The in vitro antiviral property of Azadirachta indica polysaccharides for poliovirus

Ethnopharmacological relevance

Azadirachta indica A. Juss, popularly known as neem, has been extensively used in Ayurvedic medicine by Indian population for over 2000 years. It is used traditionally for the healing of various diseases. Natural products and their derivatives provide an excellent source for new anti-viral drugs.

Aim of the study

The present study aims at evaluating the activity of two polysaccharides (P1 and P2) isolated from the leaves of Azadirachta indica and their chemical sulfated derivatives (P1S and P2S) against poliovirus type 1 (PV-1).

Materials and methods

The cytotoxicity of the compounds was analyzed by MTT and the antiviral effect was determined by plaque reduction assay in different protocols.

Results

The polysaccharides did not show any cytotoxic effects on HEp-2 cells at the highest tested concentration (200 μg/ml) and exhibited significant antiviral activity with inhibitory concentrations (IC₅₀) of 80 μg/ml, 37.5 μg/ml, 77.5 μg/ml, and 12.1 μg/ml for P1, P1S, P2 and P2S, respectively, and the selectivity indexes (SI) ranged from 18 to 131.9. The compounds demonstrated better inhibitory effect when added concomitantly with the virus infection with a dose-dependent curve inhibition. Lesser effect was observed when the compounds were added after viral infection and the least effect at pre-treatment.

Conclusions

We suggested that the polysaccharides obtained from Azadirachta indica act against PV-1 by inhibiting the initial stage of viral replication. Importantly, original polysaccharides showed better virucidal effect than their sulfated derivatives at all tested concentrations. This study provides a scientific basis for the past and present ethnomedical uses of this plant.     

In vitro antiprotozoal and cytotoxic activity of 33 ethonopharmacologically selected medicinal plants from Democratic Republic of Congo

Ethnopharmacological relevance

The antiprotozoal and cytotoxic activity of the aqueous extracts from 33 medicinal plants, used by traditional healers for the treatment of various parasitic diseases and collected after an ethnopharmacological inventory conducted in the Bolongo area, Bandundu province in DR Congo, was evaluated.

Materials and methods

Decoctions were prepared, lyophilized and evaluated for in vitro antiprotozoal activity against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum, and the chloroquine- and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Cytotoxicity against MRC-5 cells was included to assess selectivity of activity.

Results

Most of the tested extracts exhibited pronounced (IC₅₀ ≤ 5 μg/ml) or good (5 < IC₅₀ ≤ 10 μg/ml) antiprotozoal activity against one or more of the selected protozoa. A total of 19 plant extracts inhibited Trypanosoma b. brucei, especially the extract from Isolona hexaloba stem bark (IC₅₀ = 1.95 μg/ml, SI = 16.5); 8 plant extracts were active against Trypanosoma cruzi, the extracts from Enanatia chlorantha stem bark and Quassia africana root bark being the most active with IC₅₀ values of 1.87 and 1.88 μg/ml, respectively (SI = 3.0 and 3.3, respectively); 8 plant extracts showed activity against Leishmania infantum, with extracts from Napoleona vogelii stem bark and Quassia africana root bark as the most active with IC₅₀ values of 5.66 and 5.04 μg/ml (SI = 11.3 and 1.2). Finally, 9 plant extracts inhibited Plasmodium falciparum K1 with the extracts from Quassia africana (root bark and stem bark) being the most active ones with IC₅₀ values of 0.46 and 1.27 μg/ml (SI = 13.7 and 13.6). Extracts from Enantia chlorantha stem bark, Piptadeniastrum africanum stem bark and Quassia africana root bark were cytotoxic for MRC-5 cells (CC₅₀ < 10 μg/ml).

Conclusions

These results can partly support and justify the traditional use of some of these plant species for the treatment of parasitic diseases.     

Cytotoxicity and inhibition of P-glycoprotein by selected medicinal plants from Thailand

Ethnopharmacological relevance

Thai medicine has a long tradition of tonifying medicinal plants. In the present investigation, we studied the flower extracts of Jasminum sambac, Mammea siamensis, Mesua ferrea, Michelia alba, Mimusops elengi, and Nelumbo nucifera and speculated that these plants might influence metabolism and substance flow in the body.

Materials and methods

Isolation of porcine brain capillary endothelial cells (PBCECs) as well as multidrug-resistance CEM/ADR5000 leukemia cells, MDA-M;B-231 breast cancer, U-251 brain tumor, and HCT-116 colon cancer cells were used. The calcein-acetoxymethylester (AM) assay was used to measure inhibition of P-glycoprotein transport. XTT and resazurin assays served for measuring cytotoxicity.

Results

The extracts revealed cytotoxicity towards CCRF-CEM leukemia cells to a different extent. The strongest growth inhibition was found for the n-hexane extracts of Mammea siamensis and Mesua ferrea, and the dichloromethane extracts of Mesua ferrea and Michelia alba. The flower extracts also inhibited P-glycoprotein function in porcine brain capillary endothelial cells and CEM/ADR5000 leukemia cells, indicating modulation of the blood–brain barrier and multidrug resistance of tumors. Bioactivity-guided isolation of coumarins from Mammea siamensis flowers revealed considerable cytotoxicity of mammea A/AA, deacetylmammea E/BA and deacetylmammea E/BB towards human MDA-MB-231 breast cancer, U-251 brain tumor, HCT-116 colon cancer, and CCRF-CEM leukemia cells.

Conclusion

The plants analyzed may be valuable in developing novel treatment strategies to overcome the blood–brain barrier and multidrug-resistance in tumor cells mediated by P-glycoprotein.     

Proanthocyanidin-enriched extract from Myrothamnus flabellifolia Welw. exerts antiviral activity against herpes simplex virus type 1 by inhibition of viral adsorption and penetration

Aim of the study

Extracts from the aerial parts of the South African resurrection plant Myrothamnus flabellifolia Welw. have been used traditionally against infections of the upper respiratory tract and skin diseases. A polyphenol-enriched extract was investigated for potential antiviral effects against herpes simplex virus type 1 (HSV-1) and adenovirus, and the underlying mode of action was to be studied.

Materials and methods

Antiviral effects of an acetone-water extract (MF) from Myrothamnus flabellifolia on HSV-1 and adenovirus type 3 were tested in infected Vero cells by plaque reduction assay, MTT test and immunofluorescence. The influence of the extract on the HSV-1 envelope glycoprotein D was shown by Western blot. Organotypic full thickness skin models consisting of multilayer skin equivalents were used for the investigation of MF effects on HSV-1 replication.

Results

MF exhibited strong antiviral activity against HSV-1. The HSV-1-specific inhibitory concentration (IC₅₀) was determined as 0.4 μg/mL and the cytotoxic concentration (CC₅₀) against Vero cells as 50 μg/mL. A selectivity index (SI) (ratio of CC₅₀ to IC₅₀) of approximately 120 was calculated when MF was added to the virus inoculum for 1 h at 37 °C prior to infection. The replication of adenovirus 3 was not affected by MF.MF abolished virus entry into the host cell by blocking viral attachment to the cell surface. When added after attachment at a concentration of >6 μg/mL, the extract also inhibited penetration of HSV-1 into the host cell. Polyphenolic compounds from MF directly interacted with viral particles, leading to the oligomerisation of envelope proteins as demonstrated for the essential viral glycoprotein D (gD). Using organotypic full thickness tissue cultures, it was shown that treatment of HSV-1 infected cultures with the MF resulted in reduced viral spread.

Conclusions

A polyphenol-enriched extract from Myrothamnus flabellifolia strongly acts against HSV-1 by blocking viral entry into the cells.     

Jiawei-Yupingfeng-Tang,a Chinese herbal formula,inhibits respiratory viral infections in vitro and in vivo

Ethnopharmacological relevance

Jiawei-Yupingfeng-Tang (JYT) is a Chinese herbal formula that is widely used to treat respiratory tract illness. However, the effect of JYT on respiratory viruses remains unknown. The influenza virus (IFV) and the human respiratory syncytial virus (HRSV) cause millions of cases of severe illness per year, and many of these illnesses develop into lethal pneumonia. The aim of this study is to evaluate whether JYT can be used to treat these infections.

Materials and methods

The effect of JYT against IFV and HRSV was tested using a plaque reduction assay in the lower respiratory tract cell line A549. The expression of ICAM-1 was determined by real-time RT-PCR and western blotting. A mouse model infected with lethal influenza developing into interstitial pneumonia was used to evaluate the effect of JYT in vivo.

Results

JYT extract inhibited both IFV and HRSV in a dose-dependent manner when given before, during and after a viral infection. JYT was effective in blocking the entry of the virus. Furthermore, pre-treatment with JYT reduced the susceptibility of cells to the invasion of HRSV by inhibiting the expression of ICAM-1. Importantly, JYT extract increased the survival rate of lethal influenza-infected mice, prolonged the survival time and alleviated the virus-induced lung lesions, which is comparable with the effects of ribavirin treatment.

Conclusions

These data support JYT as an alternative modality to be used in the treatment of respiratory viral infection induced by HRSV and IFV.     

The traditional medical uses and cytotoxic activities of sixty-one Egyptian plants: Discovery of an active cardiac glycoside from Urginea maritima

Ethnopharmacological relevance

Medicinal plants from the Sinai desert are widely used in traditional Bedouin medicine to treat a range of conditions including, cancers, and may thus be useful sources of novel anti-tumor compounds. Information on plants used in this way was obtained through collaboration with Bedouin herbalists.

Aim of the study

To document the traditional uses of 61 species from 29 families of Egyptian medicinal plants and to investigate their biological activity using a cytotoxicity assay.

Material and methods

MeOH extracts of the 61 plant species investigated were dissolved in 10% DMSO and their cytotoxic activity was evaluated. The extracts were tested in duplicate on three separate occasions at three different concentrations (1, 10 and 100 μg/ml) against human lymphoma U-937 GTB. The most active extract was subjected to bioassay-guided fractionation using HPLC and LC/ESI–MS to isolate and identify its active components.

Results and discussion

The most potent extracts were those from Asclepias sinaica, Urginea maritima, Nerium oleander and Catharanthus roseus, followed by those from Cichorium endivia, Pulicaria undulate and Melia azedarach. Literature reports indicate that several of these plants produce cardiac glycosides. Bioassay-guided fractionation of alcoholic U. maritima extracts led to the isolation of a bioactive bufadienolide that was subsequently shown to be proscillaridin A, as determined by 1D and 2D NMR spectroscopy. This result demonstrates the value of plants used in traditional medicine as sources of medicinally interesting cytotoxic compounds.     

Xiao-Qing-Long-Tang (Sho-seiryu-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract

Ethnopharmacological relevance

Xiao-Qing-Long-Tang (XQLT, TJ-19, Sho-seiryu-to, so-cheong-ryong-tang) has been used against acute airway diseases for thousands of year in ancient China. Most of the acute airway illnesses are caused by virus. However, without activity against influenza virus, XQLT has been questioned to manage respiratory tract viral infection. Nevertheless, XQLT might be active against airway viruses other than influenza. Human respiratory syncytial virus (HRSV) is one of the most common respiratory viral pathogens without effective management. However, it is unknown whether XQLT has anti-HRSV activity.

Aim of the study

We tested the hypothesis that XQLT can effectively minimize HRSV-induced plaque formation in respiratory tract mucosal cell lines.

Materials and methods

Anti-HRSV activity of a hot water extract of XQLT was examined by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Its effects on syncytial formation and viral fusion (F) protein were examined directly by microscopy and by western blot, respectively. Ability of XQLT to stimulate IFN-β was evaluated by enzyme-linked immunosorbent assay (ELISA).

Results

Hot water extract of XQLT dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cells (P<0.0001), particularly when given before viral inoculation (p<0.0001). XQLT inhibited viral attachment (p<0.0001) and internalization (p<0.0001). 300 μg/ml XQLT could decrease both the number and the size of HRSV-induced syncytium without clear effect on the production of viral F protein. XQLT could stimulate epithelial cells to secrete IFN-β before and after viral inoculation to counteract viral infection (p<0.0001).

Conclusions

XQLT is effective against HRSV infection on airway epithelia by preventing viral attachment, internalization, syncytial formation, and by stimulating interferon secretion.     

In vitro antiprotozoal,antimicrobial and antitumor activity of Pavetta crassipes K. Schum leaf extracts

Aim of the study

To study the potential benefit of the traditional medicinal plant Pavetta crassipes K. Schum (Rubiaceae), which is widely distributed throughout West Africa, the methanol and dichloromethane extracts were isolated from the plant leaves to determine if they exhibited antiprotozoal, antibacterial, antifungal or antitumor activity in vitro.

Materials and methods

The methanol and dichloromethane extracts and their specific fractions were obtained using bioassay-guided fractionation and investigated for antiproliferative activity in vitro in microorganisms (Staphylococcus aureus, Escherichia coli and Candida albicans), protozoans (Trypanosoma cruzi, Trypanosoma brucei, Leishmania infantum and Plasmodium falciparum), and cancer (U373, PC3, MXT and A549) and normal cell lines (NHDF and MRC-5).

Results

Most of the alkaloid fractions investigated exhibited antiproliferative activity in all the cancer cell lines, microorganisms and protozoans studied.

Conclusions

The benefit of Pavetta crassipes as a traditional medicinal remedy was confirmed using antiprotozoal and cytotoxicity assays in vitro. These analyses revealed that the components present in the alkaloid extract of Pavetta crassipes are responsible for its antiprotozoal and cytotoxic efficacy.     

Sheng-Ma-Ge-Gen-Tang (Shoma-kakkon-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract

Ethnopharmacological relevance

Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) has been used against pediatric viral infection for thousands of year in ancient China. However, it is unknown whether SMGGT is effective against human respiratory syncytial virus (HRSV).

Aim of the study

HRSV is a major pediatric viral pathogen of low respiratory tract infection without effective management. This study tested the hypothesis that SMGGT effectively inhibited cytopathy induced by HRSV.

Materials and methods

Effect of the crude extract of SMGGT on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of SMGGT to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA).

Results

Crude extract of SMGGT dose-dependently inhibited HRSV-induced plaque formation. The crude extract was more effective when given before viral infection (p < 0.0001). It inhibited viral attachment dose-dependently (p < 0.0001) and could increase heparin effect on viral attachment. Furthermore, it was synergistic with very low-dose heparin on viral attachment. In addition, the crude extract time-dependently and dose-dependently (p < 0.0001) inhibited HRSV internalization into HEp-2 cells. Epithelial cells secrete IFN-β and TNF-α to counteract viral infection. The crude extract could stimulate epithelial cells to secrete these cytokines beforehand and become resistant to viral infection. It also stimulated IFN-β to defense HRSV after viral inoculation.

Conclusions

Sheng-Ma-Ge-Gen-Tang could be effective to manage HRSV infection in young children.     

The antimicrobial,antioxidative, anti-inflammatory activity and cytotoxicity of different fractions of four South African Bauhinia species used traditionally to treat diarrhoea

Ethnopharmacological importance

Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.

Aims

Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.

Materials and Methods

The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS⁺) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.

Results

The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC₅₀ ranges from 0.64±0.05 to 1.51±0.07 and 0.88±0.18 to 1.49±0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC₅₀ ranges from 1.47±0.24 to 1.70±0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible.The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.

Conclusion

The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.     

Anti-influenza virus activity of the ethanolic extract from Peperomia sui

Ethnopharmacological relevance

Peperomia sui Lin and Lu (Peperomia sui), a well-known Taiwanese folk medicine, has a broad range of biological effects, especially in treatment of upper respiratory tract diseases. However, no previous study has explored the activity of Peperomia sui against influenza virus infections. This study was carried out to evaluate the anti-influenza virus activity and the potential virucidal effect of the ethanolic extract of Peperomia sui (PSE).

Methods

The anti-H6N1 avian influenza viral activity of PSE against the influenza virus A/Chicken/TW/0518/2011 (H6N1) in chicken fibroblast DF-1 cells was evaluated by cell viability assay, hemagglutination assay, neuraminidase activity assay, indirect immunofluorescence assay and quantitative RT-PCR assay.

Results

PSE significantly increased the viability of cells that were infected by the H6N1 virus. PSE also suppressed the synthesis of viral nucleoprotein (NP), and inhibited the growth of the virus in DF-1 cells. Further, PSE inhibited the neuraminidase activity of H6N1 virus.

Conclusions

The findings of this study provide important information for the exploitation and utilization of Peperomia sui in treatment of influenza infection.     

Evaluation of antinociceptive effects of Crassocephalum bauchiense Hutch (Asteraceae) leaf extract in rodents

Ethnopharmacological relevance

The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain.

Aim of the study

In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense.

Materials and methods

Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts.

Results

The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD₅₀.

Conclusion

The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway.     

Anti-mycobacterial diynes from the Canadian medicinal plant Aralia nudicaulis

Ethnopharmacological relevance

Aralia nudicaulis, or wild sarsaparilla, is used as a traditional medicinal plant for the treatment of various illnesses by many of the Canadian First Nations. Iroquois and Algonquin First Nations of Eastern Canada use a tea prepared from dried Aralia nudicaulis rhizome as a cough medicine and for the treatment of tuberculosis. Previous investigations of aqueous extracts of Aralia nudicaulis rhizomes have shown it to possess antimycobacterial activity.

Aim of the study

To isolate and identify antimycobacterial constituents from Aralia nudicaulis rhizomes.

Materials and methods

Methanolic extracts of Aralia nudicaulis rhizomes were subjected to bioassay guided fractionation using the microplate resazurin assay (MRA) to assess inhibitory activity against Mycobacterium tuberculosis strain H37Ra. The antimycobacterial constituents were identified by NMR, MS and polarimetry.

Results

Two C17 polyacetylenes with significant antimycobacterial activity were isolated from the Aralia nudicaulis rhizome extract. The polyacetylenes were identified as (3R)-falcarinol and (3R, 9R, 10S)-panaxydol. Falcarinol and panaxydol displayed MICs of 25.6 μM and 36.0 μM and IC₅₀s of 15.3 μM and 23.5 μM against Mycobacterium tuberculosis H37Ra.

Conclusions

Falcarinol and panaxydol were identified as the principal constituents responsible for the antimycobacterial activity of Aralia nudicaulis rhizomes validating an ethnopharmacological use of this plant by the Canadian First Nations.     

Anti-inflammatory and mutagenic evaluation of medicinal plants used by Venda people against venereal and related diseases

Ethnopharmacology relevance

Inflammation is a major risk factor for various human diseases including venereal diseases, often resulting in treatment complications. Plants have been traditionally used for treatment of many different diseases and have been successfully proven to be an alternative source in treatment of infectious diseases.

Aim of the study

This study was aimed at evaluating the anti-inflammatory activities and the mutagenic properties of 12 medicinal plants used by the Venda people against venereal and related diseases.

Materials and methods

The plants were evaluated for their anti-inflammatory activity against the cyclooxygenase (COX-1 and -2) enzymes and genotoxicity using the Ames test, with and without S9 (metabolic activation) against Salmonella typhimurium tester strain TA98.

Results

DCM and PE extracts of Adansonia digitata bark, Bolusanthus speciosus bark, Pterocarpus angolensis bark and Pappea capensis leaves and EtOH and water extracts of Bolusanthus speciosus stem and Ekebergia capensis bark showed the best anti-inflammatory activity in both COX-1 and -2 assays at 250 μg/ml. These were further evaluated at three other concentrations (31.25, 62.5, and 125 μg/ml) to determine IC₅₀ values. Water extracts of Ekebergia capensis bark showed the best IC₅₀ value towards COX-1. The Ames test revealed that all plant extracts were non-mutagenic towards Salmonella typhimurium strain TA98 except for Elephantorrhiza burkei and Ekebergia capensis that showed weak mutagenicity.

Conclusion

The active plants may offer a new source of chemicals for the effective treatment of anti-inflammatory conditions related to venereal diseases.     

Fresh ginger (Zingiber officinale) has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines

Ethnopharmacological relevance

Ginger, Zingiber officinale Roscoe, is a common spice and also a widely used medicinal plant in ancient China. Ginger is an ingredient of Ge-Gen-Tang (Kakkon-to; GGT). GGT has been proved to have antiviral activity against human respiratory syncytial virus (HRSV). However, it is unknown whether ginger is effective against HRSV.

Aim of the study

To find a readily available agent to manage HRSV infection, the authors tested the hypothesis that ginger can effectively decrease HRSV-induced plaque formation in respiratory mucosal cell lines.

Materials and methods

Effect of hot water extracts of fresh and dried gingers on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of ginger to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA).

Results

Fresh ginger dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cell lines (p<0.0001). In contrast, dried ginger didn't show any dose-dependent inhibition. 300 μg/ml fresh ginger could decrease the plaque counts to 19.7% (A549) and 27.0% (HEp-2) of that of the control group. Fresh ginger was more effective when given before viral inoculation (p<0.0001), particularly on A549 cells. 300 μg/ml fresh ginger could decrease the plaque formation to 12.9% when given before viral inoculation. Fresh ginger dose-dependently inhibited viral attachment (p<0.0001) and internalization (p<0.0001). Fresh ginger of high concentration could stimulate mucosal cells to secrete IFN-β that possibly contributed to counteracting viral infection.

Conclusions

Fresh, but not dried, ginger is effective against HRSV-induced plaque formation on airway epithelium by blocking viral attachment and internalization.     

Antimicrobial and cytotoxic activities of medicinal plants of the Brazilian cerrado, using Brazilian cachaça as extractor liquid

Ethnopharmacological importance

Many species of plants in the Brazilian cerrado (savanna) are widely used in ethnomedicine. However, the safety and effectiveness of medicinal plants used in communities with little or no access to manufactured drugs should be evaluated.

Aim of the study

Evaluate the antimicrobial and cytotoxic activities of extracts from eight plant species, obtained using Brazilian cachaça as the extractor liquid.

Materials and methods

The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida parapsilosis, promastigote forms of Leishmania amazonensis, and poliovirus. In addition, cytotoxic activity was assayed in Vero cells and in human erythrocytes.

Results

The plant species Curatella americana, Sclerolobium aureum, and Plathymenia reticulata showed the best activity against yeasts, especially the crude extract of C. americana and its ethyl-acetate fraction. Kielmeyera lathrophyton showed a minimum inhibitory concentration of 250 μg/ml against S. aureus, and was inactive against Gram-negative bacteria. The extract obtained from Annona coriacea showed the best activity against the promastigote forms of Leishmania amazonensis (IC₅₀ = 175 μg/ml). Only C. americana showed potential for antipoliovirus activity. The concentrations of the crude extracts that showed toxicity to VERO cells had CC₅₀ between 31 and 470 μg/ml, and the lyophilized Brazilian cachaça showed a CC₅₀ of 307 μg/ml. None of the extracts showed toxicity against human erythrocytes.

Conclusions

Among the plant species studied, C. americana proved to be effective against microorganisms, especially as an antifungal. The results will help in the search for alternative drugs to be used in pharmacotherapy, and will contribute to establish safe and effective use of phytomedicines in the treatment of infectious diseases.     

Aegiceras corniculatum extract suppresses initial and late phases of inflammation in rat paw and attenuates the production of eicosanoids in rat neutrophils and human platelets

Aim of the study

The present study is designed to explore the anti-inflammatory potential of Aegiceras corniculatum Linn. Blanco stems extracts and their mechanism of action against various pro-inflammatory mediators and to validate its traditional use against inflammatory diseases.

Materials and methods

Rat paw edema and peritonitis models were employed for in vivo studies. For in vitro studies human platelets and rat neutrophils were stimulated with Ca²⁺-ionophore A23187 leading to the production of various pro-inflammatory metabolites, i.e., 12-HTT, 12-HETE and LTB₄ and 5-HETE which were quantified by HPLC.

Results

The highly polar methanol extract (100 mg/kg) caused ∼90% reduction in the carrageenan- and prostaglandin E2-induced paw edema in rats. It also caused the inhibition of cycloxygenase-1 metabolite, 12-HHT (IC₅₀ 41.1 ± 1.5 μg/ml) with a concomitant rise in 12-lipoxygenase metabolite, 12-HETE in A23187 stimulated human platelets. Conversely, the non-polar hexane extract attenuated (IC₅₀ 0.36 ± 0.12 μg/ml) 12-HETE formation with a parallel rise in 12-HHT, thereby displaying a selectivity towards 12-lipoxygenase. Non-polar hexane extract also antagonized the production of 5-lipoxygenase metabolites, i.e., leukotriene B₄ and 5-HETE in the rat neutrophils. Furthermore, ethyl acetate extract inhibited both COX and 5-LOX with a marked decline in the production of 12-HHT (IC₅₀ 0.08 ± 0.002 μg/ml) and LTB₄ (IC₅₀ 0.86 ± 0.03 μg/ml), respectively. The anti-inflammatory effect of hexane and ethyl acetate extracts was also reflected by the diminution of carrageenan-induced cell infiltration in rat peritoneum. Additionally, plant extracts caused ∼60% suppression in dextran-induced paw edema implying that they also ameliorate histamine and serotonin release.

Conclusion

Hexane, ethyl acetate and methanol extracts derived from Aegiceras corniculatum possess significant anti-inflammatory activity via multiple mechanisms and validate their traditional use against inflammation-related diseases.     

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 200 mg/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 400 mg/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 200 mg/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.