Terpenoids as Plant Antioxidants

Effect of Inhaling Cymbopogon martinii Essential Oil and Geraniol on Serum Biochemistry Parameters and Oxidative Stress in Rats

The effects of the inhalation of Cymbopogon martinii essential oil (EO) and geraniol on Wistar rats were evaluated for biochemical parameters and hepatic oxidative stress. Wistar rats were divided into three groups (n = 8): G1 was control group, treated with saline solution; G2 received geraniol; and G3 received C. martinii EO by inhalation during 30 days. No significant differences were observed in glycemia and triacylglycerol levels; G2 and G3 decreased (P < 0.05) total cholesterol level. There were no differences in serum protein, urea, aspartate aminotransferase activity, and total hepatic protein. Creatinine levels increased in G2 but decreased in G3. Alanine aminotransferase activity and lipid hydroperoxide were higher in G2 than in G3. Catalase and superoxide dismutase activities were higher in G3. C. martinii EO and geraniol increased glutathione peroxidase. Oxidative stress caused by geraniol may have triggered some degree of hepatic toxicity, as verified by the increase in serum creatinine and alanine aminotransferase. Therefore, the beneficial effects of EO on oxidative stress can prevent the toxicity in the liver. This proves possible interactions between geraniol and numerous chemical compounds present in C. martinii EO.

Bio-efficacy of the essential oil of oregano (Origanum vulgare Lamiaceae. Ssp. Hirtum)

The aim of this study was to investigate the bioactivity of the essential oil isolated from Origanum vulgare L. (EOv). We analyzed the in vivo anti-inflammatory properties in a mouse-airway inflammation model and the in vitro antimicrobial activity, genotoxicity over the anaphase-telophase with the Allium cepa strain and its cytotoxicity/viability in A549 culture cells. In vivo, EOv modified the levels of tumor necrosis factor -α and viable activated macrophages and was capable to mitigate the effects of degradation of conjugated dienes. In vitro, EOv reduced the viability of cultured A549 cells as well as the mitotic index and a number of chromosomal aberrations; however, it did not change the number of phases. We found that EOv presents antimicrobial activity against different Gram (-) and (+) strains, measured by disc-diffusion test and confirmed with a more accurate method, the AutoCad software. We postulate that EOv presents antibacterial, antioxidant and chemopreventive properties and could be play an important role as bioprotector agent.

Effect of fruit and vegetable antioxidants on total antioxidant capacity of blood plasma

For a long time, the increased consumption of fruits and vegetables was considered critical in protecting humans against a number of diseases, such as cancer, diabetes, neurodegenerative diseases, and heart and brain vascular diseases. Presently, it is thought that the protective properties of these foods result from the presence of low-molecular antioxidants that protect the cells and their structures against oxidative damage. The alleged effect of reducing the risk for many diseases is not only due to the effect of individual antioxidants, such as α-tocopherol, ascorbic acid, or β-carotene, but also may be the result of antioxidant compounds not yet known or synergy of several different antioxidants present in fruits and vegetables. Studies on macromolecules (DNA, nucleotides, proteins) free-radical-related damage showed that diets enriched with extra servings of fruits and vegetables rich in β-carotene, tocopherols, and ascorbic acid had only limited effect on the inhibition of oxidation processes. A number of studies have shown, however, that consuming less common fruits and vegetables contribute much more to the reduction of free-radical processes, most likely because they contain a large amount of non-vitamin antioxidants, such as polyphenols and anthocyanins.

Phenolic composition, antioxidant, anti-wrinkles and tyrosinase inhibitory activities of cocoa pod extract

BACKGROUND

Cocoa pod is an outer part of cocoa fruits being discarded during cocoa bean processing. Authors found out that data on its usage in literature as cosmetic materials was not recorded in vast. In this study, cocoa pod extract was investigated for its potential as a cosmetic ingredient.

METHODS

Cocoa pod extract (CPE) composition was accomplished using UHPLC. The antioxidant capacity were measured using scavenging assay of 1,2-diphenyl-2-picrylhydrazyl (DPPH), β-carotene bleaching assay (BCB) and ferric reducing antioxidant power (FRAP). Inhibiting effect on skin degradation enzymes was carried out using elastase and collagenase assays. The skin whitening effect of CPE was determined based on mushroom tyrosinase assay and sun screening effect (UV-absorbance at 200-400 nm wavelength).

RESULTS

LC-MS/MS data showed the presence of carboxylic acid, phenolic acid, fatty acid, flavonoids (flavonol and flavones), stilbenoids and terpenoids in CPE. Results for antioxidant activity exhibited that CPE possessed good antioxidant activity, based on the mechanism of the assays compared with ascorbic acid (AA) and standardized pine bark extract (PBE); DPPH: AA > CPE > PBE; FRAP: PBE > CPE > AA; and BCB: BHT > CPE > PBE. Cocoa pod extract showed better action against elastase and collagenase enzymes in comparison with PBE and AA. Higher inhibition towards tyrosinase enzyme was exhibited by CPE than kojic acid and AA, although lower than PBE. CPE induced proliferation when tested on human fibroblast cell at low concentration. CPE also exhibited a potential as UVB sunscreen despite its low performance as a UVA sunscreen agent.

CONCLUSIONS

Therefore, the CPE has high potential as a cosmetic ingredient due to its anti-wrinkle, skin whitening, and sunscreen effects.

Model studies on the antioxidant activity of common terpenoid constituents of essential oils by means of the 2,2-diphenyl-1-picrylhydrazyl method

The research aims to indicate which of the structural elements of monoterpenes are responsible for their antioxidant activity. The activity was determined spectrophotometrically with the use of the DPPH(•) assay. It has been shown that π bonds are responsible for the chain-breaking antioxidant activity of monoterpenes. It has been proved, for the first time, that blocking of conjugated double bonds leads to a decrease of the antioxidant activity of monoterpenes. A probable reaction mechanism between monoterpenes and DPPH(•) has been proposed. It has been indicated that the antioxidant activity of monoterpenes strongly depends on the polarity of solvent used in the experiments. The presented results may stimulate additional research in the field of terpenoid antioxidants.

Lupeol: An antioxidant triterpene in Ficus pseudopalma Blanco (Moraceae)

OBJECTIVE

To assess the antioxidant activity of Ficus pseudopalma Blanco (Moraceae) (F. pseudopalma) and characterize the active components present in it.

METHODS

Column chromatography of crude ethanol leaf extract of F. pseudopalma was performed and seven fractions were obtained, labeled as F1, F2, F3, F4, F5, F6, F7. DPPH, FRAP, Griess, Fenton and superoxide radical scavenging assays were performed to assess the antioxidant ability of the fractions. Thin layer chromatography (TLC), high performance liquid chromatography and Fourier transfer infrared spectroscopy (FTIR) were performed to identify and characterize the bioactive component present in each fractions of F. pseudopalma.

RESULTS

DPPH and FRAP assay showed that F5, F6 and F7 exhibited the good proton accepting ability and reducing power as compared to the other fractions. All fractions exhibited a good nitric oxide radical scavenging activity wherein F1, F2 and F3 showed the highest inhibition. However, all of the fractions exhibited a stimulatory activity on hydroxyl and superoxide radicals. Lupeol matched one of the spots on the thin layer chromatography chromatogram of the fractions. Linear gradient high performance liquid chromatography and spiking of lupeol with the fraction revealed the presence of 5.84 mg/L lupeol in F6. Infrared spectra of the fractions revealed the presence of C-C, OH, aromatic C=C and C=O groups.

CONCLUSIONS

The identified lupeol in F. pseudopalma may be responsible for the exhibited antioxidant property of the plant. Furthermore, knowing the antioxidant capability of the plant, F. pseudopalma can be developed into products which can help prevent the occurrence of oxidative stress related diseases.

Limonene inhibits methamphetamine-induced locomotor activity via regulation of 5-HT neuronal function and dopamine release

Methamphetamine is a psychomotor stimulant that produces hyperlocomotion in rodents. Limonene (a cyclic terpene from citrus essential oils) has been reported to induce sedative effects. In this study, we demonstrated that limonene administration significantly inhibited serotonin (5-hydroxytryptamine, 5-HT)-induced head twitch response in mice. In rats, pretreatment with limonene decreased hyperlocomotion induced by methamphetamine injection. In addition, limonene reversed the increase in dopamine levels in the nucleus accumbens of rats given methamphetamine. These results suggest that limonene may inhibit stimulant-induced behavioral changes via regulating dopamine levels and 5-HT receptor function.

Oridonin exerts protective effects against hydrogen peroxide‑induced damage by altering microRNA expression profiles in human dermal fibroblasts

The aim of the present study was to evaluate the protective effects of oridonin on hydrogen peroxide-induced cytotoxicity in normal human dermal fibroblasts (NHDFs) using microRNA (miRNA) expression profile analysis. Oridonin was not cytotoxic at low doses (≤5 µM) in the NHDFs, and pre-treatment of the cells with oridonin significantly reduced hydrogen dioxide (H2O2)-mediated cytotoxicity and cell death. Whereas oridonin showed no free radical scavenging activity in in vitro and in vivo antioxidant assays, treatment of the NHDFs with oridonin was associated with intracellular scavenging of reactive oxygen species. High-density miRNA microarray analysis revealed alterations in the expression profiles of specific miRNAs (5 upregulated and 22 downregulated) following treatment with oridonin in the H2O2-treated NHDFs. Moreover, the use of a miRNA target-gene prediction tool and Gene Ontology analysis demonstrated that these miRNAs are functionally related to the inhibition of apoptosis and cell growth. These data provide valuable insight into the cellular responses to oridonin in H2O2-induced damage in NHDFs.

Positive influence of a natural product as propolis on antioxidant status and lipid peroxidation in senescent rats

Given the importance of oxidative stress associated to aging, it would be interesting to assess the effect of oral supplementation with antioxidant substances capable of diminishing oxidative aggression and free radicals generation associated to this condition. This study investigated the effects of AIN-93 M diet supplemented either with 2 % of propolis, or with 4 % of a natural product obtained from lyophilizate vegetables, selected by its antioxidant properties, in senescent healthy Wistar rats fed ad libitum over 3 months. Propolis supplementation leads to a lower level of glucose and cholesterol concentrations together with a reduction in protein oxidation. Plasma thiobarbituric acid-reactive substance levels were lower in the rats consuming the natural vegetable product and propolis possibly due to its antioxidant components, neutralizing the free radical produced, and thus preventing cellular damage. The results of the present study suggest a synergic effect of overall propolis compounds reducing the oxidative stress and glucose and cholesterol plasma levels associated with aging.

Alternanthera sessilis Red Ethyl Acetate Fraction Exhibits Antidiabetic Potential on Obese Type 2 Diabetic Rats

The antidiabetic potential of Alternanthera sessilis Red was investigated using the obese type 2 diabetic rats induced by high fat diet and streptozotocin. Three fractions (hexane, ethyl acetate, and water) were obtained from the crude ethanol extract of Alternanthera sessilis Red. Alternanthera sessilis Red ethyl acetate fraction (ASEAF) was found to possess the most potent antihyperglycemic effect through oral glucose tolerance test. The ASEAF was subsequently given to the diabetic rats for two weeks. It was found that two-week administration of ASEAF reduces the fasting blood glucose level, triglyceride level, and free fatty acid level of the rats. ASEAF-treated diabetic rats showed higher pancreatic insulin content and pancreatic total superoxide dismutase activity compared to the untreated diabetic rats. Also, the insulin sensitivity indexes suggested that ASEAF ameliorates the insulin resistant state of the diabetic rats. In conclusion, ASEAF could be developed into a potential antidiabetic agent for the management of type 2 diabetes.

Azadirachta indica (neem) leaf dietary effects on the immunity response and disease resistance of Asian seabass, Lates calcarifer challenged with Vibrio harveyi

The present study was aimed to address the possible evaluation of Azadirachta indica (neem) leaf-supplemented diets on innate immune response in Asian seabass, Lates calcarifer fingerlings against Vibrio harveyi infection. Fish were fed for two weeks diets containing six graded levels of neem leaf at 0 g, 1 g, 2 g, 3 g, 4 g and 5 g per kg feed. Fish fed neem leaf-supplemented diet displayed significant differences (p < 0.05) in weight gain, specific growth rate (SGR) and feed conversion ratio (FCR) compared to the control group fed without neem leaf-supplemented diet. Various innate immune parameters were examined pre-challenge and post-challenge. Fish was injected intraperitoneally with a lethal dose of V. harveyi containing 10(8) cells mL(-1). Supplementation of neem leaf diet significantly increased phagocytic activity, superoxide anion production, serum lysozyme, serum bactericidal activity, serum anti-protease activity throughout the experimental period when compared with the control group. Dietary doses of neem leaf diet significantly influenced the immune parameters, haematological parameters and blood biochemical indices of treated fish. The results suggested that fish fed neem leaf-supplemented diet improved the immune system and increased survival rate in L. calcarifer fingerlings against V. harveyi infection.

Plant Essential Oils and Mastitis Disease: Their Potential Inhibitory Effects on Pro-inflammatory Cytokine Production in Response to Bacteria Related Inflammation

This paper highlights the role of plant volatile organic compounds, found in essential oils, for the treatment of bacteria related inflammation. This report is focused on tea tree oil, particularly its main compound terpinen-4-ol. Analysis of the published literature shows that many essential oils have significant antibacterial, antifungal and anti-inflammatory effects. Some of their major components, such as terpinen-4-ol, act by inhibiting pro-inflammatory cytokine expression while stimulating production of anti-inflammatory cytokines. Such observations may be exploited to encourage biotherapy against mastitis. The use of synthetic antibiotics is being increasingly discouraged because their presence in dairy milk may have potential downstream effects on population health and the agri-food chain. In the context of inflammation and related mammalian responses, understanding the interplay between volatile organic compounds, especially terpinen-4-ol, and cytokines during bacteria related inflammation should clarify their mode of action to control mastitis.

Chemical compositions and properties of Schinus areira L. essential oil on airway inflammation and cardiovascular system of mice and rabbits

The main purpose was to investigate the effects of essential plant-oil of Schinus areira L. on hemodynamic functions in rabbits, as well as myocardial contractile strength and airways inflammation associated to bacterial endotoxin lipopolysaccharide (LPS) in mice. This study shows the important properties of the essential oil (EO) of S. areira studied and these actions on lung with significant inhibition associated to LPS, all of which was assessed in mice bronchoalveolar lavage fluid and evidenced by stability of the percentage of alveolar macrophages, infiltration of polymorphonuclear leukocytes and tumor necrosis factor-α concentration, and without pathway modifications in conjugated dienes activity. Clinical status (morbidity or mortality), macroscopic morphology and lung/body weight index were unaffected by the administration of the EO S. areira. Furthermore, the ex vivo analysis of isolated hearts demonstrated the negative inotropic action of the EO of S. areira in a mice model, and in rabbits changes in the hemodynamic parameters, such as a reduction of systolic blood pressure. We conclude that EO S. areira could be responsible for modifications on the cardiovascular and/or airway parameters.

Genetic toxicology evaluation of essential oil of Alpinia zerumbet and its chemoprotective effects against H(2)O(2)-induced DNA damage in cultured human leukocytes

Essential oil (EO) of Alpinia zerumbet leaves, at non-toxic concentrations (50-300 μg/mL), did not induce genotoxicity in human leukocytes. However, at the highest concentration (500 μg/mL) tested caused a reduction in cell proliferation and viability, and an increase in DNA damage. Moreover, in vivo experiments showed that EO (400 mg/kg) did not exert mutagenicity on peripheral blood cells and bone marrow in mice. In DPPH test, EO showed scavenging effects against DPPH radicals, and other free radicals (determination of intracellular GSH and lipid peroxidation assays). Furthermore, EO was able to reduce the intracellular levels of ROS, and prevented leukocytes DNA against oxidative damage. The ability of EO to reduce H(2)O(2) toxicity was observed only when cells were treated with EO during and after exposure to H(2)O(2). With the co- and post-treatment procedures, EO decreased the frequency of apoptotic and micronucleated leukocytes as well DNA strand breaks. However, a synergistic effect was observed in cultures exposed to 500 μg/mL EO. In conclusion, EO at concentrations up to 300 μg/mL or doses up to 400mg/kg are not mutagenic in leukocytes and in mice, but do have antioxidative and protective effects against the cytotoxicity and clastogenesis induced by H(2)O(2).

Effect of dietary caraway essential oils on expression of β-catenin during 1,2-dimethylhydrazine-induced colonic carcinogenesis

We have recently reported that the inhibition of colonic premalignant lesions induced by 1,2-dimethylhydrazine (DMH) is mediated by the interference of caraway oil components in the activities of the main hepatic xenobiotic metabolizing enzymes. The present study was carried out to examine the effect of dietary caraway oils on the progression of cancer, with emphasis on β-catenin expression in the colon during DMH-induced colonic carcinogenesis. For this purpose, colon cancer was induced by DMH in rats (20 mg/kg body weight for 5 weeks) and groups of animals were given dietary caraway essential oils at two levels (0.01 and 0.1%) for 16 weeks. After 16 weeks and at the end of the experimental period the colon tissue biopsies were processed for histopathological examination and the expression of β-catenin at mRNA and protein levels was estimated by polymerase chain reaction and enzyme-linked immunosorbent assay. The formation of premalignant lesions based on aberrant crypt foci (ACF) in DMH-treated rats was greatly inhibited (72-87%) in rats given dietary essential oils when compared to respective controls. There was a correlation between the number of colonic ACF formation and the expression levels of β-catenin measured at protein and mRNA levels. These results indicate that the Wnt/β-catenin signaling pathway is activated during colon cancer promotion and that the expression of colonic β-catenin is altered in long-term caraway oil feeding, leading to suppression of DMH-induced premalignant lesions in rat colon.

Terpenoids of methanol extract of Clerodendrum infortunatum exhibit anticancer activity against Ehrlich's ascites carcinoma (EAC) in mice

CONTEXT

Clerodendrum infortunatum Linn. is a widely used plant in the Indian indigenous system of medicine for the treatment of tumors.

OBJECTIVE

The present study evaluated the anticancer activity of methanol extract of C. infortunatum (MECI) against Ehrlich's ascites carcinoma (EAC) bearing Swiss albino mice and isolation of bioactive terpenoids from it.

METHODS

HPLC analysis of the methanol extract showed the presence of three major components. Out of those, two compounds were isolated and characterized as oleanolic acid and clerodinin A. The anticancer activity of MECI was assessed by measuring the tumor growth response, percentage increase of life span, study of hematological parameters, lipid peroxidation, antioxidant enzyme activity like glutathion and CAT. In vitro cytotoxicity assay was also performed using EAC cell lines.

RESULT AND CONCLUSION

Treatment with MECI causes significant decrease in the tumor cell volume and increase in the life span. The median survival time (MST) of EAC control group was found as 19.42 ± 0.91 d, whereas the MST was increased to 23.44 ± 2.69 d and 27.57 ± 2.57 d for the groups treated with MECI at 100 and 200 mg/kg, respectively. All the hematological parameters, malonaldehyde content and antioxidant enzymes' activity were restored towards the normal level. IC(50) value of MECI was found as 498.33 µg/mL in cytotoxicity study. The experimental results suggested that MECI has significant anticancer activity, which can be attributed to the presence of oleanolic acid and clerodinin A.

Phlebodium decumanum is a natural supplement that ameliorates the oxidative stress and inflammatory signalling induced by strenuous exercise in adult humans

Strenuous exercise induces muscle damage due to a highly increased generation of free radicals and inflammatory response and therefore, in this type of exercise, it is important to reduce both oxidative stress and inflammation, at least their negative aspects. The purpose of this study was investigate, for the first time, whether a purified, standard water-soluble fraction obtained from Phlebodium decamanum could reduce the over-expression of inflammation and oxidative stress induced by strenuous exercise. The physical test consisted of a constant run that combined several degrees of high effort (mountain run and ultra-endurance), in permanent climbing. Biochemical parameters, oxidative stress and inflammatory mediators were assessed. The results showed that oral supplementation of P. decumanum during high-intensity exercise effectively reduces the degree of oxidative stress (decreased 8-hydroxy-2'-deoxyguanosine and isoprostanes generation, increased antioxidant enzyme activities in erythrocyte and total antioxidant status in plasma). The data obtained also indicate that this supplementation is efficient in reducing the inflammatory response through the decrease of TNF-α and increase of sTNF-RII, but kept the levels of IL-6 and IL-1ra. In conclusion, oral supplementation of P. decamanum extract during high-intensity exercise effectively reduces the degree of oxidative stress and has anti-inflammatory protective effects, preventing the over-expression of TNF-α but keeping the levels and effects of IL-6. These findings provide a basis for similar Phlebodium supplementation for both professional and amateur athletes performing strenuous exercise in order to reduce the undesirable effects of the oxidative stress and inflammation signalling elicited during high-intensity exercise.

Hepatoprotective activity of petroleum ether, diethyl ether, and methanol extract of Scoparia dulcis L. against CCl4-induced acute liver injury in mice

Objectives:

The present study was aimed at assessing the hepatoprotective activity of 1:1:1 petroleum ether, diethyl ether, and methanol (PDM) extract of Scoparia dulcis L. against carbon tetrachloride-induced acute liver injury in mice.

Materials and Methods:

The PDM extract (50, 200, and 800 mg/kg, p.o.) and standard, silymarin (100 mg/kg, p.o) were tested for their antihepatotoxic activity against CCl4-induced acute liver injury in mice. The hepatoprotective activity was evaluated by measuring aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total proteins in serum, glycogen, lipid peroxides, superoxide dismutase, and glutathione reductase levels in liver homogenate and by histopathological analysis of the liver tissue. In addition, the extract was also evaluated for its in vitro antioxidant activity using 1, 1-Diphenyl-2-picrylhydrazyl scavenging assay.

Results:

The extract at the dose of 800 mg/kg, p.o., significantly prevented CCl4-induced changes in the serum and liver biochemistry (P < 0.05) and changes in liver histopathology. The above results are comparable to standard, silymarin (100 mg/kg, p.o.). In the in vitro 1, 1-diphenyl-2-picrylhydrazyl scavenging assay, the extract showed good free radical scavenging potential (IC 50 38.9 ± 1.0 μg/ml).

Conclusions:

The results of the study indicate that the PDM extract of Scoparia dulcis L. possesses potential hepatoprotective activity, which may be attributed to its free radical scavenging potential, due to the terpenoid constituents.

Chemical Composition, Antioxidant Properties and Anti-cholinesterase Activity of Cordia gilletii (Boraginaceae) Leaves Essential Oil

This study aimed to investigate for the first time the chemical composition, the antioxidant properties and the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oil from the leaves of Cordia gilletii De Wild (Boraginaceae). The essential oil, characterized by 23 constituents (90.1% of the total oil), was constituted by terpene derivatives (25.6%) and non-terpene derivatives (64.5%), among which aldehydes, fatty acids and alkanes were present with the percentage of 16.5%, 18.8% and 23.1%, respectively. The antioxidant activity of C. gilletii essential oil was screened by two in vitro tests: DPPH and β-carotene bleaching test. The essential oil revealed antioxidant activity with an IC50 value of 75.0 and 129.9 μg/mL on DPPH radical and β-carotene decoloration tests, respectively. Moreover, C. gilletii inhibited AChE enzyme with an IC50 value of 105.6 μg/mL.

Evaluation of antioxidant activities and phenolic content of Berberis vulgaris L. and Berberis croatica Horvat

Antioxidant activities of the ethanolic extracts of roots, twigs and leaves of common barberry (Berberis vulgaris L.) and Croatian barberry (Berberis croatica Horvat) were studied. All the extracts were found to possess some radical-scavenging and antioxidant activities, as determined by scavenging effect on the DPPH free radical, reducing power and beta-carotene-linoleic acid model system. With the exception of the beta-carotene-linoleic acid test, antioxidant activity correlated well with the content of main plant antioxidants, phenols and flavonols, which suggests an important role of these compounds in overall antioxidant activity of investigated plant organs. The antioxidant activity varied mostly in relation to the organ, while no significant statistically differences were found between B. vulgaris and B. croatica.

Supercritical CO(2)-extracted tomato Oleoresins enhance gap junction intercellular communications and recover from mercury chloride inhibition in keratinocytes

A nutritionally relevant phytochemical such as lycopene, found in tomatoes and other fruits, has been proposed to have health-promoting effects by modulating hormonal and immune systems, metabolic pathways, and gap junction intercellular communication (GJIC). This work analyzes lycopene extracts, obtained from tomato and tomato added with grape seeds by using a safe and environmentally friendly extraction process, based on supercritical carbon dioxide technology (S-CO(2)). Analysis of the innovative S-CO(2)-extracted oleoresins showed peculiar chemical composition with high lycopene concentration and the presence of other carotenoids, lipids, and phenol compounds. The oleoresins showed a higher in vitro antioxidant activity compared with pure lycopene and beta-carotene and the remarkable ability to enhance the GJIC and to increase cx43 expression in keratinocytes. The oleoresins, (0.9 microM lycopene), were also able to overcome, completely, the GJIC inhibition induced by 10 nM HgCl(2), mercury(II) chloride, suggesting a possible action mechanism.

Chemical compositions and antioxidant/antimicrobial activities of various samples prepared from Schinus terebinthifolius leaves cultivated in Egypt

Essential oil, dichloromethane extract, and ethanol extract were prepared from fresh Schinus terebinthifolius leaves cultivated in Egypt. The essential oil was analyzed by gas chromatography and gas chromatography/mass spectrometry. The essential oil comprised 4.97% monoterpenes, 56.96% sesquiterpenes, 34.37% oxygenated monoterpenes, and 3.32% oxygenated sesquiterpenes. The major compounds in the essential oil were cis-beta-terpineol (GC peak area%, 17.87%), (E)-caryophyllene (17.56%), beta-cedrene (9.76%), and citronellal (7.03%). The major phenolic compounds identified in the ethanol extract were caffeic acid (5.07 mg/100 mg extract), coumaric acid (1.64 mg), and syringic acid (1.59 mg). The antioxidant activity of ethanol extract, which was comparable with that of butylhydroquinone, was superior to essential oil and dichloromethane extract in 2,2-diphenylpicrylhydrazyl and beta-carotene/bleaching assays. The dichloromethane extract exhibited the greatest antimicrobial activity against 6 strains, followed by the ethanol extract and the essential oil.

Seasonal variations in the leaf surface composition of field grown grapevine plants

The leaf surface is the first barrier of grapevine plants towards various environmental stressors causing damage in vineyards. For this reason, identification of leaf surface metabolites in grapevine and their putative role in plant-environment interactions is important for viticulture. In this study, the leaf surface components of 16 grapevine plants (Vitis vinifera) growing in an experimental vineyard were analyzed in two consecutive seasons - the summer and the autumn of 2007. Forty-eight individual metabolites typical of the cuticular plant wax were identified by gas chromatography-mass spectrometry (GC-MS). They belonged to the following groups of compounds: hydrocarbons, sterols, terpenes, free and esterified fatty acids, alcohols, aldehydes and ketones. The metabolic profiles of the summer and the autumn samples were statistically different (P < 0.05), which was mainly attributed to the specific insects present in the two seasons and to the adaptation of the grapevine to lower temperatures.

Dietary terpenoids and prostate cancer chemoprevention

Cancer chemoprevention by phytochemicals may be one of the most feasible approaches for cancer control. Phytochemicals obtained from vegetables, fruits, spices, teas, herbs and medicinal plants, such as terpenoids and other phenolic compounds, have been proven to suppress experimental carcinogenesis in various organs in pre-clinical models. Recent studies have indicated that mechanisms underlying chemopreventive potential may be a combination of antioxidant, anti-inflammatory, immune-enhancing, and hormone modulation effects, with modification of drug metabolizing enzymes, influence on cell cycle and cell differentiation, induction of apoptosis, suppression of proliferation and angiogenesis playing roles in the initiation and secondary modification stages of neoplastic development. Specific features of prostate cancer, such as high prevalence and long latency period provides ample opportunities for chemopreventive agents to work at various stages of disease progression. Finally, suitable populations with appropriate risk factors, including the presence of pre-malignant lesions and genetic predispositions, need to be well characterized for future chemopreventive interventions. Here we review naturally occurring dietary terpenoids as useful agents for prostate cancer chemoprevention with reference to their classes and sources.

Protection against selenite cataract in rat lens by drevogenin D, a triterpenoid aglycone from Dregea volubilis

Dregea volubilis is a woody climbing plant commonly found in the hotter parts of India. The leaves are edible and used as a green vegetable, while the plant extract has been used traditionally to treat several diseases including eye ailments. Drevogenin D is a triterpenoid aglycone that has been isolated, purified, and characterized as an active component from the leaves of D. volubilis. In this study, drevogenin D was evaluated for antioxidant and potential anticataractogenic activity in an in vitro model. 1,1-Diphenyl-2-picrylhydrazyl radical and superoxide radical scavenging activities of drevogenin D were studied and found to exhibit a 50% inhibitory concentration of 43 microg/mL and 200.6 microg/mL, respectively. Normal rat lenses cultured in 0.1 mM sodium selenite-supplemented medium were used as the experimental model for this study. Selenite-induced models are excellent mimics of oxidative stress induced cataract. Treatment with drevogenin D at a concentration of 50 microg/mL medium was found to reverse the level of activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, elevate the level of reduced glutathione and protein sulfhydryl, and lower the level of lipid peroxidation as indicated by the concentration of thiobarbituric acid-reacting substances. These results indicate good antioxidant activity and potential anticataractogenic activity for drevogenin D against selenite-induced cataractous changes, which have been reported for the first time.

Biological effects of essential oils--a review

Since the middle ages, essential oils have been widely used for bactericidal, virucidal, fungicidal, antiparasitical, insecticidal, medicinal and cosmetic applications, especially nowadays in pharmaceutical, sanitary, cosmetic, agricultural and food industries. Because of the mode of extraction, mostly by distillation from aromatic plants, they contain a variety of volatile molecules such as terpenes and terpenoids, phenol-derived aromatic components and aliphatic components. In vitro physicochemical assays characterise most of them as antioxidants. However, recent work shows that in eukaryotic cells, essential oils can act as prooxidants affecting inner cell membranes and organelles such as mitochondria. Depending on type and concentration, they exhibit cytotoxic effects on living cells but are usually non-genotoxic. In some cases, changes in intracellular redox potential and mitochondrial dysfunction induced by essential oils can be associated with their capacity to exert antigenotoxic effects. These findings suggest that, at least in part, the encountered beneficial effects of essential oils are due to prooxidant effects on the cellular level.