Screening of Caesalpinia bonduc leaves for antipsoriatic activity

Ethnopharmacological relevance

Leaves of Caesalpinia bonduc (L.) Roxb. (Caesalpiniaceae) have been used by traditional Siddha healer of Malabar region for psoriasis treatment.

Aim of the study

To evaluate the Caesalpinia bonduc decoction (CBD), Caesalpinia bonduc hydroalcoholic extract (CBHA) for antipsoriatic activity.

Materials and methods

Mouse tail test for psoriasis was used for the evaluation of antipsoriatic activity. Extracts were tested at a dose of 500 mg/kg b.w. and fractions at 250 mg/kg b.w. in Swiss albino mice. Parameters studied in the mouse tail test were changes in epidermal thickness and percentage orthokeratotic values. In vitro antiproliferant assay on HaCaT cell lines and in vitro lipoxygenase inhibition were also carried out.

Results

Butanol fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAB) and water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW) produced significant orthokeratosis (p < 0.001). In relative epidermal thickness, a significant (p < 0.05) reduction with respect to control was observed in groups treated with retinoic acid, CBD, butanol fraction of Caesalpinia bonduc decoction (CBDB), water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW). Maximum antiproliferant activity was shown by CBHA (IC₅₀, 77.5 ± 12.7 μg/ml). In lipoxygenase inhibition assay, water fraction of Caesalpinia bonduc decoction (CBDW) showed maximum activity with an IC₅₀ value of 164.71 ± 4.57 μg/ml.

Conclusions

Among all the tested samples only CBHAW showed good activity in the mouse tail test, antiproliferant activity in HaCaT cells and lipoxygenase inhibition assay. Other extracts and fractions showed varying degrees of activity. The present study supports the traditional use of Caesalpinia bonduc leaves for psoriasis treatment.     

In vitro antimicrobial activity of Caesalpinia ferrea Martius fruits against oral pathogens

Aim

In the Amazon region of Brazil, the fruits of Caesalpinia ferrea Martius (Brazilian ironwood) are widely used as an antimicrobial and healing medicine in many situations including oral infections. This study aimed to evaluate the antimicrobial activity of Caesalpinia ferrea Martius fruit extract against oral pathogens.

Materials and methods

Polyphenols estimation and spectral analysis (¹H NMR) of the methanol extract were carried out. The microorganisms Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were tested using the microdilution method for planktonic cells (MIC) and a multispecies biofilm model. Chlorhexidine was used as positive control.

Results

Polyphenols in the extract were estimated at 7.3% and ¹H NMR analysis revealed hydroxy phenols and methoxilated compounds. MIC values for Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were 25.0, 40.0, 66.0, 100.0, 66.0 μg/mL, respectively. For the biofilm assay, chlorhexidine and plant extract showed no growth at 10⁻⁴ and 10⁻⁵ microbial dilution, respectively. At 10⁻⁴ and 10⁻⁵ the growth values (mean ± SD) of the negative controls (DMSO and saline solution) for Streptococcus mutans, Streptococcus sp. and Candida albicans were 8.1 ± 0.7, 7.0 ± 0.6 and 5.9 ± 0.9 × 10⁶ CFU, respectively.

Conclusion

Caesalpinia ferrea fruit extract can inhibit in vitro growth of oral pathogens in planktonic and biofilm models supporting its use for oral infections.     

Antimicrobial activity of the extracts of Craniotome furcata (Lamiaceae)

Ethnopharmacological relevance

Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity.

Aim of the study

To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi.

Materials and methods

The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method.

Results

The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41–4.58 mg/ml.

Conclusions

The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.     

Antimicrobial activities of methanol extract and compounds from stem bark of Vismia rubescens

Ethnopharmacological relevance

The plant, Vismia rubescens (Guttiferae) is popularly used in Cameroon and in several parts of Africa as febrifugal and for the treatment of various microbial infections (skin diseases, diarrhoea and venereal diseases).

Aim of the study

This study was mapped out to evaluate the antimicrobial activities of the methanol extract and compounds from the stem bark of Vismia rubescens.

Materials and methods

Structures of the compounds obtained after column chromatography of the methanol-soluble fraction were determined by spectroscopy and in comparison with published data. The broth micro-dilution method was used to evaluate the antimicrobial activities against three bacteria species (Salmonella typhi, Stahylococcus aureus and Pseudomonas aeruginosa) and four yeast species (Candida albicans, Candida tropicalis, Candida parapsilosis and Cryptococcus neoformans).

Results

Chemical analysis of the methanol extract from the stem bark of Vismia rubescens yielded five known compounds 1,4,8-trihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), physcion (3), friedelin (4) and friedelanol (5). The crude extract and compounds 1, 2 and 3 exhibited both antibacterial and antifungal activities that varied between the microbial species (MIC = 3.12–1000 μg/ml). Compounds 2 and 3 were the most active (MIC = 3.12–100 μg/ml) while Stahylococcus aureus and Pseudomonas aeruginosa were sensitive to all the tested compounds. The antimicrobial activity of this plant as well as that of compounds 1 and 2 is being reported here for the first time.

Conclusion

These results provide promising baseline information for the potential use of this plant as well as some of the isolated compounds in the treatment of skin diseases and diarrhoea.     

Antimicrobial,anti-inflammatory activities and toxicology of phenylethanoid glycosides from Monochasma savatieri Franch. ex Maxim

Ethnopharmacological relevance

Monochasma savatieri Franch. ex Maxim is used for treating many diseases in Traditional Chinese Medicine.

Aim of the study

The present study was designed to evaluate antibacterial, anti-inflammatory activities and toxicity of the total phenylethanoid glycosides from Monochasma savatieri Franch. ex Maxim (TPG).

Materials and methods

The antibacterial activity of TPG was checked by MIC and MBC in vitro; survival of mice with Pseudomonas aeruginosa or Staphylococcus aureus infection-induced sepsis was investigated to evaluate antibacterial activity of TPG in vivo. Additionally, antibacterial activities of TPG were also investigated in a Pseudomonas aeruginosa infection-induced pneumonia in the mice model. Cotton pellet induced granuloma and xylene induced ear swelling in mice models were used to quantify the anti-inflammatory activity.

Results

TPG showed a significant possess bacteriostatic properties against five bacteria strains at a concentration between 0.0625 and 16 mg/ml. Moreover, TPG has bactericidal activity against Pseudomonas aeruginosa, Streptococcus pneumoniae or Escherichia coli. TPG (60, 120, and 180 mg/kg) prolonged survival rate of mice with Pseudomonas aeruginosa or Staphylococcus aureus infection-induced sepsis. In addition, TPG (180 mg/kg) could reduce the bacterial colony-forming units in lung tissue. Furthermore, TPG (60–180 mg/kg) had significantly reduced xylene-induced ear edema and granulomat formation induced by cotton pellet at a dose-dependent manner. In addition, administration of TPG (1.5 g/kg) for 15 days did not result in toxicities in liver, kidney, spleen and thymus tissue in rats.

Conclusion

These results indicated that TPG might be useful for the development of a novel treatment for respiratory infections or pneumonia caused by Pseudomonas aeruginosa or Staphylococcus aureus.     

Wound healing effect of Flabellaria paniculata leaf extracts

Aim of the study

This study evaluated wound healing activity of the chloroform and aqueous fractions of the methanolic extract of Flabellaria paniculata leaf on infected wounds in rats as a follow up to an initial study of the crude extract.

Materials and methods

Wounds were inflicted on Wistar rats using excision model. Local infection was introduced into rat abdominal wounds with Staphylococcus aureus and Pseudomonas aeruginosa using a 10⁸ cells/ml inoculum. Rate of wound healing was assessed by contraction and period of epithelization.

Results

Chloroform fraction exhibited significant wound healing potency (p < 0.05) as compared with controls. The test drug achieved 100% wound contraction on day 14 in non-infected group, on day 16 in Staphylococcus aureus infected group and on day 18 in Pseudomonas aeruginosa group.

Conclusions

Chloroform extract of Flabellaria paniculata proves to be a potential anti-infective and wound healing agent. Its in vitro antibacterial and in vivo wound healing activities are in good agreement with the local medicinal use of the plant for skin diseases and sores.     

Prophylactic and curative activities of extracts from Warburgia ugandensis Sprague (Canellaceae) and Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) against Plasmodium knowlesi and Plasmodium berghei

Ethnopharmacological relevance

This work reports the anti-plasmodial activities of Warburgia ugandensis and Zanthoxylum usambarense commonly used as phytomedicines against malaria by some Kenyan communities.

Aim of study

To determine the anti-plasmodial activities of extracts from Warburgia ugandensis and Zanthoxylum usambarense against Plasmodium knowlesi and Plasmodium berghei.

Materials and methods

Eight plant extracts were screened for in vitro anti-plasmodial activity against Plasmodium knowlesi, in a 96-well plate incubated at 37 °C on a RPMI culture medium supplemented with baboon serum. Of the eight, three were investigated for prophylactic and curative activities in BALB/c mice against drug-sensitive Plasmodium berghei in a 4-day test at a dose rate of 200 mg/kg/day.

Results

Inhibitory concentrations (IC₅₀) values of between 3.14 and 75 μg/ml, up to 69% chemosuppression of parasites growth and over 80% survivorship of treated mice were observed.

Conclusion

The two medicinal plants, Warburgia ugandensis and Zanthoxylum usambarense possess bioactive compounds against malaria parasites and could be exploited for further development into malaria therapy.     

Gastroprotective activity of the ethanol extract from the inner bark of Caesalpinia pyramidalis in rats

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae), known as “catingueira”, has been used in folk medicine in the treatment of various disorders such as gastritis, heartburn, indigestion, and stomach ache. However, the gastroprotective properties of this species have not yet been studied.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in rats via oral route, at the doses of 30, 100, and 300 mg/kg. The antiulcer assays were performed using the ethanol- and nonsteroidal anti-inflammatory drug-induced ulcer models. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligated model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of the ethanol extract of Caesalpinia pyramidalis was performed using the agar-well diffusion and broth microdilution methods.

Results

The ethanol extract (30, 100, and 300 mg/kg) produced dose dependent inhibition (P<0.01) on the ulcer lesion index, the total lesion area, and the percentage of lesion area in the ethanol-induced ulcer model. The ethanol extract (30, 100, and 300 mg/kg) also reduced (P<0.001) the ulcer index in the indomethacin-induced ulcer model. In the model ligature pylorus, the treatment with Caesalpinia pyramidalis ethanol extract failed to significantly change the gastric secretion parameters. However, after treatment with the ethanol extract of Caesalpinia pyramidalis (30, 100, and 300 mg/kg), there was a significant increase (P<0.05) in mucus production. The ethanol extract showed anti-Helicobacter pylori activity, with inhibition halos of 12.0±1.7 mm at 10,000 μg/mL. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the ethanol extract were of 625 and 10,000 μg/mL, respectively.

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis displays gastroprotective actions, supporting the folkloric usage of the plant to treat various gastrointestinal disturbances.     

Anxiolytic-like effect of Sonchus oleraceus L. in mice

Ethnopharmacological relevance

Sonchus oleraceus L. has been used as a general tonic in Brazilian folk medicine. Nevertheless, available scientific information regarding this species is scarce; there are no reports related to its possible effect on the central nervous system.

Aim of the study

This study was conducted to establish the anxiolytic effect of extracts from the aerial parts of Sonchus oleraceus.

Materials and methods

This study evaluated the effect of hydroethanolic and dichloromethane extracts of Sonchus oleraceus in mice submitted to the elevated plus-maze and open-field tests. Clonazepam was used as the standard drug.

Results

In the elevated plus-maze test, the Sonchus oleraceus extracts increased the percentage of open arm entries (P < 0.05) and time spent in the open-arm portions of the maze (P < 0.05). The extracts induce an anti-thigmotactic effect, evidenced by increased locomotor activity into the central part of the open field set-up (P < 0.05). The extracts administered at 30–300 mg/kg, p.o. had a similar anxiolytic effect to clonazepam (0.5 mg/kg, p.o.).

Conclusion

These data indicate that Sonchus oleraceus extract exerts an anxiolytic-like effect on mice.     

In vitro activity of Tridax procumbens against promastigotes of Leishmania mexicana

Ethnopharmacological relevance

Tridax procumbens is an active herb against leishmaniasis.

Aim of the study

Leishmaniasis is a group of diseases caused by Leishmania protozoa. We investigated the antileishmanial activity of Tridax procumbens extracts and a pure compound against promastigotes of Leishmania mexicana, the causative agent of cutaneous leishmaniasis in the New World.

Materials and methods

Extracts and (3S)-16,17-didehydrofalcarinol (1) were obtained by chromatographic methods from Tridax procumbens, and the latter identified by spectroscopic analysis. The effect of these extracts and 1 on the growth inhibition of promastigotes of Leishmania mexicana was evaluated. In order to test the safety of extracts and 1, mammalian cells were treated with them, and cell viability was assessed using trypan blue and MTT.

Results

We demonstrated that extracts of Tridax procumbens and 1 showed a pronounced activity against Leishmania mexicana. The methanol extract inhibited promastigotes growth of Leishmania mexicana with a 50% inhibitory concentration (IC₅₀) of 3 μg/ml, while oxylipin 1 exhibited the highest inhibition at IC₅₀ = 0.478 μg/ml.

Conclusions

In this study we report the biological activity of extracts and (3S)-16,17-didehydrofalcarinol (1), obtained from Tridax procumbens, on the promastigote form of Leishmania mexicana, with no effect upon mammalian cells.     

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

Aim of the study

Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine.

Materials and methods

The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively.

Results

The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC = 6.3 μg/ml for both extracts). The lowest MIC value (1.6 μg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6).

Conclusion

These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.     

In vivo anti-inflammatory and anti-ulcerogenic activities of extracts from wild growing and in vitro plants of Castilleja tenuiflora Benth. (Orobanchaceae)

Ethnopharmacological relevance

Castilleja tenuiflora Benth. (Orobanchaceae) is a perennial shrub used since the 16^th century in Mexican traditional medicine for the treatment of a number of health disorders including inflammation, stomach pain and tumors. The aim of the present study was to evaluate the cytotoxic, anti-inflammatory and anti-ulcerogenic activities of ethyl acetate (EaE), methanol (ME) and aqueous extracts (AE) of Castilleja tenuiflora wild grown (CtW) and in vitro plants (CtIv).

Material and method

Phytochemical analysis of the phenylethanoid glycoside (PhG) and iridoid glycoside (IG) components was carried out by chromatographic methods. In vitro cytotoxic activity of the extracts was evaluated in the following four carcinoma cell lines: colon (HF-6), breast (MCF-7), prostate (PC-3), and nasopharyngeal (KB). The topical anti-inflammatory activity was evaluated in mouse ear edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Anti-ulcerogenic activity was evaluated in rats using an absolute ethanol-induced acute gastric ulcer model.

Results

The main compounds in the extracts were isoverbascoside, verbascoside and aucubin and their concentration depended both on the solvent used and on the plant material origin. None of the extracts showed cytotoxicity against the tested cell lines. In contrast, CtWEaE, CtWAE and CtIvEaE (1.6 mg/ear) showed moderate anti-inflammatory activity similar to dexamethasone (1 mg/ear) with a 38.2, 39.3 and 49.1% decrease of inflammation, respectively. CtWEaE and CtIvEaE (100 mg/kg) showed high anti-ulcerogenic activity with 88.3 and 83.1% inhibition, respectively, compared to famotidine (20 mg/kg, 32.8% inhibition).

Conclusion

Castilleja tenuiflora extracts provided significant gastric protection in an acute ulcer induction model and topical anti-inflammatory activity in a mouse ear edema model. These activities are related to verbascoside and may explain the traditional use of Castilleja tenuiflora in the treatment of anti-inflammatory and gastrointestinal disorders. Cultured Castilleja tenuiflora plants (in vitro) exhibited pharmacological activities and also have the potential to produce bioactive compounds.     

Anti-Helicobacter pylori activity of plants used in Mexican traditional medicine for gastrointestinal disorders

Aim of the study

Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders.

Materials and methods

To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively.

Results

Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha × piperita (MIC 125 to <250 μg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 μg/ml) showed the highest inhibitory effect.

Conclusions

The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.     

In vitro antiplasmodial activity of plants used in Benin in traditional medicine to treat malaria

Aim of the study

The aim of the study was to evaluate the in vitro antiplasmodial activity of crude extracts of 12 plant species traditionally used in Benin for the treatment of malaria in order to validate their use.

Materials and methods

For each species, dichloromethane, methanol and total aqueous extracts were tested. The antiplasmodial activity of extracts was evaluated using the measurement of the plasmodial lactate dehydrogenase activity on chloroquine-sensitive (3D7) and resistant (W2) strains of Plasmodium falciparum. The selectivity of the different extracts was evaluated using the MTT test on J774 macrophage-like murine cells and WI38 human normal fibroblasts.

Results

The best growth inhibition of both strains of Plasmodium falciparum was observed with the dichloromethane extracts of Acanthospermum hispidum DC. (Asteraceae) (IC₅₀ = 7.5 μg/ml on 3D7 and 4.8 μg/ml on W2), Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (Rubiaceae) leaves and twigs (IC₅₀ = 13.8 and 11.3 μg/ml on 3D7 and IC₅₀ = 26.5 and 15.8 μg/ml on W2, respectively), Carpolobia lutea G.Don. (Polygalaceae) (IC₅₀ = 19.4 μg/ml on 3D7 and 8.1 μg/ml on W2) and Strychnos spinosa Lam. (Loganiaceae) leaves (IC₅₀ = 15.6 μg/ml on 3D7 and 8.9 μg/ml on W2). All these extracts had a low cytotoxicity.

Conclusion

Our study gives some justifications for the traditional uses of some investigated plants.     

Anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) against Trichostrongylid nematodes of sheep

Ethnopharmacological relevance

Ziziphus nummularia (Rhamnaceae) and Acacia nilotica (Fabaceae) are being used as anthelmintics in ethnoveterinary medicinal system of Pakistan.

Aim of the study

Present study was conducted to determine the anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) in order to justify their traditional use in veterinary medicine.

Materials and methods

In vitro anthelmintic activity of crude methanolic extract (CME) of both the plants was determined against Haemonchus contortus by the adult motility assay, the egg hatch test and the larval development assay. In vivo anthelmintic activity was evaluated in sheep naturally infected with gastrointestinal nematodes by administering increasing doses of crude powder (CP) and CME (1.0–3.0 g/kg).

Results

Both the plants exhibited dose- and time-dependent anthelmintic effects by causing mortality of worms, and inhibiting egg hatching and larval development. Acacia nilotica (LC₅₀ = 512.86 and 194.98 μg/ml) was found to be more potent than Ziziphus nummularia (LC₅₀ = 676.08 and 398.11 μg/ml) in egg hatch test and larval development assay, respectively. In vivo, maximum fecal egg count reduction (84.7%) was recorded on day 13 post-treatment in sheep treated with Ziziphus nummularia CME (3.0 g/kg) followed by 78.5% on same day with Acacia nilotica CME (3.0 g/kg).

Conclusions

These data show that both Ziziphus nummularia and Acacia nilotica possess anthelmintic activity in vitro and in vivo, justifying their use in traditional veterinary medicine in Pakistan.     

In vitro genotoxicity of Melaleuca alternifolia essential oil in human lymphocytes

Ethnopharmacological relevance

The volatile essential oil derived from the plant Melaleuca alternifolia, also called tea tree oil (TTO), is largely employed for its antimicrobial properties against several human pathogens. It is used in many topical formulations to treat cutaneous infections.

Aim of the study

Since very few studies have been done on the safety and toxicity of the crude Melaleuca alternifolia essential oil, current investigation evaluates the possible genotoxic effects of TTO in human lymphocyte cultures.

Material and methods

The composition of current TTO sample was determined by GC/MS and NMR. The level of cytotoxicity in TTO treated cultures was determined by decrease of mitotic index when compared to that in negative control. The genotoxic potential of TTO was assessed by the in vitro mammalian cell micronucleus and the chromosome aberrations (CA) tests.

Results

Twenty-seven compounds were identified, accounting for 98.9% of the constituents. Terpinen-4-ol (42.8%), γ-terpinene (20.4%), p-cymene (9.6%), α-terpinene (7.9%), 1,8-cineole (3%), α-terpineol (2.8%) and α-pinene (2.4%) were the major compounds of the oil sample. None of the tested TTO concentrations (95 μg/ml, 182 μg/ml and 365 μg/ml) caused a significant increase in the observed frequencies of micronuclei when compared to those in the untreated cultures (negative control). Additionally, no significant differences regarding the frequencies of CA were observed among the tested TTO concentrations and the negative control.

Conclusions

Results demonstrate that TTO, in the tested concentrations, is not genotoxic in in vitro mammalian cells.     

Immunomodulatory potential of rhizome and seed extracts of Nelumbo nucifera Gaertn.

Ethnopharmacological relevance

Nelumbo nucifera Gaertn. (Nymphaeaceae) is a well-known aquatic plant which has been used for the treatment of several disorders including skin disease, cough, inflammation, fever and many other disorders.

Aim of the study

To explore the immunomodulatory activity of extract of rhizome (NNRE) and seed (NNSE) of the plant.

Materials and methods

The immunomodulatory activity of NNRE and NNSE was evaluated using various in vivo models including the total and differential leukocyte count (TLC and DLC), nitroblue-tetrazolium reduction (NBT) test, neutrophil adhesion test, phagocytic response and delayed type hypersensitivity (DTH) reaction. Sheep red blood cells (SRBC, 5 × 10⁹ cells/ml) were used to immunize the animals. NNRE and NNSE at the doses of 100 and 300 mg/kg were administrated.

Result

The TLC and lymphocyte count increased significantly but the neutrophil count was decreased for NNRE and NNSE treated groups compared to the control. A dose-dependent potentiation of DTH reaction induced by SRBC was observed from the extracts. The percentage of neutrophil adhesion to the nylon fiber was increased in NNRE treated groups (63.22 and 62.91%) compared to the NNSE treated group (54.86 and 54.23%). A potential phagocytic response was seen on treatment of the extracts, and significant changes were observed in the formation of formazone crystals.

Conclusion

This finding suggests that the extract of rhizome and seed Nelumbo nucifera stimulate defense system by modulating several immunological parameters.     

In vitro and in vivo anti-Helicobacter pylori activity of Calophyllum brasiliense Camb.

Aims of the study

Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in the hilly and forested regions of Brazil. Preparations from its stem bark are popular remedies for the treatment of chronic ulcers. Since earlier investigations on bark extracts evidenced gastroprotective and gastric acid inhibitory properties, this study evaluated the effects of hydroethanolic extract (HEECb) and the dichloromethanic fraction (DCMF), from Calophyllum brasiliense stem bark, against Helicobacter pylori, in vitro and in vivo.

Materials and methods

The in vitro assays were performed using the disk diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) values. The test substances were evaluated in vivo taking into account the delay in the gastric ulcer healing in Wistar rats, infected with Helicobacter pylori.

Results

DCMF appeared the most active and potent in vitro against Helicobacter pylori growth with an MIC of 31 μg/mL. In the in vivo assays, rats ulcerated by acetic acid, and inoculated with Helicobacter pylori showed a marked delay in ulcer healing. Treatment with HEECb (50, 100 and 200 mg/kg) and DCMF (100 and 200 mg/kg) reduced the ulcerated area in a dose-dependent manner. While DCMF, at 200 mg/kg, increased the prostaglandin E₂ (PGE₂) level, both HEECb and DCMF decreased the number of urease-positive animals, as confirmed by the reduction of Helicobacter pylori presence in histopathological analysis.

Conclusion

The results suggest that the antiulcer activity of Calophyllum brasiliense is due, in part, to its anti-Helicobacter pylori action, validating the popular use of this species.     

In vitro pharmacological evaluation of three Barleria species

Ethnopharmacological relevance

Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

Aims of the study

This study investigated the antibacterial effects and underlying mechanisms of action of the anti-inflammatory activities of different parts of three Barleria species of South African origin.

Materials and methods

Crude extracts of different parts of three Barleria species were investigated in vitro for their biological activity. Antibacterial activity was evaluated using the micro-dilution assay against two Gram-positive and two Gram-negative bacteria. Anti-inflammatory activity was evaluated using the cyclooxygenase COX-1 and COX-2 assays.

Results

All the extracts showed broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.059 to 6.25 mg/ml. Twelve out of 21 crude extracts evaluated showed good activity (>70%) in the COX-1 assay while 10 extracts showed good activity in the COX-2 assay. All the petroleum ether extracts (except B. prionitis stem) exhibited good inhibition of prostaglandin synthesis in COX-1.

Conclusion

The results demonstrated the therapeutic potential of these plants as antibacterial and anti-inflammatory agents. Their anti-inflammatory properties are mediated by the inhibition of the cyclooxygenase enzymes.     

Toxicity,antimicrobial and anthelmintic activities of Vernonia guineensis Benth. (Asteraceae) crude extracts

Ethnopharmacological relevance

This study examined the antibacterial, antifungal, and anthelmintic properties of extracts obtained from the plant Vernonia guineensis, a plant commonly used in traditional Cameroonian medicine.

Materials and methods

For in vitro studies, 10 g of leaf and tuber powder from V. guineensis was extracted separately using dichloromethane, methanol and distilled water. The extracts were dried in vacuo and used for antimicrobial and anthelmintic activity studies. In the antimicrobial assay, extracts were tested against bacterial and fungal organisms including; Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Aspergillus fumigatus, Candida albicans and Trichophyton mentagrophytes. In the anthelmintic assay, larval and adult stages of the hookworm Ancylostoma ceylanicum and the mouse nematode Trichuris muris were used. For the acute toxicity test, male and female rats of 150–200 g body weight were used in the experiment. The aqueous extract of V. guineensis tubers was administered in 4 doses of 500, 1000, 2000 and 4000 mg/kg per group (n=6), respectively, and the control group received distilled water.

Results

The crude extracts exhibited weak antibacterial and antifungal activity except for the dichloromethane extract, which showed moderate activity against A. fumigatus (MIC=200 μg/ml). In the anthelmintic assay, the organic extracts of the tubers had 100% killing efficacy against T. muris at 2 mg/ml in 48 h, while the aqueous extract showed no activity. The organic leaf extracts demonstrated potent activity killing 100% of the adult worms 1 mg/ml in 24 h. The aqueous leaf extract was active at 2 mg/ml in 72 h, killing 100% of the adult worms. In the acute toxicity test, V. guineensis did not produce any toxic signs or death at the maximum concentration of 4000 mg/kg.

Conclusion

Crude extracts from V. guineensis possess anthelmintic activity against T. muris with only weak antibiotic activity. Acute administration of aqueous extract from V. guineensis tubers did not produce toxic effects in rats. The absence of acute toxicity at the highest concentration tested indicates that the tea decoction from V. guineensis extract is safe at concentrations ≤4000 mg/kg.