Anatomical, Histochemical and Biological Studies of Clusia grandiflora Splitg. (Clusiaceae)

Abstract Clusia grandiflora belongs to an important botanical family which is known for its medicinal value, however there are few reports in literature about the species, highlighting the relevance of this study. Anatomical studies with leaves and stems were performed using traditional techniques. In this investigation it was identified particularities of the species such as the presence of vascular system arranged in an opened arc-shaped with the flexed ends towards the inside of the arch with accessory bundles in the petiole. In histochemical studies, performed with different reagents, alkaloids, phenols substances, carbohydrates and lipids were located. The cytotoxic activity of the extracts was performed by tetrazole salt and showed promising results for ethanolic extracts of stems (IC50 human colon cells of 24.30 μg/ mL) and leaves (IC50 ascites gastric cells of 44.15 μg/ mL), without cell membrane disruption of erythrocytes. The antibacterial activity was evaluated by tryptic soy agar and minimal inhibitory concentration assays and showed positive results for Pseudomonas aeruginosa and Escherichia coli, with better result for adventitious roots (32 μg/ mL and 16 μg/ mL, respectively), stems (64 μg/ mL and 32 μg/ mL, respectively) and leaves (64 μg/ mL and 32 μg/ mL, respectively) ethanolic extracts. Thus, these studies were able to characterize the species and show its potential as promising source of active substances.

Antimicrobial activity in vitro of plumbagin isolated from Plumbago species

Plumbagin is a naturally occurring naphthoquinone isolated from roots of Plumbago scandens. The plant was collected at the Campus of Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. P. scandens is used as a traditional medicine for the treatment of several diseases. The antimicrobial activity of plumbagin was evaluated using the macrodilution method. The compound exhibited relatively specific activity against bacteria and yeast. The minimum inhibitory concentration test showed the growth inhibiton of Staphylococcus aureus at a concentration of 1.56 æg/ml and of Candida albicans at a concentration of 0.78 æg/ml. These results suggest the naphthoquinone plumbagin as a promising antimicrobial agent.