Antimicrobial activity of Michelia champaca

Flavonoid glycosides from the leaves of Michelia champaca

Michelia champaca L. (Magnoliaceae) was cultivated in large scale for flowers as cosmetic raw materials, whereas the value of its leaves remains to be discovered. Our chemical study on the leaves yielded four new flavonol diglycosides, champaflavosides A-D (1-4), together with twenty-three known flavonoid glycosides (5-27). Their structures were determined by spectroscopic and chemical methods. Compounds 5-21 and 23-27 were not previously reported from the genus Michelia, and kaempferol 3-O-rutinoside (22) was obtained from this species for the first time. All the compounds were evaluated for antioxidant activity by four in vitro assays. Compounds 3-12 and 20 showed more potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than l-ascorbic acid (l-AA). Compounds 2-23, 25, and 27 exhibited 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity superior to l-AA. The ferric reducing antioxidant powers (FRAP) of compounds 2-13, 17, and 19 were higher than l-AA. Further, eighteen compounds demonstrated cellular reactive oxygen species (ROS) scavenging activity, of which champaflavoside D (4), rhamnetin 3-O-neohesperidoside (8), quercetin 3-O-(6-O-E-p-coumaroyl)-neohesperidoside (9), and liquiritin (27) were more potent than curcumin. The results revealed that the renewable leaves of M. champaca are a rich source of flavonoids and antioxidants.

Do Colletotrichum gloeosporioides and Rhizopus stolonifer induce alkaloidal and antifungal responses in Annona muricata seedlings?

The benzylisoquinoline alkaloids of Annona muricata have been isolated, but their physiological or ecological role is unknown. The objective was to explore whether these secondary metabolites are involved in defense against phytopathogenic fungi. To do this, the alkaloidal response of 6-leaf seedlings of A. muricata was analyzed, previously inoculated with Colletotrichum gloeosporioides and Rhizopus stolonifer. Before and after inoculation, alkaloidal extracts of roots, stems, and leaves were obtained, and the antifungal activity was evaluated in vitro. The alkaloids anonaine, reticuline, nornuciferine, assimilobine, and coreximine were identified. C. gloeosporioides caused variable increases in the production of anonaine, reticuline and nornuciferine (10-1200%), while R. stolonifer only stimulated the increase of nornuciferin and anonaine (10%) in the stems and leaves. The alkaloidal extracts of inoculated seedlings increased the antifungal activity, both against the pathogen elicitor and against the second target pathogen. These findings suggest that the alkaloids participate in the antifungal defense mechanism.

K. J, H. R. R, Shivamurthy VKN, Patil SM, Shirahatti PS, Ramu R. New insights on the phytochemical intervention for the treatment of neuropsychiatric disorders using the leaves of Michelia champaca: an in vivo and in silico approach

CONTEXT

Michelia champaca L. (Magnoliaceae) has been known since ancient times for its rich medicinal properties.

OBJECTIVE

The ethanol extract of Michelia champaca leaves (EEMC) was evaluated on depression and anxiety using in vivo and in silico studies.

MATERIALS AND METHODS

Swiss albino mice were divided into control, standard, 100 and 200 mg/kg b.w. EEMC groups and for drug administration using oral gavage. The antidepressant activity was evaluated using forced swim test (FST) and tail suspension test (TST) whereas the anxiolytic activity through elevated plus maze and light and dark tests. The in silico studies included molecular docking against human potassium channel KCSA-FAB and human serotonin transporter, and ADME/T analysis.

RESULTS

Open arm duration and entries were comparable between 200 mg/kg b.w. group (184.45 ± 1.00 s and 6.25 ± 1.11, respectively) and that of diazepam treated group (180.02 s ± 0.40 and 6.10 ± 0.05, respectively). Time spent in the light cubicle was higher (46.86 ± 0.03%), similar to that of diazepam (44.33 ± 0.64%), suggesting its potent anxiolytic activity. A delayed onset of immobility and lowered immobility time was seen at both the treatment doses (FST: 93.7 ± 1.70 and 89.1 ± 0.40 s; TST: 35.05 ± 2.75 and 38.50 ± 4.10 s) and the standard drug imipramine (FST: 72.7 ± 3.72 and TST: 30.01 ± 2.99 s), indicative of its antidepressant ability. In silico studies predicted doripenem to induce anxiolytic and antidepressant activity by inhibiting human potassium channel KCSA-FAB and human serotonin transporter proteins, respectively.

CONCLUSIONS

EEMC is a rich source of bioactive compounds with strong antidepressant and anxiolytic properties.

Volatile Profiling of Magnolia champaca Accessions by Gas Chromatography Mass Spectrometry Coupled with Chemometrics

Magnolia champaca (L.) Baill. ex Pierre of family Magnoliaceae, is a perennial tree with aromatic, ethnobotanical, and medicinal uses. The M. champaca leaf is reported to have a myriad of therapeutic activities, however, there are limited reports available on the chemical composition of the leaf essential oil of M. champaca. The present study explored the variation in the yield and chemical composition of leaf essential oil isolated from 52 accessions of M. champaca. Through hydrodistillation, essential oil yield was obtained, varied in the range of 0.06 ± 0.003% and 0.31 ± 0.015% (v/w) on a fresh weight basis. GC-MS analysis identified a total of 65 phytoconstituents accounting for 90.23 to 98.90% of the total oil. Sesquiterpene hydrocarbons (52.83 to 65.63%) constituted the major fraction followed by sesquiterpene alcohols (14.71 to 22.45%). The essential oils were found to be rich in β-elemene (6.64 to 38.80%), γ-muurolene (4.63 to 22.50%), and β-caryophyllene (1.10 to 20.74%). Chemometrics analyses such as PCA, PLS-DA, sPLS-DA, and cluster analyses such as hierarchical clustering, i.e., dendrogram and partitional clustering, i.e., K-means classified the essential oils of M. champaca populations into three different chemotypes: chemotype I (β-elemene), chemotype II (γ-muurolene) and chemotype III (β-caryophyllene). The chemical polymorphism analyzed in the studied populations would facilitate the selection of chemotypes with specific compounds. The chemotypes identified in the M. champaca populations could be developed as promising bio-resources for conservation and pharmaceutical application and further improvement of the taxa.

Complete chloroplast genome sequence of Michelia champaca var. champaca Linnaeus, an ornamental tree species of Magnoliaceae

Michelia champaca var. champaca is an ornamentally important tree in Magnoliaceae. The paper reported the complete chloroplast genome (cpDNA) of M. champaca var. champaca and its basic annotated information. The size of cpDNA is 160,008 bp, with a typical quadripartite structure of a large single-copy (LSC) region of 88,037 bp and a small single-copy (SSC) region of 18,809 bp separated by a pair identical inverted repeat regions (IRs) of 26,581 bp each. The genome contained 131 genes (113 unique), including 86 protein-coding genes (80 unique), 37 tRNA genes (29 unique), and eight rRNA genes (four unique). Phylogenetic analysis showed that M. champaca var. champaca is affinal to M. baillonii and they form a nomophyletic group with other eight Michelia species. This Michelia clade is sister to the Aromadendron cathcartii clade with high support. All genera mentioned in this analysis are nomophyletic under the system of Magnoliaceae by Sima and Lu.

Identification and Molecular Docking Studies of Bioactive Principles from Alphonsea madraspatana Bedd. against Uropathogens

AIMS

The present study aims to determine the antimicrobial efficacy of Alphonsea madraspatana leaves extract against selected uropathogens.

BACKGROUND

The plant Alphonsea madraspatana is an endangered species, reported to exhibit high antimicrobial activity due to the presence of phenolic compounds. Prevalence of high UTI infection and increased cases of bacterial resistance directed for alternative approach to meet the challenge of drug resistance.

OBJECTIVE

Our objective is to determine antimicrobial efficacy of Alphonsea madraspatana leaves extract against selected uropathogens and subsequent in-silico analysis to predict the underlying mechanism.

METHODS

Phytochemicals extraction from the dried leaves of Alphonsea madraspatana was performed using solvent gradient technique. All the extracts were subjected to preliminary phytochemical screening using liquid chromatography-mass spectrometry. Antimicrobial activity of the prepared extract was determined against the selected uropathogens using agar diffusion method. Finally, molecular docking study of the selected bio-actives was performed against a representative bacterial resistance enzyme ''DNA Gyrase".

RESULTS

Methanolic extract exhibits relatively higher antimicrobial activity against the selected strains with Minimum Inhibitory Concentration (MIC) and minimum bactericidal concentration (MBC) of 1.56 ± 1 ug/mL and 6.25 ± 2 ug/mL, respectively. Phytochemical screening showed the presence of 3 flavonoids compounds such as Luteolin-7-O-glucoside, Kaempferol-3-O- rotinoside-7-O-rhamnoside and Genestein-7-O-glucoside. The results of molecular docking shows Luteolin-7-O-glucoside has best docking scores of -8.5 kcal/mol than other ligand molecules. Experimental simulation in presence of DNA Gyrase inhibitors showed lowest MIC and MBC value for E. Coli, which was found to be 1.56 ±1 ug/mL and 6.25±2 ug/mL respectively, support the docking outcomes.

CONCLUSION

Outcomes of this study suggested that the methanolic extract of this plant shows good anti-microbial potential against resistant uropathogens.

Assessing medicinal plants traditionally used in the Chirang Reserve Forest, Northeast India for antimicrobial activity

ETHNOPHARMACOLOGICAL RELEVANCE

Knowledge on the use of plants for different ailments by the tribals of the Chirang Reserve Forest (CRF, Northeast India) was used to assess the potential of these plants for treating viral, bacterial and fungal infections.

MATERIALS AND METHODS

Fieldwork in the CRF documented the use of plants for the treatment of various human ailments. The ethnobotanical data were analysed using different quantitative indices viz. Informant Consensus Factor (ICF), Relative Frequency Citation (RFC), Fidelity Level (FL), Relative Popularity Level (RPL) and Rank Order Priority (ROP). For each plant, four extracts were prepared with different solvents (water, ethanol, acetone and hexane) and tested for bioactivity such as antiviral (Enterovirus 71) and antimicrobial (E. coli, S. aureus, C. albicans) effects. To develop fingerprints, thin layer chromatography (TLC) was carried out with at least one extract of each active plant.

RESULTS

Thirty-seven plant species belonging to 26 families used frequently in the CRF were categorised into twenty disease(s) and markedly high ICF values (0.5-1) were found. The FL of the 19 most important plant species ranged from 10% to 100%. Aglaia spectabilis, Actinodaphne obovata, Bischofia javanica, Gmelina arborea, Hodgsonia macrocarpa and Mesua ferrea were the most popular plant species with RPL values > 0.4. The most commonly treated diseases were skin infections, worm infections, diarrhoea, dysentery, common cold and throat infections, cough and respiratory problems, fever, malaria, rheumatism, pain, stomach ache and gastric problems. Among the taxonomic families, the most represented are Lauraceae (4 species); Meliaceae (3 species), Euphorbiaceae, Elaecarpoceae, Magnoliaceae, Malvaceae, Moraceae and Myrtaceae (2 species each). Of these, 35 plants (95%) with 91 of their extracts were found to be active against S. aureus (inhibition > 50%). Similarly, over half of the tested plants inhibited growth of E. coli (19 plants with 31 extracts) while 9 plants with 14 extracts were active against C. albicans. Moreover, one-third (12) of the plants showed anti-enteroviral activity. TLC analysis of the extracts indicates the presence of different phytochemical classes such as alkaloids, flavonoids, glycosides, terpenoids and saponins based on observing characteristic spots under visible or UV light (254 or 360 nm), with or without derivatisation.

CONCLUSIONS

Thirty-seven plants commonly used by the tribes of the CRF as anti-infective agents offer perspectives for further research, as the phytochemistry and phytopharmacology for most of these plants have not been published to date.

The protective effect of some Thai plants and their bioactive compounds in UV light-induced skin carcinogenesis

Skin cancer, represents a major public health concern. While the vast majority is non-melanoma skin cancers, melanomas are mostly responsible for mortality. Solar UVB radiation is mutagenic and carcinogenic. It is primarily responsible for both non-melanoma and melanoma skin cancers via excessive production of reactive oxygen species (ROS), which mediate changes in inflammation and immunity, and have been implicated in all three stages of skin cancer development. Due to their regulatory role in numerous functions of cells, signaling pathways are targets for chemoprevention. The current standards in melanoma therapy are targeted and combination therapies, which, albeit prolong survival responses, are still prone to development of drug resistance. To this extent, drugs of natural origin continue to spark great interest. Thailand has a rich biodiversity of indigenous flora, which have traditionally been used to treat a variety of pathologies. The active components in plant extracts that have medicinal properties, termed 'bioactive compounds,' are efficient chemopreventive agents due to their antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification properties. Thai plants and their bioactive compounds have shown protective effects on UV light-induced skin cancer in different experimental models. This warrants further in vivo investigations and translation to clinical studies to determine efficacy and safety, for use as lead compounds in targeted/combination therapy or adjuvant therapy with existing regimes. Coupled with a strategy for prevention, this offers a promising outlook for protection against photocarcinogenesis.

Antimicrobial photodynamic effect of extracts and oxoaporphine alkaloid isomoschatoline from Guatteria blepharophylla

Photodynamic Therapy, a tumor therapy idealized at the beginning of the last century, emerges nowadays as a promising treatment alternative against infectious diseases. In this study we report a bioguided study of Guatteria blepharophylla phytoderivatives for antimicrobial PDT. Crude extracts and fraction from the species bark were obtained and further fractionated for substances isolation. All samples were evaluated in relation to their photophysical (absorbance and fluorescence) and photochemical properties (1,3-DPBF bleaching method). Then, bioassays were conducted using as biological models bacteria and yeast strains and a diode laser as a light source. Phytochemical analyses lead to the isolation of 5 isoquinoline alkaloids from oxoaporphine subclass, denominated GB1 to GB5. Photophysical and photochemical analysis showed that extracts, fraction and GB1 (isomoschatoline) presented absorption profile with bands at 600-700nm and were positive for singlet oxygen production. Photobiological assays indicate that these samples presented photodynamic antimicrobial activity against both gram-positive and gram-negative bacterial and some Candida ssp. yeast strains at sub-inhibitory concentrations. The susceptibility of gram-negative bacteria was significantly enhanced when CaCl2 or MgCl2 were employed. Greater energy doses and double sample's dosage also decreased microbial survival. It is suggested that GB1 photodynamic activity happens through both types I and II photochemical mechanisms, but with a predominance of the latter. Phytoderivatives of G. blepharophylla promoted antimicrobial effect, however more detailed study concerning chemical composition of the crude extracts and fractions as also photophysical and photochemical characteristics of GB1 are necessary to ensure their potential as photosensitizers at antimicrobial photodynamic inactivation.

Liriodenine, an aporphine alkaloid from Enicosanthellum pulchrum, inhibits proliferation of human ovarian cancer cells through induction of apoptosis via the mitochondrial signaling pathway and blocking cell cycle progression

Enicosanthellum pulchrum is a tropical plant from Malaysia and belongs to the Annonaceae family. This plant is rich in isoquinoline alkaloids. In the present study, liriodenine, an isoquinoline alkaloid, was examined as a potential anticancer agent, particularly in ovarian cancer. Liriodenine was isolated by preparative high-performance liquid chromatography. Cell viability was performed to determine the cytotoxicity, whilst the detection of morphological changes was carried out by acridine orange/propidium iodide assay. Initial and late apoptosis was examined by Annexin V-fluorescein isothiocyanate and DNA laddering assays, respectively. The involvement of pathways was detected via caspase-3, caspase-8, and caspase-9 analyses. Confirmation of pathways was further performed in mitochondria using a cytotoxicity 3 assay. Apoptosis was confirmed at the protein level, including Bax, Bcl-2, and survivin, while interruption of the cell cycle was used for final validation of apoptosis. The result showed that liriodenine inhibits proliferation of CAOV-3 cells at 37.3 μM after 24 hours of exposure. Changes in cell morphology were detected by the presence of cell membrane blebbing, chromatin condensation, and formation of apoptotic bodies. Early apoptosis was observed by Annexin V-fluorescein isothiocyanate bound to the cell membrane as early as 24 hours. Liriodenine activated the intrinsic pathway by induction of caspase-3 and caspase-9. Involvement of the intrinsic pathway in the mitochondria could be seen, with a significant increase in mitochondrial permeability and cytochrome c release, whereas the mitochondrial membrane potential was decreased. DNA fragmentation occurred at 72 hours upon exposure to liriodenine. The presence of DNA fragmentation indicates the CAOV-3 cells undergo late apoptosis or final stage of apoptosis. Confirmation of apoptosis at the protein level showed overexpression of Bax and suppression of Bcl-2 and survivin. Liriodenine inhibits progression of the CAOV-3 cell cycle in S phase. These findings indicate that liriodenine could be considered as a promising anticancer agent.

Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour

ETHNOPHARMACOLOGICAL RELEVANCE

Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea.

AIM OF THE REVIEW

To provide an up-to-date, comprehensive overview and analysis of the ethnobotany, phytochemistry, and pharmacology of Stephania rotunda for its potential benefits in human health, as well as to assess the scientific evidence of traditional use and provide a basis for future research directions.

MATERIAL AND METHODS

Peer-reviewed articles on Stephania rotunda were acquired via an electronic search of the major scientific databases (Pubmed, Google Scholar, and ScienceDirect). Data were collected from scientific journals, theses, and books.

RESULTS

The traditional uses of Stephania rotunda were recorded in countries throughout Southeast Asia (Cambodia, Vietnam, Laos, and India). Different parts of Stephania rotunda were used in traditional medicine to treat about twenty health disorders. Phytochemical analyses identified forty alkaloids. The roots primarily contain l-tetrahydropalmatine (l-THP), whereas the tubers contain cepharanthine and xylopinine. Furthermore, the chemical composition differs from one region to another and according to the harvest period. The alkaloids exhibited approximately ten different pharmacological activities. The main pharmacological activities of Stephania rotunda alkaloids are antiplasmodial, anticancer, and immunomodulatory effects. Sinomenine, cepharanthine, and l-stepholidine are the most promising components and have been tested in humans. The pharmacokinetic parameters have been studied for seven compounds, including the three most promising compounds. The toxicity has been evaluated for liriodenine, roemerine, cycleanine, l-tetrahydropalmatine, and oxostephanine.

CONCLUSION

Stephania rotunda is traditionally used for the treatment of a wide range of ailments. Pharmacological investigations have validated different uses of Stephania rotunda in folk medicine. The present review highlights the three most promising compounds of Stephania rotunda, which could constitute potential leads in various medicinal fields, including malaria and cancer.

Antifertility effect of hydroalcoholic leaves extract of Michelia champaca L.: an ethnomedicine used by Bhatra women in Chhattisgarh state of India

ETHNOPHARMACOLOGICAL RELEVANCE

Michelia champaca L. (family: Magnoliaceae), commonly known as Champa [Hindi], is traditionally used for fertility regulation by the women of Chhattisgarh state in India. No scientific evidence regarding the antifertility effect of this plant is available till date.

AIM OF THE STUDY

To study the anti-fertility effect of hydroalcoholic leaf extract of Michelia champaca Linn. in female rats.

MATERIALS AND METHODS

The antifertility activity of the extract (HAEMC) administered at dose levels (100 and 200mg/kg body weight, p.o.) was evaluated in two experimental animal models i.e. antiimplantation activity in female wistar rats and esterogenic/antiestrogenic activity in ovariectomized female rats. In anti-implantation activity, the extract (200 and 400mg/kg body weight, p.o.) was administered to female rats from 1 to 7 days of pregnancy and on 10th day, laprotomy was performed to count the no. of implants. For estrogenic/anti-estrogenic activity, ovariectomized female rats were administered with the extract at both the doses alone as well as along with 17α-ethinyl estradiol (1 μ/rat/day) for 7 consecutive days. On the 8th day, all animals were sacrificed and blood serum was further processed for the estimation of biochemical parameters such as estrogen level, alkaline phosphates, cholesterol, tryglycerides, total protein etc.

RESULTS

The extract (HAEMC) showed significant (p<0.01) 49.95% and 71.03% antiimplantation activities at 100 and 200mg/kg doses respectively. The extract also exhibited significant (p<0.01) estrogenic activity as evidenced by increase in body weight, uterine weight, increased thickness and height of endometrium, vaginal cornification and significant (p<0.01) increase in estrogen, cholesterol, alkaline phosphate and triglycerides levels at higher dose when administered alone as well as along with ethinyl estradiol. Phytochemical screening showed the presence of steroids, flavonoids and alkaloids in the extract.

CONCLUSIONS

Hydroalchoholic extract of Michelia champaca leaves possesses significant antifertility effect which might be due to the inhibition of implantation and estrogenic effect which in turn might be due to the presence of some phytoconstituents in the plant.

Michelia alba extract attenuates UVB-induced expression of matrix metalloproteinases via MAP kinase pathway in human dermal fibroblasts

Solar ultraviolet (UV) radiation can cause skin photoaging by inducing secretion of matrix metalloproteinases (MMPs). It has been reported that MMPs, especially MMP-1, -3 and -9, reduce elasticity of the dermis by degrading collagen. Polyphenols are a group of compounds that exist mainly in glycosides in the plants and they may transform to aglycone after hydrolysis. Polyphenols can inhibit MMP expression and elastase activity. In this study, we investigated the effects of Michelia alba extract (MAE) on expression and activity of MMPs in human skin fibroblast cultures after UVB exposure. The results showed that MAE and its hydrolysates (MAH) inhibited collagenase and elastase activities. In addition, MAE exhibited antioxidant activity, elevated hyaluronic acid content and inhibited UVB-induced MMP-1, MMP-3 and MMP-9 expression. In addition, the zymography assay revealed that MAE also inhibited MMP-9 activity. We also found that MAE inhibited UVB-induced ERK and JNK kinase but not p38 kinase expression, suggesting that MAE may regulate the UVB-induced expression of MMP-1, MMP-3 and MMP-9 via the ERK and JNK kinase pathway. MAE could restore total collagen synthesis reduced by UVB. The results also suggest that MAE treatment may prevent UVB-induced extracellular matrix damage by inhibiting the expression of MMP-1, MMP-3 and MMP-9 through the MAP kinase pathway. Our findings imply that MAE is an effective agent against UVB-induced photodamage.

Antidiabetic activity of flower buds of Michelia champaca Linn

Objective:

To identify the antihyperglycemic activity of various extracts, petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous and crude aqueous, of the flower buds of Michelia champaca, and to identify the antidiabetic activity of active antihyperglycemic extract.

Materials and Methods:

Plant extracts were tested for antihyperglycemic activity in glucose overloaded hyperglycemic rats. The effective antihyperglycemic extract was tested for its hypoglycemic activity at two-dose levels, 200 and 400 mg/kg respectively. To confirm its utility in the higher model, the effective extract of M. champaca was subjected to antidiabetic study in alloxan induced diabetic model at two dose levels, 200 and 400 mg/kg respectively. The biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein, hemoglobin and glycosylated hemoglobin were also assessed in the experimental animals.

Results:

The ethanolic extract of M. champaca exhibited significant antihyperglycemic activity but did not produce hypoglycemia in fasted normal rats. Apart from this extract, the crude aqueous and petroleum ether extracts were found active only at the end of the first hour. Treatment of diabetic rats with ethanolic extract of this plant restored the elevated biochemical parameters significantly (P<0.05) (P<0.01) and the activity was found dose dependent.

Conclusion:

This study supports the traditional claim and the ethanolic extract of this plant could be added in traditional preparations for the ailment of various diabetes-associated complications.

7,7-Dimethylaporphine alkaloids from the stem of Guatteriopsis friesiana

Phytochemical investigation of a methanolic extract of the stem of Guatteriopsis friesiana afforded two new 7,7-dimethylaporphine alkaloids, 6,6a-dihydrodemethoxyguadiscine (1) and guatteriopsiscine (3), together with demethoxyguadiscine (2), liriodenine (4), corypalmine (5), and coreximine (6). Their structures were elucidated on the basis of spectroscopic methods (UV, IR, EIMS, HRESIMS, 1D/2D NMR). The absolute configurations of 1 and 3 were determined from the circular dichroism curves. The presence of 7,7-dimethylaporphine alkaloids in this species is important for the chemotaxonomy of Guatteriopsis. Antimicrobial activity of compounds 1-5 was investigated, and 4 showed activity against Rhodococcus equi, with a MIC value of 10 microg x mL(-1).

In vitro screening for anthelmintic and antitumour activity of ethnomedicinal plants from Thailand

AIM OF STUDY

This study screened for anthelmintic and/or antitumour bioactive compounds from Thai indigenous plants and evaluated effectiveness against three different worm species and two cancer cell lines.

MATERIALS AND METHODS

Methylene chloride and methanol extracts of 32 plant species were screened for in vitro anthelmintic activity against three species of worms, the nematode Caenorhabditis elegans, the digeneans Paramphistomum epiclitum and Schistosoma mansoni (cercariae). Cytotoxicity of the extracts was evaluated against two cancer cell lines: human amelanotic melanoma (C32) and human cervical carcinoma (HeLa) by the SRB assay. Anthelmintic and anticancer activities were evaluated by the inhibiting concentration at 50% death (IC(50)) and the selectivity index (SI) relative to human fibroblasts.

RESULTS AND CONCLUSIONS

None of the extracts were active against Paramphistomum epiclitum. Plumbagin, a pure compound from Plumbago indica, had the strongest activity against Caenorhabditis elegans. The methylene chloride extract of Piper chaba fruits had the strongest activity against schistosome cercariae. Strong cytotoxicity was shown by the methylene chloride extract of Michelia champaca bark and the methanol extract of Curcuma longa rhizome against C32 and HeLa, respectively. These extracts had higher SI (>100) than positive controls in relation to either the worms or the cell lines. The methanol extract of Bouea burmanica had a slightly lower activity towards C32 cells than did Michelia champaca but had a much higher SI (>27,000).

ETHNOPHARMACOLOGICAL RELEVANCE

The plant species screened in this research was recorded by several indigenous medicinal practitioners as antiparasitic, anticancer and/or related activities to the human major organ system.

Constituintes químicos isolados dos caules de Michelia champaca L. (Magnoliaceae)

O fracionamento cromatográfico da fase diclorometânica dos caules de Michelia champaca, forneceu quatro substâncias: álcool 4-O-beta-D-glicopiranosídeo sinapílico, aldeído 4-O-beta-D-glicopiranosídeo sinápico, siringaresinol e N-acetilnonaina. Extração ácido-base de uma nova porção do extrato bruto etanólico permitiu a identificação do alcalóide liriodenina. Os derivados fenilpropanoídicos e o alcalóide N-acetilnonaina estão sendo descritos pela primeira vez no gênero Michelia. O alcalóide liriodenina e a lignana siringaresinol apresentaram atividade antifúngica moderada.

Liriodenine inhibits the proliferation of human hepatoma cell lines by blocking cell cycle progression and nitric oxide-mediated activation of p53 expression

Liriodenine was isolated from the leaves of Michelia compressa. This study was designed to assess cell cycle arrest, the production of nitric oxide (NO) and p53 expression in liriodenine-treated human hepatoma cell lines, including wild-type p53 (Hep G2 and SK-Hep-1). As evidenced by flowcytometric studies, liriodenine induced cell cycle G(1) arrest and inhibited DNA synthesis in Hep G2 and SK-Hep-1 cell lines. The p53, iNOS expression and intracellular NO level were markedly increased in Hep G2 cells after liriodenine treatment. A NO inhibitor, carboxy-PTIO inhibited the p53 expression induced by liriodenine. In addition, liriodenine could not induce obvious cytotoxicity in normal human IMR-90 cell line. These results demonstrate that NO production and p53 expression are critical factors in liriodenine-induced growth inhibition in human wild-type p53 hepatoma cells.

In Vitro Screening of Leishmanicidal Activity in Myanmar Timber Extracts

Seventy-five Myanmar timber extracts belonging to 27 families were examined for their leishmanicidal activities. Some timber extracts had significant leishmanicidal activity, especially extracts of Millettia pendula, which exhibited the most potent activity (MLC 3.1 microg/ml, MIC 1.6 microg/ml). Other timber extracts showing potent activity included those from Cedrela serrata, Cedrela toona, Cordia fragrantissima, Calophyllum kunstleri, Dalbergia cultrate, Grevillea robusta, Haplophragma adenophyllum, Michelia champaca, and Tectona grandis. From a literature search for reports on the chemical constituents of these plants, most constituents were found to be quinone derivatives or other compounds with unsaturated carbonyl groups.