The cytotoxic activity of a Salacia liana species from Monteverde, Costa Rica, is due to a high concentration of tingenone

Selective Cytotoxic Activities of Leaf Essential Oils from Monteverde, Costa Rica

The leaf essential oils of Eugenia cartagensis, Myrcia sp. nov. “fuzzy leaf”, Ocotea veraguensis, O. whitei, and Persea americana, have been obtained by hydrodistillation and the essential oil compositions determined by GC-MS. The essential oils have been screened for in-vitro cytotoxic activity against a panel of human tumor cell lines, and each of the species shows selective cytotoxic activity. E. cartagensis was active against HCT-15 and SW 620 human colorectal carcinoma cells, O. veraguensis and Myrcia “fuzzy leaf” were cytotoxic to MDA-MB-231 and MDA-MB-468 mammary adenocarcinoma cells, and O. whitei and Persea americana were toxic to M-14 melanoma cells.

Chemical Composition and Cytotoxic Activity of the Leaf Essential Oil of Ocotea tonduzii from Monteverde, Costa Rica

The leaf essential oil of Ocotea tonduzii from Monteverde, Costa Rica has been obtained by hydrodistillation and analyzed by GC-MS. The principal constituents of O. tonduzii leaf oil were the monoterpenes α-pinene (41.4%) and pinene (25.1%) and the sesquiterpenes α-humulene (6.9%), β-caryophyllene (5.8%), and germacrene D (3.8%). O. tonduzii leaf oil was notably cytotoxic on MCF-7, MDA-MB-231, MDA-MB-468, and UACC-257 cells in vitro. The major essential oil components showed cytotoxic activities comparable to doxorubicin ( LC50, 20–70 μg/mL).

Chemical Composition and Cruzain Inhibitory Activity of Croton draco Bark Essential Oil from Monteverde, Costa Rica

American trypanosomiasis, Chagas disease, is a great cause of human morbidity and mortality in the Neotropics. Although there is currently no effective treatment for this parasitic disease, a number of potential biochemical targets have been identified, including the cysteine protease cruzain. Croton draco Cham. & Schldl. (Euphorbiaceae), commonly known as sangre de drago, is used in traditional medicine for a number of maladies. In this study, Croton draco bark essential oil has been shown to inhibit the activity of cruzain. The bark oil has been analyzed by GC-MS and the major components found to be β-caryophyllene (31.9%), caryophyllene oxide (22.0%), 1,8-cineole (6.2%), and α-humulene (5.6%). The major components have been tested for cruzain inhibitory activity, but show minimal activity, so it is not clear if the activity of Croton draco bark oil is due to a synergistic effect of the essential oil components or due to very active minor components. Croton draco bark oil has also been tested for cytotoxic activity against a panel of human tumor cell lines, but shows little activity.

Inhibition of Cruzain by Triterpenoids Isolated from a Salacia Species from Monteverde, Costa Rica

The crude chloroform bark extract of an undescribed species of Salacia from Monteverde, Costa Rica, showed cruzain inhibitory activity (IC50 = 11.4 ± 0.6 μg/mL). Activity-directed chromatographic separation led to isolation of four active friedelane triterpenoids, 25,28-dihydroxyfriedelin, canophyllol, tingenone, and the novel 29-hydroxyfriedelan-3-on-28-al.

In vitro and in vivo anti-leukemia activity of the stem bark of Salacia impressifolia (Miers) A. C. Smith (Celastraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Salacia impressifolia (Miers) A. C. Smith (family Celastraceae) is a traditional medicinal plant found in the Amazon Rainforest known as "miraruíra", "cipó-miraruíra" or "panu" and is traditionally used to treat dengue, flu, inflammation, pain, diabetes, male impotency, renal affections, rheumatism and cancer.

AIM OF THE STUDY

The aim of this study was to investigate in vitro and in vivo anti-leukemia activity of the stem bark of S. impressifolia in experimental models.

MATERIALS AND METHODS

The in vitro cytotoxic activity of extracts, fractions and quinonemethide triterpenes (22-hydroxytingenone, tingenone and pristimerin) from the stem bark of S. impressifolia in cultured cancer cells was determined. The in vivo antitumor activity of the ethyl acetate extract (EAE) and of its fraction (FEAE.3) from the stem bark of S. impressifolia was assessed in C.B-17 severe combined immunodeficient (SCID) mice engrafted with human promyelocytic leukemia HL-60 cells.

RESULTS

The extract EAE, its fraction FEAE.3, and quinonemethide triterpenes exhibited potent cytotoxicity against cancer cell lines, including in vitro anti-leukemia activity against HL-60 and K-562 cells. Moreover, extract EAE and its fraction FEAE.3 inhibited the in vivo development of HL-60 cells engrafted in C.B-17 SCID mice. Tumor mass inhibition rates were measured as 40.4% and 81.5% for the extract EAE (20 mg/kg) and for its fraction FEAE.3 (20 mg/kg), respectively.

CONCLUSIONS

Ethyl acetate extract and its fraction from the stem bark of S. impressifolia exhibit in vitro and in vivo anti-leukemia activity that can be attributed to their quinonemethide triterpenes. These data confirm the ethnopharmacological use of this species and may contribute to the development of a novel anticancer herbal medicine.

Antimicrobial, Antioxidant, and Cytotoxic Activities of Ocimum forskolei and Teucrium yemense (Lamiaceae) Essential Oils

Background:Ocimum forskolei and Teucrium yemense (Lamiaceae) are used in traditional medicine in Yemen. Methods: The chemical composition, antimicrobial, antioxidant and cytotoxic activities of the essential oils isolated from the leaves of Ocimum forskolei Benth. (EOOF) and two different populations of Teucrium yemense Deflers., one collected from Dhamar province (EOTY-d), and another collected from Taiz (EOTY-t) were investigated. The antimicrobial activities of the oils were evaluated against several microorganisms with the disc diffusion test or the broth microdilution test. The essential oils were screened for in-vitro cytotoxic activity against human tumor cells. EOOF and EOTY-d were screened for free-radical-inhibitory activity using the DPPH radical scavenging assay. Results: Sixty-four compounds were identified in (EOOF) representing 100% of the oil content with endo-fenchol (31.1%), fenchone (12.2%), τ-cadinol (12.2%), and methyl (E)-cinnamate (5.1%) as the major compounds. In EOTY-d, 67 compounds were identified, which made up 91% of the total oil. The most abundant constituents were (E)-caryophyllene (11.2%), α-humulene (4.0.%), γ-selinene (5.5%), 7-epi-α-selinene (20.1%), and caryophyllene oxide (20.1%), while the major compounds in EOTY-t were α-pinene (6.6%), (E)-caryophyllene (19.1%) α-humulene (6.4%), δ-cadinene (6.5%), caryophyllene oxide (4.3%), α-cadinol (9.5%), and shyobunol (4.6%). The most sensitive microorganisms for EOOF were B. subtilis, S. aureus, and C. albicans with inhibition zones of 34, 16, and 24 mm and MIC values of, 4.3 mg/mL, 4.3 mg/mL, and 8.6 mg/mL, respectively. EOTY-t showed antimicrobial activity against S. aureus, B. cereus, A. niger, and B. cinerea with MIC values of 0.156, 0.156, 0.313 and 0.313 mg/mL, respectively. Neither essential oil showed remarkable radical inhibition (IC₅₀ = 31.55 and 31.41 μL/mL). EOTY-d was active against HT-29 human colorectal adenocarcinoma cell lines with IC₅₀ = 43.7 μg/mL. Consistent with this, EOTY-t was active against both MCF-7 and MDA-MB-231 human breast adenocarcinoma cells. Conclusions: The antimicrobial activity of Ocimum forskolei essential oil against B. subtilis and C. albicans is consistent with its traditional use in Yemeni traditional medicine to treat skin infections. Both O. forskolei and T. yemense show wide variations in their respective essential oil compositions; there remains a need to investigate both species botanically, genetically, and phytochemically more comprehensively.

The Essential Oil Compositions of Ocimum basilicum from Three Different Regions: Nepal, Tajikistan, and Yemen

The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8-cineole, and geraniol. All four of the basil oils in this study were of the linalool-rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities.

Characterization and Antimicrobial Activity of Volatile Constituents from Fresh Fruits of Alchornea cordifolia and Canthium subcordatum

Bacterial resistance has been increasingly reported worldwide and is one of the major causes of failure in the treatment of infectious diseases. Natural-based products, including plant secondary metabolites (phytochemicals), can be exploited to ameliorate the problem of microbial resistance. The fruit essential oils of Alchornea cordifolia and Canthium subcordatum were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). The essential oils were subjected to in vitro antibacterial, antifungal and cytotoxic activity screening. Thirty-eight compounds comprising 97.7% of A. cordifolia oil and forty-six constituents representing 98.2% of C. subcordatum oil were identified. The major components in A. cordifolia oil were methyl salicylate (25.3%), citronellol (21.4%), α-phellandrene (7.4%), terpinolene (5.7%) and 1,8-cineole (5.5%). Benzaldehyde (28.0%), β-caryophyllene (15.5%), (E,E)-α-farnesene (5.3%) and methyl salicylate (4.5%) were the quantitatively significant constituents in C. subcordatum fruit essential oil. A. cordifolia essential oil demonstrated potent in vitro antibacterial activity against Staphylococcus aureus (MIC = 78 μg/mL) and marginal antifungal activity against Aspergillus niger (MIC = 156 μg/mL). C. subcordatum showed antibacterial activity against Bacillus cereus and S. aureus (MIC = 156 μg/mL) and notable antifungal activity against A. niger (MIC = 39 μg/mL). However, no appreciable cytotoxic effects on human breast carcinoma cells (Hs 578T) and human prostate carcinoma cells (PC-3) were observed for either essential oil. The antimicrobial activities of A. cordifolia and C. subcordatum fruit essential oils are a function of their distinct chemical profiles; their volatiles and biological activities are reported for the first time.

Chemotaxonomic Characterization and in-Vitro Antimicrobial and Cytotoxic Activities of the Leaf Essential Oil of Curcuma longa Grown in Southern Nigeria

Curcuma longa (turmeric) has been used in Chinese traditional medicine and Ayurvedic medicine for many years.

METHODS

The leaf essential oil of C. longa from southern Nigeria was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). The essential oil was screened for in vitro antibacterial, antifungal, and cytotoxic activities. The major components in C. longa leaf oil were ar-turmerone (63.4%), α-turmerone (13.7%), and β-turmerone (12.6%). A cluster analysis has revealed this to be a new essential oil chemotype of C. longa. The leaf oil showed notable antibacterial activity to Bacillus cereus and Staphylococcus aureus, antifungal activity to Aspergillus niger, and cytotoxic activity to Hs 578T (breast tumor) and PC-3 (prostate tumor) cells. The ar-turmerone-rich leaf essential oil of C. longa from Nigeria has shown potent biological activity and therapeutic promise.

Compositional Variation and Bioactivity of the Leaf Essential Oil of Montanoa guatemalensis from Monteverde, Costa Rica: A Preliminary Investigation

BACKGROUND

Montanoa guatemalensis is a small to medium-sized tree in the Asteraceae that grows in Central America from Mexico south through Costa Rica. There have been no previous investigations on the essential oil of this tree.

METHODS

The leaf essential oils of M. guatemalensis were obtained from different individual trees growing in Monteverde, Costa Rica, in two different years, and were analyzed by gas chromatography-mass spectrometry.

RESULTS

The leaf oils from 2008 were rich in sesquiterpenoids, dominated by α-selinene, β-selinene, and cyclocolorenone, with lesser amounts of the monoterpenes α-pinene and limonene. In contrast, the samples from 2009 showed no α- or β-selinene, but large concentrations of trans-muurola-4(14),5-diene, β-cadinene, and cyclocolorenone, along with greater concentrations of α-pinene and limonene. The leaf oils were screened for cytotoxic and antimicrobial activities and did show selective cytotoxic activity on MDA-MB-231 breast tumor cells.

CONCLUSION

M. guatemalensis leaf oil, rich in cyclocolorenone, α-selinene, and β-selinene, showed selective in vitro cytotoxic activity to MDA-MB-231 cells. The plant may be a good source of cyclocolorenone.

Composition and Bioactivities of an (E)-β-Farnesene Chemotype of Chamomile (Matricaria Chamomilla) Essential Oil from Nepal

The essential oil of Matricaria chamomilla, collected from Nepal, was obtained by hydrodistillation and analyzed by gas chromatography – mass spectrometry. The major components in Nepalese chamomile oil were ( E)-β-farnesene (42.2%), α-bisabolol oxide A (22.3%), ( E,E)-α-farnesene (8.3%), cis-bicycloether (5.0%), α-bisabolol oxide B (4.5%), and α-bisabolone oxide A (4.0%). A cluster analysis based on the chemical compositions of 48 samples of chamomile oil reported in the literature has revealed seven chemotypes, and the oil from Nepal represents the ( E)-β-farnesene chemotype. The chamomile oil was screened for antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger, and toxicity toward MCF-7 breast tumor cells, Artemia salina, Chaoborus plumicornis, Caenorhabditis elegans, and Drosophila melanogaster.

Antifungal Activity of Plant Extracts against Aspergillus niger and Rhizopus stolonifer

Despite recent advances in antifungal development, fungi remain a devastating threat to human health and compromise viability of the food supply. Plant based antimicrobials represent a vast untapped source with tremendous potential. Herein we present the antifungal properties of more than 50 plant extracts against two important human and agricultural pathogens, Aspergillus niger and Rhizopus stolonifer. Multiple extracts exhibit promising MIC values of less than 100 μg/mL and are reported for both fungal species.

Composition of Essential Oil from Tagetes minuta and its Cytotoxic, Antioxidant and Antimicrobial Activities

The essential oil from the leaves of Tagetes minuta L., growing wild in Yemen, was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. A total of 28 compounds were identified representing 74.2% of total oil composition. Major components of the essential oil were ( Z)-ocimenone (15.9%), ( E)-ocimenone (34.8%), ( Z)-β-ocimene (8.3%), limonene (2.3%), ( Z)-tagetone (1.8%), dihydrotagetone (1.4%) and an unidentified dimethylvinylketone derivative (20.6%). The oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 54.7 ± 6.2 μg/mL. In the DPPH radical scavenging assay, T. minuta oil showed potent antiradical activity with an IC50 value of 36 μg/mL. Antimicrobial activity was also investigated on several microorganisms, and the essential oil exhibited high activity against methicillin-resistant Staphylococcus aureus (MRSA) with an inhibition zone of 23 mm. It also exhibited remarkable antifungal activity against Candida albicans with an inhibition zone of 26 mm.

Bioactivities and Compositional Analyses of Cinnamomum Essential Oils from Nepal: C. camphora, C. tamala, and C. glaucescens

This work examines the biological activity of essential oils of Cinnamomum camphora leaves, C. glaucescens fruit, and C. tamala root from Nepal. The oils were screened for phytotoxic activity against lettuce and perennial ryegrass, brine shrimp lethality, and antibacterial, antifungal, cytotoxic, insecticidal, and nematicidal activities. C. camphora leaf essential oil was phytotoxic to lettuce, antifungal to Aspergillus niger, and insecticidal, particularly toward midge and butterfly larvae, fruit flies, and fire ants. C. camphora oil was also toxic to brine shrimp and human breast tumor cells. C. glaucescens fruit essential oil showed notable nematicidal activity, as well as termiticidal and mosquito larvicidal activity. The root essential oil of C. tamala was toxic to mosquito larvae and fire ants.

Juglans Regia and J. nigra, Two Trees Important in Traditional Medicine: A Comparison of Leaf Essential Oil Compositions and Biological Activities

The essential oils from the leaves of Juglans regia, collected from Kathmandu, Nepal, and Juglans nigra from Huntsville, Alabama, USA, were obtained by hydrodistillation and analyzed by GC-MS. A total of 69 compounds were identified in the J. regia oil, accounting for 99.0% of the eluting components of the oil while three different samples of J. nigra were analyzed identifying a total of 99.3%, 99.4% and 99.7% of the oils. The leaf essential oil of J. regia was dominated by the aromatic compounds eugenol (27.5%) and methyl salicylate (16.2%), and the sesquiterpenes germacrene D (21.4%) and ( E)-β-farnesene (8.2%). The essential oils from three different samples of J. nigra contained ( E)-caryophyllene (17.3%–20.4%) and germacrene D (7.1%–22.5%) with smaller amounts of juglone (1.0%–8.8%), α-hydrojuglone (1.0–9.5%), and δ-cadinene (3.8%–8.7%). J. regia leaf oil, devoid of juglone, showed allelopathic activity, while J. nigra leaf oil was less phytotoxic. The presence of eugenol and methyl salicylate in the leaves of J. regia are consistent with the traditional uses of this plant to treat toothache, rheumatism, and fungal infections.

Volatile constituents of Pinus roxburghii from Nepal

Background:

Pinus roxburghii Sarg. Is one of 3 species of pine found in Nepal, the oil of which is traditionally used to treat cuts, wounds, boils, and blisters.

Objective:

To obtain, analyze, and examine the anti-microbial and cytotoxic activities of the essential oils of P. roxburghii.

Materials and Methods:

Three plant parts (cone, needle, and bark) of Pinus roxburghii were collected in Biratnagar, Nepal. The essential oils were obtained by hydrodistillation, and the chemical compositions were determined by GC-MS. The needle and cone essential oils were screened for anti-microbial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Aspergillus niger; brine shrimp (Artemia salina) lethality; and in-vitro cytotoxicity against MCF-7 cells.

Results:

GC-MS analysis for the cone oil revealed 81 compounds with 78 components being identified (95.5% of the oil) while 98.3% of needle oil was identified to contain 68 components and 98.6% of the bark oil (38 components) was identified. The 3 essential oils were dominated by sesquiterpenes, particularly (E)-caryophyllene (26.8%-34.5%) and α-humulene (5.0%-7.3%) as well as monoterpene alcohols terpinen-4-ol (4.1%-30.1%) and α-terpineol(2.8%-5.0%). The monoterpene δ-3-carene was present only in needle and cone essential oils (2.3% and 6.8%, respectively). Bio-activity assays of the cone essential oil of P. roxburghii showed remarkable cytotoxic activity (100% killing of MCF-7 cells at 100 μg/mL) along with notable brine shrimp lethality (LC₅₀ =11.8 μg/mL). The cone essential oil did not show anti-bacterial activity, but it did exhibit anti-fungal activity against Aspergillus niger (MIC=39 μg/mL).

Conclusion:

The bioactivity of P. roxburghii essential oil is consistent with its traditional medicinal use.

Bioactivities of Volatile Components from Nepalese Artemisia Species

The essential oils from the leaves of Artemisia dubia, A. indica, and A. vulgaris growing wild in Nepal were obtained by hydrodistillation and analyzed by GC-MS. The major components in A. dubia oil were chrysanthenone (29.0%), coumarin (18.3%), and camphor (16.4%). A. indica oil was dominated by ascaridole (15.4%), isoascaridole (9.9%), trans-p-mentha-2,8-dien-1-ol (9.7%), and trans-verbenol (8.4%). The essential oil of Nepalese A. vulgaris was rich in α-thujone (30.5%), 1,8-cineole (12.4%), and camphor (10.3%). The essential oils were screened for phytotoxic activity against Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass) using both seed germination and seedling growth, and all three Artemisia oils exhibited notable allelopathic activity. A. dubia oil showed in-vitro cytotoxic activity on MCF-7 cells (100% kill at 100 μg/mL) and was also marginally antifungal against Aspergillus niger (MIC = 313 μg/mL). DFT calculations (B3LYP/6-31G*) revealed thermal decomposition of ascaridole to be energetically accessible at hydrodistillation and GC conditions, but these are spin-forbidden processes. If decomposition does occur, it likely proceeds by way of homolytic peroxide bond cleavage rather than retro-Diels-Alder elimination of molecular oxygen.

Chemical Composition and Anti-Proliferative Properties of Bursera graveolens Essential Oil

Bursera graveolens is a wild tree of commercial importance native to the Neotropics, which has been widely used in folk medicine. In the present study, the chemical composition and anti-proliferative properties of the essential oil from B. graveolens were assayed. The chemical composition of the essential oil, determined by GC-MS, was complex and dominated by limonene (26.5%). Bursera oil inhibited the growth of MCF-7 breast tumor cells as well as amastigotes of L. amazonensis, with IC50 values of 48.9 ± 4.3 and 36.7 ± 4.7 μg/mL, respectively. In addition, the cytotoxicity of the oil was 103.9 ± 7.2 μg/mL against peritoneal macrophages from BALB/c mice. These results demonstrate that the essential oil from B. graveolens is a promissory antiproliferative product.

Chemical Compositions and Biological Activities of Amomum subulatum Essential Oils from Nepal

The essential oils from the seed and rind of Amomum subulatum Roxb. (collected from Nepal) were obtained by hydrodistillation and analyzed by GC-MS. A total of 87 components were identified among the two essential oils accounting for 99.1%, and 99.0% of the oils, respectively. The two essential oils were dominated by the monoterpenoids 1,8-cineole (60.8% and 39.0%), α-pinene (6.4% and 4.8%), β-pinene (8.3% and 17.7%), and α-terpineol (9.8% and 12.3%). Allelopathic testing of the seed essential oil showed an inhibition of seed germination of Lactuca sativa and Lolium perenne, with IC50 values of 1583 and 1674 μg/mL, respectively. The seed essential oil demonstrated a stronger seedling growth inhibition of L. perenne than of L. sativa. A. subulatum seed and rind oils also showed moderate brine shrimp lethality (LC50 = 28.1 ± 3.0 and 15.0 ± 9.0 μg/mL, respectively). The seed and rind oils were only marginally cytotoxic (20% and 30%% kill on MCF-7 cells at 100 μg/mL, respectively), and antibacterial (MIC ≥ 313 μg/mL), but A subulatum rind oil was appreciably active against the fungus Aspergillus niger (MIC = 19.5 μg/mL). The essential oils of A. subulatum were also screened for nematocidal activity against Caenorhabditis elegans and insecticidal activity against the fruit fly (Drosophila melanogaster) and the red imported fire ant (Solenopsis invicta × richteri). The seed oil was only marginally toxic to the fire ant (LC50 = 1500 μg/mL), but moderately toxic to the nematode and the fruit fly (LC50 = 341 and 441 μg/mL, respectively).

Chemical composition, antimicrobial, and cytotoxicity studies on S. erianthum and S. macranthum essential oils

CONTEXT

Solanum erianthum D. Don and Solanum macranthum Dunal (Solanaceae) are widely used in traditional medicine. The leaves act as an abortifacient and in particular to treat leucorrhoea, sores, and skin irritations.

OBJECTIVE

This study was undertaken to characterize the volatile constituents of the leaf and fruit essential oils of S. erianthum and S. macranthum; their antimicrobial and in vitro cytotoxic bioassay against human breast and prostate tumor cells.

METHODS

The volatile oils were obtained by hydrodistillation and analyzed for their constituents by gas chromatography-mass spectrometry (GC-MS). Minimum Inhibitory Concentrations (MIC) were determined using the microbroth dilution technique while the cytotoxic potentials were evaluated using the Cell Titre 96((R)) AQ(ueous) Non-Radioactive Cell Proliferation Assay method.

RESULTS

Solanum erianthum essential oils were characterized by the abundance of α-terpinolene (17.8%), α-phellandrene (17.5%), p-cymene (15.7%) and β-pinene (11.7%) in the leaves; α-humulene (23.1%), humulene epoxide II (20.0%), caryophyllene oxide (16.5%), methyl salicylate (11.8%) and β-caryophyllene (10.9%) in the fruits. The leaf oil of S. macranthum consisted of (E)-phytol (29.0%), pentadecanal (28.1%) and pentadecane (7.7%) while the major fruit oil constituents were α-humulene (36.5%), β-caryophyllene (17.8%), ethyl palmitate (9.4%), and methyl salicylate (8.2%). Solanum erianthum leaf volatile oil demonstrated potent inhibitory activity against Hs 578T and PC-3 human breast and prostate tumor cells respectively. In addition, the Solanum essential oils exhibited significant antimicrobial activity (19.5-625 µg/mL) on pathogens employed in the assay.

CONCLUSION

The Solanum essential oils possess strong antimicrobial activity in addition to the potent cytotoxic potential of S. erianthum leaf oil against Hs 578T and PC-3 cells.

Chemical Composition and Biological Activity of Essential Oil from Pulicaria undulata from Yemen

The chemical composition of the essential oil obtained from the leaves of Pulicaria undulata Gamal Ed Din (syn P. oriental sensu Schwartz and P. jaubertii Gamal Ed Din) was analyzed by GC-MS. Major compounds of P. undulata oil were the oxygenated monoterpenenes, carvotanacetone (91.4%) and 2,5-dimethoxy-p-cymene (2.6.%). The antimicrobial activity of the essential oil was evaluated against six microorganisms, Escherichia coli Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Candida albicans, using disc diffusion and broth microdilution methods. The oil showed the strongest bactericidal activity against Staphylococcus aureus and methicillin-resistant S. aureus, as well as Candida albicans. The essential oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 64.6 ±13.7 μg/mL. Bioautographic assays were used to evaluate the acetylcholinesterase inhibitory effect as well as antifungal activity of the oil against Cladosporium cucumerinum.

Drugs from the Cloudforest: The Search for New Medicines from Monteverde, Costa Rica

The University of Alabama in Huntsville Natural Products Research Group has been investigating the phytopharmaceutical potential of tropical rainforest higher plants from the Monteverde region of northwestern Costa Rica for the past twenty years. The group has focused primarily on anticancer agents, antimicrobial agents, and antiparasitic agents. This review presents an overview of some of our efforts in natural products drug discovery from Monteverde, Costa Rica.

Attenuation of cytotoxic natural product DNA intercalating agents by caffeine

Many anti-tumor drugs function by intercalating into DNA. The xanthine alkaloid caffeine can also intercalate into DNA as well as form π-π molecular complexes with other planar alkaloids and anti-tumor drugs. The presence of caffeine could interfere with the intercalating anti-tumor drug by forming π-π molecular complexes with the drug, thereby blocking the planar aromatic drugs from intercalating into the DNA and ultimately lowering the toxicity of the drug to the cancer cells. The cytotoxic activities of several known DNA intercalators (berberine, camptothecin, chelerythrine, doxorubicin, ellipticine, and sanguinarine) on MCF-7 breast cancer cells, both with and without caffeine present (200 μg/mL) were determined. Significant attenuation of the cytotoxicities by caffeine was found. Computational molecular modeling studies involving the intercalating anti-tumor drugs with caffeine were also carried out using density functional theory (DFT) and the recently developed M06 functional. Relatively strong π–π interaction energies between caffeine and the intercalators were found, suggesting an “interceptor” role of caffeine protecting the DNA from intercalation.

Free Radical Scavenging and Cytoprotective Activity of Salacia Euphlebia Merr

The present study reports the antioxidant activity of Salacia euphlebia stem extract. To understand the antioxidant activity of this plant, four compounds were isolated and elucidated as vitexin, 15α-hydroxyfriedelan-3-one, siphulitol and mangiferin. Mangiferin showed high free radical scavenging activity (EC50 1.10 ± 0.18 μg/mL) in comparison with quercetin (EC50 1.35 ± 0.02 μg/mL), while vitexin (IC50 37.6 ± 1.1 μg/mL) showed a good cytoprotective effect compared with quercetin (IC50 76.1 ± 1.0 μg/mL). This is the first report of the activities and bioactive compounds of S. euphlebia. These results may scientifically explain the folk and alternative-medicine use of this plant in longevity formulas.

Antiproliferative activity of pristimerin isolated from Maytenus ilicifolia (Celastraceae) in human HL-60 cells

Pristimerin has been shown to be cytotoxic to several cancer cell lines. In the present work, the cytotoxicity of pristimerin was evaluated in human tumor cell lines and in human peripheral blood mononuclear cells (PBMC). This work also examined the effects of pristimerin (0.4; 0.8 and 1.7 microM) in HL-60 cells, after 6, 12 and 24h of exposure. Pristimerin reduced the number of viable cells and increased number of non-viable cells in a concentration-dependent manner by tripan blue test showing morphological changes consistent with apoptosis. Nevertheless, pristimerin was not selective to cancer cells, since it inhibited PBMC proliferation with an IC50 of 0.88 microM. DNA synthesis inhibition assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation in HL-60 cells was 70% and 83% for the concentrations of 0.4 and 0.8 microM, respectively. Pristimerin (10 and 20 microM) was not able to inhibit topoisomerase I. In AO/EB (acridine orange/ethidium bromide) staining, all tested concentrations reduced the number of HL-60 viable cells, with the occurrence of necrosis and apoptosis in a concentration-dependent manner, results in agreement with trypan blue exclusion findings. The analysis of membrane integrity and internucleosomal DNA fragmentation by flow cytometry in the presence of pristimerin indicated that treated cells underwent apoptosis. The present data point to the importance of pristimerin as representative of an emerging class of potential anticancer chemicals, exhibiting an antiproliferative effect by inhibiting DNA synthesis and triggering apoptosis.

Cyclic hemiacetals with seven-membered rings from an undescribed SalaciaSpecies from monteverde, costa rica

The two cyclic hemiacetals of 30-hydroxyfriedelan-3-on-28-al (1R and 1S) were found in an undescribed Salacia species from Costa Rica and characterized by spectral methods.