RESUMO

The inappropriate use of antimicrobials, along with environmental conditions, can lead to the emergence of resistant microorganisms. The use of phytopharmaceuticals and herbal medicines has a positive impact and represents a promising alternative. Psidium guajava extracts have been widely reported to have antimicrobial potential; however, studies reporting their activity against resistant bacterial strains are scarce. Because of the emerging resistance, the aim of this study was to analyze the antimicrobial capacity of the aqueous extract of guava leaves against wild-type and resistant bacterial strains. The aqueous extract obtained from the leaves of P. guajava was evaluated by HPLC for the content of total phenolics and tannins, antioxidant activity, and chemical composition. The antimicrobial activity of the extracts was analyzed by the disk diffusion and broth microdilution methods. The results of the chemical analysis of the extracts showed total phenolics content of 17.02 ± 6.87 mg/g of dry extract, total tannin content of 14.09 ± 1.20 mg of tannic acid equivalents/g of dry extract, and moderate antioxidant capacity with an EC50 value of 140 µg/mL. Flavonoids are the major compounds (rutin, hesperidin, and quercetin), followed by phenolic acids. Disk diffusion test results showed the presence of inhibition halos for Gram-positive bacteria (Staphylococcus aureus, sensitive and resistant; Staphylococcus pseudintermedius, sensitive and resistant; and Streptococcus spp., beta-hemolytic), while for Gram-negative bacteria (Escherichia coli, sensitive and resistant), there was no inhibition in the tested concentration range. The Minimal Inhibitory Concentration was 6.8 mg/mL for all Gram-positive strains evaluated. The present study demonstrated the antimicrobial activity of the aqueous extract of P. guajava against sensitive and resistant Gram-positive bacteria. The better antimicrobial activity found in the present study compared with previously reported activity should be highlighted and may be related to the higher concentration of total phenolics present in the tested extract. Moreover, the content of tannins found suggests a species with high quality that produces tannins. These new findings suggest an innovative profile regarding therapeutic resources that can be adopted to combat resistant microbial strains.

RESUMO

Twenty-nine flavonoid glycosides were identified in the aqueous extract (PC) of Petroselinum crispum var. crispum leaves and apiin, the major compound, was isolated thereof. Apigenin was obtained (90% purity) by the hydrolysis of apiin. A high content of phenolics (12.49 ± 1.70 mg GAE per g of parsley extract - Folin-Ciocalteu method) and total flavonoids (15.05 ± 2.20 mg of quercetin equivalents per g of parsley extract - aluminum chloride method) was quantified in P. crispum, as well as high antioxidant activity ((EC50 - 15.50 mg mL-1, DPPH method) and (189.8 mM Fe(ii) per mg of dry plant aqueous extract - FRAP method)). In vivo analysis with Saccharomyces cerevisiae cells showed low toxicity of the aqueous extract of parsley, however, it revealed a high dose-dependent antioxidant potential, mainly in the lipoperoxidation assay. In addition, flavonoid apiin also showed antioxidant action on yeast cells under oxidative stress in the cell viability assay (0.1 mM) and lipid peroxidation (0.01 and 0.1 mM), while apigenin was slightly antioxidant. Therefore, it is likely that the antioxidant activity of apiin is related to the total antioxidant capacity of parsley.

Assuntos

Antioxidantes/análise , Petroselinum/química , Extratos Vegetais/análise , Extratos Vegetais/isolamento & purificação , Antioxidantes/farmacologia , Apigenina/análise , Apigenina/farmacologia , Flavonoides/análise , Glicosídeos/análise , Estresse Oxidativo , Fenóis/análise , Extratos Vegetais/farmacologia , Folhas de Planta/química , Saccharomyces cerevisiae/efeitos dos fármacos

RESUMO

ABSTRACT Passiflora caerulea L., P. alata Curtis and P. incarnata L. (synonym for P. edulis Sims), are the most popular representatives of the Passiflora genus in South America. In recent years, a growing attention is paid to the biological activity and phytochemical profiles of crude extracts from various species of Passiflora in worldwide. The aim of this study was to evaluate and to compare of anti-leukemic activity of the dry crude extracts from leaves of three Passiflora species from greenhouse of Poland in two human acute lymphoblastic leukemia cell lines: CCRF-CEM and its multidrug resistant variant. Two systems of liquid chromatography in order to assessment of phytochemical composition of extracts were applied. Extracts of P. alata and P. incarnata showed the potent inhibitory activity against human acute lymphoblastic leukemia CCRF-CEM, while P. caerulea not showed activity (or activity was poor). Despite similarities in quality phytochemical profile of extracts from P. caerulea and P. incarnata, differences in quantity of chemical compounds may determine their various pharmacological potency. For the activity of P. alata extract the highest content of terpenoids and a lack of flavones C-glycosides are believed to be crucial. Summarizing, the crude extract from P. alata leaves may be considered as a substance for complementary therapy for cancer patients.

RESUMO

Micropropagation of Passiflora species and its hybrids may play an important role in the production of healthy and disease-free plants which can be a source of medicinal herbal products, nutritional fruits and ornamental flowers. The rapid multiplication of elite plants to obtain pharmacognostic material, containing valuable flavonoid C-glycosides, is possible by usingcontrolled in vitro conditions, constituents of the medium and the interactions of plant growth regulators (1-naphtaleneacetic acid, benzyladenine, gibberellin GA3,kinetin, indole-3-acetyl-L-aspartic acid, indole-3-butyric acid, thidiazuron) and influencing various chemical additives (silver nitrate, coconut water, activated charcoal). Investigations of specific requirements during stages of micropropagation, such as the establishment of primary cultures (including type of explants, age of donor plant), shoot multiplication (by direct and indirect organogenesis and embryogenesis), rooting and acclimatization of regenerated plants are summarized in this review. The following species were recently studied for micropropagation: P. alata, P. caerulea, P. cincinnata, P. edulis, P. foetida, P. setacea, P. suberosa. It seems that for awide range of applications of in vitro clones of Passiflora, interdisciplinary studies including genetic and phytochemical aspects are needed.