Chemical composition, antioxidant and cytotoxic activities of extracts from the pericarp of Tecoma stans (L.) Juss. Ex Kunth (Bignoniaceae).

Tecoma stans (L.), popularly known as ipê-mirim, is used in traditional medicine for the treatment of diabetes and digestive problems. The components of the hexane (HE) and methanol (ME) extracts obtained from the pericarp of T. stans were identified by gas chromatography-mass spectrometry (GC-MS) in their methyl ester forms (FAME). The antioxidant and cytotoxic activities of extracts, fatty acids, and methyl esters were evaluated. Methyl linolenate, methyl linoleate, and methyl palmitate were the major compounds in the HE, while methyl hexacosanoate was the main component in the ME. The samples exhibited significant antioxidant potential by DPPH assay. In the Artemia salina larvae bioassay, FAME (HE) and FAME (ME) were considered toxic. This study showed, for the first time to our knowledge, the chemical composition of the hexane and methanol extracts from T. stans pericarp, as well as the antioxidant and cytotoxic activities of the extracts, fatty acids, and methyl esters.

Phytotoxic and antioxidant effects of dichloromethane fraction of Smilax Brasiliensis Sprengel.

Dichloromethane (DCM) fraction and sub-fractions obtained from Smilax brasiliensis leaves were examined in order to determine their phytotoxic and antioxidant effects. The dichloromethane fraction was submitted to a preparative layer chromatography leading to seven sub-fractions (DCM1-DCM7). Gas chromatography-mass spectrometry (GC-MS) was performed on the dichloromethane sub-fractions. The DCM sub-fractions presented phytotoxic potential; at a concentration of 125 µg per plate, DCM6 and DCM4 showed the strongest results on Lactuca sativa and Allium cepa, respectively. The DCM fraction and DCM4 sub-fraction were more effective than 2,6-di-tert-butyl-4-methylphenol (BHT) at scavenging the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Analysis by GC-MS showed the presence of methyl palmitate (33.05%) in DCM4 and methyl palmitate (17.29%) and methyl oleate (50.96%) in DCM6, suggesting that the activities exhibited by the sub-fractions may be attributed, at least partially, to these major compounds. These results indicate that the DCM sub-fractions of S. brasiliensis could be used as natural herbicides and antioxidants.

Chemical composition, antioxidant, anti-inflammatory and antinociceptive activities of the ethanol extract of ripe fruits of Solanum lycocarpum St. Hil. (Solanaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Solanum lycocarpum St. Hil. (Solanaceae) is widely distributed in the Brazilian Cerrado and is used in folk medicine for treatment of inflammatory disorders, such as asthma and hepatitis, as weel as antirheumatic. AIM OF THE STUDY: The aims of this study were to evaluate the antioxidant, anti-inflammatory and antinociceptive activities of the ethanol extract (EE) obtained from the ripe fruits of S. lycocarpum and to identify its chemical constituents. MATERIALS AND METHODS: The extract was obtained by percolation with ethanol. This extract was analyzed by liquid chromatography coupled to a diode array detector and mass spectrometer (LC-DAD-MS) for identify its chemical constituents. The antioxidant activity was determined by the reaction with 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). In vivo anti-inflammatory potential was assessed using carrageenan-induced paw edema model, while qualitative and quantitative histological analyses evaluated of the inflammatory infiltrate at different times and treatments. The antinociceptive effect of the EE was evaluated by acetic acid-induced abdominal writhing test, formalin-induced nociception and hot-plate test. RESULTS: The main compounds identified in EE were steroidal glycoalkaloids (such as robeneoside B or hydroxysolasonine isomers and solanandaine isomers), the aglycone alkaloids peiminine and solasodine, di- and tri-O-caffeoylquinic acid derivatives, O-coumaroyl caffeoylquinic acid derivatives, N1,N10-bis-(dihydrocaffeoyl)spermidine, di-O-hexoside, and hexonic acid. In addition, the EE showed significant antioxidant activity. Intraperitoneal (i.p.) treatment with EE (300 mg/kg) exhibited anti-inflammatory activity. Qualitative and quantitative histological analyses showed that EE significantly reduced the cell infiltrate in acute inflammation. The EE, in all doses evaluated, significantly reduced the abdominal contortions in mice. Besides, reduced licking time was found in both phases in the formalin test after treatment with EE (100 and 300 mg/kg). In addition, the opioid receptor antagonist naloxone reversed the antinociceptive activity of morphine in the both phases the test, but it did not reverse the antinociceptive activity of the EE. The EE (300 mg/kg) also caused an increase in the latency to response in the hot-plate test. CONCLUSION: The ripe fruits of S. lycocarpum exhibit antioxidant, anti-inflammatory, and antinociceptive activities, attributed mainly to the presence of alkaloids, such as solasodine and peiminine, as well as caffeoylquinic acids in their chemical composition. These results contribute to use of S. lycocarpum ripe fruits for the treatment of inflammatory and painful process.

Assessment of allelopathic, cytotoxic, genotoxic and antigenotoxic potential of Smilax brasiliensis Sprengel leaves.

Smilax brasiliensis (Smilacaceae) is a native Brazilian plant found in the Cerrado biome and commonly used in folk medicine. The aim of this study was to evaluate the allelopathic, cytotoxic, genotoxic, and antigenotoxic potential of extract and fractions of Smilax brasiliensis leaves. Quercetin and rutin isomers were observed in the subfractions. The dichloromethane fraction (1000 µg/mL) decreased lettuce (Lactuca sativa) seed vigor, while and ethyl acetate and hydromethanol fractions (1000 µg/mL) affected the germination, and quercetin and rutin affected the vigor and germination of onion seeds. The extract, fractions, quercetin, and rutin inhibited or promoted lettuce hypocotyl and radicle growth. The extract and fractions inhibited onion hypocotyl growth at all concentrations. With regards to radicle growth, the results were diversified: growth was either inhibited or promoted. Rutin and quercetin inhibited onion hypocotyl and radicle growth at all concentrations. The extract and fractions of Smilax brasiliensis, rutin, and quercetin did not cause cytotoxic effect evaluated by mitotic index. The extract and fractions showed genotoxic effects. Quercetin and rutin did not cause genotoxic effects. On the other hand, the extract and fractions showed antigenotoxic effects at all tested concentrations, where they were able to revert chromosomal abnormalities caused by glyphosate. However, additional studies are required to evaluate the possible use of the S. brasiliensis leaf methanol extract and fractions as natural sources of bioherbicides.

Phenolic compounds: antioxidant and larvicidal potential of Smilax brasiliensis Sprengel leaves.

Smilax brasiliensis is a medicinal species of the Brazilian Cerrado. The extract and fractions of this plant were analysed by LC-DAD-MS. Identified constituents included glycosylated and non-glycosylated flavonoids, especially quercetin, and phenylpropanoids, such as chlorogenic acids. The antioxidant activity was significantly more pronounced for the methanol extract and fractions than that of the commercial antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT). Maximum larvicidal activity of 85.83% was recorded in the dichloromethane fraction (LC50 = 469.78 µg mL-1). The methanol extract and fractions presented low toxicity to larvae of the shrimp brine Artemia salina, indicating selectivity for C. quinquefasciatus. These results contribute to the phytochemical study of S. brasiliensis. These compounds were identified for the first time in this species and encourage additional work on the isolation of compounds present in the extract and fractions of S. brasiliensis to evaluate the possibility of using them as natural sources of antioxidants, since cytotoxic effects were not demonstrated.

Allelopathic effect of the ethanol extract and fractions of the aerial parts of Lippia alba (Verbenaceae).

Lippia alba, belonging to the Verbenaceae family, is one of the most commonly utilized medicinal plants in folk medicine. The allelopathic activity was assessed using seeds of Lactuca sativa (lettuce) and Allium cepa (onion) by assessing the growth of the radicle and hypocotyl. The tests showed allelopathic efficiency in inhibiting the growth of lettuce and onion seeds. The best results for allelopathic activity were presented by the dichloromethane (DCM) fraction of the fresh plant, which inhibited radicle (23.04-100% lettuce and 64.17-66.36% onion) and hypocotyl (16.77-100% lettuce and 65.10-69.43% onion) formation, and as well as the DCM fraction of the dry plant, which also inhibited radicle (30.74-82.83% lettuce and 63.50-93.67% onion) and hypocotyl (24.12-70% lettuce and 69.07-79.95% onion) formation. Based on these results, it was found that the aerial parts of L. alba are rich in bioactive substances, suggesting the possibility of using of L. alba as a natural herbicide.

Phytochemical characterisation and bioprospection for antibacterial and antioxidant activities of Lippia alba Brown ex Britton & Wilson (Verbenaceae).

Ethanol extract and fractions obtained from fresh and dry aerial parts of Lippia alba were examined in order to determine their phytochemical composition, antioxidant capacity and antibacterial activities. The ethanol extracts and fractions exhibited an antioxidant effect by the DPPH assay, especially samples of fresh plant. HPLC analysis of the ethyl acetate fractions identified the presence of phenolic acids and flavonoids. The ethanol extract and fractions showed activity against reference and multidrug-resistant strains of Staphylococcus aureus and Enterococcus faecalis (MIC range 2000-250 µg/mL). The hexane and dichloromethane fractions of fresh plant showed better activity against reference strains of Escherichia coli (MIC of 250 and 125 µg/mL, respectively), but all extracts and fractions were less active against multidrug-resistant strains of all the Gram-negative species evaluated. The results showed that the extract and fractions of L alba aerial parts showed antibacterial activity, even against multidrug-resistant Gram-positive bacteria, and antioxidant effect (DPPH assay).

Chemical composition, antioxidant and cytotoxic activities of extracts from the leaves of Smilax brasiliensis Sprengel (Smilacaceae).

The antioxidant and cytotoxic activities of petroleum ether and methanol extracts, fatty acids and methyl esters from leaves of Smilax brasiliensis were evaluated, and the composition of the extracts was determined. Palmitic, linoleic and linolenic acids were major components of the extracts. For antioxidant activity, all samples exhibited IC50 values lower than BHT (2,6-di-tert-butyl-4-methylphenol). The extracts, fatty acids and methyl esters from S. brasiliensis presented no toxicity to larvae of the brine shrimp, Artemia salina. Among the purified substances, only methyl linolenate showed toxicity (LD50 = 21.47 µg/mL). This study showed, for the first time, the composition of petroleum ether and methanol extracts from S. brasiliensis leaves, as well as the antioxidant and cytotoxic activities of extracts, fatty acids and methyl esters.