184, 0.158 ± 0.012, 0.847 ± 0.342, and 0.304 ± 0.075 mg/mL, respectively). VAE was also found to be active in reducing Ca2+ released from the sarcoplasmic reticulum and blocking calcium channels. CONCLUSIONS: The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI2 signalling pathways, and modulation of calcium/potassium channels, and muscarinic and ß2-adrenergic receptor levels.

Nypa fruticans Wurmb. Vinegar's Aqueous Extract Stimulates Insulin Secretion and Exerts Hepatoprotective Effect on STZ-Induced Diabetic Rats.

BACKGROUND: 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. METHODS: 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. RESULTS: 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 ß-cell regeneration, despite significant increase in insulin production. AE-treated groups, however, showed overall restoration of the hepatic histoarchitecture of STZ-induced liver damage, suggesting a possible hepatoprotective effect. The pancreatic effect of AE was further studied through RIN-5F cell culture, which revealed a positive stimulatory effect on insulin release at a basal glucose concentration (1.1 mM). CONCLUSION: Nypa fruticans Wurmb. vinegar's aqueous extract exerts its antihyperglycaemic activity, at least in part, through insulin stimulatory and hepatoprotective effects.

Phyllanthus Niruri Standardized Extract Alleviates the Progression of Non-Alcoholic Fatty Liver Disease and Decreases Atherosclerotic Risk in Sprague-Dawley Rats.

Non-alcoholic fatty liver disease (NAFLD) is one of the major global health issues, strongly correlated with insulin resistance, obesity and oxidative stress. The current study aimed to evaluate anti-NAFLD effects of three different extracts of Phyllanthus niruri (P. niruri). NAFLD was induced in male Sprague-Dawley rats using a special high-fat diet (HFD). A 50% methanolic extract (50% ME) exhibited the highest inhibitory effect against NAFLD progression. It significantly reduced hepatomegaly (16%) and visceral fat weight (22%), decreased NAFLD score, prevented fibrosis, and reduced serum total cholesterol (TC) (48%), low-density lipoprotein (LDL) (65%), free fatty acids (FFAs) (25%), alanine aminotransferase (ALT) (45%), alkaline phosphatase (ALP) (38%), insulin concentration (67%), homeostatic model assessment of insulin resistance (HOMA-IR) (73%), serum atherogenic ratios TC/high-density lipoprotein (HDL) (29%), LDL/HDL (66%) and (TC-HDL)/HDL (64%), hepatic content of cholesterol (43%), triglyceride (29%) and malondialdehyde (MDA) (40%) compared to a non-treated HFD group. In vitro, 50% ME of P. niruri inhibited α-glucosidase, pancreatic lipase enzymes and cholesterol micellization. It also had higher total phenolic and total flavonoid contents compared to other extracts. Ellagic acid and phyllanthin were identified as major compounds. These results suggest that P. niruri could be further developed as a novel natural hepatoprotective agent against NAFLD and atherosclerosis.

Vasodilatory Effects of Combined Traditional Chinese Medicinal Herbs in Optimized Ratio.

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 (PT95), and P. notoginseng (PN95) were found to be the most effective for eliciting vasodilation. Thus, these five extracts were used for orthogonal stimulus-response compatibility group studies by using L25 (55) formula. The best combination ratio for GE50, UR95, PT95, PN95, and AO50, which was assigned as Formula 1 (F1), was found at EC0, EC25, EC20, EC20, and EC10, respectively. The vasodilatory effect of the extracts prepared from different extraction methods using F1 ratio was also studied. From the results, the EC50 and Rmax of total 50% ethanolic extract of five herbs using F1 ratio (F1-2) were 0.028 ± 0.005 mg/mL and 101.71% ± 3.64%, with better values than F1 (0.104 ± 0.014 mg/mL and 97.80% ± 3.12%, respectively). In conclusion, the optimum ratio and appropriate extraction method (F1-2) for the new TCM formula were revealed.

Acute and subchronic toxicity studies of methanol extract of Polygonum minus leaves in Sprague Dawley rats.

Medicinal plant preparations may contain high levels of toxic chemical constituents to potentially cause serious harm to animals and/or humans. Thus, toxicity studies are important to assess the toxic effects of plant derived products. Polygonum minus is used traditionally for different ailments in Southeast Asia. This study was conducted to establish the acute and subchronic toxicity profile of the methanol extract of P. minus leaves. The acute toxicity study showed that the methanol extract of P. minus is safe even at the highest dose tested of 2000 mg/kg in female Sprague Dawley rats. There were no behavioural or physiological changes and gross pathological abnormalities observed. The subchronic toxicity study of methanol extract of P. minus at 250, 500, 1000 and 2000 mg/kg were conducted in both sexes of Sprague Dawley rats. There were no changes observed in the extract treated animal's body weight, food and water intake, motor coordination, behaviour and mental alertness. The values of haematological and biochemical parameters were not different between the treated and control animals. The relative organ weights of extract-treated animals did not differ with that of control animals. Based on the present findings, the methanol extract of P. minus leaves could be considered safe up to the dose of 2000 mg/kg.

Caffeoylquinic Acids Rich versus Poor Fractions of Gynura procumbens: Their Comparative Antihyperlipidemic and Antioxidant Potential.

BACKGROUND: Ethanolic extract of G. procumbens leaves has been previously shown to possess antihyperlipidemic effects. OBJECTIVE: This study was designed to prepare caffeoylquinic acids rich and poor fractions of the ethanolic extract using resin column technology and compare their antihyperlipidemic and antioxidant potentials. RESULTS: Among the treatment groups, caffeoylquinic acids rich fraction (F2) and chlorogenic acid (CA, one of the major caffeoylquinic acids) showed potent antihyperlipidemic effects, with significant reductions in total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C), atherogenic index (AI) and coronary risk index (CRI) (p<0.01 or better) compared to the hyperlipidemic control at the 58 h. The effect was better than that of ethanolic extract. In addition, only F2 significantly increased the high-density lipoproteincholesterol (HDL-C) level (p<0.05). F2 showed better effect than CA alone (60 mg) despite the fact that it only contained 9.81 mg CA/1000 mg dose. The findings suggest that the di-caffeoylquinic acids (86.61 mg/g dose) may also in part be responsible for the potent antihyperlipidemic effect shown by the F2. Likewise, F2 showed the highest antioxidant activity. Thus, simple fractionation of ethanolic extract using the Amberlite XAD-2 resin technique had successfully enriched the caffeoylquinic acids into F2 with improved antihyperlipidemic and antioxidant capacities than that of the ethanolic extract. CONCLUSION: The resin separation technology may find application in caffeoylquinic acids enrichment of plant extracts for pre-clinical studies. The F2 has potential for development into phytopharmaceuticals as adjunct therapy for management of hyperlipidemia.