Medicinal Potential of Isoflavonoids: Polyphenols That May Cure Diabetes.

In recent years, there is emerging evidence that isoflavonoids, either dietary or obtained from traditional medicinal plants, could play an important role as a supplementary drug in the management of type 2 diabetes mellitus (T2DM) due to their reported pronounced biological effects in relation to multiple metabolic factors associated with diabetes. Hence, in this regard, we have comprehensively reviewed the potential biological effects of isoflavonoids, particularly biochanin A, genistein, daidzein, glycitein, and formononetin on metabolic disorders and long-term complications induced by T2DM in order to understand whether they can be future candidates as a safe antidiabetic agent. Based on in-depth in vitro and in vivo studies evaluations, isoflavonoids have been found to activate gene expression through the stimulation of peroxisome proliferator-activated receptors (PPARs) (α, γ), modulate carbohydrate metabolism, regulate hyperglycemia, induce dyslipidemia, lessen insulin resistance, and modify adipocyte differentiation and tissue metabolism. Moreover, these natural compounds have also been found to attenuate oxidative stress through the oxidative signaling process and inflammatory mechanism. Hence, isoflavonoids have been envisioned to be able to prevent and slow down the progression of long-term diabetes complications including cardiovascular disease, nephropathy, neuropathy, and retinopathy. Further thoroughgoing investigations in human clinical studies are strongly recommended to obtain the optimum and specific dose and regimen required for supplementation with isoflavonoids and derivatives in diabetic patients.

Modulation of metabolic alterations of obese diabetic rats upon treatment with Salacca zalacca fruits extract using 1H NMR-based metabolomics.

Fruit of salak (Salacca zalacca) is traditionally used and commercialized as an antidiabetic agent. However, the scientific evidence to prove this traditional use is lacking. This research was aimed to evaluate the metabolic changes of obese-diabetic (OBDC) rats treated with S. zalacca fruit extract using proton-nuclear magnetic resonance (1H NMR)-based metabolomics approach. This research presents the first report on the in vitro antidiabetic effect of S. zalacca fruits extract using this approach. The obtained results indicated that the administration of 400 mg/kg bw of 60% ethanolic S. zalacca extract for 6 weeks significantly decreased the blood glucose level and normalized the blood lipid profile of the OBDC rats. The potential biomarkers in urine were 2-oxoglutarate, alanine, leucine, succinate 3-hydroxybutyrate, taurine, betaine, allantoin, acetate, dimethylamine, creatine, creatinine, glucose, phenyl-acetylglycine, and hippurate. Based on the data obtained, the 60% ethanolic extract could not fully improved the metabolic complications of diabetic rats. The extract of S. zalacca fruit was able to decrease the ketones bodies as 3-hydroxybutyrate and acetoacetate. It also improved energy metabolism, involving glucose, acetate, lactate, 2-hydroxybutyrate, 2-oxoglutarate, citrate, and succinate. Moreover, it decreased metabolites from gut microflora, including choline. This extract had significant effect on amino acid metabolism, metabolites from gut microflora, bile acid metabolism and creatine. The result can further support the traditional claims of S. zalacca fruits in management of diabetes. This finding might be valuable in understanding the molecular mechanism and pharmacological properties of this medicinal plant for managing diabetes mellitus.

Phytochemicals and biological activity of Tetracera scandens Linn. Merr. (Dilleniaceae): A short review.

Tetracera scandens is a southeast Asian shrub that belongs to family Dilleniaceae. Over the years, different parts of the plant have been used for the management of different diseases, including diabetes mellitus, hypertension, rheumatism, diarrhea, hepatitis, and inflammation. This variety of medical indications has attracted the attention of many researchers to this plant species, leading to the conduction of many research studies on different parts of the plant. These studies have confirmed some of the aforementioned activities of the plant, whereas other indications remain to be ascertained. This article is an attempt to summarize the studies conducted on T. scandens and to explore the isolated phytochemicals.

Investigation of α-Glucosidase Inhibitory Metabolites from Tetracera scandens Leaves by GC-MS Metabolite Profiling and Docking Studies.

Stone leaf (Tetracera scandens) is a Southeast Asian medicinal plant that has been traditionally used for the management of diabetes mellitus. The underlying mechanisms of the antidiabetic activity have not been fully explored yet. Hence, this study aimed to evaluate the α-glucosidase inhibitory potential of the hydromethanolic extracts of T. scandens leaves and to characterize the metabolites responsible for such activity through gas chromatography-mass spectrometry (GC-MS) metabolomics. Crude hydromethanolic extracts of different strengths were prepared and in vitro assayed for α-glucosidase inhibition. GC-MS analysis was further carried out and the mass spectral data were correlated to the corresponding α-glucosidase inhibitory IC50 values via an orthogonal partial least squares (OPLS) model. The 100%, 80%, 60% and 40% methanol extracts displayed potent α-glucosidase inhibitory potentials. Moreover, the established model identified 16 metabolites to be responsible for the α-glucosidase inhibitory activity of T. scandens. The putative α-glucosidase inhibitory metabolites showed moderate to high affinities (binding energies of -5.9 to -9.8 kcal/mol) upon docking into the active site of Saccharomyces cerevisiae isomaltase. To sum up, an OPLS model was developed as a rapid method to characterize the α-glucosidase inhibitory metabolites existing in the hydromethanolic extracts of T. scandens leaves based on GC-MS metabolite profiling.

Evaluation and Comparison of Trachyspermum ammi Seed Extract for Its Anti-inflammatory Effect.

AIMS AND OBJECTIVES: The present study was aimed to evaluate the antiinflammatory effect of different seed extracts of Trachyspermum ammi at different doses. MATERIALS AND METHODS: Three different seed extracts were prepared through Soxhlet extraction method by using n-hexane, chloroform and methanol solvents. Acute toxicity test performed at dose of 400 mg/ kg, 800 mg/kg, 1600 mg/kg and 3200 mg/kg. Two different strengths of seed extracts (minimum therapeutic dose of 500 mg/kg and maximum therapeutic dose of 1000 mg/kg) were given to Wistar rats to measure anti-inflammatory activity through Carrageenan induced paw edema method. RESULTS: The standard drug diclofenac sodium was (percentage of inhibition of paw edema 29.68%) more effective as compared to test drug. When efficacy of all extracts compared with each other, n-hexane extract showed more anti-inflammatory effect (percentage inhibition of paw edema 22.21%) at maximum effective dose 1000 mg/kg. CONCLUSION: Seed extracts of T. ammi showed anti-inflammatory activity by potentiating the neurotransmission of GABA and also by repression glutamate receptor.

GC-MS analysis of metabolites from soxhlet extraction, ultrasound-assisted extraction and supercritical fluid extraction of Salacca zalacca flesh and its alpha-glucosidase inhibitory activity.

Different extraction processes were employed to extract bioactive metabolites from Salacca zalacca flesh by a range of aqueous and organic solvents. The highest extraction yield was obtained by 50% ethanol extract of SE (73.18 ± 4.35%), whereas SFE_1 showed the lowest yield (0.42 ± 0.08%). All extracts were evaluated for in vitro α-glucosidase inhibitory activity, measured by their IC50 values in comparison to that of quercetin, the positive control (IC50 = 2.7 ± 0.7 µg/mL). The lowest α-glucosidase inhibitory activity was indicated by water extract of SE (IC50 = 724.3 ± 42.9 µg/mL) and the highest activity was demonstrated by 60% ethanol extract by UAE (IC50 = 16.2 ± 2.4 µg/mL). All extracts were analysed by GC-MS and identified metabolites like carbohydrates, fatty acids, organic acids, phenolic acids, sterols and alkane-based compounds etcetera that may possess the potential as α-glucosidase inhibitor and may attribute to the α-glucosidase inhibitory activity.

Comparison and Evaluation of Different Seed Extracts of Trachyspermum ammi for Immunomodulatory Effect on Cell-Mediated Immunity through Delayed-Type Hypersensitivity Assay Skin Thickness Method.

OBJECTIVE: The aim and objective of this study was to find the immunostimulant and immunomodulatory effect of T. ammi seed extracts. METHODS: Seeds of T. ammi were extracted using three different solvents n-hexane, chloroform, and methanol by using soxhlet apparatus. To assess the immunomodulatory effect, delayed-type hypersensitivity (DTH) assay method was used and by the DTH assay, the effect of T. ammi on the skin thickness of rats was estimated. To find the exact dose for administration, acute toxicity test was performed using crude methanolic extract at a dose of 400, 800, 1600, and 3200mg/kg. After acute toxicity test, 500mg/kg dose was determined as safe for therapeutic effect and immunomodulatory effect was evaluated at this dose. Dose of 500mg/kg was administered to Wistar rats daily for 14 days and skin thickness of rats was measured at 24, 48, and 72h. RESULTS: Results were obtained from six groups of rats, which were positive control group, negative control group, and the groups receiving the test drugs. Standard drug was the combination of sodium selenite, vitamin E, and sodium chloride and it showed more positive results as compared to that of test drug. Furthermore, among the three extracts, methanol extract showed more effectiveness on skin thickness. CONCLUSION: There was a meaningful difference was observed between the skin thickness of rats which shows that T. ammi have good immunomodulatory as well as immunostimulant activity.

Use of Oral Cleaning Devices and Their Perceived Benefits among Malaysians in Kuala Lumpur and Johor Bahru: An Exploratory Structured Approach.

BACKGROUND AND OBJECTIVES: Various devices have been used to maintain oral hygiene. These include toothbrush and toothpaste, mouthwash, dental floss, miswak, and toothpick. This study attempts to investigate the use of various oral cleaning devices and their perceived benefits among Malaysians. METHODS: A quantitative cross-sectional study conducted in two different cities of Malaysia. A convenience sampling approach was adopted. A total of 787 participants agreed to participate in the current research. A validated questionnaire translated into national language was used for data collection. STATISTICAL ANALYSIS USED: Data analysis was performed using Statistical Package for Social Sciences version 20. RESULTS: About 302 respondents were in the age range of 18 - 25 years old (38.4%). There were marginally more females (55.7%) than males (44.3%). Although 99.9% of the participants used a toothbrush, a significant majority (n = 590, 75%) used more than a single device to maintain their oral hygiene. Only 311 respondents knew that toothpicks were inappropriate to use to remove food between teeth and gums, while a majority (n = 592, 75.2%) did not realize that some mouthwashes can stain the teeth. Less than half (42.1%) knew that improper use of miswak might harm the teeth. CONCLUSIONS: Although their oral hygiene behaviors are relatively at a higher level, their perceived oral health benefits did not compare well.

Correlation of FT-IR Fingerprint and α-Glucosidase Inhibitory Activity of Salak (Salacca zalacca) Fruit Extracts Utilizing Orthogonal Partial Least Square.

Salak fruit (Salacca zalacca), commonly known as snake fruit, is used indigenously as food and for medicinal applications in Southeast Asia. This study was conducted to evaluate the α-glucosidase inhibitory activity of salak fruit extracts in correlation to its Fourier transform infrared spectroscopy (FT-IR) fingerprint, utilizing orthogonal partial least square. This calibration model was applied to develop a rapid analytical method tool for quality control of this fruit. A total of 36 extracts prepared with different solvent ratios of ethanol⁻water (100, 80, 60, 40.20, 0% v/v) and their α-glucosidase inhibitory activities determined. The FT-IR spectra of ethanol⁻water extracts measured in the region of 400 and 4000 cm−1 at a resolution of 4 cm−1. Multivariate analysis with a combination of orthogonal partial least-squares (OPLS) algorithm was used to correlate the bioactivity of the samples with the FT-IR spectral data. The OPLS biplot model identified several functional groups (C⁻H, C=O, C⁻N, N⁻H, C⁻O, and C=C) which actively induced α-glucosidase inhibitory activity.

α-Glucosidase Inhibitory Activity of Selected Malaysian Plants.

Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs) from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.

Moxibustion (Artemisia Plant at Acupuncture Point) as Alternative Therapy in Hypertension: A Promising Approach.

Hypertension is a pathological condition in which the blood pressure is higher than under normal physiological conditions, i.e., 140/90 mmHg or higher. Blood pressure is measured as the force exerted by the blood pumped by the heart against the walls of arteries (aorta) and distributed throughout the body. Use of complementary and alternative medicine as a cure for hypertension is a common phenomenon because of the high risk of cardiovascular complications and kidney diseases caused by conventional Western medicine. It is reported that high blood pressure causes ~49% of myocardial infarction and 62% of strokes. Effective treatment of hypertension is restricted by adverse effects and cost of the medication. Moxibustion is the application of heat by burning a small bundle of tightly bound moxa, to targeted acupoint, and sometimes it is used along with acupuncture. Encouraging results have been reported on randomized trials indicating the efficacy of moxibustion. But more controlled clinical trials are required to further establish the potential efficacy of moxibustion approach in hypertension.

Use of Complementary and Alternative Medicine among Osteoarthritic Patients: A Review.

INTRODUCTION: One of the most important indications of complementary and alternative medicines (CAM) is in arthritis. The popularity of CAM in arthritis is consistently on the rise because of the potential side effects of the conventional therapy (Methotrexate) of arthritis. In view of this, it was important to summarize the information, for healthcare professionals and the patients, about the safety and effectiveness of various CAM use in arthritis. MATERIALS AND METHODS: This comprehensive review is based on the content derived through a thorough literature search using 5 electronic databases such as Science direct, Springer link, PubMed, Jet P and Google scholar. Equivalent terms in thesauruses or Medical Subject Heading (MeSH) browsers were used whenever possible. We included all the articles those are used CAM medications for the treatment of arthritis around the globe and searched for the required articles published in English in peer reviewed journals from January 1999 to February 2014. Reports were then arranged and analysed on the basis of country specific studies. RESULTS: Initially, a total of 156 articles were retrieved, after further screening, 27 articles were selected according to meet objectives of the study and those articles which did not qualify, were excluded. Seventeen appropriate studies were finally included in the review. Indeed most of the studies that fulfilled the objective of this review were carried out in US (n=8, 47%), then in India (n=2, 11.76%), UK (n=1, 5.88%), Canada (n=1, 5.88%), Australia (n=1, 5.88%), Korea (n=1, 5.88%), Thailand (n=1, 5.88%), Turkey (n=1, 5.88%) and Malaysia (n=1, 5.88%). CONCLUSION: The review revealed that family, friend, past experiences and lack of effectiveness of conventional therapy are the major factors that influenced patients' decision of initiating and persisting with CAM therapy. The review highlighted the need to conduct future studies by using some more specific health related outcome measures.

The use of psychotropic substances among students: The prevalence, factor association, and abuse.

This detailed review analyzed the previously published studies related to the prevalence of psychotropic substances use, associated factors, and the misuse of the psychotropics among students. A comprehensive literature search covering six databases was performed. References from published articles and reports were extracted. This helped in identifying the available information on the use of psychotropic drugs. A total of 16 articles were included in this review. There is an upsurge of using psychotropics with the preceding years. More students are exposed to the risk of using psychotropic substances due to the multiple factors like stress, increased academic workload, etc. The misuse is found to be common with prescribed psychotropic substances. Students need to be aware of the bad outcomes of using psychotropic substances. Participation of every stakeholder to curb this menace needs to be emphasized. More extensive studies are required to know about the increasing prevalence, factors, and misuse of psychotropics.

Analysis of L-citrulline and L-arginine in Ficus deltoidea leaf extracts by reverse phase high performance liquid chromatography.

BACKGROUND: Ficus deltoidea (FD) is one of the native plants widely distributed in several countries in Southeast Asia. Previous studies have shown that FD leaf possess antinociceptive, wound healing and antioxidant properties. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids and flavonoids. OBJECTIVE: The aim was to develop a reverse phase high-performance liquid chromatography method with ultraviolet detection that involves precolumn derivatisation with O-phthaladehyde for simultaneous analysis of two amino acids L-citrulline and L-arginine in FD leaf extracts. MATERIALS AND METHODS: An isocratic elution program consisting of methanol: acetonitrile: Water at 45:45:10 v/v (solvent A) and 0.1 M phosphate buffer pH 7.5 (solvent B) at A: B v/v ratio of 80:20 on Zorbax Eclipse C18 SB-Aq column (250 × 4.6 mm, 5 µm) were used. The flow rate was set at 1 ml/min and detection was carried out at 338 nm with 30 min separation time. RESULTS: Good linearity for L-citrulline and L-arginine was obtained in the range 0.1-1000 µg/ml at R (2) ≥ 0.998. The limit of detection and limit of quantification values for both L-citrulline and L-arginine were 1 and 5 µg/ml, respectively. The average of recoveries was in the range 94.94-101.95%, with relative standard deviation (%RSD) less than 3%. Intra- and inter-day precision was in the range 96.36-102.43% with RSD less than 2%. CONCLUSION: All validation parameters of the developed method indicate the method is reliable and efficient for simultaneous determination of L-citrulline and L-arginine for routine analysis of FD.

Role of complementary and alternative medicine in geriatric care: A mini review.

Since time immemorial homo sapiens are subjected to both health and diseases states and seek treatment for succor and assuagement in compromised health states. Since last two decades the progressive rise in the alternative form of treatment cannot be ignored and population seems to be dissatisfied with the conventional treatment modalities and therefore, resort to other forms of treatment, mainly complementary and alternative medicine (CAM). The use of CAM is predominantly more popular in older adults and therefore, numerous research studies and clinical trials have been carried out to investigate the effectiveness of CAM in the management of both communicable and non-communicable disease. In this current mini review, we attempt to encompass the use of CAM in chronic non-communicable diseases that are most likely seen in geriatrics. The current review focuses not only on the reassurance of good health practices, emphasizing on the holistic development and strengthening the body's defense mechanisms, but also attempts to construct a pattern of self-care and patient empowerment in geriatrics. The issues of safety with CAM use cannot be sidelined and consultation with a health care professional is always advocated to the patient. Likewise, responsibility of the health care professional is to inform the patient about the safety and efficacy issues. In order to substantiate the efficacy and safety of CAMs, evidence-based studies and practices with consolidated standards should be planned and executed.

Understanding of antibiotic use and resistance among final-year pharmacy and medical students: a pilot study.

INTRODUCTION: This study is aimed to investigate the understanding of antibiotic use and antibiotic resistance and its correlate factors among final-year medical and pharmacy students at International Islamic University Malaysia (IIUM). METHODOLOGY: This was a cross-sectional study. The study instrument was developed by extensive literature search and was subjected to face validity and content validity to medical and pharmacy academics. A pilot study was conducted to ascertain the reliability coefficient. Data was entered to SPSS version 17 and descriptive and inferential statistics were applied. RESULTS: A total of 123 questionnaires were included in the study. Out of 123 respondents, 58.5% (n = 72) were final-year medical students, while 41.5% (n = 51) were final-year pharmacy students. The majority of the respondents showed adequate knowledge regarding the course contents related to antibiotics (n = 116; 94.3%). Almost all the respondents correctly reported the difference between bactericidal and bacteriostatic antibiotics. Only 15.4% (n = 19) and 27.6% (n = 34) of students were able to recognize Streptococcus pyogenes as non-pencillin resistant bacterium and Enterococcus as vancomycin-resistant bacterium, respectively. CONCLUSIONS: The students showed good understanding regarding antibiotic resistance. In comparison to medical students, pharmacy students showed better understanding and more adequate knowledge, as the mean value for each domain was slightly higher for pharmacy students. Extensively improving the curriculum and educating healthcare professionals, especially physicians and pharmacists, right from the time of their educational training can inculcate a moral responsibility toward the judicious use of antibiotics, which can serve to eradicate antibiotic resistance.

Reasons of using complementary and alternative medicines (CAM) among elderly Malaysians of Kuala Lumpur and Selangor states: An exploratory study.

BACKGROUND: This study is aimed to explore the types of CAM and reasons of using CAM among elderly Malaysians. METHOD: This cross-sectional study was conducted on a sample of 256 conveniently selected elderly Malaysians who were residing in the states of Selangor and Kuala Lumpur. A pre-validated interview-administered questionnaire was used to gather information. Data was entered into PASW version 18 and analyzed. RESULTS: A total of 256 questionnaires were included in the study. A response rate of 64% was achieved. Out of 256 respondents, 92 (35.9%) were male while 164 (64.1%) were female. More than half of the respondents (n = 141; 55.1%) agreed that CAM is more effective than allopathic medicine. Chinese respondents showed strong belief in the effectiveness of CAM. In terms of safety of CAM, close to three quarters of respondents (n = 178; 69.5%) believed that CAM is safer than allopathic medicine. A large majority of respondents agreed that CAM has less side effects compared to allopathic medicine (n = 201; 78.5%) and also agreed that CAM is good to maintain overall health and wellbeing (n = 212; 82.8%). A majority of the respondents expressed that they use CAM because allopathic medicine is less effective (n = 113; 44.1%). CONCLUSION: The current study reflects the reasons of using CAM among lay public from different ethnicities. There are no reports of adverse effects related to CAM use. Future approaches should be intended for awareness campaigns for consumers, highlighting safety profile of CAM and as well as forbidding their use without the consultation of healthcare professional.

Potent α-glucosidase and α-amylase inhibitory activities of standardized 50% ethanolic extracts and sinensetin from Orthosiphon stamineus Benth as anti-diabetic mechanism.

BACKGROUND: In the present study, we tested a 50% ethanolic extract of Orthosiphon stamineus plants and its isolated bioactive compound with respect to their α-glucosidase and α-amylase inhibitory activities. METHODS: Bioactive flavonoid sinensetin was isolated from 50% ethanolic extract of Orthosiphon stamineus. The structure of this pure compound was determined on the NMR data and the α-glucosidase and α-amylase inhibitory activities of isolated sinensetin and 50% ethanolic extract of Orthosiphon stamineus were evaluated. RESULTS: In vitro studies of a 50% ethanolic extract of O. stamineus and the isolated sinensetin compound showed inhibitory activity on α-glucosidase (IC50: 4.63 and 0.66 mg/ml, respectively) and α-amylase (IC50: 36.70 mg/ml and 1.13 mg/ml, respectively). Inhibition of these enzymes provides a strong biochemical basis for the management of type 2 diabetes via the control of glucose absorption. CONCLUSION: Alpha-glucosidase and α-amylase inhibition could the mechanisms through which the 50% ethanolic extract of O. stamineus and sinensetin exert their antidiabetic activity, indicating that it could have potential use in the management of non-insulin-dependent diabetes.

Simultaneous determination of secondary metabolites from Vinca rosea plant extractives by reverse phase high performance liquid chromatography.

BACKGROUND: Vinca rosea (Apocynaceae) is one of the most important and high value medicinal plants known for its anticancer alkaloids. It is the iota of the isolated secondary metabolites used in chemotherapy to treat diverse cancers. Several high performance liquid chromatography (HPLC) methods have been developed to quantify the active alkaloids in the plant. However, this method may serve the purpose in quantification of V. rosea plant extracts in totality. OBJECTIVE: To develop and validate the reverse phase (RP)-HPLC method for simultaneous determination of secondary metabolites, namely alkaloids from V. rosea plant extracts. MATERIALS AND METHODS: The quantitative determination was conducted by RP-HPLC equipped with ultraviolet detector. Optimal separation was achieved by isocratic elution with mobile phase consisting of methanol:acetonitrile:ammonium acetate buffer (25 mM) with 0.1% triethylamine (15:45:40 v/v) on a column (Zorbax Eclipse plus C(18), 250 mm % 4.6 mm; 5 µm). The standard markers (vindoline, vincristine, catharanthine, and vinblastine) were identified by retention time and co-injected with reference standard and quantified by external standard method at 297 nm. RESULTS: The precision of the method was confirmed by the relative standard deviation (R.S.D.), which was lower than 2.68%. The recoveries were in the range of 98.09%-108%. The limits of detection (LOD) for each marker alkaloids were lower than 0.20 µg. Different parts of the V. rosea extracts shows different concentrations of markers, flower samples were high in vinblastine content, while methanol extract from the leaves contains all the four alkaloids in good yield, and there is no significant presence of markers in water extracts. CONCLUSION: HPLC method established is appropriate for the standardization and quality assurance of V. rosea plant extracts.

Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta.

AIM OF THE STUDY: The present study was aimed to investigate the pharmacological basis for the use of Loranthus ferrugineus in hypertension. MATERIALS AND METHODS: Loranthus ferrugineus methanol extract (LFME) was obtained using Soxhelt extractor and then successively fractionated using chloroform, ethyl acetate and n-butanol. The n-butanol fraction of LFME (NBF-LFME) was studied using isolated rat thoracic aorta. RESULTS: NBF-LFME (1.0 x 10(-5) to 3.0mg/ml) was found to be the most potent to concentration-dependently relax the endothelium-intact phenyephrine (PE, 1 microM)- and high K(+) (80 mM)-precontracted rat aortic rings. Removal of the endothelium completely abolished the vascular relaxing properties of NBF-LFME. Pretreatment with atropine (1 microM), L-NAME (10 microM), indomethacin (10 microM) and methylene blue (10 microM) significantly blocked NBF-LFME-mediated relaxation. Endothelium-dependent and -independent relaxations induced by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were significantly enhanced in aortic rings pretreated with NBF-LFME when compared to those observed in control aortic rings. On the contrary, glibenclamide (10 microM), propranolol (1 microM) and prazosin (0.01 microM) did not alter NBF-LFME-induced relaxation. CONCLUSIONS: The results suggest that NBF-LFME induced vascular relaxation by stimulating muscarinic receptors, activating the endothelium-derived nitric oxide-cGMP-relaxant pathway, promoting prostacyclin release and/or possibly through its ability to lengthen the released nitric oxide half-life. The present data further supports previous in vivo findings and explain the traditional use of Loranthus ferrugineus as an anti-hypertensive agent.