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 0.049mg/ml. The best antifungal activity was observed from a DCM extract of Syzygium cordatum leaves with a MIC value of 0.195mg/ml. The methanolic and water extracts of the same plant exhibited high inhibitory effects towards AChE with IC(50) values of 0.22 and 0.26mg/ml, respectively. The highest levels of flavonoids and gallotannins were detected in Spirostachys africana bark; 11.57 and 48.88μg/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.

Antimicrobial properties and phenolic contents of medicinal plants used by the Venda people for conditions related to venereal diseases

ETHNOPHARMACOLOGY RELEVANCE

Many people are infected by venereal diseases and the human immunodeficiency virus (HIV) in rural areas. Sexual transmitted diseases are considered a disgrace in the community because of the stigmas attached to them. Indigenous people tend to use several medicinal plants to treat these infectious diseases rather than western medicines.

AIM OF THE STUDY

This study was aimed to evaluate the antibacterial, antifungal, antigonococcal, HIV-type 1 reverse transcriptase (RT) and to determine phenolic content of twelve medicinal plants used by the Venda people to treat venereal diseases.

MATERIALS AND METHODS

The dried plant materials of twelve medicinal plants were extracted with petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water. The extracts were evaluated for their antimicrobial properties against two Gram-positive (Bacillus subtilis and Staphylococcus aureus), three Gram-negative (Neisseria gonorrhoeae, Escherichia coli and Klebsiella pneumoniae) bacteria and a fungus Candida albicans. The phenolic contents including total phenolics, flavonoids, gallotannins and condensed tannins of the methanolic extracts of the same plants were also determined.

RESULTS

DCM and EtOH extracts of Bolusanthus speciosus bark and stems exhibited good activity (<0.1mg/ml) against Escherichia coli and Staphylococcus aureus with MIC values ranging from 0.098 to 0.012 mg/ml. The DCM extracts of Bolusanthus speciosus bark showed the best activity against Candida albicans with MIC and MFC values of 0.012 mg/ml. Water and 50% methanol extracts of Acacia karroo bark, Bolusanthus speciosus stems and Ximenia caffra roots and leaves showed good RT inhibition percentages (>70%) at 1mg/ml. All tested extracts exhibited dose dependent IC(50) values ranging from (0.1 to 0.6 mg/ml). Almost all plant species investigated contained phenolic compounds, which were greater than 5mg/g with the exception of Adansonia digitata bark and Aloe chabaudii roots. The highest level of flavonoids (11.9 μg/g) were detected in Ximenia caffra leaves. Whereas the highest amount of gallotannins were detected in Ekebergia capensis bark (69 μg/g). Condensed tannins were higher in Ekebergia capensis bark and Ximenia caffra roots (0.47 and 0.48% respectively). Adansonia digitata bark and Aloe chabaudii roots exhibited low levels of phenolic compounds as well as antimicrobial activities.

CONCLUSION

The presented results offer supporting evidence for effective use of selected plant extracts. More in vitro confirmatory tests using other assays and/or in vivo tests are required. Toxicity studies are urgently needed to support the safe usage of these plants.