BMC Complementary and Alternative Medicine
1472-6882
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Các bài báo tiêu biểu
Dose escalation of a curcuminoid formulation Abstract
Background
Curcumin is the major yellow pigment extracted from turmeric, a commonly-used spice in India and Southeast Asia that has broad anticarcinogenic and cancer chemopreventive potential. However, few systematic studies of curcumin's pharmacology and toxicology in humans have been performed.
Methods
A dose escalation study was conducted to determine the maximum tolerated dose and safety of a single dose of standardized powder extract, uniformly milled curcumin (C
3
Complex ™, Sabinsa Corporation). Healthy volunteers were administered escalating doses from 500 to 12,000 mg.
Results
Seven of twenty-four subjects (30%) experienced only minimal toxicity that did not appear to be dose-related. No curcumin was detected in the serum of subjects administered 500, 1,000, 2,000, 4,000, 6,000 or 8,000 mg. Low levels of curcumin were detected in two subjects administered 10,000 or 12,000 mg.
Conclusion
The tolerance of curcumin in high single oral doses appears to be excellent. Given that achieving systemic bioavailability of curcumin or its metabolites may not be essential for colorectal cancer chemoprevention, these findings warrant further investigation for its utility as a long-term chemopreventive agent.
Tập 6 Số 1 - 2006
Antioxidant and free radical scavenging activity of Spondias pinnata Abstract Background Many diseases are associated with oxidative stress caused by free radicals. Current research is directed towards finding naturally-occurring antioxidants of plant origin. The aim of the present study was to evaluate thein vitro antioxidant activities ofSpondias pinnata stem bark extract. Methods A 70% methanol extract ofSpondias pinnata stem bark was studiedin vitro for total antioxidant activity, for scavenging of hydroxyl radicals, superoxide anions, nitric oxide, hydrogen peroxide, peroxynitrite, singlet oxygen and hypochlorous acid, and for iron chelating capacity, reducing power, and phenolic and flavonoid contents. Results The extract showed total antioxidant activity with a trolox equivalent antioxidant concentration (TEAC) value of 0.78 ± 0.02. The IC50 values for scavenging of free radicals were 112.18 ± 3.27 μg/ml, 13.46 ± 0.66 μg/ml and 24.48 ± 2.31 μg/ml for hydroxyl, superoxide and nitric oxide, respectively. The IC50 for hydrogen peroxide scavenging was 44.74 ± 25.61 mg/ml. For the peroxynitrite, singlet oxygen and hypochlorous acid scavenging activities the IC50 values were 716.32 ± 32.25 μg/ml, 58.07 ± 5.36 μg/ml and 127.99 ± 6.26 μg/ml, respectively. The extract was found to be a potent iron chelator with IC50 = 66.54 ± 0.84 μg/ml. The reducing power was increased with increasing amounts of extract. The plant extract (100 mg) yielded 91.47 ± 0.004 mg/ml gallic acid-equivalent phenolic content and 350.5 ± 0.004 mg/ml quercetin-equivalent flavonoid content. Conclusion The present study provides evidence that a 70% methanol extract ofSpondias pinnata stem bark is a potential source of natural antioxidants.
Tập 8 Số 1 - 2008
Antibacterial activity of Thymoquinone, an active principle of Nigella sativa and its potency to prevent bacterial biofilm formation
Tập 11 Số 1 - 2011
Comparison of Crocus sativus L. and imipramine in the treatment of mild to moderate depression: A pilot double-blind randomized trial [ISRCTN45683816]
Tập 4 Số 1 - 2004
Potent α-amylase inhibitory activity of Indian Ayurvedic medicinal plants Abstract
Background
Indian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic α-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents.
Methods
Analysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc. ) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting≥ 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry).
Results
Of the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz ., seeds of Linum usitatisumum (540 μgml-1 ), leaves of Morus alba (1440 μgml-1 ) and Ocimum tenuiflorum (8.9 μgml-1 ). Acarbose as the standard inhibitor exhibited an IC50 (half maximal inhibitory concentration)value of 10.2 μgml-1 . Phytochemical analysis revealed the presence of alkaloids, tannins, cardiac glycosides, flavonoids, saponins and steroids with the major phytoconstituents being identified by GC-MS.
Conclusions
This study endorses the use of these plants for further studies to determine their potential for type 2 diabetes management. Results suggests that extracts of Linum usitatisumum , Morus alba and Ocimum tenuiflorum act effectively as PPA inhibitors leading to a reduction in starch hydrolysis and hence eventually to lowered glucose levels.
- 2011
Antibacterial activities of selected edible plants extracts against multidrug-resistant Gram-negative bacteria Abstract
Background
In response to the propagation of bacteria resistant to many antibiotics also called multi-drug resistant (MDR) bacteria, the discovery of new and more efficient antibacterial agents is primordial. The present study was aimed at evaluating the antibacterial activities of seven Cameroonian dietary plants (Adansonia digitata, Aframomum alboviolaceum, Aframomum polyanthum, Anonidium. mannii, Hibiscus sabdarifa, Ocimum gratissimum and Tamarindus indica ).
Methods
The phytochemical screening of the studied extracts was performed using described methods whilst the liquid broth micro dilution was used for all antimicrobial assays against 27 Gram-negative bacteria.
Results
The results of the phytochemical tests indicate that all tested extracts contained phenols and triterpenes, other classes of chemicals being selectively present. The studied extracts displayed various degrees of antibacterial activities. The extracts of A. digitata, H. sabdarifa, A. polyanthum, A. alboviolaceum and O. gratissimum showed the best spectra of activity, their inhibitory effects being recorded against 81.48%, 66.66%, 62.96%, 55.55%, and 55.55% of the 27 tested bacteria respectively. The extract of A. polyanthum was very active against E. aerogenes EA294 with the lowest recorded minimal inhibitory concentration (MIC) of 32 μg/ml.
Conclusion
The results of the present work provide useful baseline information for the potential use of the studied edible plants in the fight against both sensitive and MDR phenotypes.
Tập 13 Số 1 - 2013
Comparative study of the antioxidant and reactive oxygen species scavenging properties in the extracts of the fruits of Terminalia chebula, Terminalia belerica and Emblica officinalis Abstract
Background
Cellular damage caused by reactive oxygen species (ROS) has been implicated in several diseases, and hence natural antioxidants have significant importance in human health. The present study was carried out to evaluate the in vitro antioxidant and reactive oxygen species scavenging activities of Terminalia chebula , Terminalia belerica and Emblica officinalis fruit extracts.
Methods
The 70% methanol extracts were studied for in vitro total antioxidant activity along with phenolic and flavonoid contents and reducing power. Scavenging ability of the extracts for radicals like DPPH, hydroxyl, superoxide, nitric oxide, hydrogen peroxide, peroxynitrite, singlet oxygen, hypochlorous acid were also performed to determine the potential of the extracts.
Results
The ability of the extracts of the fruits in exhibiting their antioxative properties follow the order T. chebula > E. officinalis > T. belerica . The same order is followed in their flavonoid content, whereas in case of phenolic content it becomes E. officinalis > T. belerica > T. chebula . In the studies of free radicals' scavenging, where the activities of the plant extracts were inversely proportional to their IC50 values, T. chebula and E. officinalis were found to be taking leading role with the orders of T. chebula > E. officinalis > T. belerica for superoxide and nitric oxide, and E. officinalis > T. belerica > T. chebula for DPPH and peroxynitrite radicals. Miscellaneous results were observed in the scavenging of other radicals by the plant extracts, viz., T. chebula > T. belerica > E. officinalis for hydroxyl, T. belerica > T. chebula > E. officinalis for singlet oxygen and T. belerica > E. officinalis > T. chebula for hypochlorous acid. In a whole, the studied fruit extracts showed quite good efficacy in their antioxidant and radical scavenging abilities, compared to the standards.
Conclusions
The evidences as can be concluded from the study of the 70% methanol extract of the fruits of Terminalia chebula , Terminalia belerica and Emblica officinalis , imposes the fact that they might be useful as potent sources of natural antioxidant.
- 2010