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One hundred methanolic plant extracts were screened for antiviral activity against seven viruses. Twelve extracts were found to have antiviral activity at the non-cytotoxic concentrations tested. The extracts of Rosa nutkana and Amelanchier alnifolia, both members of the Rosaceae, were very active against an enteric coronavirus. A root extract of another member of the Rosaceae, Potentilla arguta, completely inhibited respiratory syncytial virus. A Sambucus racemosa branch tip extract was also very active against respiratory syncytial virus while the inner bark extract of Oplopanax horridus partially inhibited this virus. An extract of Ipomopsis aggregata demonstrated very good activity against parainfluenza virus type 3. A Lomatium dissectum root extract completely inhibited the cytopathic effects of rotavirus. In addition to these, extracts prepared from the following plants exhibited antiviral activity against herpesvirus type 1: Cardamine angulata, Conocephalum conicum, Lysichiton americanum, Polypodium glycyrrhiza and Verbascum thapsus.

Strong antiviral and antimicrobial activities were detected in methanolic extracts of 24 plants used medicinally in the treatment of skin infections in four different regions of Colombia. Thirteen extracts displayed activity against herpes simplex virus (HSV) whereas none was active against poliovirus. The antiviral activity was indicated by a total inhibition of viral cytopathic effects (CPE) at a non-cytotoxic concentration of the extract. The most potent extract was obtained from Byrsonima verbascifolia (L.) HBK. which showed anti-HSV activity at a concentration as low as 2.5 microg/ml. Antimicrobial screening was conducted using the disc diffusion assay against Klebsiella pneumoniae, Escherichia coli, Streptococcus faecalis, Mycobacterium phlei, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium and the human pathogenic yeast, Candida albicans. Anti-Candida activity was observed for Piper lanceaefolium HBK. and Juglans neotropica Diels. Twenty-two extracts displayed activity against Gram-positive bacteria whereas none was active against the Gram-negative species. We concluded that these Colombian medicinal plants represent an untapped source of potentially useful antivirals and are worthy of further study.

Research on the ethnobotany of Mestizos in Suni Miraño in 1994 documented 60 plant species used for medicinal purposes. Some cultural data on traditional healing and etiology were also collected. Of these 60 species, 31 were submitted to antibacterial and antifungal assays in the presence and absence of UV light and a number of species were shown to be active.

In a screening of plants used traditionally in Nepal to treat diseases that could be caused by viruses, twenty-one methanol extracts from twenty species were quantitatively assayed for activity against three mammalian viruses: herpes simplex virus, Sindbis virus and poliovirus. Assays were performed in ultraviolet (UV)-A or visible light, as well as dark, and cytotoxicity was also noted. Impressive antiviral activities were exhibited by species of Bauhinia (Fabaceae), Carissa (Apocynaceae), Milletia (Fabaceae), Mallotus (Fabaceae), Rumex (Polygonaceae), Streblus (Moraceae), Terminalia (Combretaceae) and Tridax (Asteraceae). The Carissa extract was the most active, showing activity against all three viruses at a concentration of 12 micrograms/ml. Many of the other extracts showed partial inactivation of one or more test viruses.

The antimicrobial properties of some traditional Carrier herbal preparations were evaluated using an agar dilution method. Pitch preparations were screened against known human pathogens: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus. The results indicated definite antimicrobial activity in the pitch preparations of Picea glauca and Pinus contorta and provide a starting point for pharmacognostic evaluation of these species. In addition, cytoxicity assays, to test the anticancer activity of methanolic extracts of Alnus incana and Shepherdia canadensis against mouse mastocytoma cells, were shown to be positive.

The antimicrobial activity of the methanol extract and isolated constituents of Rhus glabra (Anacardiaceae), a species used in folk medicine by North American native people, was evaluated against 11 microorganisms, including gram-positive and gram-negative bacteria. The extract was subsequently fractionated and monitored by bioassays leading to the isolation of three antibacterial compounds, the methyl ester of 3,4,5-trihydroxybenzoic acid (methyl gallate) (minimal inhibition concentration (MIC) 12.5 micrograms/ml), 4-methoxy-3,5-dihydroxybenzoic acid (MIC 25 micrograms/ml) and gallic acid (MIC > 1000 micrograms/ml). The first two compounds are reported here for the first time from Rhus glabra. Their structures were established using spectroscopic and chemical methods.

In an ethnopharmacological screening of medicinal plants used in Yunnan province of China, ethanol extracts from 31 plant species were assayed for inhibition of murine cytomegalovirus and Sindbis virus infections. Parallel assays were carried out with and without exposure to UVA radiation to test for photo-mediation of activity. Antiviral activity was observed with 16 of the plant extracts. Eight plant extracts have been selected for further studies, with the objective of characterizing the antiviral constituents.

Wood and bark extracts of 14 eastern North American hardwood tree species which were used traditionally as medicine by First Nation's people were screened for antimicrobial activities with eight strains of bacteria and six strains of fungi. Eighty-six percent of the bark extracts were active against methicillin sensitive Staphylococcus aureus; 71% against Bacillus subtilus and 79% against Mycobacterium phlei. The bark extract of Juglans cinerea was active against Pseudomonas aeruginosa 187, Salmonella typhiumurium, and Klebsiella pneumoniae. The wood extracts were less active: 72% were active against S. aureus (methicillin-sensitive), 36% against B. subtilus and 43% against M. phlei. Results from antifungal tests indicated that 36% of the extracts were active against at least one fungal strain and that bark extracts were more active than wood extracts. The bark extract from Juglans cinerea had the broadest spectrum of activities against Candida albicans, Saccharomyces cerevisiae, Cryptococcus neoformans, Trichophyton mentagrophytes, Microsporum gypseum, and Aspergillus fumigatus. In general, the extracts were more active against gram positive bacteria than gram negative bacteria and against filamentous fungi than yeast-like fungi. The study also demonstrated a correlation between frequency of traditional medicinal use by the First Nations people and antimicrobial activity of extracts indicating that the traditional knowledge encompasses an understanding of aspects of chemical ecology.

In a screening of plants used traditionally in Nepal to treat diseases that could be caused by viruses, methanol extracts from 21 species were assayed for activity against three mammalian viruses: herpes simplex virus, Sindbis virus and poliovirus. Assays were performed in UV-A or visible light, as well as dark. Individual species of Hypericum, Lygodium, and Maesa exhibited impressive antiviral activities, although their selective effects on the three viruses suggested that the antiviral ingredients were different in each extract. In addition, many of the other extracts showed partial inactivation of one or more test viruses.

The Carrier, an Athapaskan-speaking people of northcentral British Columbia, occupy the sub-boreal spruce forests of the central interior. This report, which is based on field study, documents some traditional and contemporary knowledge of the medicinal use of plants by the Carrier people. Important medicinal plants include: Abies lasiocarpa, Alnus incana, Arctostaphylos uva-ursi, Artemisia frigida, Fragaria virginiana, Juniperus communis, Picea glauca, Pinus contorta, Populus tremuloides, Rubus idaeus and Shepherdia canadensis.

In an ethnopharmacological screening of selected medicinal plants used in Nepal, methanol extracts from 21 plant species were assayed for activity against 8 strains of bacteria and 5 strains of fungi. Duplicate assays were conducted with and without exposure to UV-A radiation to test for light-activated or light-enhanced activity. All 21 of the extracts showed activity against at least 2 bacterial strains, and 20 showed activity against at least 2 fungi. Six extracts were active only when exposed to UV-A light, and the antibiotic or antifungal effect of 14 extracts was enhanced upon exposure to light.

One hundred methanolic plant extracts were screened for antifungal activity against 9 fungal species. Eighty-one were found to have some antifungal activity and 30 extracts showed activity against 4 or more of the fungi assayed. The extracts with the greatest fungal inhibition were prepared from Alnus rubra catkins, Artemisia ludoviciana aerial parts, Artemisia tridentata aerial parts, Geum macrophyllum roots, Mahonia aquifolium roots and Moneses uniflora aerial parts. In addition to these, extracts prepared from the following plants also exhibited antifungal activity against all 9 fungi: Asarum caudatum whole plant, Balsamorhiza sagittata roots, Empetrum nigrum branches, Fragaria chiloensis leaves, Gilia aggregata aerial parts and roots, Glehnia littoralis roots, Heracleum lanatum roots, Heuchera cylindrica roots and Rhus glabra branches.

One hundred methanolic plant extracts, 96 of which had documented medicinal uses by British Columbian native peoples, were screened for antibiotic activity against 11 bacterial strains. Eighty-five percent were found to have significant antibiotic activity against at least two of the bacteria tested. Ninety-five percent of the plants categorized as potential antibiotics based on their ethnobotanical usage were found to exhibit significant antibiotic activity. Seventy-five were found to be active against methicillin-resistant Staphylococcus aureus, 46 were active against an antibiotic supersusceptible strain of Pseudomonas aeruginosa and 18 of these were also active against a wild type strain. The extracts with the broadest spectra of activity were prepared from: Alnus rubra bark and catkins, Fragaria chiloensis leaves, Moneses uniflora aerial parts, and Rhus glabra branches.

Ayahuasca is a hallucinogenic beverage derived by boiling the bark of the Malpighiaceous liana Banisteriopsis caapi together with the leaves of various admixture plants, viz. Psychotria viridis, Psychotria carthagenensis , or Diplopterys cabrerana . B. caapi contains harmine, harmaline, and tetrahydroharmine while the admixtures contain N,N-dimethyltryptamine (DMT). DMT, a potent hallucinogen, is inactive orally due to degradation by visceral monoamine oxidase (MAO). The beta-carbolines, however, are highly active reversible inhibitors of MAO and may protect the DMT from deamination by MAO and render it orally active. This mechanism has been proposed to underlie the oral activity of ayahuasca but has not been experimentally confirmed. In the present study the constituents of the admixture plants and the alkaloids of eight ayahuasca samples from Peru were qualitatively and quantitatively analyzed using two-dimensional thin-layer chromatography (TLC), high pressure liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS). Several B. caapi cultivars were quantitatively compared for variations in alkaloid content. Three admixture plants used rarely in the manufacture of ayahuasca were also screened for alkaloids. A selected sample of beta-carbolines were screened for activity as MAO inhibitors using an in vitro assay system, and structure/activity relationships were compared. Inhibition observed with single compounds was compared with the activity of selected samples of ayahuasca which were screened in the system and also with the activity of mixtures of beta-carbolines. The levels of DMT and beta-carbolines found in the ayahuasca samples examined in the present study were an order of magnitude greater than the levels reported in a previous study. Ayahuasca was found to be an extremely effective inhibitor of MAO in vitro and the degree of inhibition was directly correlated with the concentration of MAO-inhibiting beta-carbolines. Inhibition experiments using mixtures of beta-carbolines indicated that their effects in combination are additive, rather than synergistic or antagonistic. Implications of the results in understanding the pharmacology of ayahuasca are discussed.

The use of the resin of Virola elongata as an arrow poison was investigated. Aqueous and methanolic extracts of the dried bark were not observed to have toxic effects when administered intraperitoneally to mice. In an attempt to determine if the hallucinogenic indole alkaloid constituents of the bark, which form the basis for the alternate use of this material as a ceremonial snuff, could also be responsible for its use as an arrow poison, alkaloidal and non-alkaloidal extracts were compared with respect to their behavioral effects on mice. The non-alkaloidal extract was more effective in producing an observable alteration in behavior. This consisted of a marked reduction in spontaneous locomotor activity. The extract was fractionated and 13 of the major constituents assayed for their ability to reduce spontaneous locomotor activity. Most of this biological activity of the extract was attributable to the presence of the bis-tetrahydrofuran lignans, episesartemin, sesartemin, epi-yangambin and yangambin. Each of these compounds was also observed to reduce isolation induced aggression when administered to mice.

The use of Justicia pectoralis var. stenophylla as a Virola snuff admixture and also as the sole ingredient of a snuff was investigated. Extracts of the plant did not contain alkaloids, although the ubiquitous compound, betaine, was isolated because of its reaction with alkaloid reagents. Nor did extracts have any significant effect upon the gross behavioral effects, or increased spontaneous motor activity, elicited in mice by 5-methoxy-N,N-dimethyl-tryptamine (5-MeODMT), the primary psychotropic constituent of the Virola resin snuff. Coumarin and umbelliferone were identified because they are major constituents of the plant and because of their ability to relax smooth muscle.

Alkaloid constituents in Myristicaceous bark and leaf samples and in purportedly hallucinogenic preparations derived from Myristicaceous sources were qualitatively and quantitatively analyzed using TLC, GC, alkaloid precipitation tests and GC/MS. Fourteen of the 27 bark and leaf samples analyzed contained detectable amounts of alkaloids. The major bases were N,N-dimethyltryptamine (DMT) and/or 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT); much smaller amounts of tryptamine and/or N-methyl-tryptamine (NMT) were also usually present. beta-Carbolines were not detected in the bark or leaf samples. Considerable variation in alkaloid profiles was found, extending to different collections of the same species. Fourteen of the 20 Virola samples contained alkaloids; none of the 6 Iryanthera species had detectable alkaloids. Osteophloem platyspermum contained an indolic base, identified as N-methyl-tryptophan methyl ester. Seven samples of an orally-ingested drug made from Virola spp. were analyzed. All except one contained substantial amounts of tryptamines; the types and proportions of tryptamines present varied greatly between samples. Samples of Yanomama snuff including various admixtures were analyzed and all components but one contained tryptamines. The drug samples having the highest concentrations of alkaloids contained 15-20 mg/g dry wt while the Myristicaceous bark and leaf samples had much lower concentrations ranging from 0.04 to 0.25 mg/g dry wt. beta-Carbolines were detected as trace constituents in only two of the Myristicaceous drug samples. Four Myristicaceous paste samples were bioassayed in self-experiments. Two of the samples were devoid of detectable hallucinogenic or physiological activity, while some degree of oral activity was detected in two other samples. The activity of a number of tryptamine derivatives as monoamine oxidase inhibitors (MAOI) was investigated using an in vitro enzyme assay. Activity was measured using single compounds and mixtures of compounds and the results were compared to the activity of samples of orally-ingested Myristicaceous pastes. Tryptamine derivatives had significantly less MAOI activity than the activity of beta-carboline derivatives measured in a previous study. Some structural correlations for MAOI activity were found for the tryptamine derivatives. Samples of orally-ingested Myristicaceous pastes were assayed for MAOI activity. The inhibition elicited by the paste samples was closely matched by mixtures of tryptamine standards having comparable proportions and concentrations.(ABSTRACT TRUNCATED AT 400 WORDS)

Plant material from 34 Amazonian species of the family Euphorbiaceae were collected and extracts prepared. Sixteen of these species have a documented use as a medicinal agent. The extracts were tested for their ability to inhibit the growth of the bacteria, Escherichia coli and Staphylococcus aureus; the yeasts, Saccharomyces cerevisiae and Candida albicans; the dermatophytic fungi, Microsporum canis, Microsporum fulvum, Microsporum gypseum and Trichophyton gallinae; the viruses, Sindbis virus and murine cytomegalovirus; and tumours induced on potato discs by Agrobacterium tumefaciens. They were also examined for their toxicity to brine shrimp, Artemia salina. The results are discussed with respect to ethnobotanical information available for some of the species.