A new lignan rhamnoside from Bauhinia retusa seed pods (Caesalpiniaceae)

Genus Bauhinia (Fabaceae): A review from phytochemistry to pharmacology- Exploring traditional uses and toxicological insights across Asia

BACKGROUND

The genus Bauhinia and its species has been known since ages by tribal people and medicinal practitioners in tropical and subtropical regions for the treatment of diabetes, diarrhea, cough, fever, stomach disorders, skin diseases, and other diseases.

STUDY DESIGN

Our aim was to collect and explore the literature available on the traditional applications and medicinal potential of genus Bauhinia across Asia, so that this review can be used as standard to analyze the immense potential of this genus and can be explored further for clinical use.

METHODS

The information was rigorously gathered from Google Scholar, Pub Med, Elsevier, Wiley Online Search, Science Direct, and other literature sources.

RESULTS

As per the literature, this genus possesses antimicrobial, antioxidant, nephroprotective, anticancer, hepatoprotective, antidiabetic, anti-inflammatory, and antidepressant activities both in vitro and in vivo, due to the presence of flavonoids, steroidal saponins, bauhinioxepins, chromanones, and phenolic compounds.

CONCLUSION

In this review, we have detailed for the first time the categorized information about traditional uses, geographical distribution, morphological features, phytochemistry, pharmacological, and toxicological effects, and patents associated with Bauhinia species. However, more research is needed to explore the mechanisms of action, pharmacokinetics of the phytoconstituents, and clinical evaluation for their future use in treating various ailments.

Antibacterial constituents of three Cameroonian medicinal plants: Garcinia nobilis, Oricia suaveolens and Balsamocitrus camerunensis

BACKGROUND

Multidrug resistance is a worrying cause of treatment failure in bacterial infections. The search of bioactive constituents from medicinal plants against multidrug resistant (MDR) bacteria has significantly evolved in the two last decades. In the present study, twenty-two compounds (three terpenoids, eleven phenolics and eight alkaloids) isolated from three Cameroonian medicinal plants, namely Garcinia nobilis, Oricia suaveolens and Balsamocitrus camerunensis, as well as the crude extracts were tested for their antibacterial activities against Mycobacterium tuberculosis and Gram-negative bacteria amongst which were MDR active efflux pumps expressing phenotypes.

METHODS

The microplate alamar blue assay (MABA) and the broth microdilution methods were used to determine the minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of the studied samples.

RESULTS

The results of the MIC determinations indicate that, the best crude extract was that from G. nobilis (GNB), its inhibitory effects being noted against 12 of the 14 tested bacteria. The extract of GNB also exhibited better anti-tuberculosis (MIC of 128 μg/ml M. tuberculosis against ATCC 27294 strain) and antibacterial (MIC of 64 μg/ml against Escherichia coli ATCC10536) activities compared to the extracts of O. suaveolens and B. camerunensis. Interestingly, 4-prenyl-2-(3,7-dimethyl-2,6-octadienyl)-1,3,5,8-tetrahydroxyxanthone (2), isolated from the most active extract GNB, also showed the best activity amongst compounds, inhibiting the growth of all the fourteen tested microorganisms. The lowest MIC value obtained with compound 2 was 8 μg/ml against M. tuberculosis ATCC 27294 and M. tuberculosis clinical MTCS2 strains. Other compounds showed selective activities with 11 of the 14 tested bacteria being sensitive to the xanthone, morusignin I (5) and the alkaloid, kokusaginine (13).

CONCLUSIONS

The results of the present investigation provide evidence that the crude extract from G. nobilis, O. suaveolens and B. camerunensis as well as some of their compounds, and mostly compound 2 (isolated from G. nobilis,) could be considered as interesting natural antibacterial products.