Inulin-rich fractions from Vernonia kotschyana roots have anti-ulcer activity

Ethnopharmacological relevance

Roots from Vernonia kotschyana are on the national list of essential drugs in Mali (West-Africa). It is sold under the name Gastrosedal and it used against ailments like gastritis and gastric ulcer. To evaluate the anti-ulcer, immunomodulating activities and toxicity of 50 and 100 °C water extracts, Vk50-I and Vk100-I respectively, from the roots of Vernonia kotschyana.

Materials and methods

Characterization of extracts was carried out by GC, colorimetric and biological methods. Vk50-I and Vk100-I were administrated 50 min before induction of gastric ulcers in mice with 0.3 M HCl–60% EtOH. Inhibition of ulcer formation was calculated based on lesion index. Immunological activities were measured by complement fixation and macrophage activation. Toxicity assay was carried out on brine shrimps.

Results

Vk50-I (98% inulin) and Vk100-I (83% inulin) from Vernonia kotschyana significantly inhibited the formation of gastric lesions in mice (100 mg/kg). No immunomodulating activities or toxicity were found.

Conclusions

Our results show that inulin is probably partly responsible for the anti-ulcer activity of Gastrosedal. In addition, it is possible that water soluble polysaccharides (mainly inulin) have an indirect impact on the general health of the GI.     

Enzyme inhibition,antioxidant and immunomodulatory activities,and brine shrimp toxicity of extracts from the root bark,stem bark and leaves of Terminalia macroptera

Ethnopharmacological relevance

The root bark, stem bark and leaves of Terminalia macroptera have been traditionally used against a variety of ailments such as wounds, hepatitis, malaria, fever, cough, and diarrhea as well as tuberculosis and skin diseases in African folk medicine. Boiling water extracts of Terminalia macroptera, administered orally, are the most common preparations of this plant used by the traditional healers in Mali. This study aimed to investigate the inhibition of the activities of α-glucosidase, 15-lipoxygenase and xanthine oxidase, DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of different extracts obtained by boiling water extraction (BWE) and by ASE (accelerated solvent extraction) with ethanol, ethanol–water and water as extractants from different plant parts of Terminalia macroptera.

Materials and methods

27 different crude extracts were obtained by BWE and ASE from root bark, stem bark and leaves of Terminalia macroptera. The total phenolic and carbohydrate contents, enzyme inhibition activities (α-glucosidase, 15-lipoxygenase and xanthine oxidase), DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of these extracts were evaluated. Principal component analysis (PCA) was applied for total biological activities evaluation.

Results

Several of the extracts from root bark, stem bark and leaves of Terminalia macroptera obtained by BWE and ASE showed potent enzyme inhibition activities, radical-scavenging properties and complement fixation activities. None of the extracts are toxic against brine shrimp larvae in the test concentration. Based on the results from PCA, the ASE ethanol extracts of root bark and stem bark and the low molecular weight fraction of the 50% ethanol–water extract of leaves showed the highest total biological activities. The boiling water extracts were less active, but the bark extracts showed activity as α-glucosidase inhibitors and radical scavengers, the leaf extract being less active.

Conclusion

The observed enzyme inhibition activities, radical scavenging properties and complement fixation activities may explain some of the traditional uses of this medicinal tree, such as in wound healing and against diabetes.     

Contribution to the ethnopharmacological and anti-Helicobacter pylori knowledge of Cyrtocarpa procera Kunth (Anacardiaceae)

Ethnopharmacological relevance

Cyrtocarpa procera Kunth (Anacardiaceae) is a Mexican endemic tree; its bark has been traditionally employed in Mexico since prehispanic times to relieve digestive disorders.

Aim of the study

To perform an acute evaluation of the toxicity, gastroprotective, and anti-inflammatory properties, as well as the anti-Helicobacter pylori action of C. procera bark extracts, in order to determine polypharmalcological activities.

Materials and methods

Five different polarity extracts (hexanic, CH₂Cl₂, CH₂Cl₂-MeOH, methanolic, and aqueous) were prepared. Each of them was evaluated in the following acute mice models: toxicity Lorke test, ethanol-induced gastric ulcer, TPA-induced ear edema; and the in vitro anti-H. pylori activity with a broth dilution method.

Results

None of the extracts were toxic under acute administration. The methanolic, hexanic, and aqueous extracts possess remarkable gastroprotective activity. All the extracts inhibit H. pylori growth, being the hexanic the most active, and only this one showed significant anti-inflammatory effect.

Conclusions

This work demonstrates that C. procera bark has polypharmacological activities; which makes it a promising asset to the development of an integral treatment for gastritis or peptic ulcer related or not to H. pylori. Our findings contribute to the ethnopharmacological knowledge about this species.     

Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock

Ethnopharmacological relevance

An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine.

Aim of study

Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity.

Materials and methods

Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice.

Results

Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID₅₀ (dose giving 50% oedema inhibition) values ranging from 112 μg/cm² (Byrsonima crassifolia) to 183 μg/cm² (Sphagneticola trilobata). As reference, ID₅₀ of the non-steroidal anti-inflammatory drug indomethacin was 93 μg/cm².

Conclusions

Lipophilic extracts from these species can be regarded as potential sources of anti-inflammatory principles.     

Anti-Helicobacter pylori, gastroprotective,anti-inflammatory,and cytotoxic activities of methanolic extracts of five different populations of Hippocratea celastroides collected in Mexico

Ethnopharmacological relevance

The root barks of Hippocratea celastroides have been used for decades in Mexican traditional medicine to treat gastritis and ulcers. To investigate the anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts obtained from the leaves, stems, and root bark of Hippocratea celastroides collected in five different localities in Mexico, during the winter of 2009, in order to establish differences in biological activities in terms of plant organs, as well as places of collection.

Materials and methods

Whole individuals were collected in five separate localities in Mexico: La Mancha, Veracruz (VL), Yautepec, Morelos (MY), Jojutla, Morelos (MJ), Temalac, Guerrero (GT), and Landa de Matamoros, Querétaro (QL). Methanolic crude extracts from wild plant specimens were tested using in vivo ethanol-induced mice gastric ulcer model, and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ear edema in mice assay, and in vitro anti-Helicobacter pylori model, and carcinoma cell line cytotoxic assays.

Results and conclusions

The leaves, stems, and root bark from MY specimens, as well as the leaves and root bark of materials from VL, presented the highest activity against Helicobacter pylori (MIC values ranging from 7.81 to 31.25 μg/ml). Most gastroprotective effects were displayed by the leaves of plants collected in MY, with 89.85±1.91% of protection (300 mg/kg) and an ED₅₀=27 mg/kg, which was corroborated by histological analysis. The root bark extracts from MY achieved the highest edema inhibition values (ED₅₀=0.18 mg/ear), which were comparable to indomethacin (ED₅₀=0.16 mg/ear). Finally, all extracts from MY (three plant parts) were cytotoxic against nasopharyngeal (KB), breast (MCF-7), and colon (HCT-116) carcinoma cell lines with IC₅₀ values between 1.18 and 9.77 μg/ml, except that no activity was detected for root bark extracts against HCT-116 normal fibroblasts. The activities of methanolic extracts from leaves, stems and root bark of plants collected in five different locations varied considerably, representing a notable problem facing the quality control of the plant material from Hippocratea celastroides used for medicinal purposes. The ethnomedical information of this plant in regards to treating gastritis and ulcers was strongly evidenced by the findings of the experimental models employed in this study.     

Studies of biological properties of Uncaria tomentosa extracts on human blood mononuclear cells

Ethnopharmacological relevance

Uncaria tomentosa (Willd.) DC is a lignified climbing plant from South and Central America, which (under the name of “vilcacora” or “cat's claw”) has become highly popular in many countries due to its proven immunostimmulatory and anti-inflammatory activities and also with respect to its anticancer and antioxidative effects. There are insufficient data on the mechanism of U. tomentosa action on normal blood mononuclear cells.

Aim of the study

The aim of the study was to analyze the impact of ethanol and aqueous extracts from bark and leaves of Uncaria tomentosa on the structure and function of human mononuclear cells and to find out whether the kind of extractant used modulates biological activity of the extracts studied.

Materials and methods

Plant material consisted of four different extracts: (1) ethanol extract from leaves, (2) aqueous extract from leaves, (3) ethanol extract from bark and (4) aqueous extract from bark. The effect of these extracts on protein damage as well as on free-radical formation in human peripheral blood mononuclear cells was analyzed. Moreover, changes in viability, size, and granularity as well as apoptotic alterations in human blood mononuclear cells exposed to U. tomentosa extracts were investigated.

Results

The oxidative changes were observed in mononuclear blood cells exposed to both ethanol and aqueous extracts obtained from bark and leaves. Moreover, in the cells studied the extracts from U. tomentosa induced apoptosis and a decrease in viability of mononuclear blood cells, with the exception of aqueous extract from leaves. Additionally, no statistically significant changes in the cell size were observed both for aqueous extracts from leaves and bark. Changes in the blood mononuclear cell granularity were observed at 250 μg/mL for all extracts examined. The strongest changes were observed for the ethanol extract of the bark, which increased cell granularity at 50 μg/mL and changed cell size at 100 μg/mL.

Conclusion

The conducted research showed differences in biological activity between aqueous and ethanol extracts. It was observed that ethanol extracts exhibited stronger negative effects on mononuclear blood cells. The kind of extractant used had a significant influence of the chemical composition of the tested extracts. The ethanol extract from bark containing a high amount of polyphenols and alkaloids revealed the highest pro-apoptotic effect.     

Davilla elliptica and Davilla nitida: Gastroprotective,anti-inflammatory immunomodulatory and anti-Helicobacter pylori action

Ethnopharmacological relevance

Davilla elliptica and Davilla nitida are species commonly found in the Brazilian Cerrado biome.

Aim of the study

Based on ethnopharmacological and phytochemical analyses, methanolic extracts from leaves of Davilla elliptica (EDE) and Davilla nitida (EDN) were evaluated for their anti-ulcer, anti-inflammatory, immunological and anti-Helicobacter pylori activities.

Materials and methods

The gastroprotective action of both extracts was evaluated in rodent experimental models (HCl/ethanol, ethanol or NSAID). We also evaluated anti-inflammatory (carrageenin-induced rat hind paw edema), immunomodulatory (murine peritoneal macrophages) and antibacterial action of both extracts against a standard strain of Helicobacter pylori.

Results

EDE and EDN (500 mg/kg) were able to protect gastric mucosa against HCl/ethanol solution (EDE 63%; EDN 59%), absolute ethanol (EDE 95%; EDN 88%), and also against injurious effect of NSAID (EDE 77%; EDN 67%). When EDE and EDN were challenged with sulfhydryl depleter compound, the gastroprotective action of both extracts was completely abolished. EDE had gastroprotective effect related to increase of glutathione bioavailability and stimulated higher levels of NO, H₂O₂ and TNF-α production. Otherwise EDN showed better anti-Helicobacter pylori action than EDE. Neither extracts presented anti-inflammatory activity by oral route.

Conclusion

The phytochemical investigation showed that both extracts possess phenolic acid derivatives, acylglycoflavonoids and condensed tannins with evident quantitative variations that probably influenced the pharmacological differences between extracts.     

Complement activity of polysaccharides from three different plant parts of Terminalia macroptera extracted as healers do

Ethnopharmacological relevance

Water decoctions of the root bark, stem bark and leaves of Terminalia macroptera are used by traditional healers in Mali to cure a wide range of illnesses, such as wounds, hepatitis, malaria, fever, cough and diarrhea as well as tuberculosis. Plant polysaccharides isolated from crude water extracts have previously shown effects related to the immune system. The aims of this study are comparing the properties of the polysaccharides among different plant parts, as well as relationship between chemical characteristics and complement fixation activities when the plant material has been extracted as the traditional healers do, with boiling water directly.

Materials and methods

Root bark, stem bark and leaves of Terminalia macroptera were extracted by boiling water, and five purified polysaccharide fractions were obtained by anion exchange chromatography and gel filtration. Chemical compositions were determined by GC of the TMS derivatives of the methyl-glycosides and the linkage determined after permethylation and GC–MS of the derived partly methylated alditol acetates. The bioactivity was determined by the complement fixation assay of the crude extracts and purified fractions.

Results

The acidic fraction TRBD-I-I isolated from the root bark was the most active of the fractions isolated. Structural studies showed that all purified fractions are of pectic nature, containing rhamnogalacturonan type I backbone. Arabinogalactan type II side chains were present in all fractions except TRBD-I-II. The observed differences in complement fixation activities among the five purified polysaccharide fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.

Conclusion

The crude extracts from root bark and stem bark have similar total activities, both higher than those from leaves. The root bark, leaves and stem bark are all good sources for fractions containing bioactive polysaccharides. But due to sustainability, it is prefer to use leaves rather than the other two plant parts, and then the dosage by weight must be higher when using leaves.     

Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts

Aim of the study

The present study was carried out to investigate analgesic and anti-inflammatory activities of Cassia siamea Lam stem bark extracts. We have also determined the cytotoxicity of each extract.

Materials and methods

C. siamea, a widespread medicinal plant traditionally used in sub-Saharan Africa, was collected in Congo Brazzaville. Stem bark was extracted with petroleum ether (CSE1), chloroform (CSE2), ethanol (CSE3) and water (CSE4). Analgesic, anti-inflammatory and antipyretic activities of these extracts were assessed in rats with hot plate test, paw pressure and carrageenan induced paw oedema. Cytotoxicity was assessed against KB and Vero cells.

Results

At the doses used (100, 200, and 400 mg/kg) ethanol and water extracts showed significant and dose-dependent analgesic and anti-inflammatory effects. None of the extracts had cytotoxic activity on KB and Vero cell lines and the most active extracts (CSE3 and CSE4) had no acute toxicity.

Conclusions

The study highlighted the analgesic and anti-inflammatory of C. siamea stem bark. Four major families of compounds present in the plant may explain these activities: triterpenes (lupeol, oleanolic acid, ursolic acid, friedelin, betulin), flavonoids (apigenin, kaempferol, luteolin), anthraquinones (emodin), phytosterols (stigmasterol, beta-sitosterol).     

Anti-ulcer activity of Cyrtocarpa procera analogous to that of Amphipterygium adstringens, both assayed on the experimental gastric injury in rats

Ethnopharmacological relevance

The bark of Amphipterygium adstringens (Aa) is commonly mixed or adulterated with the bark of Cyrtocarpa procera (Cp) and sold in Mexican markets. Aa is a well known species in Mexico used as decoction to relieve ulcers. Scientific reports reinforcing the anti-ulcer activity of Aa have been previously described, but those describing the anti-ulcer properties of Cp as a substitute for Aa in folk medicine are scarce.

Aim of the study

To investigate anatomical and phytochemical differences between these species, as well as to assess the anti-ulcer effect of Cp extracts in comparison to the Aa extracts.

Material and methods

Anatomical micro-technique and physical and spectroscopic data were used to analyze differences between Cp and Aa. Regard to the pharmacological activity, it was assessed by using the ethanol-induced gastric damage model in rats.

Results

Whereas the bark anatomy of Aa was characterized by vertical canals in the periderm and the rare occurrence of fibers in its phloem, a periderm without vertical canals and abundant fibers in the phloem were distinctive features of Cp. Phytochemical analysis allowed the identification of tirucallane, masticadienonic and 3α-hydroxymasticadienonic acids as major components in Aa, while β-amyrin and β-sitosterol were obtained from Cp. Gastric lesions observed in the control group decreased in the presence of 100 mg/kg of hexane, ethyl acetate and methanol extracts from the normal or regenerated bark of Cp, thus resembling the anti-ulcer effect of Aa. Nevertheless, major anti-ulcer potency was observed with the most active methanol extract from Cp obtained from normal [the effective dose fifty ED₅₀ = 45.54 mg/kg] or regenerated (ED₅₀ = 36.68 mg/kg) bark in comparison to Aa (ED₅₀ = 115.64 mg/kg).

Conclusion

Chemical and anatomical differences were found between these species, but since the anti-ulcer activity of Cp is similar to that shown by Aa our results reinforce the use of both species for the relief of gastric ulcer in folk medicine.     

In vitro evidence of phyto-synergy for plant part combinations of Croton gratissimus (Euphorbiaceae) used in African traditional healing

Aim of the study

Despite the extensive traditional use of Croton gratissimus Burch. var. gratissimus for medicinal purposes, scientific studies validating the therapeutic properties of this indigenous plant are lacking. As the bark, roots and leaves of C. gratissimus are used separately as well as in combination, this study focused on determining antimicrobial efficacies of the plant parts independently and in combination to assess possible pharmacological interactions (e.g. synergy, antagonism).

Material and Methods

The hydro-distilled leaf essential oil and extracts of bark, root and leaf were comparatively assessed for antimicrobial activity by means of microdilution minimum inhibitory concentration (MIC). The fractional inhibitory concentrations (FIC) were determined for the leaf and root (1:1), bark and root (1:1), leaf and bark (1:1) combination. Isobolograms were plotted to demonstrate interactions between various ratios of the roots and leaves.

Results

The MIC and FIC results indicated variable efficacies for the various plant part combinations, the greatest of which was noted for Cryptococcus neoformans in the root and leaf combination (MIC 0.4 mg/ml and FIC of 0.4). Isobolograms indicated the greatest synergy for Bacillus cereus, Candida albicans and Cryptococcus neoformans.

Conclusion

The observed synergistic interactions clearly indicate that the reductionist approach may often be short-sighted and that biological activity may be improved through combination therapy, where different complex metabolic pools collectively contribute to the enhanced effect.     

Alpha-amylase inhibitory activity of two Anthocleista species and in vivo rat model anti-diabetic activities of Anthocleista djalonensis extracts and fractions

Ethnopharmacological relevance

Anthocleista djalonensis (A. Chev) and Anthocleista vogelii Planch are plants being used in West Africa traditionally to treat various diseases such as malaria, hernia, hypertension, stomach aches, hemorrhoids, syphilis, and diabetes. Diabetes causes about 5% of all deaths globally each year. Chemotherapeutic agents such as biguanides, sulfonylureas, and thiozolidinediones are available for the treatment of diabetes, however, they have undesirable side effects. The need for newer, more effective and less toxic drugs is imperative and the biodiversity of Nigeria has a high potential for drug discovery based on plants used in the ethnomedicine.

Aim of the study

To investigate the leaves, stem bark and roots of these plants for their probable alpha-amylase inhibitory activities and establish their anti-diabetic activities. The overall goal is do bioassay-guided fractionation and isolation of active anti-diabetic compounds.

Materials and methods

Powdered samples (leaves, stem bark and roots) macerated with 80% aqueous methanol were evaluated in vitro using alpha-amylase inhibitory assay while in vivo investigations were carried out on hyperglycemic rats. Diabetes was induced in albino rats by an intraperitoneal injection of alloxan monohydrate (80 mg/kg). Plant extracts (1 g/kg) were given orally for 7 days, while blood glucose levels were monitored using a one touch glucometer. The crude methanol extracts found to be most active were further partitioned into hexane and ethyl acetate fractions which were also tested in vivo on the diabetic animals.

Results

The leaves and stem bark crude methanol extracts of Anthocleista djalonensis gave comparable α-amylase inhibition of 73.66% and 72.90%, respectively which were quite higher than the 38.93% and 22.90% of the same plant parts given by Anthocleista vogelii. The crude stem bark extract of Anthocleista djalonensis exhibited significant peak blood glucose reduction on day 6 (72.59%, p<0.05) which was higher than the leaves or roots which gave 45.73% and 47.46% (p<0.05), respectively The stem bark ethyl acetate fraction of Anthocleista djalonensis gave reduction in blood glucose level of 60.86% (p<0.05).

Conclusion

From our results, the leaves, stem bark and whole root of both plants exhibited α-amylase inhibitory activities with Anthocleista djalonensis also showing good anti-diabetic activities in vivo indicating that they contain active principles for the management of diabetes. There is justification for the use of the plants traditionally to manage diabetes.     

Phenological and geographical influence in the concentration of selected bioactive 4-phenylcoumarins and chlorogenic acid in Hintonia latiflora leaves

Ethnopharmacological relevance

Hintonia latiflora is a Mexican medicinal plant with well-documented ethnomedical record comprising more than 400 years; in modern Mexico is used for treating several maladies such as diabetes and gastric ulcers. Although the pharmacological actions of the stem-bark and leaves have been demonstrated, the phenological and geographical effect on the concentration of active principles remains unexplored.

Aim of the study

The main goals of this study were to analyze the amount of selected 4-phenylcoumarins and chlorogenic acid in the leaves in order to assess the best harvesting period, and consequently their pharmacological efficacy. In addition, the preclinical antidiabetic efficacy of the infusion of the leaves was corroborated using standard pharmacological tests.

Materials and methods

The aqueous extracts from the leaves of Hintonia latiflora were prepared by infusion. For phenological and geographical comparison, leaves of Hintonia latiflora were collected in two different regions in Chihuahua and Michoacán. The material was analyzed by UPLC applying an analytical method that developed and validated for this purpose following the ICH guidelines. Investigation of the antidiabetic action was accomplished using an acute hypoglycemic test and oral glucose and sucrose tolerance tests.

Results

The validated analytical method was successfully applied for quantifying chlorogenic acid (1) and 4-phenylcoumarins (2–5) in the leaves of 12 different batches (1–12) during one-year period, and seven different batches for each geographical region; the concentration of the metabolites at the phenological cycle was significantly different, their concentration increased during the pre-senescence phase whereas in the leaf renovation stage the highest concentration of 2–5 was reached. The overall analysis of the active compounds concentration between the two populations investigated seems to be less important than the phenological variations. The aqueous extract of the leaves of Hintonia latiflora exerted its antidiabetic effect by different mechanisms showing comparable effect to the organic extract.

Conclusions

The findings of the present investigation reveal that the best harvest season for the leaves of Hintonia latiflora is between the leaves renovation and senescence stages avoiding the flowering period. In addition, no significant differences were found among the two different geographical populations analyzed. The infusions of the leaves, rich in 4-phenylcoumarins and chlorogenic acid, showed comparable antidiabetic action than the organic extract.     

Role of Sida cordifolia L. leaves on biochemical and antioxidant profile during myocardial injury

Ethnopharmacological relevance

The Sida cordifolia L. (Family: Malvaceae) is a widely allocated herb by folk tribes of Gujarat state of India for the treatment of coronary manifestations. However, no published data relevant to use of the plant is available.

Aim of the study

The aim of the present study was to evaluate the antioxidant and biochemical profile of hydroalcoholic extract of Sida cordifolia L. (HESC) leaves against myocardial infarction (MI) in rats.

Materials and methods

Albino rats were administered HESC (100 and 500 mg/kg) and propranolol (10 mg/kg) once daily orally for 30 days. At the end of treatment period, MI was induced by administering isoproterenol (ISO) or by subjecting heart to ischemia reperfusion injury (IRI). Endogenous biomarkers (LDH and CK-MB) and antioxidants (SOD and catalase) were estimated in serum/perfusate and heart tissue homogenate (HTH).

Results

The LDH and CK-MB activities were elevated in HTH and depleted in serum/perfusate of HESC and propranolol groups when compared to ISO/IRI control. Further, it was found that both doses significantly increased endogenous antioxidants in HTH. Moreover, biochemical findings were supported by histopathological observations.

Conclusion

The result confirm, at least in part, for the use of Sida cordifolia in folk medicine to treat MI.     

Antimicrobial,anti-inflammatory and mutagenic investigation of the South African tree aloe (Aloe barberae)

Ethnopharmacology relevance

In recent times, many products ranging from aloe drinks to aloe gels, powders, capsules, and creams have appeared on the commercial market prepared from different aloe species including Aloe barberae. These products are used in ethnomedicine to treat various conditions including gastrointestinal disorders, insect bites, skin burns and other skin injuries by traditional communities.

Aim of the study

This study was aimed at evaluating the antibacterial, antifungal and anti-inflammatory activities as well as genotoxic effects of different extracts of Aloe barberae.

Materials and methods

Organic and water extracts of the upper stem, young bark, mature bark, leaves and roots of the South African tree aloe (Aloe barberae) were evaluated for their antimicrobial [Gram-positive (Bacillus subtilis and Staphylococcus aureus), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria as well as the fungus Candida albicans], anti-inflammatory (COX-1 and COX-2) and mutagenic properties (Ames test). Thin layer chromatography (TLC) was used to compare the phytochemical profiles of different extracts of Aloe barberae.

Results

The petroleum ether (PE) and dichloromethane (DCM) extracts of the mature bark, leaves and roots exhibited good activity against all the bacteria and fungus Candida albicans with minimum inhibitory concentrations (MIC) ranging from 0.195 to 1.56 mg/ml. All the PE extracts evaluated showed a high activity (>70%) in both COX-1 and COX-2 assays. Apart from the organic extracts of the root with consistently good activity (>70%), all the remaining extracts showed moderate activity (40–69%) in COX-1 assay. The PE extracts also showed a dose dependent increase in activity. Ultraviolet (UV) spectrum of the leaves and root EtOH extracts indicated the presence of compounds that could absorb UV light (wavelength: 190–820 nm). None of the extracts had a mutagenic effect in the Salmonella/microsome assay against a tester strain, TA98.

Conclusion

Activity observed in the bark, leaves and roots of Aloe barberae validates its use in commercial herbal products, ethnobotany and ethnoveterinary medicine by South African communities and small scale farmers to treat various conditions.     

Antiprotozoal screening and cytotoxicity of extracts and fractions from the leaves,stem bark and root bark of Alstonia congensis

Ethnopharmacological relevance

To evaluate the antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Alstonia congensis (Apocynaceae), used in traditional medicine against parasitic diseases.

Materials and methods

The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root bark of Alstonia congensis were tested in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, Trypanosoma cruzi, Lesihamania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Their cytotoxicity on MRC-5 cells (human lung fibroblasts) was evaluated as well.

Results

The aqueous and 80% MeOH extracts and a series of subfractions of each plant part exhibited pronounced antiprotozoal activity against the K1 strain of Plasmodium falciparum with IC₅₀ values ranging from 2 to 5 µg/ml, and good activity against Trypanosoma brucei brucei and Trypanosoma cruzi with IC₅₀ values ranging between 5 and 10 µg/ml. The residual 80% MeOH extract from the leaves, and the total alkaloid extract from stem and root bark were the only subfractions active against Leishmania infantum with IC₅₀ values <10 µg/ml. None of the samples from the root bark was cytotoxic against MRC-cell lines (CC₅₀>64 µg/ml). In general, the aqueous extract (traditional decoction) showed the highest selectivity, especially against Plasmodium falciparum.

Conclusion

These results can partly support and justify the traditional use of these plant parts of Alstonina congensis as raw materials for the preparation of traditional remedies to treat parasitic diseases such as malaria and trypanosomiasis.     

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.     

Evaluation of the anti-stress and anticonvulsant activities of leaf extract of Alchornea cordifolia in mice

Aim of the study

The extract of the leaves of Alchornea cordifolia (AC) is extensively used in ethnomedicine for ulcers, rheumatic pains, febrile convulsions and for enhancing physical performance. In this study, the anti-stress and anticonvulsant activities of the aqueous leaf extract of Alchornea cordifolia were investigated in mice.

Materials and methods

The anti-stress activity was assessed based on the ability of the extract to alter the duration of immobility, in the forced swim endurance test, whilst a picrotoxin-treated animal, was employed as the model for convulsive seizures.

Results

The extract (100–400 mg/kg) given orally was found to significantly (p < 0.05) reduce the duration of immobility, which suggest an anti-stress/anti-fatigue property. However, AC when tested at doses between 100 and 400 mg/kg did not prevent convulsions induced by picrotoxin in mice. The acute toxicity study carried out in mice revealed that the extract was well tolerated by the animals, as no death was observed at oral doses of 500–4000 mg/kg.

Conclusions

The results of this preliminary study provide evidence, which may support the use of Alchornea cordifolia against stress or fatigue in ethnomedicine.     

Protective effect of ethyl acetate fraction of Acacia ferruginea DC. against ethanol-induced gastric ulcer in rats

Ethnopharmacological relevance

In traditional systems of medicine, stem bark of Acacia ferruginea DC. is used for the treatment of itching, leucoderma, ulcers, stomatitis and diseases of the blood. In the present study, we determined antioxidant and anti-ulcerogenic activities of Acacia ferruginea stem bark.

Materials and methods

Acetone extract and its sub-fractions of Acacia ferruginea stem bark were subjected to assess their antioxidant potential using various in vitro systems such as DPPH^•, ABTS^•+ scavenging, FRAP and phosphomolybdenum reduction activities. Based on the antioxidant potential, the ethyl acetate fraction was used to evaluate the protective effect of ethanol-induced gastric damage in rat model. Enzyme activities such as superoxide dismutase, glutathione, catalase and lipid peroxidation were also determined in the stomach tissues.

Results

Ethyl acetate fraction (AFE) of Acacia ferruginea stem bark registered higher antioxidant and free radical scavenging activities than the crude acetone extract and other fractions. In addition, AFE exhibited that the IC₅₀ values of DPPH (2.5 µg/ml) and ABTS (1.8 µg/ml) were lower when compared to the standard quercetin (12.4 µg/ml and 4.7 µg/ml, respectively). In ethanol induced gastric ulcer, administration of AFE at doses of 10 mg/kg, 50 mg/kg and 100 mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently significant changes were observed in enzyme activities such as SOD, CAT, GSH and LPO in the stomach tissues when compared with ethanol control group.

Conclusion

It is concluded that the ethyl acetate fraction of Acacia ferruginea stem bark possessed higher antioxidant and anti-ulcerogenic activities. Based on the results, we suggest that Acacia ferruginea stem bark has potential to provide a therapeutic approach to ethanol mediated ulcer as an effective anti-ulcer agent.