Antidepressant-Like Effect and Phenolic Profile of Brazilian Native and Exotic Species from Psidium Genus.

Depression is one of the disorders involving mental health that most affects the population worldwide. Considering the available pharmacological therapies for the treatment of depression are ineffective in most patients, the search for new alternatives is crucial. In line with this, we investigated the phenolic profile, antidepressant-like, and antioxidant effects triggered by the administration of aqueous extracts from Psidium guajava L. (GUA), Psidium cattleianum Sw. (CAT), and Psidium guineense Sabine (GUI) leaves in mice. Our results show that quercetin is the major compound of GUA and GUI, and o-coumaric acid in CAT extracts. The acute and subchronic administrations of the three plant extracts exerted an antidepressant-like effect in mice exposed to the tail suspension test, without changes on locomotor performance evaluated by the open field test. Furthermore, the GUI and CAT decreased oxidative stress markers, mainly lipid peroxidation and nitrites in the hippocampus, prefrontal cortex, liver, and plasma. Notably, GUA and CAT increased non-protein thiols in all tissues. Therefore, the Psidium extracts demonstrated an antidepressant-like effect in mice, and the antioxidant capacity of the extracts seems to underlie the behavioral effect.

Phenolic profile, antidepressant-like and neuroprotective effects of Maclura tinctoria leaves extract.

Considering the drawbacks elicited by the conventional antidepressants, the interest in natural products for the management of major depressive disorder has increased in the last years. Therefore, this study investigated the phenolic profile of Maclura tinctoria leaf aqueous extract (MtAE) and its possible antidepressant-like effect in mice. The LC-MS/MS analysis demonstrated MtAE has epicatechin as the major phenolic, followed by catechin, gallic acid, quercetin, syringaldehyde, ferulic acid, and syringic acid. Moreover, the acute treatment of MtAE elicited an antidepressant-like response in mice. Importantly, this antidepressant-like effect produced by MtAE was reinforced in the chronic corticosterone (20 mg/kg p.o.) administration model. MtAE treatment was also effective to protect hippocampal and cerebrocortical slices against glutamatergic excitotoxicity. Our results indicated that MtAE displayed antidepressant-like and neuroprotective effects and these responses could be associated with the presence of the phenolic compounds identified.

Biological agents for 2,4-dichlorophenoxyacetic acid herbicide degradation.

Phenoxy herbicides are the most widely used family of herbicides worldwide. The dichlorophenoxyacetic acid (2,4-D) is extensively used as a weed killer on cereal crops and pastures. This herbicide is highly water-soluble, and even after a long period of disuse, considerable amounts of both 2,4-D and its main product of degradation, 2,4 dichlorophenol (2,4-DCP), might be found in nature. Biological decomposition of pesticides is an expressive and effective way for the removal of these compounds from the environment. The role of bacteria as well as the enzymes and genes that regulate the 2,4-D degradation has been widely studied, but the 2,4-D degradation by fungi, especially regarding the ability of white-rot basidiomycetes as agent for its bioconversion, has been not extensively considered. This review discusses the current knowledge about the biochemical mechanisms of 2,4-D biodegradation, focused on the role of white-rot fungi in this process. Finally, the cultivation conditions and medium composition for the growth of 2,4-D-degrading microorganisms are also addressed.

Increasing the instrumental throughput of gas chromatography method using multiple injections in a single experimental run: application in determination of friedelan-3-ol and friedelin in Maytenus ilicifolia.

The aim of this study was to develop a separation method using multiple injections in a single experimental run (MISER) employing gas chromatography with flame ionization detection (GC-FID) for the first time, without instrument modification, to increase the instrumental throughput. The method was applied to the determination of the triterpenes friedelan-3-ol and friedelin in a plant extract obtained from Maytenus ilicifolia leaves. The column used in the chromatography system was a ZB-50 (30 m × 0.25 mm × 0.15 µm) with 50% phenyl-50% methyl-polysiloxane. The samples (1.0 µL) were injected using the split mode (1:90), with the injector at 280 °C and FID detector at 320 °C. The column temperature was programmed to isothermal mode at 300°C. Helium was used as the carrier gas with a constant flow of 1.5 mL min(-1). It was possible to perform three injections in the same run using the MISER method. An increase in the instrumental throughput by a factor of around 2.6 was observed when the use of multiple injections was compared with the single injection method. This method showed good linearity for both analytes with R(2)>0.99 and the values for the limit of detection were 0.24 mg L(-1) and 0.44 mg L(-1), for friedelan-3-ol and friedelin, respectively. Furthermore, the values for the limits of quantification were 0.79 mg L(-1) for friedelan-3-ol and 1.16 mg L(-1) for friedelin. The proposed method has potential for other GC applications, allowing an increase in the instrumental throughput of the methods by applying this separation technique.