Comparative analysis of active constituents in Centella asiatica samples from Madagascar: application for ex situ conservation and clonal propagation

A comparative quantitative analysis of the active triterpenoids in Centella asiatica samples collected in different locations in Madagascar was carried out to evaluate the natural variability in triterpenoid content and to select elite samples for further ex situ germplasm conservation and clonal propagation. The highest asiaticoside content (6.42%) was measured in samples collected in Mangoro region. In vitro propagation of C. asiatica was successfully achieved in hormone-free medium. Although lower asiaticoside content was detected in 8-week-old vitro plants, the Mangoro sample still showed the highest content in this triterpenoid constituent (1.78%). Acetoxycentellynol, a C(15)-polyacetylene, was found to be accumulated up to 18 times more in in vitro plants as compared to plant material collected in situ.     

A new antiplasmodial coumarin from Toddalia asiatica roots

A new antiplasmodial coumarin, 5,7-dimethoxy-8-(3'-hydroxy-3'methyl-1'-butene)-coumarin (1), has been isolated from the roots of Toddalia asiatica. This finding supports the traditional use of this plant for the treatment of malaria.     

Evaluation of antimicrobial activity of Cleome viscosa and Gmelina asiatica

The ethanolic extracts of the leaves and flowers of Cleome viscosa and roots of Gmelina asiatica were tested for antimicrobial activity. The two plants exhibited a broad spectrum of antimicrobial activity, particularly significative against Escherichia coli , Proteus vulgaris and Pseudomonas aeruginosa. The leaf extract of C. viscosa showed moderate activity against pathogenic fungi.     

Comparison of bioactive compounds content, free radical scavenging and anti-acne inducing bacteria activities of extracts from the mangosteen fruit rind at two stages of maturity

Contents of bioactive components, free radical scavenging and anti-acne producing bacteria activities of young and mature fruit rind extracts of mangosteen were compared. The young fruit rind extract contained significantly higher contents of phenolics and tannins and promoted higher free radical scavenging activity than the mature fruit rind extract, while the later extract contained higher contents of flavonoids and α-mangostin xanthone and gave higher anti-acne producing bacteria activity than the young fruit rind extract. Thus, the young and mature stages of mangosteen fruit rind should be beneficial for further development of antioxidant and anti-acne pharmaceutical preparations, respectively.     

Preliminary antinociceptive, antioxidant and cytotoxic activities of Leucas aspera root

The ethanolic extract of Leucas aspera root was subjected to acetic acid induced writhing inhibition, 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging assay and brine shrimp lethality bioassay for screening of antinociceptive, antioxidant and cytotoxic activity, respectively. The extract produced significant writhing inhibition in acetic acid induced writhing in mice at the doses of 250 and 500 mg/kg. The extract showed a significant free radical scavenging activity with an IC(50) of 8 microg/ml. The extract showed significant lethality to brine shrimp with an LC(50) value.     

Antimutagenic, antioxidant and antimicrobial properties of Maytenus krukovii bark

The hydroalcoholic extract of Maytenus krukovii bark was investigated for its in vitro mutageno-protective activities by means of the Ames Salmonella/microsome assay. The extract showed an inhibitory effect in both T98 and T100 strains against the mutagenic activity of promutagen 2-aminoanthracene but was not protective against directly acting mutagens sodium azide and 2-nitrofluorene. When tested as a radical scavenger and antioxidant it produced a dose-dependent inhibition. The extract did not show significant antibacterial properties, and was weakly active against dermatophyte and phytopathogenic fungi, but inhibited the growth of phytopathogen Pithyum ultimum.     

Two new antioxidant bergenin derivatives from the stem of Rivea hypocrateriformis

Two new bergenin derivatives, named rivebergenin A and B (1, and 2), together with two known compounds, bergenin (3) and norbergenin (4) were isolated from the stem of Rivea hypocrateriformis (Desr.) Choisy. The structures of the new compound have been assigned from ¹H and ¹³C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. Compounds 1-4 showed the strong antioxidant activity.     

Antioxidant activity of Litsea cubeba

The antioxidant activity of Litsea cubeba was studied in terms of three different assay systems: DPPH assay, peroxidase/guaiacol assay, and TBA test. The L. cubeba methanol extract and its fractions showed remarkable antioxidant activity in comparison with alpha-tocopherol and ascorbic acid.     

Antioxidant and antimicrobial activities of Onosma argentatum and Rubia peregrina

The n-hexane-dichloromethane (1:1) extract of the roots of Onosma argentatum and the methanol extract (partitioned between water and chloroform, ethyl acetate and n-butanol, respectively), of the underground parts (roots and rhizomes) of Rubia peregrina were tested in vitro for their antioxidant and antimicrobial activities. The highest antioxidant activity (98%) was observed at 0.1% concentration for the roots of O. argentatum. It was 96% at 0.25% concentration on the ethyl acetate fraction of R. peregrina. O. argentatum extract was effective on Staphylococcus aureus, Bacillus subtilis and Escherichia coli. The ethyl acetate and chloroform fractions of R. peregrina were effective on S. aureus and E. coli, respectively. These two species did not have any antifungal activity.     

In vitro antioxidant and antibacterial activity of Rhaphidophora pertusa stem

Methanol extract of Rhaphidophora pertusa stem was analyzed for its antioxidant (DPPH, reducing power and Fe(3+) metal chelation methods) and antibacterial activities. The extract was found effective against the three antioxidant test models and exhibited strong and moderate antibacterial activity against the tested pathogenic bacteria.     

Anthraquinone production by callus cultures of Rubia cordifolia

Munjistin and purpurin were identified as the major components of anthraquinone pigments produced by callus cultures of R. cordifolia. Anthraquinone content in calluses was 0.62–1.22% (by dry wt.) depending on the source of explants. Selection of coloured aggregates yielded a cell line with twofold increase in anthraquinone production.     

Lignan production inDaphne odora cell cultures

Lignan production in callus and cell suspension cultures ofDaphne odora is reported for the first time. The cell suspension culture produced pinoresinol, lariciresinol, secoisolariciresinol, matairesinol, and wikstromol. The production of matairesinol in the cell suspension culture was much higher than that inDaphne odora stem tissues.Part of this report was presented at the 51th annual meeting of the Japan Wood Research Society, Tokyo, April 2001     

Effects of Erigeron breviscapus ethanol extract on neuronal oxidative injury induced by superoxide radical

Antioxidant activity of the ethanol extract of Erigeron breviscapus (EEEB) were studied by using neuron oxidative injury model induced by superoxide radical. EEEB at the dose of 10-140 mug/ml reduced significantly the lipid peroxidation levels and lactic dehydrogenase (LDH) release from neuron exposed to superoxide radical (generated by xanthine and xanthine oxidase). These results suggest that neuroprotective actions of EEEB may be due to its antioxidant or radical scavenging activity.     

Crototropone, a new tropone derivative from Croton zehntneri

Crototropone (3-hydroxy-5,6-dimethoxy-2-methylcyclohepta-2,4,6-trien-1-one) was isolated from roots of Croton zehntneri. The structure was established by spectroscopic methods.     

Antioxidant and antibacterial activities of aqueous extract of Seabuckthorn (Hippophae rhamnoides) seeds

Seabuckthorn (Hippophae rhamnoides) seeds aqueous extract was screened for antioxidant and antibacterial activities. The antioxidant activities (reducing power, DPPH and liposome model system) showed a good antioxidant activity. The extract was also found to possess antibacterial activity with a MIC values with respect to Listeria monocytogenes and Yersinia enterocolitica found to be 750 and 1000 ppm, respectively. The antioxidant and antimicrobial effects of the extract implicate its potential for natural preservation.     

Antioxidant activity of Erica arborea

The antioxidant properties of the methanol extract of leaves and flowers of Erica arborea and the ethyl acetate, butanol and water soluble fractions were investigated. The ethyl acetate extract was found to be the richest for phenolic and flavonoid content which showed the highest antioxidant activity.     

New cell line establishment of a cell line from embryos ofDendrolimus superans

A new cell line was established from 5-day-old embryonated eggs ofDendrolimus superans and has been designated NEAU-Ds-950821. The cell line consists of mixture of cell types, including majority of spherical shaped cells and a few of spindle shaped cells. The cell line has a population of doubling time of 52.6 h. Chromosome analysis revealed typical lepidopteran chromosomes. Isozyme characterization of Esterase showed the patterns were different from other three cell lines (Ms-927311, Xc-920730, and SF-21AE). Virus infectivity tests revealed the cell line can supportD. superans cytoplasmic polyhedrosis virus. The project is supported by National Science Foundation of China Responsible editor: Chai Ruihai     

A new seco-friedelolactone acid from the bark and twigs of Itoa orientalis

A new seco-friedelolactone, named itoaic acid, together with 5 known compounds was isolated from the bark and twigs of Itoa orientalis. The structure was elucidated by means of MS, 1D and 2D NMR techniques. Anti-inflammatory activity against COX-2 was evaluated for several compounds from I. orientalis and another Flacourtiaceae plant Xylosma controversum.     

Anti-leishmanial and immunomodulatory activities of extracts from Portulaca hirsutissima and Portulaca werdermannii

Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies.     

Antimicrobial activity of some medicinal plants from India

The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported.