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Crude plant products were first tested in the Drug Research and Development Program, Division of Cancer Treatment, NCI, in 1956. The first materials were voluntarily submitted and later materials were acquired through various contracts. A review is given of the tumor systems which have been used for the evaluation of these plant products and of in vitro assays utilized to expedite fractionation and isolation.
A method based on micellar electrokinetic capillary chromatography (MECC) has been developed for the determination of shikimate in water and crude plant extracts. The analytes are separated in a cholate-taurine buffer by MECC at pH 7.3 and measured by direct UV detection at 206 nm. Shikimate showed linearity up to 12.5 mM, with a squared correlation coefficient (r(2)) of 0.9997. The method has concentration limit of detection (cLOD) and concentration limit of quantification (cLOQ) at 24.4 and 67.8 microM, respectively, corresponding to detection in the femtomol range. The number of theoretical plates (N) was estimated to 245,000 for the optimized system using a capillary with an effective length of 560 mm. The method was tested on plant samples by measuring the shikimate content in leaves of rapeseed plants grown in hydroponic solutions containing the herbicide glyphosate, a well-known inhibitor of the shikimate pathway. In crude extracts of these plants, shikimate was found to accumulate in the leaves, confirming earlier reports of shikimate as a potential biomarker for glyphosate treatment. The method now developed was also able to detect shikimate-3-phosphate, but this compound was not accumulated in glyphosate inhibited plants as found for shikimate.
Acute and chronic toxicities of plant extracts for external use were studied on a model of cell monolayer. This method detects the toxic dose of the agent during the first stage of the study; the activity of this dose and severity of damaging effect can be further studied on experimental animals. An advantage of the method is high informative value of preliminary investigation in the development of new low-toxic agents.
Enveloped animal viruses such as human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, human papillomavirus, Marburg, and influenza are major public health concerns around the world. The prohibitive cost of antiretroviral (ARV) drugs for most HIV-infected patients in sub-Saharan Africa and the serious side effects in those who have access to ARV drugs make a compelling case for the study of complementary and alternative therapies. Such therapies should have scientifically proved antiviral activity and minimal toxic effects. A plant extract, Secomet-V, with an anecdotal indication in humans for promise as an anti-HIV treatment, was investigated. Using a previously described attenuated vaccinia virus vGK5, we established the antiviral activity of Secomet-V. Chemical analysis showed that it has an acidic pH, nontoxic traces of iron (<10 ppm), and almost undetectable levels of arsenic (<1.0 ppm). The color varies from colorless to pale yellow to dark brown. The active agent is heat stable at least up to sterilizing temperature of 121 degrees C. The crude plant extract is a mixture of several small molecules separable by high-pressure liquid chromatography. The HIV viral loads were significantly reduced over several months in a few patients monitored after treatment with Secomet-V. Secomet-V was also found to have antiviral activity against the SARS virus but not against the West Nile virus. Secomet-V, therefore, is a broad-spectrum antiviral, which possibly works by neutralizing viral infectivity, resulting in the prevention of viral attachment.
OBJECTIVE: To assess the clinical efficacy of a neurotonic component containing fixed quantities of two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium versus placebo in mild-to-moderate anxiety disorders with associated functional disturbances, under usual general practice prescription conditions. RESEARCH DESIGN AND METHODS: A total of 264 patients (81% female; mean age: 44.6 years) presenting with generalised anxiety (DSM-III-R) of mild-to-moderate intensity (total Hamilton anxiety scale score between 16 and 28) were included in a double-blind, randomised, placebo-controlled trial. Patients were randomly assigned to two groups: 130 received the study drug (Sympathyl), and 134 a placebo (two tablets twice daily for 3 months). Efficacy and safety data were recorded before first administration and 7, 14, 30, 60 and 90 days after start of treatment. MAIN OUTCOME MEASURES: Efficacy was assessed by (a) change in Hamilton anxiety scale total and somatic scores; (b) change in patient self-assessment; (c) number and percentage of responsive subjects (reduction of at least 50% in Hamilton or self-assessment score); and (d) the physician's clinical global impression. Tolerance was assessed by undesirable events spontaneously reported by the patients over the study period. RESULTS: Total and somatic Hamilton scale scores and subjective patient-rated anxiety fell during treatment, indicating clinical improvement. The decrease was greater in the study drug than in the placebo group. End of treatment clinical improvement, as measured by the mean difference between final and pre-treatment scores, was, for the study drug and placebo groups respectively: -10.6 and -8.9 on the total anxiety score (p = 0.005); -6.5 and -5.7 on the somatic score (p = 0.054); and -38.5 and -29.2 for subjectively assessed anxiety (p = 0.005). The risk/benefit ratio as judged by the investigating physicians was also significantly greater in the study drug than in the placebo group. In all, 15 patients (11.5%) in the study drug group and 13 patients (9.7%) in the placebo group experienced 22 and 15 adverse events, respectively. Undesirable events were mainly mild or moderate digestive or psychopathological disorders. CONCLUSIONS: The preparation containing fixed quantities of Crataegus oxyacantha, Eschscholtzia californica, and magnesium proved safe and more effective than placebo in treating mild-to-moderate anxiety disorders. Sympathyl is produced and marketed by Laboratoire Innotech International, Arcueil, France.
This study evaluated the effectiveness of synthetic and natural antioxidants, green tea, commercial grape seed extracts/combinations, and TBHQ, with varying concentrations of lipid oxidation of nonirradiated and irradiated chicken breast meats stored at 5 degrees C for 12 days. Fresh boneless and skinless chicken breast meats were vacuum-infused with varying concentrations of antioxidants: green tea, grape seed extracts alone/in combination, and TBHQ. The irradiation dosage was 3.0 kGy. Carbonyl values of raw chicken meat and thiobarbituric acid reactive substances (TBARS) values of raw and cooked chicken meat were determined for 0-12 days at 5 degrees C storage. TBARS values for 0-12 days of storage at 5 degrees C ranged from 1.21 to 7.3 and 1.22 to 8.51 mg malondialdehyde/100 g chicken for nonirradiated and irradiated raw chicken, respectively. TBARS values of cooked chicken ranged from 2.19 to 35.83 and 2.45 to 45.72 mg malondialdehyde/100 g chicken for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS values of both controls and plant extracts. The carbonyl content in meat lipid ranged from 1.7 to 2.9 and 1.7 to 4.41 micromol acetophenone/10 g of nonirradiated and irradiated chicken meat, respectively, and meat protein ranged from 1.4 to 2.07 and 1.41 to 2.72 micromol/10 g meat. Infusion of chicken meat with selected plant extracts is an effective method to minimize lipid oxidation and volatiles developments caused by irradiation.
By using carboxymethyl (CM)-curdlan, a polysaccharide linked with the dye Remazol Brilliant Blue (RBB) as a substrate in polyacrylamide gels, the beta-1,3-glucanase in plant extracts can be detected directly by native polyacrylamide gel electrophoresis. In contrast to the usually used procedures for the detection of glucanases, e.g., colorimetric assay, overlay technique, enzyme activity staining using laminarin as a substrate, this method is rapid and allows both the determination of the activity and the location of the relative position of the multiple forms of beta-1,3-glucanases.
Antifungal activities of extracts of sixteen plants were tested against Ceratocystis paradoxa which causes soft rot of pineapples. Xanthium strumarium was the most effective followed by Allium sativum. The effectiveness of various extracts against C. paradoxa was in the decreasing order of Meriandra bengalensis, Mentha piperita, Curcuma longa, Phlogacanthus thyrsiflorus, Toona ciliata, Vitex negundo, Azadirachta indica, Eupatorium birmanicum, Ocimum sanctum and Leucas aspera. Extracts of Cassia tora, Gynura cusimba, Calotropis gigantea and Ocimum canum showed poor fungitoxicity. Ethanol was suitable for extraction of the inhibitory substance from X. strumarium. Acetonitrile was highly toxic to this fungus. Millipore filter-sterilized extracts had a more inhibitory effect on the fungus than the autoclaved samples. Treatment of pineapple fruits infested with C. paradoxa by X. strumarium extract reduced the severity of the disease.
OBJECTIVE: To determine the major groups of bacteria associated with burn infections, isolation of Pseudomonas aeruginosa from burn cases, and the testing of antibacterial activity of some plant extracts in comparison with the standard antibiotics. METHODS: A total of 92 burn cases, covered with tetracycline (40 cases) and non-covered with tetracycline (52 cases) from both sex and various ages, were collected from various hospitals in Basrah City, Iraq on the year 2001. Bacteriological investigation for isolation of bacterial pathogens especially Pseudomonas aeruginosa was carried out. Two methods were used to evaluate the anti-bacterial activity of various concentrations of aqueous extracts of leaves of Myrtus communis and Eucalyptus with comparison to 6 antibiotics, these methods were to determine the growth inhibition zones and minimal inhibitory concentration. RESULTS: From a total 92 cases, 78 (84.8%) gave positive cultures. One hundred and fifty eight isolates were identified as bacterial pathogens. Pseudomonas aeruginosa was the predominant bacterial pathogen from 35.9% of the tetracycline covered burns and 42.3% of the non-tetracycline covered burns followed by other bacterial types in various percentages. Aqueous leaves extracts of myrtus communis and eucalyptus gave an excellent effect on bacterial growth and their effects were located within the limits of antibiotic effects. CONCLUSION: Pseudomonas aeruginosa was the predominant bacterial isolate followed by Staphylococcus aureus, then other type of bacterial was isolated in various percentage from each tetracycline covered burns and non-tetracycline covered burns. Most concentrations of the extracts of the studied plants showed a high antibacterial activity against Pseudomonas aeruginosa, and showed significant differences between susceptibility of Pseudomonas aeruginosa isolated from each tetracycline covered burn and non-tetracycline covered burn.
Aqueous extracts of 10 plants were tested for their ability to inhibit Trichophyton rubrum and Microsporum canis, the aetiological agents of dermal fungal infections in humans. These extracts were also evaluated for their activity against some bacteria. Aqueous extracts from the leaves of Inula viscosa produced detectable antifungal activity against these dermatophytes.
The effect of a plant extract containing Rhizoma curcumae, Fructus silybi mariani, Herba chelidonii, Aloe, Radix podophylli paltati, Radix gentianae and Cortex chinae on the evacuation of feces and on the metabolism of bile acids was investigated with 8 healthy women for a period of 14 days. In the preliminary period there was a stoolweight of 105 +/- 16 g/day. Under treatment the weight of stool rose to 422 +/- 104 g/day. Frequency of stools increased from 1.1 +/- 0.2 evacuations/day to 3.3 +/- 1.1 evacuation/day. Transit time decreased from 64 +/- 20 hours to 18 +/- 4 hours. Elimination of bile acid amounted to 549 +/- 397 mumol/day. It increased under treatment to 908 +/- 832 mumol/day. No changes were found in the laboratory blood tests. The concentration of potassium in the blood also remained constant.
A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH* as a model radical and an HPLC-DAD-SPE-NMR system. Using this method a commercial rosemary extract was investigated. All major compounds present in the extract were collected on SPE cartridges after their separation. Advantages of on-line SPE peak trapping are the possibility to perform HPLC with non-deuterated solvents, a concentration effect and being able to record NMR spectra in pure 100% deuterated solvents. After comparing DAD and DPPH scavenging chromatograms, 1H NMR spectra of compounds having radical scavenging activities were recorded. Afterwards all compounds were collected and infused into an ESI-MS. The five main active compounds - carnosol, carnosic acid carnosaldehyde, 12-methoxycarnosic acid and epiisorosmanol could be identified from the combined UV, NMR and mass spectral data without actually isolating them. It was possible to record on-line an HMBC spectrum of carnosic acid. Also one compound was tentatively identified as epirosmanol methyl ether.
One hundred ninety hexanic and ethanolic extract from 27 plant species from the Cerrado biome of Brazil were tested for larvicidal activity against 3rd-stage Aedes aegypti larvae at 500 microg/ml. Fourteen extracts from 7 species showed activity (>65% mortality) against the larvae. Of these Dugeutia furfuracea, Piptocarpha rotundifolia, Casearia sylvestris var. lingua, Serjania lethalis, and Xylopia aromatica were active at 56.6, 162.31, 232.4, 285.76, and 384.37 microg/ml, respectively. Annona crassiflora and Cybistax antisyphilitica showed activity at 23.06 and 27.61 microg/ml. The larvicidal properties of these species are described for the first time, and may prove to be promising in active chemical compound isolation.
Structurally novel compounds able to block voltage-gated Ca2+ channels (VGCCs) are currently being sought for the development of new drugs directed at neurological disorders. Fluorescence techniques have recently been developed to facilitate the analysis of VGCC blockers in a multi-well format. By utilising the small cell lung carcinoma cell line, NCI-H146, we were able to detect changes in intracellular Ca2+ concentration ([Ca2+](i)) using a fluorescence microplate reader. NCI-H146 cells have characteristics resembling those of neuronal cells and express multiple VGCC subtypes, including those of the L-, N- and P-type. We found that K+-depolarisation of fluo-3 loaded NCI-H146 cells causes a rapid and transient increase in fluorescence, which was readily detected in a 96-well plate. Extracts of Australian plants, including those used traditionally as headache or pain treatments, were tested in this study to identify those affecting Ca2+ influx following membrane depolarisation of NCI-H146 cells. We found that E. bignoniiflora, A. symphyocarpa and E. vespertilio caused dose-dependent inhibition of K+-depolarised Ca2+ influx, with IC(50) values calculated to be 234, 548 and 209 microg/ml, respectively. This data suggests an effect of these extracts on the function of VGCCs in these cells. Furthermore, we found similar effects using a fluorescence laser imaging plate reader (FLIPR) that allows simultaneous measurement of real-time fluorescence in a multi-well plate. Our results indicate that the dichloromethane extract of E. bignoniiflora and the methanolic extract of E. vespertilio show considerable promise as antagonists of neuronal VGCCs. Further analysis is required to characterise the function of the bioactive constituents in these extracts and determine their selectivity on VGCC subtypes.
FIA with pulsed amperometric detection (PAD) is used for the determination of metal-binding carbohydrates in plant extracts. Results of direct FIA measurements agree very well with those of corresponding HPLC-PAD analyses. The proposed method is used to determine total carbohydrates in isolated low-molecular-weight fractions of plant roots, which have been obtained after extraction at different pH values. The results are compared with those obtained by corresponding metal determinations (Ca, Mg, Zn, Mn) by AAS and also with constant potential amperometric detection at a copper working electrode. The latter detection mode is more sensitive, but less selective for carbohydrates.
OBJECTIVES: This study was conducted to search for xanthine oxidase inhibitors in natural products obtained from plants collected in Puerto Rico and to assess the influence of these extracts in the prevention of cataractogenesis. BACKGROUND: Allopurinol is currently a xanthine oxidase inhibitor used in the treatment of gout. New alternatives with increased therapeutic activity and less side effects should be investigated. Preclusion of cataractogenesis in diabetic rats is also the focus of this investigation. Natural products in the form of plant extracts from Puerto Rico offer a rich and relatively untapped source for the discovery of new drugs that may address these kind of problems. METHODS: Nineteen collections of Myrtaceae plant extracts were screened for xanthine oxidase inhibition. A spectrophotometrical method was used employing allopurinol as positive control and a blank as negative control. A protocol of the assay with slight modifications was followed from the literature. Two extracts with the highest percentages of xanthine oxidase inhibition were evaluated for possible prevention of cataractogenesis in streptozotocin diabetic rats. The animals were given to drink these plant extracts ad libitum for three months while controls received water. The appearance of cataracts was assessed physically. RESULTS: Two of the nineteen plant extracts showed high inhibition percentages of xanthine oxidase. Eucalyptus deglupta and Syzygium malaccense displayed 51% and 64% inhibitions (IC50 44.5 micrograms/ml and IC50 51 micrograms/ml), respectively. As for the cataractogenesis inhibition, laboratory animals that drank E. deglupta for three months did not develop cataracts. CONCLUSIONS: Two plant extracts provided positive results with varying degrees of inhibition of xanthine oxidase. S. malaccense demonstrated the greatest xanthine oxidase inhibitory activity whereas E. deglupta presented the best finding for cataractogenesis prevention. The procedures used in this investigation are useful for the in vitro screening of xanthine oxidase inhibition and the in vivo evaluation of cataractogenesis prevention.
Ingestion of the Namibian shrub Salsola tuberculatiformis Botsch. by virgin female rats extends the dioestrus period of their oestrous cycles. Methanol extracts of the plant also inhibit adrenal steroidogenesis in the rat. With the aid of a bioassay, in which vaginal smears were used to follow the oestrous cycles of virgin rats, active fractions could be obtained which indicated that the plant contains a number of active compounds. The most active of these are highly unstable compounds which could not be isolated in pure form. However, two stable but less active compounds were identified as 4-hydroxyacetophenone and 4-hydroxy-3-methoxyacetophenone. This study investigated the influence of these acetophenones, their glucosides, and that of ethanol extracts of S. tuberculatiformis on adrenal steroidogenesis. Acetovanillon, a structurally related natural product also known as compound Z, was included in this study. Results show that the shrub contains active substances which interfere with adrenal 11 beta-hydroxylase, the terminal enzyme in glucocorticoid biosynthesis. This interaction with the cytochrome P-450(11)beta-dependent hydroxylase, as well as the inhibition of the conversion of deoxycorticosterone to corticosterone, was used to develop two sensitive and reliable assays for the rapid identification of small amounts of active compounds from S. tuberculatiformis.
The efficacy of Momordica charantia (MC), Eugenia jambolana (EJ), Tinospora cordifolia (TC) and Mucuna pruriens (MP) was assessed in the prevention of murine alloxan dibetic cataract. Alloxan (120 mg/kg) was used as the diabetogenic agent. While controls and diabetic controls did not receive any plant extract, treated rats received lyophilized aqueous extract of MC and EJ (200 mg/kg p.o.), alcohol extract of TC (400 mg/kg) and MP (200 mg/kg p.o.) every day until 4 months. Serum glucose concentration was assessed and cataracts examined with both the naked eye and through a slit lamp. Of the eight animals in the diabetic control group, four developed cortical cataract (stage IV) by day 90 while the remaining four developed it by day 100. The incidence rate of cataract in MC, EJ, TC and MP treated groups at 120 days was only 0, 0, 1 and 2. Oral feeding of MC, EJ, TC and MP extracts for 1 month produced a fall of 64.33%, 55.62%, 38.01% and 40.17%, respectively, in the serum glucose levels in comparison with the 48 h level. After 2 months of treatment, the respective values were 66.96%, 59.85%, 40.41% and 45.63%. MC and EJ prevented the development of cataract while the protective effect was less with TC and MP along with a significant reduction of plasma glucose levels (p < 0.001).