Antibacterial and antitumor activities of a lectin-rich preparation from Microgramma vacciniifolia rhizome.

The rhizome of Microgramma vacciniifolia contains a lectin (carbohydrate-binding protein) called MvRL. Studies demonstrated that a MvRL-rich fraction did not show in vivo genotoxicity and acute toxicity in mice. This study aimed to evaluate the MvRL-rich fraction from M. vacciniifolia rhizome for antibacterial activity in vitro and in vivo as well as antitumor effect in vivo using the Ehrlich carcinoma model in mice. The fraction showed antibacterial activity against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus with minimal inhibitory concentrations ranging from 31.2 to 125.0 â€‹µg/mL and minimal bactericidal concentrations from 62.5 to 200 â€‹µg/mL. The fraction was also effective in vivo against infection caused by these bacteria on Tenebrio molitor larvae considering the parameters evaluated. In regard to the antitumor activity, the treatments of Ehrlich carcinoma-bearing mice with the fraction at 100 and 200 â€‹mg/kg per os resulted in 62.58% and 75.43% of tumor inhibition, respectively. In conclusion, the MvRL-rich fraction showed in vivo antibacterial and antitumor activities and thus can be considered as an alternative of natural origin for the development of candidates for therapy.

Toxicity assessment of saline extract and lectin-rich fraction from Microgramma vacciniifolia rhizome.

Microgramma vacciniifolia is broadly used in folk medicine but safety information is unavailable. Therefore, we evaluated the toxicity of a saline extract and a lectin-rich fraction of M. vacciniifolia rhizome. The extract showed hemolytic activity on mice erythrocytes at 1000 µg/mL, whereas the fraction promoted hemolysis (8.57-26.15%) at all tested concentrations (10-1000 µg/mL). Acute toxicity test in mice indicated an LD50 of >5000 mg/kg. Hematological alterations and increased serum alkaline phosphatase level were observed in the treated animals. Transaminases and urea levels increased in the groups treated with the extract or fraction at 5000 mg/kg. Leukocyte infiltration was observed in the liver of extract-treated animals and in the liver and lungs of mice treated with the fraction. The kidneys of animals treated with the fraction at 5000 mg/kg presented hydropic degeneration. The extract and fraction did not induce oxidative stress in the liver and did not show genotoxicity, as examined by micronucleus and comet assays. In conclusion, the preparations were not lethal to mice but caused some signs of toxicity, mainly the fraction. The results indicated the need to evaluate the toxicity of M. vacciniifolia rhizome in other models and in chronic assays.

Evaluation of Toxicity and Antimicrobial Activity of an Ethanolic Extract from Leaves of Morus alba L. (Moraceae).

This work evaluated an ethanolic extract from Morus alba leaves for toxicity to Artemia salina, oral toxicity to mice, and antimicrobial activity. Phytochemical analysis revealed the presence of coumarins, flavonoids, tannins, and triterpenes in the extract, which did not show toxicity to A. salina nauplii. No mortality and behavioral alterations were detected for mice treated with the extract (300 and 2000 mg/kg b.w.) for 14 days. However, animals that received the highest dose showed reduced MCV and MCHC as well as increased serum alkaline phosphatase activity. In treatments with the extract at both 300 and 2000 mg/kg, there was a reduction in number of leukocytes, with decrease in percentage of lymphocytes and increase in proportion of segmented cells. Histopathological analysis of organs from mice treated with the extract at 2000 mg/kg revealed turgidity of contorted tubules in kidneys, presence of leukocyte infiltration around the liver centrilobular vein, and high dispersion of the spleen white pulp. The extract showed antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Candida krusei, Candida tropicalis, and Aspergillus flavus. In conclusion, the extract contains antimicrobial agents and was not lethal for mice when ingested; however, its use requires caution because it promoted biochemical, hematological, and histopathological alterations.