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Melissa officinalis (MO, English: lemon balm, Lamiaceae), one of the oldest and still most popular aromatic medicinal plants, is used in phytomedicine for the prevention and treatment of nervous disturbances. The aim of our study was to assess the effect of subchronic (28-fold) administration of a 50% ethanol extract of MO leaves (200 mg/kg, p.o.) compared with rosmarinic acid (RA, 10 mg/kg, p.o.) and huperzine A (HU, 0.5 mg/kg, p.o.) on behavioral and cognitive responses in scopolamine-induced rats. The results were linked with acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and beta-secretase (BACE-1) mRNA levels and AChE and BuChE activities in the hippocampus and frontal cortex of rats. In our study, MO and HU, but not RA, showed an improvement in long-term memory. The results were in line with mRNA levels, since MO produced a decrease of AChE mRNA level by 52% in the cortex and caused a strong significant inhibition of BACE1 mRNA transcription (64% in the frontal cortex; 50% in the hippocampus). However, the extract produced only an insignificant inhibition of AChE activity in the frontal cortex. The mechanisms of MO action are probably more complicated, since its role as a modulator of beta-secretase activity should be taken into consideration.

Flax and hemp fibers are known as textile raw materials with pro-health properties. This paper presents results of research aimed at investigating the antioxidant activity of the fibers in order to explain a mechanism for the favorable influence of textiles made of these fibers when in contact with human skin. The study presents a new approach in evaluation of textile fibers in terms of their inherent pro-health properties. Antioxidant properties of flax and hemp fibers were tested with the use of FRAP and DPPH methods. The content of phenolic acids: syringic, sinapinic, p-coumaric and ferulic acid was determined with the use of HPLC. The results proved that the antioxidant activity of the tested fibers depends on a type and variety of fibrous plants, a method of fiber extraction and subsequent stages of preliminary processing of the fibers. Both decorticated flax and hemp fibers showed higher antioxidant activity in comparison to the fibers obtained with other extraction methods, while decorticated flax of different varieties presented the highest value of the FRAP. Wet methods of fiber extraction and processing caused reduction of phenolic acids content and significantly lower values of the FRAP and DPPH.

No abstract

The aim of the study was to evaluate analgesic activity (“hot plate” test), anti-inflammatory activity (carrageenan-induced paw edema) and locomotor activity in rats under the influence of three fractions of Chelidonium majus herb extract: full water extract (FWE), protein enriched fraction (PEF), and non-protein fraction (NPF). Effects of the fractions on the level of chosen cytokines and their mRNA levels were also assessed using lipopolysaccharide (LPS) administration as a proinflammatory cue. All fractions and diclofenac did not affect the locomotor activity of rats in comparison with the control group. FWE and PEF three hours after administration showed statistically significant analgesic activities comparable to morphine (p < 0.05). A slight reduction in rat paw edema was observed after three (comparable with diclofenac) and six hours in the NPF group. FWE revealed a statistically significant pro-inflammatory effect after three hours in comparison with the control group. Peripheral IL-1 and IL-4 cytokine concentrations were reduced under FWE and NPF, PEF fractions. The combination of FWE, PEF and NPF together with LPS showed only the effects of LPS. We suggest that protein enriched fraction (PEF) produced centrally mediated (morphine-like) analgesic action, whereas the anti-inflammatory potential was shown only after LPS-induced inflammation. The precise mechanisms involved in the production of anti-nociceptive and anti-inflammatory responses of studied fractions are not completely understood, but they may be caused rather by the presence of protein more than alkaloids-enriched fraction. This fraction of the extract could be used as an alternative therapy for the prevention of inflammatory-related diseases in the future, but further studies are needed.