Inhibitory effects of Alpinia speciosa K. SCHUM on the porphyrin photooxidative reaction

Spinacia oleracea Linn Considered as One of the Most Perfect Foods: A Pharmacological and Phytochemical Review

Background: :

Leaves of Spinacia oleracea have been widely used as vegetarian foods. Some studies on the chemical composition of spinach have shown that it contains a high content of micronutrients (vitamins and minerals), and has an important economic value with some agronomic advantages. S. oleracea in traditional medicine is reported to cure more than one health problem.

Objective: :

This review focuses on the ethnopharmacological uses and pharmacological and phytochemical studies of Spinacia oleracea.

Method: :

Information on S. oleracea was obtained via electronic search of scientific databases such as Scopus, PubMed, Google Scholar, Scirus, Science Direct, Scielo, Web of Science, Medline, Springerlink, BioMed Central (BMC), and SciFinder for publications on this plant. In addition, books on medicinal herbs were also consulted.

Results: :

Approximately 100 chemical compounds were isolated and characterized from S. oleracea. The major active components of the plant are flavones, flavanols, methylenedioxyflavonol glucuronides, glucuronides, and carotenoids, which were extensively investigated. This review revealed potential pharmacological properties of these isolated compounds such as anti-obesity, anti-α-amylase, bileacid binding capacity, anti-mutagenic, anti-oxidant, anticancer, anti-inflammatory, cognitive and mood effect, hypoglycemic, and anti-hypertriglyceridemia.

Conclusions::

S. oleracea is an important edible plant also used for ethnomedical therapy of obesity, inflammation of lungs, lumbago, flatulence, and treatment of urinary calculi. Pharmacological and phytochemical studies of this plant including bioactives, which have been adequately studied, support its uses in traditional medicine. Additionally, prospects and future trends of this plant are proposed.

Cytotoxic and anti-kinetoplastid potential of the essential oil of Alpinia speciosa K. Schum

Alpinia speciosa K. Schum, known as colônia (colony), is native to tropical Asia and found in parts of tropical America. Its leaves are used to wrap food, rhizomes for food preparation and seeds for health maintenance, and have been widely used by the population as a diuretic, antihypertensive, antiulcerogenic and sedative. The present study aimed to verify the leishmanicidal and trypanocidal potential, as well as the cytotoxicity, of the A. speciosa essential oil, in vitro. A. speciosa presented 1,8-cineole (28.46%), camphor (17.10%) and sabinene (9.95%) as major constituents. The cytotoxic activity of the essential oil presented a low value, while the antipromastigote and antiepimastigote activity presented values considered clinically relevant, since it had an action below 500 μg/mL. In relation to this study, it can be concluded that this is a pioneer in the potential of the A. speciosa essential oil and in the use against the parasites Trypanosoma cruzi Chagas and Leishmania brasiliensis Vianna, having its importance also rooted in this fact. Still in accordance with the results, A. speciosa was effective because it presented values of clinical relevance and low toxicity. It was also observed that the chemical constitution of the above identified compounds with remarkable antiparasitic activities.

Effects of the Essential Oil from Leaves of Alpinia zerumbet on Behavioral Alterations in Mice

In phytotherapy, the essential oil from the leaves of Alpinia zerumbet ( Alpinia speciosa K. Schum.) (EOAZ) is used for neuropsychiatric symptoms, such as depression, stress and anxiety, and chronic problems that are associated with reproductive hormone imbalances in women. The chemical composition of EOAZ was analyzed by GC/MS, and the EOAZ properties inducing behavioral alterations in mice were examined by behavioral observations (BO) and an elevated plus-maze task (EPM), widely used as a method for assessing anxiolytic-like behaviors. Five major compounds, p-cymene (28.0 ± 5.0%), 1,8-cineole (17.9 ± 4.2%), terpinen-4-ol (11.9 ± 6.3%), limonene (6.3 ± 2.2%), and camphor (5.2 ± 2.1%) were identified by retention indices, mass spectra and comparison with standards. Inhalational administration of EOAZ (8.7 ppm) induced unique jumping behaviors in mice. To further investigate the behavioral regulatory mechanisms of EOAZ, we administered an intraperitoneal injection of either 10 mg/kg 5-HTP or 10 mg/kg fluoxetine prior to the EOAZ inhalations. By 5-HTP or fluoxetine pretreatments, the jumping frequencies were significantly decreased. In EPM, EOAZ (0.087 and 8.7 ppm) obviously showed the anxiolytic-like activity in mice.

Effects of essential oil of Alpinia zerumbet on the compound action potential of the rat sciatic nerve

Alpinia zerumbet, known popularly as "colônia" in Northeastern Brazil, is a medicinal plant that has been used widely in folk medicine as teas and infusions for the treatment of intestinal and cardiovascular diseases, including arterial hypertension. Our previous studies have demonstrated that the essential oil of A. zerumbet (OEAZ) is very active on excitable tissues, such as smooth muscle, and in this study we verified its effects on the compound action potential (CAP) of rat sciatic nerve. EOAZ induced a dose-dependent blockade of the CAP. Control peak-to-peak amplitude and conduction velocity of CAPs were 7.6 +/- 0.43 mV and 80.6 +/- 3.19 m/s, respectively. At 60 microg/ml, EOAZ induced no demonstrable effect. Conduction velocity was significantly reduced at 180 min of preparation exposure to 100 microg/ml of EOAZ. At 300, 600 and 2000 microg/ml doses of EOAZ, the peak-to-peak amplitudes of CAPs following 180 min exposure of the nerve to the drug were reduced significantly, to 75.3 +/- 7.36%, 50.45 +/- 2.17% and 0% respectively, of control value. Conduction velocity was reduced significantly by 300, 600 and 2000 microg/ml of EOAZ, at 180 min, to 83.61 +/- 3.28%, 64.06 +/- 8.21% and 22.7 +/- 5.79%, respectively, of control value. All these effects developed slowly and were reversible upon a 180-min wash.

Scavenging of reactive oxygen species by a novel glucurinated flavonoid antioxidant isolated and purified from spinach

NAO is a natural water soluble antioxidant that was isolated and purified from spinach leaves. Using HPLC, NMR, and CMR spectroscopy, the main components were identified as flavonoids and p-coumaric acid derivatives. The NAO was found to be a very effective antioxidant in several in vivo and in vitro biological systems. In the present study, the antioxidant activity of the novel antioxidant glucurinated flavonoid (GF) isolated and characterized from NAO, is compared to well-known antioxidants. In addition, the direct free radical scavenging properties of the purified component GF were studied using the electron spin resonance (ESR) technique. GF and NAO were found to be superior to EGCG and NAC and to the Vitamin E homologue Trolox in inhibiting reactive oxygen species (ROS) formation in the autooxidation system of linoleic acid and in fibroblasts exposed to metal oxidation. GF and NAO were found to inhibit the ESR signal intensity of DMPO-O(2) radical formation during the riboflavin photodynamic reaction. 10 mM GF caused approximately 90% inhibition in the intensity of the ESR signal, while NAO at a concentration of 60 microg/ml caused an inhibition of about 50%. Using the Fenton reaction, GF and NAO were found to inhibit DMPO-OH radical formation. A concentration of 2 mM GF caused a 70% inhibition in the intensity of the DMPO-OH radical ESR signal, while propyl gallate at the same concentration caused only 50% inhibition. Furthermore, both GF and NAO also inhibited the (1)O(2) dependent TEMPO radical generated in the photoradiation TPPS4 system. About 80% inhibition was obtained by 4 mM GF. The results obtained indicate that the natural antioxidants derived from spinach may directly affect the scavenging of ROS and, as a consequence, may be considered as effective sources for combating oxidative damage.

Inhibitory effect of Rumex Japonicus Houtt on the porphyrin photooxidative reaction

Rumex Japonicus Houtt (RJH), a plant indigenous to Okinawa, Japan, has been used traditionally by the local people for treatment of acute and chronic cutaneous diseases; however, its pharmacological effect is not clearly understood. To investigate its active function, we examined the antioxidative effect of RJH on the hematoporphyrin-induced photooxidative reaction. We measured intracellular reactive oxygen species (ROS) in cultured transformed human vascular endothelial cells (ECV-304) by flow cytometry, lipid peroxide (LPO) in erythrocyte ghosts by spectrofluorometry, and hemolysis by spectrophotometry. Results showed the generation of intracellular ROS in ECV-304, LPO production in erythrocyte ghosts, and hemolysis after visible light irradiation in the presence of hematoporphyrin. In the RJH root extract treated group, generation of intracellular ROS, LPO production, and hemolysis were inhibited significantly. It has been reported that the RJH root contains emodin and chrysophanic acid. In our study, three fractions were separated from the RJH root extract by thin layer chromatography (TLC). We found that fraction 1 (near the origin) showed a strong inhibitory effect on LPO levels; however, fraction 2 (equal to emodin) and fraction 3 (equal to chrysophanic acid) showed no inhibitory effect on LPO levels. Our experiments verified that RJH has an antioxidative effect against photohemolysis and supports our hypothesis that RJH may have potential as a protective agent against oxidative stress associated with some diseases such as porphyrias.