[show abstract][hide abstract] ABSTRACT: Cajanus cajan L, a member of the family Fabaceae, was identified from the Nigerian antimalarial ethnobotany as possessing antimalarial properties. The bioassay-guided fractionation of the crude methanol extract of C. cajan leaves was done in vitro using the multiresistant strain of Plasmodium falciparum (K1) in the parasite lactate dehydrogenase assay. Isolation of compound was achieved by a combination of chromatographic techniques, while the structure of the compound was elucidated by spectroscopy. This led to the identification of a cajachalcone, 2',6'-dihydroxy-4-methoxy chalcone, as the biologically active constituent from the ethyl acetate fraction. Cajachalcone had an IC50 value of 2.0 μ g/mL (7.4 μ M) and could be a lead for anti-malarial drug discovery.
Journal of Parasitology Research 01/2013; 2013:703781.
[show abstract][hide abstract] ABSTRACT: The roots of Caesalpinia benthamiana (synonym. Mezoneuron benthamianum) are considered to be an effective remedy in Ghana for the management of skin diseases and wounds. Bioactivity-guided fractionation of the chloroform extract of the root bark of the plant has resulted in the isolation of a novel cassane-type furanoditerpenoid, designated as benthaminin 3. The structure of the compound was elucidated by the use of spectroscopic techniques. The antibacterial activity of the compound has been assessed using the microdilution assay method. The lowest MIC (63μg/mL) was recorded against Staphylococcus aureus and Bacillus subtilis. The compound was also observed to have a mild inhibitory effect against resistant strains of bacteria including methicillin-resistant S. aureus, tetracyline-resistant S.
aureus and erythromycin-resistant S. aureus with MIC values greater than 1000μg/mL.
Journal of Pharmacy and Nutrition Sciences. 01/2012; 1(2):1-6.
[show abstract][hide abstract] ABSTRACT: Ethnobotany encompasses the cultural uses of plants by humans, including their uses as medicines (ethnopharmacology). The reputed medicinal properties of plants have been documented for centuries in different cultures, and there are many plant species that have been traditionally used for memory disorders, which are now being explored to determine any scientific basis for their reputed uses. Plants have been a valuable source of drugs, and phytochemicals have also provided templates to develop synthetic drugs (e.g. rivastigmine, based on the chemical structure of physostigmine from Physostigma venenosum). Although drug development from botanical origin is one aim, the use of plants as herbal medicines is still popular. Scientific evidence for efficacy and safety has been explored for many species, although more research is needed, particularly to identify active phytochemicals to produce standardised herbal products. For Alzheimer's disease (AD) there are relatively few drugs available to treat symptoms, and there is a lack of successful therapies that modulate disease progression. Since two of the currently licensed drugs for AD are based on natural products (galantamine and rivastigmine), it is not surprising that many plants are now being investigated as a potential source of new therapies for AD. This review discusses those plants that have ethnobotanical uses suggestive of alleviation of AD pathology and associated symptoms, for cognitive and for behavioural and psychological symptoms of dementia (BPSD). An emphasis is placed on those plants that have shown some promising effects in clinical studies with dementia patients (e.g. Crocus sativus, Ginkgo biloba, Salvia species), but other plants and their phytochemicals showing relevant mechanistic effects for AD (e.g. Bacopa monnieri, Centella asiatica, Ptychopetalum olacoides) are also discussed.
Current Alzheimer research 01/2012; 9(1):67-85. · 4.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: ETHOPHARMACOLOGICAL RELEVANCE: Coreopsis tinctoria flowering tops infusion is traditionally used in Portugal for treating the symptoms of diabetes. Recent studies have revealed its antihyperglycemic activity when administered for 3 weeks to a STZ-induced glucose intolerance model in the rat and glucose tolerance regain was even clearer and pancreatic function recovery was achieved when administering Coreopsis tinctoria flavonoid-rich AcOEt fraction. In this study we aimed to evaluate the protective effect of Coreopsis tinctoria flowering tops aqueous extract, AcOEt fraction and the pure compounds marein and flavanomarein, against beta-cell injury, in a mouse insulinoma cell line (MIN6) challenged with pro-oxidant tert-butyl-hydroperoxide (tBHP) or cytokines.
The protective effects of Coreopsis tinctoria flowering tops extracts and pure compounds were evaluated through pre-incubating MIN6 cells with samples followed by treatment with tBHP (400 μM for 2 h) after which viability was determined through ATP measurements. In order to assess whether plant extracts were involved in decreasing reactive oxygen species, superoxide anion production was determined through a lucigenin-enhanced chemiluminescent method. Lastly, the direct influence of Coreopsis tinctoria extracts and main compounds on cell survival/apoptosis was determined measuring caspase 3 and 7 cleavage induced by cytokines.
Coreopsis tinctoria flowering tops extracts (25-100 μg/mL) and pure compounds (200-400 μM), when pre-incubated with MIN6 cells did not present any cytotoxicity, instead they increased cell viability in a dose dependent manner when challenged with tBHP. Treatment with this pro-oxidant also showed a rise in superoxide radical anion formation in MIN6 cells. This increase was significantly reduced by treatment with superoxide dismutase enzyme (SOD) but not by pre-treatment with Coreopsis tinctoria flowering tops extracts. Caspase 3/7 activation measurements show that Coreopsis tinctoria flowering tops extracts, as well as marein and flavanomarein, significantly inhibit apoptosis.
Coreopsis tinctoria extracts and pure compounds show cytoprotection that seems to be due to inhibition of the apoptotic pathway, and not through a decrease on superoxide radical production.
Journal of ethnopharmacology 11/2011; 139(2):485-92. · 2.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: Medicinal plants belonging to the Caesalpinia (Ceasalpiniaceae) genus are widely distributed in most tropical
countries and have been frequently employed in folkloric medicine worldwide in the treatment of various ailments including
skin diseases, malaria, cancer, infections, erectile dysfunction, pain and wounds. Interest in this genus has increased
considerably over the years and the biological properties of different phytoconstituents, such as the cassane-type diterpenoid
isolates, have been studied. Over the past 60 years, a number of cassane-type diterpenoids have been isolated from species
of this genus and some of them possess interesting biological activities. Recently, three novel cassane-type diterpenoids,
benthaminin 1, 2 and 3, which demonstrate antimicrobial and antioxidant properties, have been isolated from Caesalpinia
benthamiana growing in Ghana. This review seeks among other things to collate all these isolated compounds, recognising
their diversity and commenting on their relevance as bioactive compounds.
[show abstract][hide abstract] ABSTRACT: The importance of cyclic compounds as anti-cancer and anti-viral agents has been recognized for some time. We have studied a series of macrocyclic amide derivatives for activity against HIV infection of T lymphocytes in-vitro.Compounds containing aromatic rings and sulphur atoms were generally active, however the selectivity was greatly enhanced when two benzene rings were bridged by a disulphide linkage to produce 7-methyl-6,7,8,9-tetrahydrodibenzo[c,k][1,2,6,9]-dithiadiazacyclodode-cine-5,10-dione (SRR-SB3). This compound was studied in detail with different cell and virus infections including macrophages and chronically infected H9 cells. It was active with an EC50 (the dose affording 50% inhibition of infection) of 0.05—0.1 μgmL−1 and a TC50 (concentration reducing uninfected cell growth by 50%) of 50μmL−1. The compound did not inhibit protease, but seemed to act by inhibiting maturation of progeny virus, by interfering with precursor protein processing. It was synergistic with AZT (3′-azido-3′-deoxythymidine; zidovudine) when tested in-vitro.The unusual mode of action and potent anti-HIV activity in T lymphocytes and macrophages makes this compound a potential candidate for clinical trials.
Journal of Pharmacy and Pharmacology. 04/2011; 50(12):1339 - 1342.
[show abstract][hide abstract] ABSTRACT: This study evaluated the in vitro inhibition of carbohydrate-hydrolysing enzymes, the stimulation of insulin secretion, and the in vivo metabolic effects in mice of Citrus medica L. cv Diamante peel extract. The quantitative analysis of selected phytochemicals were determined to investigate their relationship with the biological activities. Citrus extract exhibited an inhibitory activity against both α-amylase and α-glucosidase with IC50 values of 258.7 and 263.2 μg/ml, respectively. Measurements of the effects of peel extract on the mouse insulinoma MIN6 β-cells indicated that it did exert direct stimulatory effects on the exocytotic release of insulin in a concentration-dependent manner. The supplementation of the C. medica cv Diamante was able to reduce plasma glucose (GLU) concentration and lowered the levels of plasma cholesterol (COL) and triglycerides (TG). The obtained results underline the potential health benefits as a result of consuming C. medica cv Diamante and suggest that it could be used as new potential source with functional properties for food or nutraceutical products.
[show abstract][hide abstract] ABSTRACT: Infusions of Coreopsis tinctoria Nutt. flowering tops have been used traditionally in Portugal to control hyperglycaemia and a previous study revealed that daily administration of the infusion during a 3-week period promoted the recovery of glucose tolerance by a mechanism different from inhibition of glucose absorption and direct promotion of insulin secretion. We know report the study of the ethyl acetate fraction of Coreopsis tinctoria flowers infusion aiming to confirm flavonoids as bioactive metabolites. To give one step forward into the antihyperglycaemic mechanism of action of this traditionally used plant we also studied the activity of Coreopsis tinctoria flavonoids on the pancreatic function of glucose-intolerant rats. A standard antioxidant, Trolox, was also studied for comparative purposes as the antioxidant mechanism has been frequently purposed as one of the mechanisms mediating antihyperglycaemic effects of flavonoid-rich extracts.
Thirteen compounds, mainly of flavanone and chalcone flavonoidal type, have been identified in this fraction by HPLC-DAD-ESI-MS/MS, and the major one (marein) quantified by HPLC-UV. The fraction (125 mg containing 20 mg of marein/kg b.w.) and Trolox (50 mg/kg b.w.) were administered daily by oral gavage to normal and STZ (40 mg/kg b.w.)-induced glucose-intolerant Wistar rats for 3 weeks. Blood glucose levels were measured weekly by Oral Glucose Tolerance Test. Pancreatic function was evaluated by plasma lipase of treated and non-treated glucose-tolerant and- intolerant rats after the 3-week treatment period.
After 2 weeks oral treatment with Coreopsis tinctoria AcOEt fraction the animals were no longer glucose-intolerant, an effect maintained over the remaining experimental period. Additionally, plasma lipase values of glucose-intolerant animals treated with the AcOEt fraction (13.5 ± 0.84 U/L) showed a clear reduction when compared with the glucose-intolerant group (34.60 ± 1.76 U/L; P<0.001) and normoglycaemic control (8.35 ± 0.69 U/L) demonstrating recovery of pancreatic function. On the other hand, treatment with standard antioxidant Trolox had no effect on glucose homeostasis of glucose-intolerant rats. The oral treatment with Coreopsis tinctoria fraction caused no hepatotoxicity, as determined by blood alanine and aspartate transaminases, and had also no effect on glucose homeostasis and pancreatic function of normal rats.
AcOEt fraction, containing the same amount of marein as the infusion, promoted glucose tolerance regain in the rats more quickly, which means that the bioactivity is probably due to the several flavonoids present in Coreopsis tinctoria extracts and not to marein alone. The results also strongly suggest that these compounds act by promoting pancreatic cell function recovery from STZ-induced injury, possibly through a mechanism of action other than merely antioxidant mediated.
Journal of ethnopharmacology 11/2010; 132(2):483-90. · 2.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: Novel lupane triterpenoids from Paullinia pinnata L., a Ghanaian plant traditionally used for wound healing, were examined for in-vitro fibroblast stimulatory activity using the 142BR cell line.
Bioactivity-guided isolation of the crude extract of P. pinnata L. was carried out in order to determine the nature of the compounds responsible for the stimulation of fibroblast proliferation.
Two novel compounds were isolated and characterised, namely, 6beta-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-one (1) and 6beta-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-ol (2), together with three known compounds, friedelin (3), beta-sitosterol (4) and beta-sitosterol-3-D-glucoside (5). The methanol extract of the roots of P. pinnata caused a significant in-vitro increase (94%) in 142BR cell line proliferation at 20 microg/ml compared with the control.
Compounds 1 and 2, which were isolated from the active chloroform fraction, have not previously been reported and showed a dose-dependent increase in proliferation of 142BR cells up to 3 microM; compounds 3, 4 and 5 had no effect on the 142BR cell line at the concentrations tested.
The Journal of pharmacy and pharmacology. 05/2010; 62(5):663-8.
[show abstract][hide abstract] ABSTRACT: There is only scant literature on the anticancer components of medicinal plants from Nigeria, yet traditional healers in the area under study claim to have been managing the disease in their patients with some success using the species studied.
To document plants commonly used to treat cancer in South-western Nigeria and to test the scientific basis of the claims using in vitro cytotoxicity tests.
Structured questionnaires were used to explore the ethnobotanical practices amongst the traditional healers. Methanol extracts of the most common species cited were screened for cytotoxicity using the sulforhodamine B (SRB) assay in both exposure and recovery experiments. Three cancer cell lines (human breast adenocarcinoma cell line MCF-7, human large cell lung carcinoma cell line COR-L23 and human amelanotic melanoma C32) and one normal cell line (normal human keratinocytes SVK-14) were used for the screening of the extracts and the fractions obtained. The extract of Cajanus cajan showed considerable activity and was further partitioned and the dichloromethane fraction was subjected to preparative chomatography to yield six compounds: hexadecanoic acid methyl ester, alpha-amyrin, beta-sitosterol, pinostrobin, longistylin A and longistylin C. Pinostrobin and longistylins A and C were tested for cytotoxicity on the cancer cell lines. In addition, an adriamycin-sensitive acute T-lymphoblastic leukaemia cell line (CCRF-CEM) and its multidrug-resistant sub-line (CEM/ADR5000) were used in an XTT assay to evaluate the activity of the pure compounds obtained.
A total of 30 healers from S W Nigeria were involved in the study. 45 species were recorded with their local names with parts used in the traditional therapeutic preparations. Cytotoxicity (IC(50) values less than 50 microg/mL) was observed in 5 species (Acanthospermum hispidum, Cajanus cajan, Morinda lucida, Nymphaea lotus and Pycnanthus angolensis). Acanthospermum hispidum and Cajanus cajan were the most active. The dichloromethane fraction of Cajanus cajan had IC(50) value 5-10 microg/mL, with the two constituent stilbenes, longistylins A and C, being primarily responsible, with IC(50) values of 0.7-14.7 microM against the range of cancer cell lines.
Most of the species tested had some cytotoxic effect on the cancer cell lines, which to some extent supports their traditional inclusion in herbal preparations for treatment of cancer. However, little selectivity for cancer cells was observed, which raises concerns over their safety and efficacy in traditional treatment. The longistylins A and C appear to be responsible for much of the activity of Cajanus cajan extract.
Journal of ethnopharmacology 03/2010; 128(2):501-12. · 2.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: The present study shows for the first time the chemical profile and the in vitro properties (antioxidant and inhibition of nitric oxide [NO] production) of the aromatic plant Pimpinella anisoides V Brig. (Family Apiaceae). The ethanolic extract of the fruits is characterized by 23 major components. Fourteen monoterpenes, two sesquiterpenes, one fatty acid, five methyl esters and one aldehyde were identified. Among them the most abundant components were the monoterpenes trans-anethole (54.5%), limonene (13.5%), and sabinene (4.4%). The extract showed significant antioxidant activity (50% inhibitory concentration [IC(50)], 3.02 mg/mL) using the 2,2-diphenyl-1-picrylhydrazyl test. The test for inhibition of NO production was performed using the murine monocytic macrophage cell line RAW 264.7. The ethanolic extract had significant activity with an IC(50) value of 72.7 microg/mL, and this might indicate that it would have an anti-inflammatory effect in vivo. Among the pure compounds that most effectively inhibited lipopolysaccharide-induced NO production were the most abundant constituents, trans-anethole and limonene, with IC(50) values of 102.7 microg/mL and 70.1 microg/mL, respectively. The cytotoxic effect of P. anisoides extract and pure compounds in the presence of lipopolysaccharide (1 microg/mL) was evaluated but found to be negligible.
Journal of medicinal food 02/2010; 13(1):137-41. · 1.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: The essential oils of Origanum ehrenbergii and O. syriacum collected in Lebanon were analysed by GC and GC–MS and evaluated for their anticholinesterase, NO production inhibitory activities, and antioxidant properties. O.ehrenbergi essential oil was characterised by the presence of 37 components, representing 94.9% of the total oil of which thymol (19%) and p-cymene (16.1%) were the main abundant compounds. Thirty-six compounds characterised the O.syriacum essential oil, representing 90.6% of the total oil. The most abundant components were thymol (24.7%) and carvacrol (17.6%). O. ehrenbergii demonstrated interesting scavenging effects on DPPH with an IC50 value of 0.99 μg/ml. In addition, both O. ehrenbergii and O. syriacum oils inhibited oxidation of linoleic acid after 30 min of incubation, as well as after 60 min of incubation with IC50 values of 42.1 and 33.6 μg/ml, and 46.9 and 58.9 μg/ml, respectively. Interestingly, O. ehrenbergii oil inhibited NO production in the murine monocytic macrophage cell line RAW 264.7 with an IC50 value of 66.4 μg/ml. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of the Ellman’s method. O. ehrenbergii exhibited a strong activity against both cholinesterases with IC50 values of 0.3 μg/ml. The data suggest that O. ehrenbergii and O. syriacum oils could be used as a valuable new flavour with functional properties for food or nutriceutical products with particular relevance to supplements for the elderly.
[show abstract][hide abstract] ABSTRACT: Infusions of Coreopsis tinctoria flowering tops have traditionally been used in Portugal to control hyperglycaemia but no pharmacological or toxicological studies have been reported until now. The chalcones marein and okanin were isolated from the aqueous extract, together with the 2S-3',4',7,8-tetrahydroxyflavanone. The content of marein in extracts was determined by HPLC-UV and the radical scavenging capacity evaluated by the DPPH method (EC(50) = 21 microg/mL). Glucose intolerance was induced by a single intraperitoneal injection of streptozotocin in saline (40 mg/Kg). After three weeks of oral treatment with C. tinctoria extract (500 mg/Kg/day) the animals were no longer glucose-intolerant (p > 0.05). Additionally, this oral treatment caused no hepatotoxicity in the rats, as determined by blood alanine and aspartate transaminases. A single administration of extract had no effect on oral glucose tolerance in normal Wistar rats. The extract also had no effect on insulin secretion by MIN6 cells. In conclusion, C. tinctoria infusion is able to abolish the streptozotocin-induced glucose-intolerance in rats after three weeks of oral treatment by a mechanism other than induction of insulin secretion. The recovery of beta-pancreatic function mediated by an antioxidant mechanism is a possibility that deserves further investigation.
Phytotherapy Research 10/2009; 24(5):699-705. · 2.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: Eurycomanone is a cytotoxic compound found in Eurycoma longifolia Jack. Previous studies had noted the cytotoxic effect against various cancer cell lines. The aim of this study is to investigate the cytotoxicity against human hepato carcinoma cell in vitro and the mode of action. The cytotoxicity of eurycomanone was evaluated using MTT assay and the mode of cell death was detected by Hoechst 33258 nuclear staining and flow cytometry with Annexin-V/propidium iodide double staining. The protein expression Bax, Bcl-2, p53 and cytochrome C were studied by flow cytometry using a spesific antibody conjugated fluorescent dye to confirm the up-regulation of p53 and Bax in cancer cells.
The findings suggested that eurycomanone was cytotoxic on cancerous liver cell, HepG2 and less toxic on normal cells Chang's liver and WLR-68. Furthermore, various methods proved that apoptosis was the mode of death in eurycomanone-treated HepG2 cells. The characteristics of apoptosis including chromatin condensation, DNA fragmentation and apoptotic bodies were found following eurycomanone treatment. This study also found that apoptotic process triggered by eurycomanone involved the up-regulation of p53 tumor suppressor protein. The up-regulation of p53 was followed by the increasing of pro-apoptotic Bax and decreasing of anti-apoptotic Bcl-2. The increased of cytochrome C levels in cytosol also results in induction of apoptosis.
The data suggest that eurycomanone was cytotoxic on HepG2 cells by inducing apoptosis through the up-regulation of p53 and Bax, and down-regulation of Bcl-2.
Cancer Cell International 02/2009; 9:16. · 2.09 Impact Factor
[show abstract][hide abstract] ABSTRACT: During the past decade, it has been reported that the consumption of certain foods and spices such as pepper may have a positive effect on health. The present study evaluates the influence of fruit ripening on total phenols, flavonoids, carotenoids and capsaicinoids content and antioxidant, hypoglycaemic and anticholinesterase activities of Capsicum chinense Jacq. cv Habanero. The chemical investigation showed a different composition between the two stages of ripening (immature and mature). Generally, the concentration of carotenoids and capsaicinoids increased as the peppers reached maturity, whereas the concentration of phenols declined. The immature fruits showed the highest radical scavenging activity (IC50 of 97.14 μg/ml). On the contrary, the antioxidant activity evaluated by the β-carotene bleaching test showed a significant activity for mature peppers (IC50 value of 4.57 μg/ml after 30 min of incubation). Mature peppers inhibited α-amylase with an IC50 of 130.67 μg/ml. The lipophilic fractions of both mature and immature peppers exhibited an interesting and selective inhibitory activity against α-amylase with IC50 values of 29.58 and 9.88 μg/ml, respectively. Both total extracts of mature and immature peppers inhibited butyrylcholinesterase selectively. The obtained results underline the potential health benefits as a result of consuming C. chinense Habanero and suggest that it could be used as new valuable flavour with functional properties for food or nutriceutical products on the basis of the high content of phytochemicals and found biological properties.