Anti-inflammatory,anticholinesterase, antioxidant and phytochemical properties of medicinal plants used for pain-related ailments in South Africa

Ethnopharmacological relevance

Extracts of seven South African medicinal plants used traditionally for the treatment of pain-related ailments were evaluated.

Aims of the study

The study was aimed at evaluating medicinal and therapeutic potentials of the investigated traditional medicinal plants. Plant extracts were evaluated for anti-inflammatory activity and other pharmacological properties such as anticholinesterase and antioxidant activities. Phytochemical analysis of total phenolic contents, condensed tannins, gallotannins and flavonoids in the aqueous methanol extracts of the medicinal plants were also carried out.

Materials and methods

The evaluation of anti-inflammatory activity of 50% methanol (50% MeOH), petroleum ether (PE), dichloromethane (DCM) and ethanol (EtOH) plant extracts was done against cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes. 50% MeOH, PE, DCM and EtOH extracts were tested for acetylcholinesterase (AChE) inhibition, while 50% MeOH extracts were tested for 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and ferric-reducing power in the antioxidant assays. Total phenolic compounds, condensed tannins, gallotannins and flavonoids were quantitatively determined using spectrophotometric methods.

Results

At the screening assay concentration (0.25 μg/μl), 13 extracts showed good COX-1 inhibitory activity (>50%), while good activity was observed in 15 extracts against COX-2 enzyme. All the extracts of Crinum moorei (bulbs) showed good inhibition against both COX-1 and COX-2 enzymes. Though not significantly different (P = 0.05), the highest COX-1 percentage inhibition (100%) was shown by Aloe ferox leaf PE and Colocasia antiquorum tuber DCM extracts, while Colocasia antiquorum tuber PE extract exhibited the highest (92.7%) percentage inhibition against COX-2. Crinum moorei bulb DCM extract showed the lowest EC₅₀ value (2.9 μg/ml) in the AChE assay. In addition, good to moderate bioactivities were observed in some extracts of Aloe ferox (leaves), Crinum moorei (bulbs) and Pycnostachys reticulata (leaves) in all the assays. The presence and/or amounts of phenolic compounds varied with plant species.

Conclusion

The results obtained in this study validate the use of the investigated medicinal plants in South African traditional medicine for pain-related ailments.     

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.     

Inhibition of arachidonic acid metabolism by the Andean crude drug Parastrephia lucida (Meyen) Cabrera

Ethnopharmacological relevance

Parastrephia lucida (Meyen) Cabrera is used in the traditional medicine of Argentinean highlands as an antiseptic and anti-inflammatory medicinal plant. To give scientific support to the ethnopharmacological claim of Parastrephia lucida as an anti-inflammatory crude drug the effect of Parastrephia lucida extracts and fractions was assessed on key enzymes of the biosynthesis of pro-inflammatory eicosanoids mediators from arachidonic acid (AA).

Materials and methods

A bio-guided fractionation of the plant extract was carried out to find out the compounds or mixtures responsible for the anti-inflammatory effect. The extracts and fractions were tested in vitro for their ability to inhibit the enzymes cyclooxygenase (COX)-1 and COX-2, lipoxygenase (LOX) and phospholipase (sPLA2). Fractions were analyzed by HPLC–MS, HPLC–ESI-MS/MS and NMR to relate the effect with groups of secondary metabolites.

Results

Parastrephia lucida was more effective inhibiting COX and sPLA₂ than LOX. Assay-guided isolation led to the active fractions C and F which showed different effect on the selected enzymes. The fraction C was more effective inhibiting LOX while fraction F showed better activity against sPLA₂ and COX-2. Both fractions were further worked-up following the isolation of the anti-inflammatory agents with the selected enzyme assays. The main compounds identified in the most active fractions were 5,4′-dihydroxi-7-methoxyflavanone, apigenin, apigenin methyl ether and apigenin trimethyl ether, methyl and dimethyl ethers from quercetin, kaempferol and luteolin methyl ether, ferulic acid esters, cinnamic acid and vanillin.

Conclusions

Parastrephia lucida extract inhibit AA metabolism via several enzymes. The results give support to the traditional use of this plant for the treatment of inflammatory disorders.     

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.     

Pharmacological properties and protein binding capacity of phenolic extracts of some Venda medicinal plants used against cough and fever

Ethnopharmacology relevance

Several ailments are caused by infectious bacteria and in other diseases; they act as co-infection which complicate human life by causing health hazards. In Venda (South Africa), many plants are used in traditional medicine to treat cough and fever.

Aim of the study

This study was aimed at evaluating the antibacterial and antifungal properties, cyclooxygenases (COX), acetylcholinesterase (AChE) enzyme inhibitory effects and the phenolic composition as well as mutagenic properties of six medicinal plants used by the Venda people of Limpopo Province of South Africa against cough and fever.

Materials and methods

The petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of six plants were tested against four infectious bacteria (Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus) and a fungus Candida albicans. The same extracts were evaluated for their ability to inhibit COX-1 and -2 enzymes. Methanolic and water extracts of the same plant were tested for acetylcholinesterase inhibitory effects. Total phenolics, flavonoids, gallotannins and condensed tannins were determined. The ability of the extracts to bind and precipitate proteins was also investigated. The extracts were investigated for genotoxicity with and without S9 (metabolic activation) against three Salmonella typhimurium tester strains TA98, TA100 and TA102.

Results

The organic extracts of Rhus lancea leaves exhibited the best antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.0061 to 0.049 mg/ml. The best antifungal activity was observed from a DCM extract of Syzygium cordatum leaves with a MIC value of 0.195 mg/ml. The methanolic and water extracts of the same plant exhibited high inhibitory effects towards AChE with IC₅₀ values of 0.22 and 0.26 mg/ml, respectively. The highest levels of flavonoids and gallotannins were detected in Spirostachys africana bark; 11.57 and 48.88 μg/g, respectively. The highest percentages (1.2%) of condensed tannins were detected in Uvaria caffra leaves. The high levels of phenolic compounds may have been responsible for high antimicrobial activities for extracts of S. africana bark and U. caffra leaves. S. cordatum leaves represented the highest affinity for protein binding with 93%. All the extracts were non-mutagenic towards the three tested strains with and without S9 metabolic activation.

Conclusion

The result obtained in this study goes a long way in validating the ethnobotanical usage of these medicinal plants in the treatment of cough and fever by the Venda people. However, more evidence obtainable from other assays not performed here are urgently required to confirm these results.     

In vitro antimicrobial, anthelmintic and cyclooxygenase-inhibitory activities and phytochemical analysis of Leucosidea sericea

Ethnopharmacological relevance

Leucosidea sericea is used as a vermifuge and in the treatment of ophthalmia by various tribes in southern African countries.

Aim of the study

The study aimed at screening leaves and stems of Leucosidea sericea for pharmacological activity and validating the plant's traditional use. A general phytochemical screening was also carried out.

Materials and methods

Petroleum ether (PE), dichloromethane (DCM), ethanol (EtOH) and water extracts of the plant parts were investigated for antimicrobial, anthelmintic and cyclooxygenase (COX) inhibitory activities. Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and Candida albicans were used for the antimicrobial evaluation. Caenorhabditis elegans was used for the anthelmintic assay using the microdilution technique. Cyclooxygenase-1 and -2 (COX-1 and -2) were used to evaluate the anti-inflammatory potential of the plant extracts. Phytochemical analysis for phenolic compounds, including gallotannins, condensed tannins and flavonoids was done using 50% methanol extracts of the leaves and stems employing spectrophotometric methods.

Results

The leaf extracts exhibited broad spectrum antibacterial activity ranging from 0.025 to 6.25 mg/ml. The most noteworthy minimum inhibitory concentration (MIC) of 0.025 mg/ml was exhibited by PE and DCM leaf extracts against Bacillus subtilis and Staphylococcus aureus, respectively. In the anthelmintic assay, the best minimum lethal concentration (MLC) value of 0.26 mg/ml was observed for the DCM and EtOH leaf extracts. Both leaf and stem organic solvent extracts exhibited high to moderate inhibition against COX-1 and -2 at a screening concentration of 250 μg/ml. At lower concentrations, the extracts displayed a dose-dependent inhibition, with the lowest IC₅₀ values of 0.06 μg/ml (COX-1) and 12.66 μg/ml (COX-2) exhibited by the PE extract of the leaves. Generally, the leaf extracts exhibited better pharmacological activities and contained higher amounts of phenolic compounds than the stem extracts. Alkaloids and saponins were only detected in the leaf and stem extracts, respectively.

Conclusion

The reported results support the local use of Leucosidea sericea against eye infections and as a vermifuge. The pharmacological activities exhibited by the leaf extracts are probably due to their higher phenolic levels.     

Ethnopharmacological study of plants from Pondoland used against diarrhoea

Ethnopharmacological relevance

Waterborne diseases such as diarrhoea are common world wide, including in Bizana, South Africa where the majority of rural dwellers depend largely on water from unprotected sources. The people from Bizana use medicinal plants as their first line of health care to cure and prevent diarrhoea.

Aim of the study

To record and document plants used for the treatment of diarrhoea in Bizana, to evaluate antibacterial and anti-inflammatory activities of selected plant extracts as well as to perform genotoxicity testing of evaluated plants.

Materials and methods

An ethnobotanical approach was used to select plants used for treating diarrhoea in Bizana for pharmacological assays using questionnaires. Nine plants were selected for bioassays based on their frequency index and the fact that they have never been evaluated against diarrhoea causing-microorganisms. The petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH), and water extracts were evaluated for antibacterial (Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli and Shigella flexneri) activity using the microdilution technique, their ability to inhibit COX-1 and COX-2 enzymes. Genotoxicity was evaluated using the Salmonella microsome assay.

Results

This study revealed that 34 plant species belonging to 27 families are used for the treatment of diarrhoea in Bizana. The extracts showed good inhibitory activity with MIC values ranging from 0.39 to 12.5 mg/ml. The best activity was exhibited by DCM extracts of Rapanea melanophloeos, and EtOH extracts of Ficus craterostoma and Maesa lanceolata with MIC values of 0.098 mg/ml. The inhibitory activity against COX-1 enzyme was higher than COX-2, with 19 plant extracts for the former and 7 for the latter. All the tested plant extracts were not mutagenic at all concentrations tested against all tester strains of bacteria.

Conclusion

In view of the fact that the plants were selected based on their ethnobotanical usage for treating diarrhoea, the activities reported here goes a long way in validating the plants for traditional use.     

Antimycobacterial,anti-inflammatory and genotoxicity evaluation of plants used for the treatment of tuberculosis and related symptoms in South Africa

Ethnopharmacological relevance

Emergence of drug-resistant tuberculosis strains and long duration of treatment has established an urgent need to search for new effective agents. The great floral diversity of South Africa has potential for producing new bioactive compounds, therefore pharmacological screening of plant extracts within this region offers much potential. To assess the in vitro antimycobacterial, anti-inflammatory and genotoxicity activity of selected plants that are used for the treatment of TB and related symptoms in South Africa.

Materials and methods

Ground plant materials from 10 plants were extracted sequentially with four solvents (petroleum ether, dichloromethane, 80% ethanol and water) and a total of 68 extracts were produced. A broth microdilution method was used to screen extracts against Mycobacterium tuberculosis H37Ra. The cyclooxygenase-2 (COX-2) enzyme was used to evaluate the anti-inflammatory activity of the extracts and the Salmonella microsome assay using two Salmonella typhimurium strains (TA98 and TA100) to establish genotoxicity.

Results

Six out of 68 extracts showed good antimycobacterial activity. Three extracts showed good inhibition (>70%) of COX-2 enzyme. All the extracts tested were non-genotoxic against the tested Salmonella strains.

Conclusion

The results observed in this study indicate that some of the plants such as Abrus precatorius subsp. africanus, Ficus sur, Pentanisia prunelloides and Terminalia phanerophlebia could be investigated further against drug-resistant TB strains.     

Pharmacological, genotoxic and phytochemical properties of selected South African medicinal plants used in treating stomach-related ailments

Ethnopharmacological relevance

The evaluated medicinal plants are used in South African traditional medicine in treating stomach-related ailments.

Aims of the study

The study aimed at evaluating the pharmacological, genotoxic and phytochemical properties of the seven selected medicinal plants used for treating stomach-related ailments.

Materials and methods

: Ethyl acetate (EtOAc), ethanol (EtOH) 70% and water extracts of the selected plant parts were evaluated for their antimicrobial and anthelmintic activities using microdilution assays. Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), Gram-negative bacterium (Escherichia coli) and Candida albicans were used for antimicrobial assays. Caenorhabditis elegans was used for the anthelmintic assay. Plant extracts were also assayed for their cyclooxygenase-inhibitory activity against cyclooxygenase-1 and -2 enzymes. The Ames test was used to evaluate the genotoxicity of the plant extracts. A spectrophotometric method was used to determine the total phenolics, gallotannins, flavonoids and saponins.

Results

Twelve extracts exhibited minimum inhibitory concentration (MIC) <1 mg/mL against the bacterial test strains, and five extracts exhibited MIC <1 mg/mL against Candida albicans. The EtOAc extract of Tetradenia riparia had the best minimum lethal concentration (MLC) value (0.004 mg/mL) against Caenorhabditis elegans. All the EtOAc extracts exhibited percentage inhibition in the range of 50.7-94.7% against COX-1 and -2 enzymes at 250 μg/mL. All the plant extracts were non-mutagenic towards Salmonella typhimurium tester strains TA98, TA100 and TA1537 without metabolic activation. Phytochemical analysis revealed relatively high amounts of total phenolics, gallotannins and flavonoids in the evaluated plant extracts.

Conclusions

The general pharmacological activities exhibited by some of the plant extracts in this study support the traditional uses of the selected plants in treating stomach-related ailments. The Ames test showed that all the plant extracts were non-mutagenic but cytotoxicity tests are needed to ascertain the safety for long-term consumption.     

Bioactivity guided evaluation of anti-inflammatory and antinociceptive activities of Arceuthobium oxycedri (D.C.) M. Bieb.

Ethnopharmacological relevance

Arceuthobium oxycedri (D.C.) M. Bieb. (Loranthaceae) or dwarf mistletoe is a rare semi-parasitic plant that lives on the branches of Juniperus oxycedrus as the host plant. In Turkish folk medicine, the plant is prescribed as a panacea for every kind of diseases, including, against infectious and inflammatory disorders of upper respiratory system and gastro-intestinal complaints or as a hypotensive remedy.

Aim of the study

In the current study, in vivo anti-inflammatory and antinociceptive effects of Arceuthobium oxycedri have been investigated.

Material and methods

The crude ethanolic extract of the whole plant was sequentially fractionated into five subextracts; explicitly, n-hexane, chloroform, ethyl acetate (EtOAc), n-butanol, and remaining water extracts. Further studies were carried out on the most active subextract, i.e. the EtOAc subextract, was further subjected to fractionation through successive column chromatographic applications on Silica gel 60, Sephadex LH-20 and LiChropep RP-18. For the activity assessment, each extract or fraction was submitted to bioassay systems; carrageenan-induced hind paw edema model for anti-inflammatory activity and p-benzoquinone induced abdominal contraction test for antinociceptive activity assessment.

Results

Among the extracts obtained, the ethanolic extract, EtOAc and n-butanol subextracts showed significant inhibitory activity in the bioassay systems. From the EtOAc subextract, a major component was isolated and its structure was determined as (+)-catechin by means of spectral techniques.

Conclusion

Present study confirms the claimed utilization of the plant against inflammatory complaints in Turkish folk medicine.     

Pharmacological evaluation of Alstonia scholaris: Anti-inflammatory and analgesic effects

Ethnopharmacological relevance

Alstonia scholaris (Apocynaceae) has been historically used in “dai” ethnopharmacy to treat chronic respiratory diseases. The leaf extract, developed as a commercially available traditional Chinese medicine, used to release tracheitis and cold symptom, has also been prescribed in hospitals and sold over the counter in drug stores.

Aim of the study

The investigation evaluated the anti-inflammatory and analgesic activities of the ethanolic extract, fractions and main alkaloids of Alstonia scholaris leaf to provide experimental evidence for its traditional and modern clinical use. Besides, to discover the active fraction and components for further better use in Chinese medicine is hopeful.

Materials and methods

The leaf of Alstonia scholaris was extracted with ethanol and then separated into different fractions. Furthermore, alkaloids were isolated by phytochemical method. The analgesic activities were investigated using acetic acid-induced writhing, hot-plate and formalin tests in mice. The anti-inflammatory activities were carried out in vivo and in vitro, including xylene-induced ear edema and carrageenan-induced air pouch formation in mice, and COX-1, -2 and 5-LOX inhibition.

Results

It has been exhibited that the EtOAc and alkaloid fractions reduced acetic acid-induced writhing response in mice, significantly. The ethanolic extract, EtOAc and alkaloid fractions remarkably inhibited xylene-induced ear edema. Further investigation was focused on the alkaloids fraction and three main alkaloids isolated from the alkaloids fraction, in different animal models. Alkaloids reduced acetic acid-induced writhing response, and xylene-induced ear edema in mice. In the hot-plate test, alkaloids did not increase the latency period of mice obviously. In the formalin test, alkaloids did not inhibit the licking time in first phase, but significantly inhibited the licking time in second phase of mice. Alkaloids increased significantly SOD activity and decreased levels of NO, PGE2 and MDA significantly, in air pouch mice model. Moreover, some alkaloids isolated from the leaf of Alstonia scholaris exhibited inhibition of COX-1, COX-2 and 5-LOX in vitro anti-inflammatory assay, which supported alkaloids as the bioactive fraction.

Conclusions

The alkaloids fraction of Alstonia scholaris leaf, three main alkaloids, picrinine, vallesamine and scholaricine, may produce the anti-inflammatory and analgesic effect peripherally based on several in vivo assays. In in vitro tests, alkaloids exhibited inhibition of inflammatory mediators (COX-1, COX-2 and 5-LOX), which is accordant with results on animal models. Besides, COX-2/5-LOX dual inhibitors found in the experiment, such as 16-formyl-5α-methoxystrictamine, picralinal, and tubotaiwine might be valuable for further attention.     

Investigation for anti-inflammatory and anti-thrombotic activities of methanol extract of Capparis ovata buds and fruits

Ethnopharmacological relevance

Capparis ovata Desf. has wide natural distribution in Turkey and it is consumed in pickled form. Flower buds, root bark, and fruits of the plant are used traditionally due to their analgesic, anti-inflammatory, wound healing, anti-rheumatismal, tonic, and diuretic effects.

Aim of the study

The aim of this study was to investigate the possible anti-inflammatory and anti-thrombotic effects of methanol extracts prepared from flower buds (CBE) and fruits (CFE) of C. ovata.

Materials and methods

Anti-inflammatory effects of CBE and CFE were assessed using carrageenan-induced and prostaglandin E₂-induced mouse paw edema models. For the anti-thrombotic effect evaluation, carrageenan-induced tail thrombosis model was performed in mice. The extracts were administered intraperitonally (i.p.) at the doses of 100, 200, and 300 mg/kg. The anti-inflammatory effect of Capparis extracts were tested in comparison to 10 mg/kg diclofenac and anti-thrombotic activity to 10 and 100 IU heparin.

Results

CBE at the doses of 200, and 300 mg/kg and CFE at the doses of 100, 200, and 300 mg/kg showed significant anti-inflammatory activity and CFE reached therapeutic concentration early than CBE in carrageenan inflammation model. In prostaglandin E₂ inflammation model, CBE and CFE exhibited significant inhibitory effects. The C. ovata extracts did not show remarkable anti-thrombotic effect.

Conclusions

Based on the results obtained, it can be concluded that fruits of C. ovata have more potent anti-inflammatory effect than flower buds. It has been suggested that inhibition of cyclooxygenase pathway is one of the mechanisms of the activity. C. ovata may be potentially used as therapeutic agents for inflammatory diseases.     

In vitro pharmacological effects of manufactured herbal concoctions used in KwaZulu-Natal South Africa

Ethnopharmacology relevance

Manufactured and packaged herbal mixtures, known locally as muthi concoctions, have become a new feature of traditional medicine in South Africa. These herbal concoctions are often claimed to cure several diseases ranging from minor illness to life threatening conditions.

Aim of the study

To document the prevalence, variety and evaluate the efficacy of selected herbal concoctions sold in KwaZulu-Natal.

Materials and methods

Nine herbal concoctions were evaluated for their effects as antibacterial and antifungal agents as well as their ability to inhibit the cyclooxygenase (COX-1 and COX-2) enzymes using standard in vitro methods.

Results

Imbiza ephuzwato and Ibhubezi™, both multipurpose mixtures showed high abilities to inhibit bacterial and fungal growth as well as inhibit the COX-1 and COX-2 enzymes. Umzimba omubi and Umuthi wekukhwehlela ne zilonda, both remedies for wounds, boils and chest infections were not active against the two Gram-positive and two Gram-negative bacterial strains tested. Vusa umzimba and Supreme one hundred were active against Candida albicans.

Conclusions

Four of the herbal concoctions showed no activity in all of the assays tested while only two showed good activity. Activity cannot be ruled out as there are many mechanisms upon which natural products can act.     

Evaluation of Cissus quadrangularis extracts as an inhibitor of COX, 5-LOX, and proinflammatory mediators

Ethnopharmacological relevance

Cissus quadrangularis is an ancient medicinal plant. It is an active ingredient of one Ayurvedic formula called “Laksha Gogglu”. Its stem is used in food preparation in India. Traditionally it is used to treat various diseases like asthma, indigestion, ear diseases, irregular menstruation, skin diseases, piles, fractured bones, etc.

Aim of the study

This study aimed to evaluate the ability of the plant extracts to inhibit cycloxygenase (COX-1), cycloxygenase (COX-2), and 5-lipoxygenase (5-LOX) enzyme activity. Western blot analysis was also carried out in the quest to determine the effect of active acetone fraction of Cissus quadrangularis (AFCQ) on proinflammatory mediators as acetone extract is found to be the most effective in this study.

Materials and methods

The differential extract of the stem were tested for enzyme inhibition of COX and 5-LOX using spectroscopic and polarigraphic method. Effective acetone extract was partially purified by silica column, one of the active fraction showed dual inhibition against COX and 5-LOX. Western blotting shows downregulation of proinflammatory mediators as well as upregulation of phase-II enzymes.

Results

AFCQ extract showed COX and 5-LOX inhibition with IC₅₀ values of 7 μg/ml, 0.4 μg/ml, and 20 μg/ml for COX-1, COX-2 and 5-LOX respectively. It also showed anti-inflammatory activity on RAW 264.7 cell line with IC₅₀ value 65 μg/ml. In addition to this it is showing inhibition of proinflammatory mediators like iNOS and TNFα, along with translocation of Nrf-2 and upregulation of HO-1.

Conclusion

AFCQ is a COX and 5-LOX inhibitor isolated from the stems of Cissus quadrangularis. It is also effectively downregulate the iNOS, TNFα, and upregulation of HO-1.     

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.     

Ethnopharmacological in vitro studies on Austria's folk medicine—An unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs

Ethnopharmacological relevance

In Austria, like in most Western countries, knowledge about traditional medicinal plants is becoming scarce. Searching the literature concerning Austria's ethnomedicine reveals its scant scientific exploration.Aiming to substantiate the potential of medicinal plants traditionally used in Austria, 63 plant species or genera with claimed anti-inflammatory properties listed in the VOLKSMED database were assessed for their in vitro anti-inflammatory activity.

Material and methods

71 herbal drugs from 63 plant species or genera were extracted using solvents of varying polarities and subsequently depleted from the bulk constituents, chlorophylls and tannins to avoid possible interferences with the assays. The obtained 257 extracts were assessed for their in vitro anti-inflammatory activity. The expression of the inflammatory mediators E-selectin and interleukin-8 (IL-8), induced by the inflammatory stimuli tumor necrosis factor alpha (TNF-α) and the bacterial product lipopolysaccharide (LPS) was measured in endothelial cells. The potential of the extracts to activate the nuclear factors PPARα and PPARγ and to inhibit TNF-α-induced activation of the nuclear factor-kappa B (NF-κB) in HEK293 cells was determined by luciferase reporter gene assays.

Results

In total, extracts from 67 of the 71 assessed herbal drugs revealed anti-inflammatory activity in the applied in vitro test systems. Thereby, 30 could downregulate E-selectin or IL-8 gene expression, 28 were strong activators of PPARα or PPARγ (inducing activation of more than 2-fold at a concentration of 10 µg/mL) and 21 evoked a strong inhibition of NF-κB (inhibition of more than 80% at 10 µg/mL).

Conclusion

Our research supports the efficacy of herbal drugs reported in Austrian folk medicine used for ailments associated with inflammatory processes. Hence, an ethnopharmacological screening approach is a useful tool for the discovery of new drug leads.     

Antioxidant, antimicrobial and antiverotoxic potentials of extracts of Curtisia dentata

Ethnopharmacological relevance

There is an increase in antimicrobial resistance and complexities arising from verotoxic related bacterial infections as well as rise in demand for application of natural antioxidants to combat oxidative damage by free radicals in many oxidative stress-mediated disease conditions such as cancer. Thus the potential of Curtisia dentata as antimicrobial, antioxidant and antiverotoxin against environmental isolates of Escherichia coli and Acinetobacter spp. as well as the presence of phytochemicals and some organic compounds, was determined.

Materials and methods

Phytochemical analysis was carried out using standard methods and antioxidant activity was determined using the DPPH radical scavenging activity. Effect of extracts on bacterial cell wall was also determined.

Results

Extracts contained anthraquinones, alkaloids, essential oils, glycosides, phenols, steroids, saponins, tannins, quinones, anthocyanins, amines and carboxylic acids as phytochemicals. Extracts demonstrated high antimicrobial activity and low minimum inhibitory concentrations as well as inhibitory action against the expression of both Vtx1 and Vtx2 genes in Escherichia coli, Acinetobacter haemolyticus and Acinetobacter lwoffii. Ethanol root bark extracts consistently showed the highest DPPH radical scavenging activity (62.43%), total phenol content (TPH) (57.62 26 mg GAE/g) and reducing power (RP) (41.32%), followed by those of the stem bark and leaf extracts with the respective values of 54.68%, 37.77 mg GAE/g and 21.83%. The extracts induced the leakage of Na⁺ and K⁺ ions from both test bacteria.

Conclusion

Curtisia dentata is a very effective source of antioxidant and a possible alternative to sourcing antiverotoxic antibiotics with novel mechanism of action.     

In vitro anti-inflammatory effects of arctigenin,a lignan from Arctium lappa L., through inhibition on iNOS pathway

Ethnopharmacological relevance

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet.

Aim of the study

To investigate the anti-inflammatory mechanism of arctigenin.

Materials and methods

Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2.

Results

Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-α and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin.

Conclusions

These results indicated that potent inhibition on NO, TNF-α and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.