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The foundation for the use of olive oil in skin care and botanical cosmeceuticals
Abstract
Recent epidemiologic evidence suggests an association between olive oil consumption and a lower incidence of cardiovascular disease and certain cancers. The use of topical oil has also been reported in recent years to be effective in treating xerosis, rosacea, psoriasis, atopic dermatitis, contact dermatitis, eczema (including severe hand and foot eczema), seborrhea, pruritus, and various inflammations. The antiinflammatory and antioxidant properties displayed by olive oil are thought to account for its efficacy in addressing cutaneous disorders. At a more granular level the benefits to the skin derived from the use of olive oil are ascribed to key constituents such as oleuropein, oleocanthal, and hydroxytyrosol. Novel and encouraging signs have recently been associated with olive oil aiding in wound healing and protecting against the damage incurred from ultraviolet radiation exposure. Olive oil is currently used in topical applications for the treatment of several skin conditions, including dry skin, itch, and inflammation as well as disorders such as rosacea.
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Objectives. To evaluate the tolerability and efficacy of Olea europaea subcutaneous immunotherapy (SCIT) on patients with rhinoconjunctivitis. Methods. In this open clinical trial patients were assigned to an abbreviated build-up scheme. The outcomes were: number, percentage, and severity of adverse reactions. Secondary outcomes included: changes in immunoglobulin titers and changes in dose-response skin prick tests. Results. Only 8 systemic reactions were registered, which represented 7/47 (14.9%) of patients and 8/429 (1.9%) of administered doses. Regarding immunological parameters the significant increases of sIgG and sIgG4 evidenced the changes in the patient immune system. Cutaneous reactivity decreased significantly. Conclusions. Olea europaea SCIT (Allergovac® depot ROXALL Medicina España S.A.) showed a good safety and tolerability profile. Immunological changes with induction of blocking IgG and decreases in cutaneous reactivity were detected in the patients.
Hydroxytyrosol is discovered in a form of elenolic acid ester oleuropein in olive leaf and oil. The anti-carcinogenic, antioxidant, and anti-inflammatory effects of hydroxytyrosol have been reported in the food, medical, pharmaceutical, and life science fields. But it has not been studied on skin biology field. This study is demonstrated using UVA-induced cellular aging model of human dermal fibroblast. The cell survival rate was measured using the principle of water-soluble tetrazolium salt-1 assay, which is a measurement method for cell survival rate. The quantitative real-time PCR (qRT-PCR) was used to quantitatively analyze the gene expression changes in human dermal fibroblasts (HDFs) by hydroxytyrosol. Senescence-associated β-galactosidase (SA-β-gal) assay was implemented to dye β-galactosidases (used as a cell aging biomarker) to measure HDF cell aging by UVA. Hydroxytyrosol decreased the SA-β-galactosidase activity in a dose-dependent manner in UVA-exposed HDFs. Also, the elevated expression of MMP-1 and MMP-3 by UVA were decreased by hydroxytyrosol in a dose-dependent manner. To examine the anti-inflammatory effect of hydroxytyrosol in UV exposed HDFs, the expression of inflammatory interleukins IL-1β, IL-6, and IL-8 were analyzed. Quantitative RT-PCR showed that hydroxytyrosol decreased the expression of IL-1β, IL-6, and IL-8 gene. Through this research, we demonstrate that hydroxytyrosol has effects on anti-inflammatory and anti-aging in HDFs damaged by UVA. We suggest that hydroxytyrosol is fully worthy of using as a cosmetic material effective to anti-inflammatory and to delay cellular senescence on HDFs.
Plant oils have been utilized for a variety of purposes throughout history, with their integration into foods, cosmetics, and pharmaceutical products. They are now being increasingly recognized for their effects on both skin diseases and the restoration of cutaneous homeostasis. This article briefly reviews the available data on biological influences of topical skin applications of some plant oils (olive oil, olive pomace oil, sunflower seed oil, coconut oil, safflower seed oil, argan oil, soybean oil, peanut oil, sesame oil, avocado oil, borage oil, jojoba oil, oat oil, pomegranate seed oil, almond oil, bitter apricot oil, rose hip oil, German chamomile oil, and shea butter). Thus, it focuses on the therapeutic benefits of these plant oils according to their anti-inflammatory and antioxidant effects on the skin, promotion of wound healing and repair of skin barrier.
Background:
The main goals in treating burns are to accelerate tissue renovation and prevent infection. Topical antibiotics are used in the treatment of burns, but they can cause side effects. Recently, a traditional ointment (Olea) has been used in Iran in the treatment of burns. This study examines the effect of topical honey ointment in healing of burn patients.
Materials and methods:
In this randomized controlled trial (RCT), 30 hospitalized patients selected by conventional sampling (10 in Olea group and 20 in Acetate Mafenide ointment group) were evaluated. Inclusion criteria were: having second-degree burns and body surface area equal to or < 40%. One group was treated using topical Olea ointment and the other with Acetate Mafenide ointment (8.5%). Chi-square, Fisher exact test, and Kaplan-Meier were used. Significance level was considered as P < 0.05.
Results:
None of the patients in the Olea group needed surgery for debridement, while in the second group, 13 patients (65%) needed debridement (P = 0.001). In the Olea group, 1 patient (10%) and in the second group, 19 patients (95%) had positive cultures after 7 days (P < 0.001). The mean time of granulation tissue formation in the Olea group was 12 days (10.3-13.6) and in the other group, it was 17 days (13.3-20.6) (P < 0.001).
Conclusions:
Olea ointment is a useful treatment for burns, and it can prevent infections, accelerate tissue repair, and facilitate debridement. Therefore, using this ointment is recommended for the treatment of burns.
Oleuropein promoted cultured human follicle dermal papilla cell proliferation and induced LEF1 and Cyc-D1 mRNA expression and β-catenin protein expression in dermal papilla cells. Nuclear accumulation of β-catenin in dermal papilla cells was observed after oleuropein treatment. Topical application of oleuropein (0.4 mg/mouse/day) to C57BL/6N mice accelerated the hair-growth induction and increased the size of hair follicles in telogenic mouse skin. The oleuropein-treated mouse skin showed substantial upregulation of Wnt10b, FZDR1, LRP5, LEF1, Cyc-D1, IGF-1, KGF, HGF, and VEGF mRNA expression and β-catenin protein expression.
These results demonstrate that topical oleuroepin administration induced anagenic hair growth in telogenic C57BL/6N mouse skin. The hair-growth promoting effect of oleuropein in mice appeared to be associated with the stimulation of the Wnt10b/β-catenin signaling pathway and the upregulation of IGF-1, KGF, HGF, and VEGF gene expression in mouse skin tissue.
Reactive oxygen species have been shown to play a role in ultraviolet light (UV)-induced skin carcinogenesis. Vitamin E and green tea polyphenols reduce experimental skin cancers in mice mainly because of their antioxidant properties. Since olive oil has also been reported to be a potent antioxidant, we examined its effect on UVB-induced skin carcinogenesis in hairless mice. Extra-virgin olive oil was applied topically before or after repeated exposure of mice to UVB. The onset of UVB-induced skin tumors was delayed in mice painted with olive oil compared with UVB control mice. However, with increasing numbers of UVB exposures, differences in the mean number of tumors between UVB control mice and mice pretreated with olive oil before UVB exposure (pre-UVB group) were lost. In contrast, mice that received olive oil after UVB exposure (post-UVB group) showed significantly lower numbers of tumors per mouse than those in the UVB control group throughout the experimental period. The mean number of tumors per mouse in the UVB control, pre-UVB and postUVB groups was 7.33, 6.69 and 2.64, respectively, in the first experiment, and 8.53, 9.53 and 3.36 in the second experiment. Camellia oil was also applied, using the same experimental protocol, but did not have a suppressive effect. Immunohistochemical analysis of DNA damage in the form of cyclobutane pyrimidine dimers (CPD), (6‐4) photoproducts and 8-hydroxy-2-deoxyguanosine (8OHdG) in samples taken 30 min after a single exposure of UVB showed no significant difference between UVBirradiated control mice and the pre-UVB group. In the post-UVB group, there were lower levels of 8-OHdG in epidermal nuclei, but the formation of CPD and (6‐4) photoproducts did not differ. Exposure of olive oil to UVB before application abrogated the protective effect on 8OHdG formation. These results indicate that olive oil topically applied after UVB exposure can effectively reduce UVB-induced murine skin tumors, possibly via its antioxidant effects in reducing DNA damage by reactive oxygen species, and that the effective component may be labile to UVB.
Oleuropein is generally the most abundant phenolic compound in olive leaves. In this study, therapeutic effects of oleuropein were studied on wounded skin in young male Balb/c mice.
Four-month-old male Balb/c mice were randomized into 2 groups, a control and an experimental group. Under ether anesthesia, hair on the neck of mice in both groups was shaved and 1-cm long full-thickness incisions were made and left unsutured. The experimental group was injected intradermally with a daily single dose of oleuropein (50 mg/kg) for a total of 7 days. The control group received only distilled water. On days 3 and 7 post-incision, mice were sacrificed and skin around the area of the incisions were dissected and processed for hematoxylin and eosin and Van Gieson's staining. Portions of dissected tissues were also lysed and used for western blot analysis to evaluate the level of vascular endothelial growth factor (VEGF) protein expression.
The analyses showed oleuropein reduced cell infiltration into the wound sites on day 3 and 7 postincision; however, it significantly increased collagen fiber deposition and caused faster reepithelialization when compared to the control group (P < 0.05). Furthermore, western blot analysis showed a significant increase in VEGF protein level compared to the control group (P < 0.05).
In summary, oleuropein showed healing effects on wounded skin by accelerating the reepithelialization process, enhancing collagen fiber generation, and increasing the blood supply to the wounded area by upregulation of VEGF protein expression.
Objective:
The purpose of this study is to evaluate the healing effect of silver sulfadiazine (SSD), sea buckthorn, olive oil, and 5% sea buckthorn and olive oil mixture on full-thickness burn wounds with respect to both gross and histopathologic features.
Methods:
Full-thickness burns were induced on 60 rats; the rats were then were divided into 5 groups and treated with sea buckthorn, olive oil, a 5% sea buckthorn/olive oil mixture, SSD, and normal saline (control). They were observed for 28 days, and the wounds' healing process was evaluated.
Results:
Wound contraction occurred faster in sea buckthorn, olive oil, and the sea buckthorn/olive oil mixture groups compared with the SSD and control groups. The volume of the exudates was controlled more effectively in wounds treated with the sea buckthorn/olive oil mixture. Purulent exudates were observed in the control group, but the others did not show infection. The group treated with sea buckthorn/olive oil mixture revealed more developed re-epithelialization with continuous basement membrane with a mature granulation tissue, whereas the SSD-treated group showed ulceration, necrosis, and immature granulation. The results show that sea buckthorn and olive oil individually are proper dressing for burn wounds and that they also show a synergetic effect when they are used together.
Conclusion:
A sea buckthorn and olive oil mixture could be considered as an alternative dressing for full-thickness burns because of improved wound healing characteristics and antibacterial property.
Objective: Olive oil and olive leaf extract are used for treatment of skin diseases and wounds in Iran. The main component of olive leaf extract is Oleuropein. This research is focused on the effects of Oleuropein on skin wound healing in aged male Balb/c mice.
Materials and Methods: In this experimental study, Oleuropein was provided by Razi Herbal Medicine Institute, Lorestan, Iran. Twenty four male Balb/c mice, 16 months of age, were divided equally into control and experimental groups. Under ether anesthesia, the hairs on the back of neck of all groups were shaved and a 1 cm long full-thickness incision was made. The incision was then left un-sutured. The experimental group received intradermal injections with a daily single dose of 50 mg/kg Oleuropein for a total period of 7 days. The control group received only distilled water. On days 3 and 7 after making the incision and injections, mice were sacrificed, and the skin around incision area was dissected and stained by hematoxylin and eosin (H&E) and Van Gieson’s methods for tissue analysis. In addition, western blot analysis was carried out to evaluate the level of vascular endothelial growth factor (VEGF) protein expression. The statistical analysis was performed using SPSS (SPSS Inc., Chicago, USA). The t test was applied to assess the significance of changes between control and experimental groups.
Results: Oleuropein not only reduced cell infiltration in the wound site on days 3 and 7 post incision, but also a significant increase in collagen fiber deposition and more advanced re- epithelialization were observed (p
OBJECTIVE AND DESIGN: The aim of the present study was to examine the effect of a virgin olive oil enriched diet in acute and chronic inflammation models in rats
and to determine the effect of supplementing this oil with a higher content of
its polyphenolic fraction. The response was compared to oils rich in
monounsaturated fatty acids (high oleic sunflower oil and palm olein) and rich in
polyunsaturated fatty acids (fish oil). DIETS: Groups of 6-8 male Wistar rats
were fed from weaning on six purified diets differing in type of oil: 2% corn oil
(basal diet, BD), 15% high oleic sunflower oil (HOSO), 15% virgin olive oil
(VOO), 15% virgin olive oil supplemented with 600 p.p.m. polyphenols from this
oil (PSVOO), 15% palm olein (POL), and 15% fish oil (FO).
MATERIALS AND METHODS: Rats were fed for 8 weeks with BD, HOSO, VOO, PSVOO, POL
and FO diets before injecting carrageenan. Rats were fed for 3 weeks with BD,
PSVOO and FO diets before induction of adjuvant arthritis. Dietary treatment with
or without indomethacin continued during 3 weeks. The data were evaluated using
an analysis of variance (ANOVA) followed by the least-significant differences.
RESULTS: In carrageenan oedema test, the inflammation indices of animals fed on a
diet rich in olive oil (VOO) were lower compared to animals fed with oils high in
oleic acid (HOSO, POL) and polyunsaturated fatty acids (FO), and markedly
diminished in the group fed on PSVOO. In established adjuvant arthritis, the
PSVOO diet was even more effective than FO diet in the prevention of
inflammation. Both groups of animals showed an increase in weight during the
latter days of the experiment compared to the BD. Indomethacin administered to
every diet group, exerted a strong inhibitory effect on the inflammatory process
throughout which was augmented by the PSVOO and FO diets.
CONCLUSIONS: This study demonstrates that virgin olive oil with a higher content
of polyphenolic compounds, similar to that of extra virgin olive oil, shows
protective effects in both models of inflammation and improves the disease
associated loss of weight. This supplementation also augmented the effects of
drug therapy.
The aim of this research was to analyse the use of olive oil as a means of prevention and treatment of sports injuries in the ancient world. The method adopted was based on a thorough study of Greek and world literature. Writings of major ancient philosophers and physicians such as Hippocrates, Aristotle, Philostratus, and Lucian have been analysed in depth. According to the results, the use of massage, together with olive oil rub, helped to reduce muscle fatigue, to remove lactic acid, and to prevent the occurrence of sports injuries through flexibility provided to the skin of athletes. The therapeutic use of oil in the ancient world was fully recognized; and as a result Athenian athlothetes (sponsors of sporting events) provided free oil to all sport facilities where athletes could make free use of it [1].
Leaves and fruits of Olea europaea L. (olive) have been used externally as an emollient for skin ulcers and for healing of inflammatory wounds. n-Hexane and aqueous extracts, prepared from the dried leaves of olive, were evaluated for their wound healing activity by using in vivo wound models of linear incision and circular excision in comparison with the reference ointment Madecassol® (Bayer, Istanbul, Turkey). The group of animals treated with the aqueous extract demonstrated increased contraction (87.1%) on excision and a significant increase in wound tensile strength (34.8%) on incision models compared to the other groups. Moreover, the antioxidant activity assay showed that aqueous extract has higher scavenging ability than the n-hexane extract. According to the experimental data, the aqueous extract of O. europaea leaves displayed wound healing activity. Secoiridoid oleuropein (4.6059%) was identified as the major active compound according to high-performance liquid chromatography analysis of the aqueous extract.
Atopic dermatitis (AD) skin is dry and readily colonized by Staphylococcus aureus (SA). Coconut and olive oils are traditionally used to moisturize and treat skin infections.
To compare virgin coconut oil (VCO) and virgin olive oil (VOO) in moisturizing dryness and removing SA from colonized AD skin.
This was a double-blind controlled trial in two outpatient dermatology clinics with adult AD patients who were diagnosed by history, pattern, evolution, and skin lesions and who were randomized to apply VCO or VOO twice daily at two noninfected sites. SA cultures, photography, and objective-SCORAD severity index (O-SSI) scoring were done at baseline and after 4 weeks.
Twenty-six subjects each received VCO or VOO. Of those on VCO, 20 were positive for SA colonies at baseline versus 12 on VOO. Post intervention, only 1 (5%) VCO subject remained positive versus 6 (50%) of those on VOO. Relative risk for VCO was 0.10, significantly superior to that for VOO (10:1, p = .0028; 95% CI, 0.01-0.73); thus, the number needed to treat was 2.2. For the O-SSI, the difference was not significant at baseline (p = .15) but was significantly different post treatment (p = .004); this was reduced for both oils (p < .005) but was greater with VCO.
VCO and monolaurin's O-SSI reduction and in vitro broad-spectrum activity against SA (given clinical validity here), fungi, and viruses may be useful in the proactive treatment of AD colonization.
Reactive oxygen species have been shown to play a role in ultraviolet light (UV)-induced skin carcinogenesis. Vitamin E and green tea polyphenols reduce experimental skin cancers in mice mainly because of their antioxidant properties. Since olive oil has also been reported to be a potent antioxidant, we examined its effect on UVB-induced skin carcinogenesis in hairless mice. Extra-virgin olive oil was applied topically before or after repeated exposure of mice to UVB. The onset of UVB-induced skin tumors was delayed in mice painted with olive oil compared with UVB control mice. However, with increasing numbers of UVB exposures, differences in the mean number of tumors between UVB control mice and mice pretreated with olive oil before UVB exposure (pre-UVB group) were lost. In contrast, mice that received olive oil after UVB exposure (post-UVB group) showed significantly lower numbers of tumors per mouse than those in the UVB control group throughout the experimental period. The mean number of tumors per mouse in the UVB control, pre-UVB and post-UVB groups was 7.33, 6.69 and 2.64, respectively, in the first experiment, and 8.53, 9.53 and 3.36 in the second experiment. Camellia oil was also applied, using the same experimental protocol, but did not have a suppressive effect. Immunohistochemical analysis of DNA damage in the form of cyclobutane pyrimidine dimers (CPD), (6-4) photoproducts and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in samples taken 30 min after a single exposure of UVB showed no significant difference between UVB-irradiated control mice and the pre-UVB group. In the post-UVB group, there were lower levels of 8-OHdG in epidermal nuclei, but the formation of CPD and (6-4) photoproducts did not differ. Exposure of olive oil to UVB before application abrogated the protective effect on 8-OHdG formation. These results indicate that olive oil topically applied after UVB exposure can effectively reduce UVB-induced murine skin tumors, possibly via its antioxidant effects in reducing DNA damage by reactive oxygen species, and that the effective component may be labile to UVB.
Health benefits of lycopene from tomato products have been suggested to be related to its antioxidant activity. Dietary fat may influence the absorption and hence the plasma levels and antioxidant activity of lycopene. In the present study, we have compared the effect of consumption of tomato products with extra-virgin olive oil vs. tomato products plus sunflower oil on plasma lycopene and antioxidant levels. Results show that the oil composition does not affect the absorption of lycopene from tomato products because similar levels of plasma lycopene (mean +/- SD) were obtained on feeding tomatoes (providing approximately 46 mg lycopene/d) for 7 d with either olive oil (0.66 +/- 0.26 vs 1.20 +/- 0.20 micromol/l, p <.002) or sunflower oil (0.67 +/- 0.27 vs. 1.14 micromol/l, p <.001). However, consumption of tomato products with olive oil significantly raised the plasma antioxidant activity (FRAP) from 930 +/- 150 to 1118 +/- 184 micromol/l, p <.01) but no effect was observed when the sunflower oil was used. The change (supplementation minus start values) in FRAP following the consumption of tomato products with oil was significantly higher for olive oil (190 +/- 101) than for sunflower oil (-9.6 +/- 99, p <. 005). In conclusion, the results of the study show that consumption of tomato products with olive oil but not with sunflower oil improves the antioxidant activity of the plasma.
Interest in the health-promoting effects of virgin olive oil, an important part of the "Mediterranean diet", prompted us to determine the antiinflammatory effects of erythrodiol, beta-sitosterol and squalene, identified as major components of the so-called "unsaponifiable fraction" of virgin olive oil, as well as of the phenolic compounds from the "polar fraction": oleuropein, tyrosol, hydroxytyrosol and caffeic acid. Their activities were compared to those of both, total unsaponifiable and polar fractions. This study was designed to analyse the antiinflammatory effect of these specific compounds from virgin olive oil on edema in mice induced by either arachidonic acid (AA) or 12-O-tetradecanoylphorbol acetate (TPA). The inhibition of the myeloperoxidase (MPO), marker enzyme of the accumulation of neutrophils in the inflamed tissue, was also investigated by the TPA model. The topical application of the olive oil compounds (0.5 mg/ear) produced a variable degree of antiinflammatory effect with both assays. In the auricular edema induced by TPA, beta-sitosterol and erythrodiol from the unsaponifiable fraction of the oil showed a potent antiedematous effect with a 61.4% and 82.1% of inhibition respectively, values not very different to that of the reference indomethacin (85.6%) at 0.5 mg/ear. The four phenolics exerted a similar range of inhibition (33-45%). All compounds strongly inhibited the enzyme myeloperoxidase, indicating a reduction of the neutrophil influx in the inflamed tissues. The strongest inhibitor of AA edema was the total unsaponifiable fraction which inhibition was 34%, similar to that obtained by the reference drug dexamethasone at 0.05 mg/ear. Among the phenolics, oleuropein also produced an inhibition of about 30% with the same dose, but all the other components were found less active in this assay. The anti-inflammatory effects exerted by both unsaponifiable and polar compounds might contribute to the potential biological properties reported for virgin olive oil against different pathological processes.
This study addressed whether food and nutrient intakes were correlated with skin wrinkling in a sun-exposed site.
177 Greek-born subjects living in Melbourne (GRM), 69 Greek subjects living in rural Greece (GRG), 48 Anglo-Celtic Australian (ACA) elderly living in Melbourne and 159 Swedish subjects living in Sweden (SWE) participating in the International Union of Nutritional Sciences IUNS "Food Habits in Later Life" study had their dietary intakes measured and their skin assessed. Food and nutrient intakes were assessed using a validated semi-quantitative food frequency questionnaire (FFQ). Skin wrinkling was measured using a cutaneous microtopographic method.
SWE elderly had the least skin wrinkling in a sun-exposed site, followed by GRM, GRG and ACA. Correlation analyses on the pooled data and using the major food groups suggested that there may be less actinic skin damage with a higher intake of vegetables (r(s)=-0.31, p<0.0001), olive oil (r(s)=-0.29, p<0.0001), fish (r(s)=-0.24, p<0.0001) and legumes (r(s)=-0.16, p<0.0001), and lower intakes of butter (r(s)=0.46, p<0.0001) and margarine (r(s)=0.24, p<0.001), milk products (r(s)=0.16, p<0.01) and sugar products (r(s)=0.12, p<0.01). Similar findings were obtained using regression analyses, except fish was no longer significant; 32% of the variance for actinic skin damage was predicted by six out of the ten major food groups. In particular, a high intake of vegetables, legumes and olive oil appeared to be protective against cutaneous actinic damage (collectively explaining 20% of the variance); a high intake of meat, dairy and butter appeared to be adverse (explaining <5% of the variance). Prunes, apples and tea explained 34% of variance amongst ACA.
This study illustrates that skin wrinkling in a sun-exposed site in older people of various ethnic backgrounds may be influenced by the types of foods consumed.
Fish oil has a preventive role in cardiovascular and inflammatory diseases, but little is known about the effect of olive oil, which is widely consumed in Mediterranean regions. We examined the influence of dietary olive oil, corn oil and fish oil-rich diets on the production of superoxide anion (O2-) and nitric oxide (.NO) by resident macrophages stimulated by phorbol 12-myristate 13-acetate (PMA) and their effect on arachidonic acid release, prostaglandin G/H synthase-2 (PGHS-2) expression and the subsequent prostaglandin E(2) production. Resident peritoneal macrophages stimulated by PMA from rats fed with olive oil or corn oil had the same level of O2- production, but these levels were increased by the fish oil diet. Olive oil and the fish oil diets increased .NO and decreased arachidonic acid mobilization and the production of prostaglandin E(2). PGHS-2 expression, however, was not affected by diet. We conclude that although olive oil and fish oil reduce arachidonic acid mobilization and subsequent metabolism through the PGHS-2 pathway in PMA-stimulated macrophages, only olive oil offers an additional beneficial effect by increasing .NO/O2- production.
Nutritional factors exert promising actions on the skin, but only scant information is available on the modulating effects of physiologic concentrations of nutrients on the skin condition of humans.
The objective was to evaluate whether nutrient concentrations in serum and diet are associated with the skin condition of humans.
A cross-sectional study was conducted in which data on serum concentrations of nutrients, dietary intake of nutrients, and the hydration, sebum content, and surface pH of skin were obtained from 302 healthy men and women. Skin condition was measured with the use of noninvasive techniques. Dietary intake was assessed with 2 complementary food-frequency questionnaires. Multiple regression analysis was used to evaluate associations of serum vitamins and carotenoids and of dietary micro- and macronutrients with skin condition.
After adjustment for potential confounders, including sex, age, and smoking, statistically significant associations were shown in the total population between serum vitamin A and skin sebum content and surface pH and between the dietary intake of total fat, saturated fat, monounsaturated fat, and skin hydration. Monounsaturated fat intake was also associated with surface pH. Associations between serum beta-cryptoxanthin and skin hydration and between surface pH and fluid and calcium intakes were observed in men only.
Several associations between nutrients in serum and diet and skin condition were observed, indicating that changes in baseline nutritional status may affect skin condition.
Objective
Photodynamic therapy (PDT) is an effective treatment against skin field cancerization. Its main side effect is local inflammation in the treated area. The phenolic compound oleocanthal (decarboxy methyl ligstroside aglycone), which is present in extra virgin olive oil (EVOO), has anti-inflammatory properties.
The purpose of this study was to evaluate the topical efficacy of an oily fluid enriched with oleocanthal (OC) extract, in comparison with a conventional oily fluid, in reducing the degree of inflammatory reaction after conventional PDT.
Methods
Quasi-experimental pilot study, before-after with a control group, performed with a cohort of consecutive patients diagnosed with actinic keratosis/field cancerization (AK/FC) in the forehead and/or scalp, treated by PDT. The study was carried out from April 2016 to November 2017 at a speciality hospital in southern Spain.
A group of 24 consecutive patients received the topical application, three times daily for one week, of an emollient oily fluid in the area treated with PDT. Subsequently, another group, of 23 consecutive patients, received the same treatment pattern with an oily fluid enriched with OC extract.
The post-PDT inflammatory reaction was measured by an independent member of the hospital’s dermatology department, using the following visual scale of erythema (from 0 to 4).The assessment was conducted at 30 min and at 48 h post-PDT.
Results
In the assessment at 48 h after treatment, the inflammation had improved more among the patients treated with OC (median: 25%, 95%CI: -5.3 to 28.5) than in the non-OC group (median: 0%; 95%CI: -45.2 to -6.2). The difference was statistically significant (p<0.01), and the Cohen’s d value was 0.89 (large effect). At three months after PDT, a complete response had been obtained by 60.9% of the patients treated with OC compared to 29.2% of the non-OC group, and the difference was close to statistical significance (p=0.059).
Conclusions
The topical application of an oily fluid enriched with OC extract achieved a greater reduction in post-PDT cutaneous inflammation and a better treatment response, in comparison with the application of a conventional oily fluid.
Olea europaea oil is one of the most important part of the "Mediterranean dietary pattern", and a lot of epidemiological evidences showed that people with the Mediterranean diet having a lower morbidity of the cardiovascular system diseases, skin cancer and colon cancer. The health benefits of a Mediterranean diet not only attributed to monounsaturated fatty acids and vitamins and other nutrients in O. europaea oil, but also the phenolic compounds named as antioxidant effect. Studies have shown that O. europaea leaf contains much more antioxidant activity composition than the fruit, and oleuropein, flavonoids such polyphenols are the main active ingredients in O. europaea leaf. A small amount of O. europaea was introduced into China in 1956, after widely cultivated in Fujian, Guangdong, Taiwan, Sichuan, Shaanxi, Yunnan, and Longnan in Gansu province is the biggest O. europaea planting area in the country. In every winter pruning O. europaea will produce a large number of the leaves, which could be a high added value products (phenolic compounds) of rich source. This article through consulting the literature at home and abroad, classified and summarized the biological activity research status of O. europaea leaf extract and the possible mechanisms, including antimicrobial, antitumor, antioxidation, and on the function of brain, cardiovascular system, anti-diabetes, anti-inflammatory and analgesia and so on. At the same time looked ahead to its development prospects of O. europaea leaf extract, it has variety and high content of active ingredients, and antioxidant synergy, which provide a theoretical basis for the further development and utilization of O. europaea leaf. And O. europaea leaf extract has a rich cheap source and good bioavailability, which provided a broad space in the application of medical and health care.
Natural plant oils are commonly used as topical therapy worldwide. They are usually easily accessible and are relatively inexpensive options for skin care. Many natural oils possess specific compounds with antimicrobial, antioxidant, anti-inflammatory, and anti-itch properties, making them attractive alternative and complementary treatments for xerotic and inflammatory dermatoses associated with skin-barrier disruption. Unique characteristics of various oils are important when considering their use for topical skin care. Differing ratios of essential fatty acids are major determinants of the barrier repair benefits of natural oils. Oils with a higher linoleic acid to oleic acid ratio have better barrier repair potential, whereas oils with higher amounts of irritating oleic acid may be detrimental to skin-barrier function. Various extraction methods for oils exist, including cold pressing to make unrefined oils, heat and chemical distillation to make essential oils, and the addition of various chemicals to simulate a specific scent to make fragranced oils. The method of oil processing and refinement is an important component of selecting oil for skin care, and cold pressing is the preferred method of oil extraction as the heat- and chemical-free process preserves beneficial lipids and limits irritating byproducts. This review summarizes evidence on utility of natural plant-based oils in dermatology, particularly in repairing the natural skin-barrier function, with the focus on natural oils, including Olea europaea (olive oil), Helianthus annus (sunflower seed oil), Cocos nucifera (coconut oil), Simmondsia chinesis (jojoba oil), Avena sativa (oat oil), and Argania spinosa (argan oil).
Antioxidants are highly important gradients used to preserve cosmetic products and reduce the effect of oxidative stress on the skin. The present work explores the possibility of using phenolic compounds of olive mill wastewater as effective alternatives to the commercial antioxidants used in cosmetic formulations deemed by their allergic and carcinogenic effects. Esterification of tyrosol and hydroxytyrosol extracted from olive mill wastewater with various fatty acids was conducted using Novozyme 435 lipase as biocatalyst. Upon synthesis, butyrate, caprate, laurate and palmitate tyrosyl and hydroxytyrosyl esters were isolated and evaluated for their antioxidant and antibacterial activities. Results showed that laurate derivatives are the most efficient in preventing lipid oxidation and in inhibiting growth of pathogenic strains. In the prospective of industrial use, laurate tyrosyl and hydroxytyrosyl derivatives were incorporated in a formulation of moisturizer in order to substitute the commercial antioxidant butylated hydroxyltoluene. Oleuropein, extracted from olive leaves powder, was also tested as an anti-aging ingredient in cosmetic formulations. The evaluation of physicochemical, microbiological and sensorial properties of the new cosmetic products indicated that oleuropein and lipophilic derivatives do not affect the properties of the standard formulation. Oleuropein and lipophilic derivatives can be added as active ingredients to stabilize cosmetic preparations. This article is protected by copyright. All rights reserved.
Background:
The overproduction of reactive oxygen species (ROS) and exacerbated inflammatory response are the main events that impair healing of pressure ulcers. Therefore, olive oil may be a good alternative to improve the healing of these chronic lesions due to its anti-inflammatory and antioxidant properties.
Objective:
This study investigated the effect of olive oil administration on wound healing of pressure ulcers in mice.
Methods:
Male Swiss mice were daily treated with olive oil or water until euthanasia. One day after the beginning of treatment, two cycles of ischemia-reperfusion by external application of two magnetic plates were performed in skin to induced pressure ulcer formation.
Results:
The olive oil administration accelerated ROS and nitric oxide (NO) synthesis and reduced oxidative damage in proteins and lipids when compared to water group. The inflammatory cell infiltration, gene tumor necrosis factor-α (TNF-α) expression and protein neutrophil elastase expression were reduced by olive oil administration when compared to water group. The re-epithelialization and blood vessel number were higher in the olive oil group than in the water group. The olive oil administration accelerated protein expression of TNF-α, active transforming growth factor-β1 and vascular endothelial growth factor-A when compared to water group. The collagen deposition, myofibroblastic differentiation and wound contraction were accelerated by olive oil administration when compared to water group.
Conclusion:
Olive oil administration improves cutaneous wound healing of pressure ulcers in mice through the acceleration of the ROS and NO synthesis, which reduces oxidative damage and inflammation and promotes dermal reconstruction and wound closure.
Phenolic compounds, the biggest group of natural antioxidants, have attracted much attention due to their known and wide-ranging biological activities, as well as to their health effects. In particular, regardless their antioxidant activity, they play a key role in the control of several inflammation-associated processes as well as in improving antioxidant defense system. In an our previous work we have demonstrated the ability of Hydroxytyrosol, an ortho-diphenolic compound, essential component of oleuropein, in preventing apoptotic cell death induced by UVB radiation in HaCaT cell lines in vitro. In olive oil, besides Hydroxytyrosol, there are appreciable amounts of Tyrosol and its secoiridoid derivatives. It has been well established that Tyrosol has a significantly lower antioxidant activity than Hydroxytyrosol, but despite this, recent studies suggest that Tyrosol exerts a powerful protective effect against oxidative injuries in cell systems and that it is able to improve the intracellular antioxidant defenses. Here, Tyrosol effect has been evaluated in HaCaT cells exposed to UVB radiation by means of morphological and molecular analyses which revealed the polyphenol ability in reducing apoptotic markers and in protecting HaCaT cells from damage. These findings suggest an important role of Tyrosol in protecting cells from apoptotic cell death and encourage the use of this phytochemical as biological ingredient in topical preparations as possible tool to prevent skin damage.
Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Olive oil is commonly recommended by health professionals to new parents for use in the prevention and treatment of the term baby's dry skin, and for baby massage. There is no evidence to support this practice. The use of olive oil may be harmful to skin, affecting skin barrier function. This effect may be a contributory factor in the prevalence of childhood conditions such as atopic eczema. This paper discusses a national online audit of UK maternity hospitals (n = 67) and neonatal units (n = 33) performed between November 2010 and January 2011. Our findings confirm that oil use on babies' skin is common practice. As the direct cost to the NHS for treatment of atopic eczema is high, it is imperative that further research in this area is performed, preferably in the form of a randomized controlled trial. Health professionals will then be in a position to provide accurate information to parents with regard to oil in baby skin care regimens.
As olive oil production increases, so does the amount of olive oil by-products, which can cause environmental problems. Thus, new ways to utilize the by-products are needed. In the present study, five bioactive characteristics of olive oil by-products were assessed, namely their antioxidant, anti-bacterial, anti-melanogenesis, anti-allergic, and collagen-production-promoting activities. First, the extracts of leaves (May and October), stems (May and October), flowers, olive milled waste, fruit pulp and seeds were prepared using two safe solvents, ethanol and water. According to HPLC and LC/MS analysis and Folin-Ciocalteu assay, the ethanol extracts of the leaves (May and October), stems (May and October) and flowers contained oleuropein, and the ethanol extract of the stems showed the highest total phenol content. Oleuropein may contribute to the antioxidant and anti-melanogenesis activities of the leaves, stems, and flowers. However, other active compounds or synergistic effects present in the ethanol extracts are also likely to contribute to the anti-bacterial activity of the leaves and flowers, the anti-melanogenesis activity of some parts, the anti-allergic activity of olive milled waste, and the collagen-production-promoting activity of the leaves, stems, olive milled waste and fruit pulp. This study provides evidence that the by-products of olive oil have the potential to be further developed and used in the skin care industry. Copyright © 2015 John Wiley & Sons, Ltd.
Copyright © 2015 John Wiley & Sons, Ltd.
Natural oils are advocated and used throughout the world as part of neonatal skin care, but there is an absence of evidence to support this practice. The goal of the current study was to ascertain the effect of olive oil and sunflower seed oil on the biophysical properties of the skin. Nineteen adult volunteers with and without a history of atopic dermatitis were recruited into two randomized forearm-controlled mechanistic studies. The first cohort applied six drops of olive oil to one forearm twice daily for 5 weeks. The second cohort applied six drops of olive oil to one forearm and six drops of sunflower seed oil to the other twice daily for 4 weeks. The effect of the treatments was evaluated by determining stratum corneum integrity and cohesion, intercorneocyte cohesion, moisturization, skin-surface pH, and erythema. Topical application of olive oil for 4 weeks caused a significant reduction in stratum corneum integrity and induced mild erythema in volunteers with and without a history of atopic dermatitis. Sunflower seed oil preserved stratum corneum integrity, did not cause erythema, and improved hydration in the same volunteers. In contrast to sunflower seed oil, topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis. The use of olive oil for the treatment of dry skin and infant massage should therefore be discouraged. These findings challenge the unfounded belief that all natural oils are beneficial for the skin and highlight the need for further research.
Plants in the Mediterranean basin, such as vine and olive trees, have developed an array of antioxidant defences to protect themselves from environmental stress. Accordingly, the incidence of coronary heart disease and certain cancers is lower in the Mediterranean area, where olive oil is the dietary fat of choice. As opposed to other vegetable oils, extra virgin olive oil, which is obtained by physical pressure from a whole fruit, is rich in phenolic components that are responsible for the particular stability of the oil. We have investigated the scavenging actions of some olive oil phenolics, namely hydroxytyrosol and oleuropein, with respect to superoxide anion generation, neutrophils respiratory burst, and hypochlorous acid. The low EC50s indicate that both compounds are potent scavengers of superoxide radicals and inhibitors of neutrophils respiratory burst: whenever demonstratedin vivo,these properties may partially explain the observed lower incidence of CHD and cancer associated with the Mediterranean diet.
To address how interactions between polyunsaturated fatty acid (PUFA) levels and depressive symptoms were related to proinflammatory cytokine synthesis. Depression and stress promote proinflammatory cytokine production. Dietary intakes of omega-3 (n-3) and omega-6 (n-6) PUFAs also influence inflammation; high n-6:n-3 ratios enhance proinflammatory cytokine production, although n-3 has anti-inflammatory properties.
Blood samples from 43 older adults (mean age = 66.67 years, SD = 10.09) provided data on PUFAs and tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-6 soluble receptor (sIL-6r). Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale.
Depressive symptoms and n-6:n-3 ratios worked together to enhance proinflammatory cytokines beyond the contribution provided by either variable alone, with substantial variance explained by their interaction: 13% for IL-6 and 31% for TNF-alpha, whereas full models accounted for 18% and 40%, respectively. Although predicted cytokine levels were consistent across n-6:n-3 ratios with low depressive symptoms, higher n-6:n-3 ratios were associated with progressively elevated TNF-alpha and IL-6 levels as depressive symptoms increased. Higher levels of sIL-6r were associated with higher n-6:n-3 ratios. Six individuals who met the criteria for major depressive disorder had higher n-6:n-3 ratios and TNF-alpha, IL-6, and sIL-6r levels than those who did not meet the criteria; excluding these six individuals reduced the variance explained by the depressive symptoms and n-6:n-3 ratio interaction.
Diets with high n-6:n-3 PUFA ratios may enhance the risk for both depression and inflammatory diseases.
Olive (Olea europaea L.) leaves have long been used in folk medicine and herbal tea in Europe and the Mediterranean area. The Mediterranean climate is characterized by high temperatures, and by strong ultraviolet B (UVB) radiation causing the skin to age, increasing wrinkling, pigmentation and skin thickness. The aim of this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage caused by acute UVB irradiation in C57BL/6J mice. The extract (300 or 1000 mg/kg) and oleuropein (25 or 85 mg/kg) were administered orally twice daily for 14 days. UVB was administered daily at a dose of 120 mJ/cm(2) for the first 5 days and then every other day for 9 days. Both treatments inhibited the increases in skin thickness induced by radiation. They also inhibited increases in the Ki-67- and 8-hydroxy-2'-deoxyguanosine-positive cell numbers, melanin granule area and matrix metalloproteinase-13 (MMP-13) expression. These preventive effects on UVB-induced skin damage might be caused in part by inhibiting the degradation of extracellular matrixes in the corium, and by the proliferation of epidermal cells through the inhibition of increases in MMP-13 levels and reactive oxygen species induced by irradiation.
Chronic exposure to solar UV radiation damages skin, increasing its thickness and reducing its elasticity, and causes skin cancer. Our aim in this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage and the incidence of skin tumors caused by long-term UVB irradiation in hairless mice. Male hairless mice (5 wk old) were divided into 6 groups, including a non-UVB group, a vehicle-treated UVB group (control), 2 olive leaf extract-treated UVB groups, and 2 oleuropein-treated UVB groups. Five groups were UVB irradiated (36-180 mJ/cm(2)) 3 times each week for 30 wk and skin thickness and elasticity after UVB irradiation were measured every week. Olive leaf extract (300 and 1000 mg/kg) and oleuropein (10 and 25 mg/kg) were administered orally twice daily every day for 30 wk. The extract and oleuropein significantly inhibited increases in skin thickness and reductions in skin elasticity, and skin carcinogenesis and tumor growth. Furthermore, they prevented increases in the expression of matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 as well as in levels of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in the skin. Based on histological evaluation, they prevented increases in the expression of Ki-67 and CD31-positive cells induced by the irradiation. These results suggest that the preventative effects of the olive leaf extract and oleuropein on chronic UVB-induced skin damage and carcinogenesis and tumor growth may be due to inhibition of the expression of VEGF, MMP-2, MMP-9, and MMP-13 through a reduction in COX-2 levels.
Development of the skin barrier continues up to 12 months after birth; therefore, care must be taken when cleansing and bathing infants' skin. Available guidelines for skin care in newborns are, however, limited. In 2007, the 1st European Round Table meeting on 'Best Practice for Infant Cleansing' was held, at which a panel of expert dermatologists and paediatricians from across Europe aimed to provide a consensus on infant bathing and cleansing.
Based on discussions at the meeting and a comprehensive literature review, the panel developed a series of recommendations relating to several aspects of infant skin care, including initial and routine bathing, safety while bathing, and post-bathing procedures. The panel also focused on the use of liquid cleansers in bathing, particularly relating to the benefits of liquid cleansers over water alone, and the criteria that should be used when choosing an appropriate liquid cleanser for infants. Alkaline soaps have numerous disadvantages compared with liquid cleansers, with effects on skin pH and lipid content, as well as causing skin drying and irritation. Liquid cleansers used in newborns should have documented evidence of their mildness on skin and eyes, and those containing an emollient may have further benefits. Finally, the panel discussed seasonal differences in skin care, and issues relating to infants at high risk of atopic dermatitis. The panel further discussed the need of clinical studies to investigate the impact of liquid cleansers on skin physiology parameters on newborns' and infants' skin.
Bathing is generally superior to washing, provided basic safety procedures are followed, and has psychological benefits for the infant and parents. When bathing infants with a liquid cleanser, a mild one not altering the normal pH of the skin surface or causing irritation to skin or eyes should be chosen.
The rate constant of quenching of singlet oxygen (kQ) by squalene (SQ) is found to be much larger than those of the lipids in human skin surface. SQ is the first target lipid in human skin surface by oxidative stresses such as sun light exposure. kQ of SQ is similar to that of 3,5-di-t-butyl-4-hydroxytoluene (BHT). The large kQ of SQ is due to the small ionization potential. SQ consists of six 2-methyl-2-pentene units and kQ of SQ is about 6-times as large as that of 2-methyl-2-pentene. The electron donating property of methyl groups bonded to quaternary carbons of SQ is essential to the large kQ. SQ is not very susceptible to peroxidation and is stable for attacks by peroxide radicals. The chain reaction of lipid peroxidation is unlikely to be propagated with SQ in human skin surface. It is concluded that SQ functions as an efficient quencher of singlet oxygen and prevents the corresponding part of lipid peroxidation in human skin surface.
Although there is no firm evidence to support the "ideal" or even "appropriate" healthy level of dietary fat, the habitual fat consumption pattern in Japan seems to be a criterion for the recommended allowance both in the quantitative and qualitative points of view as judged from the life expectancy and the incidence of degenerative diseases. The new recommended dietary allowance of Japan, fifth revision effective for five years starting in 1995, adopted dietary fat levels of 20-25 energy percent, the ratio of saturated, monounsaturated, and polyunsaturated fatty acids at 1:1.5:1 and the ratio of n-6/n-3 at 4. The recommended fat level is similar to that previously consumed in Japan, and is even lower than that in diets used to treat hyperlipidemia in Western countries, current recommendations in those countries being 30 energy percent fat. Convincing data for the beneficial effects of n-3 polyunsaturated fatty acids on human health, in particular for healthy people, have been presented in only a few reports. However, the recommended n-6/n-3 ratio of 4 seems reasonable compared with the ratio of around 10 in other developed countries. In this context, it is more important to fully understand the nutritional and physiological roles of fat in healthy people rather than in those with chronic disease. At present, the low-fat dietary pattern in Japan appears to be a healthy way of eating.
Adverse cutaneous reactions to topically applied olive oil are seldom reported, and positive patch tests to it are mostly regarded as allergic. To evaluate such "positive" patch test reactions, 77 female (mean age: 44 years) and 23 male eczema patients (mean age: 46 years) were prospectively patch tested with freshly prepared olive oil. Tests were performed openly (including ROAT) as well as using Al-tests and Finn Chambers on Scanpor. 5 patients (2 male) showed "positive" test reactions (all patients at the Al-test site, 3 at the Finn Chamber site, 1 with ROAT). In only 1 patient could the reaction be classified as probably allergic, in contrast to previous reports. In conclusion, olive oil is very weakly irritant in general, but bears relevant irritant capacity when applied under occlusive conditions. Therefore, olive oil appears to be less than suitable for the topical therapy of patients with venous insufficiency and associated eczema of the lower extremities.
Epidemiologic studies of breast and pancreatic cancer in several Mediterranean populations have demonstrated that increased dietary intake of olive oil is associated with a small decreased risk, or no increased risk, of cancer, despite a high overall lipid intake. Experimental animal models in high dietary fat and cancer also indicate that olive oil either has no effect, or a protective effect, on the prevention of a variety of chemically induced tumors. As a working hypothesis, it is proposed that the high squalene content of olive oil, as compared to other human foods, is a major factor in the cancer-risk reducing effect of olive oil. Experiments in animal models suggest a tumor-inhibiting role for squalene. A mechanism is proposed for the tumor-inhibitory activity of squalene based on its known strong inhibitory activity of HMG-COA reductase catalytic activity in vivo, thus reducing farnesyl pyrophosphate (FPP) availability for "prenylation" of ras oncogene, which relocates this oncogene to cell membranes and is required for the signal-transducing function of ras. Reduction of mutated ras oncogene activation may be useful in breast and colon cancer and may be particularly applicable to pancreatic cancers that are strongly associated with ras oncogenes.
Reactive oxygen species (ROS) have been shown to be responsible for inducing DNA damage after ultraviolet radiation (UV). Antioxidant, vitamin E and epigallocatechin gallate extracted from green tea, applied topically to the skin, delayed the onset of UV-induced skin cancer in mice. Since olive oil is reported to have a potent antioxidative effect in in vitro system, we asked whether, topical use of olive oil reduces the number and delays the onset of UV-induced skin cancer in mice. We found that super virgin olive oil painted immediately after UVB radiation significantly delayed the onset and reduced the number of skin cancer, but pretreatment of super virgin olive oil and pre- and/or post treatment by regular olive oil neither retarded nor reduced skin cancer formation in UV-irradiated mice. Further, 8-hydroxy-deoxyguanosine (8-OHdG) formation in mice epidermis was apparently reduced by super virgin olive oil painted immediately after UV radiation, although cyclobutane pyrimidine dimers and (6-4) photoproducts were not reduced by olive oil treatment. Our results suggest that daily topical use of super virgin olive oil after sun bathing may delay and reduce UV-induced skin cancer development in human skin, possibly by decreasing ROS-induced 8-OHdG which is responsible for gene mutation.
Because olive oil is an important component of the Mediterranean diet, it is necessary to establish unequivocal identification of the major potential antioxidant phenolic compounds it contains.
The major phenolic antioxidants in extra virgin olive oil were isolated and purified. Structural analysis was conducted using several spectroscopic techniques, including mass spectrometry and nuclear magnetic resonance (NMR). In particular, detailed (1)H and (13)C NMR data are presented, and several assignment errors in the literature are corrected.
The data show for the first time that the lignans (+)-1-acetoxypinoresinol and (+)-pinoresinol are major components of the phenolic fraction of olive oils. These lignans, which are potent antioxidants, are absent in seed oils and virtually absent in refined virgin oils but are present at concentrations of up to 100 mg/kg (mean +/- SE, 41.53+/-3.93 mg/kg; range, 0.65-99.97 mg/kg) in extra virgin oils. As with the simple phenols and secoiridoids, there is considerable interoil variation in lignan concentrations. Foods containing high amounts of lignan precursors have been found to be protective against breast, colon, and prostate cancer.
Lignans, as natural components of the diet, may be important modulators of cancer chemopreventive activity.
The aim of the present study was to examine the effect of a virgin olive oil enriched diet in acute and chronic inflammation models in rats and to determine the effect of supplementing this oil with a higher content of its polyphenolic fraction. The response was compared to oils rich in monounsaturated fatty acids (high oleic sunflower oil and palm olein) and rich in polyunsaturated fatty acids (fish oil). DIETS: Groups of 6-8 male Wistar rats were fed from weaning on six purified diets differing in type of oil: 2% corn oil (basal diet, BD), 15% high oleic sunflower oil (HOSO), 15% virgin olive oil (VOO), 15% virgin olive oil supplemented with 600 p.p.m. polyphenols from this oil (PSVOO), 15% palm olein (POL), and 15% fish oil (FO).
Rats were fed for 8 weeks with BD, HOSO, VOO, PSVOO, POL and FO diets before injecting carrageenan. Rats were fed for 3 weeks with BD, PSVOO and FO diets before induction of adjuvant arthritis. Dietary treatment with or without indomethacin continued during 3 weeks. The data were evaluated using an analysis of variance (ANOVA) followed by the least-significant differences.
In carrageenan oedema test, the inflammation indices of animals fed on a diet rich in olive oil (VOO) were lower compared to animals fed with oils high in oleic acid (HOSO, POL) and polyunsaturated fatty acids (FO), and markedly diminished in the group fed on PSVOO. In established adjuvant arthritis, the PSVOO diet was even more effective than FO diet in the prevention of inflammation. Both groups of animals showed an increase in weight during the latter days of the experiment compared to the BD. Indomethacin administered to every diet group, exerted a strong inhibitory effect on the inflammatory process throughout which was augmented by the PSVOO and FO diets.
This study demonstrates that virgin olive oil with a higher content of polyphenolic compounds, similar to that of extra virgin olive oil, shows protective effects in both models of inflammation and improves the disease associated loss of weight. This supplementation also augmented the effects of drug therapy.
The major phenolics from the polar fraction of virgin olive oil (caffeic acid, oleuropein, tyrosol and hydroxytyrosol) have well-established antioxidant activities but their effects on reactive nitrogen species and nitrergic neurotransmission have not been fully investigated. The three catechol compounds were active as scavengers of nitric oxide generated spontaneously from the decomposition of sodium nitroprusside (approximately 50% inhibition achieved at 75 microM), and had similar ability to scavenge chemically generated peroxynitrite, as determined by an alpha1-antiproteinase inactivation assay (67.2%-92.4% reduction when added at 1 mM). Tyrosol was less active in these tests, but does not possess the catechol functionality. Despite their ability to interact with chemically prepared nitric oxide, neither oleuropein nor hydroxytyrosol at 5 microM altered NO*-mediated relaxations of the nerve-stimulated rat anococcygeus preparation, but this may be because the nitrergic transmitter is protected from the effects of externally applied scavengers. In conclusion, the phenolics found in virgin olive oil possess ability to scavenge reactive oxygen and nitrogen species that are implicated in human pathologies, but their impact may be restricted to those species present in the extracellular environment.
Olive oil is the principal source of fats in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Phenolic compounds, e.g., hydroxytyrosol and oleuropein, in extra-virgin olive oil are responsible for its peculiar pungent taste and for its high stability. Recent findings demonstrate that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and possess other potent biological activities that could partially account for the observed healthful effects of the Mediterranean diet.
In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important constituent of the diet, and is considered a major factor in preserving a healthy and relatively disease-free population. Epidemiological data show that the Mediterranean diet has significant protective effects against cancer and coronary heart disease. We present evidence that it is the unique profile of the phenolic fraction, along with high intakes of squalene and the monounsaturated fatty acid, oleic acid, which confer its health-promoting properties. The major phenolic compounds identified and quantified in olive oil belong to three different classes: simple phenols (hydroxytyrosol, tyrosol); secoiridoids (oleuropein, the aglycone of ligstroside, and their respective decarboxylated dialdehyde derivatives); and the lignans [(+)-1-acetoxypinoresinol and pinoresinol]. All three classes have potent antioxidant properties. High consumption of extra-virgin olive oils, which are particularly rich in these phenolic antioxidants (as well as squalene and oleic acid), should afford considerable protection against cancer (colon, breast, skin), coronary heart disease, and ageing by inhibiting oxidative stress.
Recent epidemiological evidence and animal studies suggest a relationship between the intake of olive oil and a reduced risk of several malignancies. The present study assesses the effect of hydroxytyrosol, a major antioxidant compound of virgin olive oil, on proliferation, apoptosis and cell cycle of tumour cells. Hydroxytyrosol inhibited proliferation of both human promyelocytic leukaemia cells HL60 and colon adenocarcinoma cells HT29 and HT29 clone 19A. The con-centrations of hydroxytyrosol which inhibited 50% of cell proliferation were approximately 50 and approximately 750 micromol/l for HL60 and both HT29 and HT29 clone 19A cells, respectively. At concentrations ranging from 50 to 100 micromol/l, hydroxytyrosol induced an appreciable apoptosis in HL60 cells after 24 h of incubation as evidenced by flow cytometry, fluorescence microscopy and internucleosomal DNA fragmentation. Interestingly, no effect on apoptosis was observed after similar treatment of freshly isolated human lymphocytes and polymorphonuclear cells. The DNA cell cycle analysis, quantified by flow cytometry, showed that the treatment of HL60 cells with hydroxytyrosol 50-100 micromol/l arrested the cells in the G0/G1 phase with a concomitant decrease in the cell percentage in the S and G2/M phases. These results support the hypothesis that hydroxytyrosol may exert a protective activity against cancer by arresting the cell cycle and inducing apoptosis in tumour cells, and suggest that hydroxytyrosol, an important component of virgin olive oil, may be responsible for its anticancer activity.
Minor components of virgin olive oil may explain the healthy effects of the Mediterranean diet on the cardiovascular system and cancer development. The uncontrolled production of reactive oxygen species (ROS) and arachidonic acid (AA) metabolites contributes to the pathogenesis of cardiovascular disease and cancer, and inflammatory cells infiltrated in the atheroma plaque or tumor are a major source of ROS and eicosanoids. We aimed to determine the effects of squalene, beta-sitosterol, and tyrosol, which are representative of the hydrocarbons, sterols, and polyphenols of olive oil, respectively, on superoxide anion (O2(-)), hydrogen peroxide (H2O2), and nitric oxide (*NO) levels. We also studied AA release and eicosanoid production by phorbol esters (PMA)-stimulated macrophages RAW 264.7. beta-Sitosterol and tyrosol decreased the O2(-) and H2O2 production induced by PMA, and tyrosol scavenged the O2(-) released by a ROS generating system. These effects were correlated with the impairment of [3H]AA release, cyclooxygenase-2 (COX-2) expression, and prostaglandin E(2)/leukotriene B(4) synthesis in RAW 264.7 cultures stimulated by PMA. beta-Sitosterol exerted its effects after 3-6 h of preincubation. Tyrosol inhibited the [3H]AA release induced by exogenous ROS. beta-Sitosterol and tyrosol also reduced the *NO release induced by PMA, which was correlated with the impairment of inducible nitric oxide synthase (iNOS) levels. This may be correlated with the modulation of NF-kappaB activation. Further studies are required to gain more insight into the potential healthy effects of minor components of extra virgin olive oil.