Evaluation of the antioxidant activity, antimicrobial effect and acute toxicity from leaves of Allophylus edulis (A. St.-Hil., A. Juss. Cambess .) Hieron. ex Niederl

Antibacterial Effect of Ethanolic Extracts of Dodonaea viscosa L. Jacq. and Mammea americana L. against Staphylococci Isolated from Skin Lesions

Background

The resistance to antibiotics shown by some dermatological pathogenic microorganisms has increased the interest of pharmaceutical and cosmetic industries in developing natural products that possess different biological activities, including antimicrobial effects.

Methods

In the present investigation, the antibacterial activity of ethanolic extracts of Dodonaea viscosa aerial part and Mammea americana leaves and seed was evaluated against resistant strains of Staphylococcus isolated from skin lesions and against S. aureus ATCC 25923 (reference strain). Column chromatography (CC) and preparative thin-layer chromatography (PTLC) were used to obtain separate fractions of the seed extract of M. americana. We also determined the antimicrobial resistance of the strains against antibiotics using the agar disc diffusion assay. In addition, phytochemical screening was performed by colorimetric standard techniques.

Results

M. americana seed extract showed the highest antibacterial activity with MBC from 2.3 μg/mL to 19.5 μg/mL without differences with gentamicin (p = 0.998). The isolated strain S. epidermidis I showed the highest antimicrobial resistance against the tested antibiotics. PTLC-fractions of M. americana seed extract showed MBC from 3.2 μg/mL to 40.7 μg/mL against S. epidermidis I and S. aureus 25923 (reference), respectively, which suggests a synergistic effect of the secondary metabolites present in the crude ethanolic extract compared to its active PTLC-fractions, where only coumarins and compounds with lactone groups were detected in the phytochemical screening.

Conclusion

M. americana seed extract has promising effects that should be considered in further studies as an alternative or adjuvant in treating skin infections caused by staphylococci.

Mineral Content, Antioxidant Activity and Essential Oil of Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Radlk. Leaves: Plant from South American Biodiversity

Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Radlk. (Sapindaceae) is an edible plant from the South American biodiversity that is a potential source of bioactive compounds. The mineral content and antioxidant activity of Allophylus edulis leaves were investigated, as well as the composition and the antioxidant activity of the essential oil. The mineral content was determined by ICP - OES and the antioxidant assays were assessed by ABTS, DPPH and FRAP. The essential oil was obtained by hydrodistillation and analyzed by GC/MS. Calcium, potassium, phosphorus, sulfur, and magnesium were the main minerals found in A. edulis leaves. Of the toxic metals that were present, a low level of aluminum was detected. The essential oil of A. edulis has (E)-nerolidol as major compound and both, the leaves, and the essential oil isolated from the leaves have antioxidant potential. These findings could provide a framework for developing new food and non-food products with A. edulis leaves.

Antioxidant and Protective Effects of Schinus terebinthifolius Raddi Against Doxorubicin-Induced Toxicity

Doxorubicin is an anticancer drug whose toxic effects on non-cancer cells are associated with increased oxidative stress. This study investigated the chemical composition, antioxidant activity of the methanolic extract of Schinus terebinthifolius Raddi leaves (MESL) as well as effects against doxorubicin-induced toxicity in human erythrocytes, K562 human erythroleukemia cells, and mouse hearts. The chemical composition indicated the presence of phenolic compounds, flavonoids, tannins, and ascorbic acid. MESL showed antioxidant activity by scavenging free radicals and inhibiting hemolysis and lipid peroxidation in human erythrocytes incubated with an oxidizing agent, and was able to increase the enzymatic activity of superoxide dismutase and glutathione peroxidase in human erythrocytes, without influencing the activity of enzyme catalase. The increase of oxidative hemolysis and malondialdehyde levels in erythrocytes incubated with doxorubicin was reduced by treatment with MESL. The cytotoxic activity of doxorubicin in erythroleukemia cells treated with MESL was unmodified. Additionally, the extract protected mice against the doxorubicin-induced cardiotoxicity. In conclusion, the MESL exhibits antioxidant activity, reducing doxorubicin-induced oxidative stress without changing the anticancer action of the drug, and protects against doxorubicin-induced cardiotoxicity. Hence, these findings suggest that these effects are via anti-oxidative by inhibiting free radicals, decreased oxidative stress, and increased antioxidant enzyme activity.

Anti-inflammatory, antioxidant and anti-Mycobacterium tuberculosis activity of viridiflorol: The major constituent of Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Radlk

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Radlk. (Sapindaceae) are traditionally used as a natural anti-inflammatory agent; however, there are no scientific studies demonstrating its activity essential oil. The content of essential oil in A. edulis may be the chemical basis to explain its ethnobotanical uses, since infusions of this plant are used to treat inflammation in the traditional medicine in Brazil.

AIM OF THE STUDY

This study evaluated the anti-inflammatory, antioxidant and anti-mycobacterial activities of the essential oil (EOAE) and viridiflorol, its main compound.

MATERIAL AND METHODS

Essential oil from fresh leaves of A. edulis (EOAE) was obtained by hydrodistillation in a Clevenger-type apparatus. Forty-one compounds, accounting for 99.10% of the oil, were identified by gas chromatography-mass spectrometry (GC-MS). The major constituent of the oil was viridiflorol (30.88%). Additionally, the essential oil and viridiflorol were evaluated using an in vitro test against Mycobacterium tuberculosis and in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Both EOAE (30 and 100mg/kg) and viridiflorol (3 and 30mg/kg) by oral administration were assayed in carrageenan-induced mice paw oedema and pleurisy using subcutaneous injection of dexamethasone (0.5mg/kg) as the positive control.

RESULTS

EOAE and viridiflorol displayed moderate in vitro activity in the M. tuberculosis assay. In all tests, EOAE and viridiflorol showed moderate antioxidant activity compared with reference standards. Both EOAE and viridiflorol showed significant inhibition in the carrageenan-induced mice paw oedema via oral administration of the oil (30 and 100mg/kg), compound (3 and 30mg/kg), and subcutaneous injection of dexamethasone (0.5mg/kg, reference drug). Also EOAE and viridiflorol significantly inhibited carrageenan (Cg) induced pleurisy, reducing the migration of total leucocytes in mice by 62±5% (30mg/kg of oil), 35±8% (100mg/kg of oil), 71±5% (3mg/kg of viridiflorol) and 57±3% (30mg/kg of viridiflorol).

CONCLUSION

For the first time, the results from this work corroborate the literature, showing that A. edulis can be used as a natural anti-inflammatory agent. Moreover, both EOAE and viridiflorol exhibited biological activities, such as anti-mycobacterial, anti-inflammatory and antioxidant activity.

Antimicrobial, Antioxidant, Anti-Inflammatory, and Cytotoxic Activities of Propolis from the Stingless Bee Tetragonisca fiebrigi (Jataí)

Propolis from stingless bees Tetragonisca fiebrigi found in Brazil is used in folk medicine by their nutritional and therapeutic properties. However, there are no scientific records evidencing such properties. The present study was designed to investigate the chemical composition and the biological properties of propolis from T. fiebrigi. For this, the chemical composition of the ethanol extract of propolis (EEP) was determined by GC-MS and presented phenolic compounds, alcohol, and terpenes as its major class compounds. The antimicrobial activity was accessed in gram-positive and gram-negative bacteria and in fungi, isolated from different biological fluids and reference strains. The EEP was active against all microorganisms and showed antioxidant activity by scavenging free radicals, inhibiting hemolysis and lipid peroxidation in human erythrocytes incubated with an oxidizing agent. The anti-inflammatory potential of the EEP was confirmed by inhibition of the hyaluronidase enzyme. The cytotoxic activity was concentration-dependent against K562 cells, with a predominance of death by necrosis. Taken together, these results show that propolis from T. fiebrigi has important therapeutic activities, which suggest its potential application in the pharmaceutical industry, as well as in health foods, beverages, and nutritional supplements.