Safflower
Scientific Name(s): Carthamus tinctorius L.
Common Name(s): American saffron, Bastard saffron, Dyer's saffron, False saffron, Gami-Honghwain, Hong hua, Safflower, Zafran
Medically reviewed by Drugs.com. Last updated on Nov 21, 2023.
Clinical Overview
Use
Safflower has demonstrated antioxidant and anti-inflammatory activities and has been investigated for use (though often as a control or comparator agent) in cardiovascular conditions, diabetes, obesity, and pruritus. Animal studies also suggest reproductive, hair growth–promoting, and lung and tendon injury–attenuating effects. However, clinical trial data are lacking to recommend use of safflower for any indication.
Dosing
Safflower oil dosages of 6 g/day and 8 g/day (in divided doses) were used in 2 small studies of obese women to evaluate effects on weight and glycemic indices.
Contraindications
Safflower is contraindicated in pregnancy.
Pregnancy/Lactation
Use is contraindicated in pregnancy; abortifacient and emmenagogue effects have been suggested.
Interactions
None well documented.
Adverse Reactions
Allergy to the flowers has been reported. Safflower oil was generally well tolerated when used as a control in clinical trials. A few cases of acute liver disease have been associated with use of safflower oil supplements.
Toxicology
No data.
Scientific Family
- Asteraceae (daisy)
Botany
Safflower is native to the Middle East and is widely cultivated throughout Europe, China, India, and the United States. Safflower is a bushy annual that reaches approximately 1 m in height, with shiny, oval, spiny-edged leaves that alternate around a single, smooth, upright stem. The plant produces profuse yellow to deep red flowers and a dry, one-seeded fruit known as an "achene" that is generally small and white and used for its edible oil. Seeds are produced in August and enclosed in a mass of down.Asgarpanah 2013, USDA 2019, vanWyk 2004 Safflower roots extend 2 to 3 m into the soil, making them useful as rain-fed cropping systems.Asgarpanah 2013
History
Although safflower is now recognized primarily as a source of healthy edible oil, traditional uses have not focused on the oil. Safflower was originally valued for the yellow and red dyes yielded by its flowers, which have been used for centuries to color cosmetics and fabrics. The use of safflower extract to dye the wrappings of mummies has also been reported.Duke 2008 Safflower had been used as a replacement for saffron but lost popularity because of its lack of taste. Safflower tea has been used in traditional medicine to induce sweating and reduce fever. The oil has been used as a laxative, and as a solvent in paints.Dobelis 1986 A biblical reference is made to saffron in Song of Solomon 4:13-14.Duke 2008
Chemistry
Safflower oil is characterized by the presence of a high proportion of n-6 polyunsaturated fatty acids, including linoleic (approximately 75%), oleic (13%), palmitic (6%), and stearic (3%), as well as other minor straight-chained fatty acids.Kwon 1991, Paschos 2007, Windolz 1983 Alpha- and gamma-tocopherol have also been described.Masterjohn 2007 Although safflower oil is a rich source of linoleic acid, the activity of delta 6-desaturase is required for its conversion to dihomogammalinolenic acid (DHGA) and arachidonic acid. In contrast, evening primrose oil appears to be a more bioavailable source of fatty acids for the production of DHGA.Abraham 1990
More than 200 compounds have been isolated from C. tinctorius, including flavonoids, phenylethanoid glucosides, coumarins, fatty acids, steroids, and polysaccharides.Asgarpanah 2013
The seeds contain a lignan glycoside known as trachelosideKim 2008; serotonin derivatives and their glucosides have been found in the seed extract.Kim 2008, Takii 1999
Uses and Pharmacology
Safflower oil has been used as a control or comparator agent in many clinical trials and experimental studies evaluating effects on conditions such as dyslipidemia, diabetes, cardiovascular conditions, and cancer.Barre 2008, Bloomer 2005, Burton-Freeman 2004, Close 2007, Paschos 2007, Steck 2007, Tsuzuki 2004, Walser 2006 Few quality clinical trials specifically investigating the effects of safflower have been published.
Antioxidant activity
Animal and in vitro data
Safflower's antioxidant activity is responsible for inhibiting the production of oxidized low-density lipoprotein (LDL) to ultimately reduce atherosclerosis.Berraaouan 2013 N-(p-coumaroyl) serotonin is a potent antioxidant compound present in safflower oil and has been shown to exert growth-promoting activity for mouse fibroblasts and human fibroblasts in vitro. Antioxidant activity and inhibitory effects on proinflammatory cytokine production from human monocytes were observed at N-(p-coumaroyl) serotonin doses between 10 and 100 mcM.Takii 1999
Cardiovascular effects
Animal and in vitro data
In a study of mice with isoproterenol-induced acute myocardial ischemia, injections of C. tinctorius (0.625 g/kg and 2.5 g/kg) given intraperitoneally each day for 5 days inhibited ST segment and T-wave elevation (P<0.05) and also decreased levels of the inflammatory cytokines interleukin-6 and tumor necrosis factor alpha (P<0.05).Wan 2011 Animal studies investigating the effects of phospholipids from safflower and soybean showed decreased hepatic lipid levels via decreased liver cholesterol and increased fecal neutral steroid.Cohn 2008
Clinical data
Safflower showed no effect on blood pressure, heart rate, or brachial artery vascular conductance when used as placebo in clinical trials of healthy subjects.Iwata 2007, Walser 2006
Safflower oil consumption has been reported to have variable effects on plasma lipids.Abraham 1990, Cox 1998, Jackson 2005, Joseph 2011, Solanki 2005, Wardlaw 1991, Williams 2001
In studies of healthy subjects and dyslipidemic patients, decreased expression of adhesion molecules, induced by oxidized LDL, has been observed following consumption of meals rich in safflower. The clinical importance of this effect is unclear.Masterjohn 2007, Nicholls 2006, Rallidis 2004 Effects of safflower oil on platelet linoleic acid and thromboxane B2 levels were equivocal in small studies.Herbel 1998 In a 12-week, double-blind, randomized, placebo-controlled trial in patients with high-normal blood pressure or mild hypertension (N=92), supplementation with safflower seed extract (serotonin derivative dose of 70 mg/day) provided no benefit between groups in arterial stiffness, blood pressure, oxidative status, or proinflammatory biomarkers at study end. Of the 6 arterial stiffness measures taken at weeks 4, 8, and 12, only the 4-week vascular age was statistically significantly improved with safflower.Suzuki 2010
Diabetes
Animal and in vitro data
In an in vitro study, N-p-coumaroyl serotonin and N-feruloyl serotonin isolated from safflower seed inhibited alpha-glucosidase, a well-known drug target in the management of diabetes.Takahashi 2012 In a study of rabbits, C. tinctorius extract at doses of 200 mg/kg and 300 mg/kg administered for 30 days increased insulin levels and caused a hypoglycemic effect.Qazi 2014 Daily intraperitoneal injections of C. tinctorius extract 200 mg/kg in rats increased insulin levels and decreased fasting blood glucose and cholesterol parameters.Asgary 2012
Clinical data
In a double-blind, crossover clinical trial in obese postmenopausal women with type 2 diabetes (N=35 evaluable), conjugated linoleic acid (CLA) was compared with safflower oil for effects on body weight and composition. The 2 oils were administered at doses of 8 g/day (administered as two 1 g capsules with each of 3 main meals and a snack) for 16 weeks, with a 4-week washout period between treatments. CLA, but not safflower oil, decreased body mass index (BMI) and total adipose mass. Safflower oil, but not CLA, produced reductions in trunk adipose tissue and fasting blood glucose, and increased lean tissue and adiponectin levels.Norris 2009 Benefits observed with safflower oil, and not CLA, included reduced hemoglobin A1c and C-reactive protein and increased high-density lipoprotein cholesterol.Asp 2011
As a component of medical nutrition therapy for patients with type 1 or 2 diabetes, the American Diabetes Association Standards of Care (2014) guidelines recommend an increase in foods containing alpha-linolenic acid based on observed beneficial effects on lipoprotein profiles, heart disease prevention, and overall positive health in patients with diabetes (moderate-quality evidence). Likewise, as a component of medical nutrition therapy for patients with type 2 diabetes, the American Diabetes Association Standards of Care (2014) guidelines recommend higher-quality dietary fat intake as an alternative to decreased fat intake by replacing saturated and/or trans fats with mono- and polyunsaturated fatty acids in the diet. This Mediterranean-style approach to eating may improve glycemic control and cardiovascular disease risk factors (moderate-quality evidence).ADA 2014
Estrogen deficiency–related osteoporosis
Animal and in vitro data
In rat models, linoleic acid, found in high levels in safflower seed oil, appeared to exert anti-inflammatory effects in bone by moderating prostanoid formation, correcting bone loss due to ovariectomy, and increasing the intestinal absorption of calcium.Asgarpanah 2013 An herbal formulation containing C. tinctorius seed demonstrated an anabolic effect on bone through promotion of osteoblastic differentiation.Kim 2008
Hair growth
Animal and in vitro data
In a study including both in vivo and in vitro models, C. tinctorius extract increased the length of hair follicles in a manner similar to that of minoxidil. Mice treated with C. tinctorius had hair growth at day 15 similar to that observed in mice treated with minoxidil.Junlatat 2014
Human papillomavirus–induced laryngeal papillomatosis
Clinical data
A small, randomized, double-blind, crossover clinical trial in pediatric patients evaluated safflower oil rich in oleic acid (control arm) versus CLA in patients requiring surgical intervention for human papillomavirus (HPV)–induced laryngeal papillomatosis. Each oil was administered at 2.5 g/day for 8 weeks, with a 6-week washout period between treatments. CLA produced greater improvement in HPV-induced laryngeal papillomatosis scores and required fewer surgical procedures compared with the safflower control group.Louw 2012
Lung dysfunction
Animal data
In a study of rats, hydroxysafflor yellow A, a flavonoid component derived from C. tinctorius, attenuated gasoline engine exhaust–mediated lung damage. The compound improved measures of pulmonary function and increased adenosine 3′,5'-cyclic phosphate levels and protein kinase A activity while decreasing interleukin-6 and tumor necrosis factor alpha levels.Wang 2014
Obesity
Clinical data
In a double-blind, randomized, placebo-controlled trial conducted in 75 obese women, administration of safflower oil 6 g/day (administered as two 1 g capsules before main meals) for 8 weeks resulted in significantly better reductions (P<0.001) in weight and BMI compared with baseline relative to placebo (soybean oil) but not compared with coconut or chia oils. Likewise, the safflower group exhibited significantly better results (P<0.001) for anthropomorphic parameters (waist circumference, waist-hip-ratio, percent body fat, and percent lean mass) compared with baseline relative to placebo. Mean absolute variations in glycemia and HbA1c were higher with coconut oil relative to safflower oil.Oliveira-de-Lira 2018
One 8-week, randomized, double-blind clinical trial conducted in obese males compared the benefits of CLA, safflower oil, heated safflower oil, and olive oil for weight loss and vascular endothelial function, with heated safflower oil and olive oil used for additional descriptive control. CLA was superior to safflower oil for reductions in body weight and BMI, but was inferior for postprandial vascular endothelial function improvement.Pfeuffer 2011 A double-blind, randomized, crossover trial evaluated weight-loss and lipid-lowering effects of CLA compared with safflower oil as a control. There were no changes in BMI or lipid levels compared with baseline following 8-week courses of CLA or safflower oil.Joseph 2011
Pruritus in renal disease
Clinical data
Safflower oil supplementation resulted in clinically unimportant reductions in symptoms of pruritus in a small study of hemodialysis patients.Begum 2004
Spermatogenesis
Animal data
In a study of rats with busulfan-induced infertility, C. tinctorius extract 10 mg/kg daily for 35 days significantly improved sperm morphology, motility, and count compared to control (P=0.02, P=0.03, and P=0.00001, respectively). Higher doses of C. tinctorius (ie, 25 mg/kg and 50 mg/kg) generally did not improve these measures; the 25 mg/kg dose slightly, but not significantly, improved sperm count.Bahmanpour 2012 In another murine model, C. tinctorius extract exerted toxic effects on testicular tissue.Mirhoseini 2012
Tendon injury
Animal data
The effect of safflower yellow on tendon injury was assessed in a study of chickens. Local application of safflower increased expression of basic fibroblast growth factor and collagen type I protein, improved tensile strength of the tendon, and increased adhesion.Liu 2011
Topical application
Clinical data
In a tertiary care neonatal intensive care unit setting, safflower oil 3 mL was applied topically by massage 4 times a day to neonates to study the transcutaneous absorption and fatty acid profiles associated with massage in this population. This method of administration resulted in absorption, as indicated by altered lipid profiles in the neonates, suggesting possible availability for nutritional purposes. Further studies are needed to confirm therapeutic benefits.Solanki 2005
Dosing
Safflower oil dosages of 6 g/day and 8 g/day (in divided doses) were used in 2 small studies of obese women to evaluate effects on weight and glycemic indices.Asp 2011, Norris 2009, Oliveira-de-Lira 2018
Pregnancy / Lactation
Use is contraindicated in pregnancy; abortifacient and emmenagogue effects have been suggested.Brinker 1998, Ernst 2002 A study in mice demonstrated that C. tinctorius extract administered intraperitoneally at doses of 1.4 mg/kg and 2.8 mg/kg caused toxic changes in the structure of the placenta compared with controls. Neonate survival rates (calculated at days 5, 15, 25, and 42 after birth) were decreased in the C. tinctorius extract group compared with controls.Monfared 2011
Another study in rats with maternal diabetes showed that diets supplemented with safflower oil and folic acid reduced malformation rates as well as decreased matrix metalloproteinase-2 and -9 activities.Higa 2012
Interactions
None well documented.
Adverse Reactions
Case reports of immunoglobulin E–mediated allergy (eg, rhinitis, urticaria, asthma) to the flowers exist.Compes 2006 In a review of 14 case reports of allergic shock from the clinical use of safflower injection in China, the majority of cases occurred less than 30 minutes after administration.Sun 2013 A few cases of acute liver failure induced by linoleic acid, the main component of safflower oil, have been reported. Additionally, in 3 female patients who presented for liver transplant, acute liver failure was suspected to be due to their use of safflower oil supplements after ruling out the most frequent etiologies (ie, viral hepatitis, autoimmune disease, neoplasias, adverse drug effects).de Ataide 2018
Trials using safflower oil as a control report few adverse reactions.
Safflower oil–induced n-3 deficiency (high n-6 to n-3 ratio) had a deleterious effect on cognition in mice.Calon 2005 In another experiment in mice, a safflower oil–rich diet (ie, depleted n-3 fatty acids) resulted in a decrease in insulin-degrading enzyme, which was associated with an increase in beta-amyloid levels, defects similar to those found in Alzheimer disease.Zhao 2004
Toxicology
Toxicologic information is limited. Foods are often cooked in safflower oil, and the oil is commonly used as a placebo in clinical trials. A study to determine the safety of safflower oil showed no adverse effects on liver enzymes and renal parameters (eg, uric acid, blood urea nitrogen, creatinine) at 10 g of oil per day.Iwata 2007 In one study in mice, C. tinctorius extract doses of 1.4 mg/kg and 2.8 mg/kg for 49 consecutive days caused detrimental effects on kidney tissue.Monfared 2013
References
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