Food Sci. Biotechnol. Vol. 15, No. 3, pp. 329 338 (2006)
`
`RESEARCH REVIEW
`
`Food Science
`and Biotechnology
`
`© The Korean Society of Food Science and Technology
`
`Health Promoting Properties of Natural Flavor Substances
`Mira Jun1,2, Woo-Sik Jeong3 *, and Chi-Tang Ho1
`1 Department of Food Science, Rutgers, The State University of New Jersey, 65 Dudley Rd., New Brunswick, NJ 08901-8520, USA
`2Division of Applied Biology & Chemistry, Kyungpook National University, Daegu 702-701, Korea
`3Food Science Institute, School of Food and Life Science, Inje University, Gimhae, Gyeongnam 621-749, Korea
`
`Abstract The study of health promoting and disease preventing compounds in food or by themselves, so called
`nutraceuticals or functional foods, has become a major field of research in food science. Natural flavor compounds are usually
`present in food, essential oils, spices, and herbs. These compounds can produce aroma, not only by themselves, but also in
`combination with other compounds. Today, however, greater interest is being paid to the health promoting properties of
`natural flavor substances rather than their flavoring properties. In fact, a number of naturally occurring flavor compounds that
`possess health promoting and disease preventing properties have been extensively studied and identified. The beneficial
`properties of natural volatile flavor compounds as well as non-volatile substances in spices and herbs discussed in this review
`include antioxidant, anticarcinogenic, anti-inflammatory, and immune enhancing activities.
`Keywords: flavor, herb, spice, antioxidant, anticancer, anti-inflammatory, immune-enhancing
`
`significantly prevents or delays a pro-oxidant initiated
`oxidation of the substrate (7). As of today, antioxidants
`from food sources, spices, and medicinal herbs have been
`extensively studied.
`Naturally occurring antioxidants include vitamin E,
`vitamin C, carotenoids, phenolic compounds including
`flavonoids, and sulfur-containing antioxidants such as
`glutathione, camosine, etc. Antioxidant properties are also
`found in several flavor compounds such as vanillin (8-10),
`allicin (11-13), S-allyl cysteine (14-16), eugenol (17, 18),
`thymol and carvacrol (19-22), gingerol (23-25), etc. (Fig.
`1 ). Besides these flavor compounds, essential oils, spices
`and herbs with flavoring properties have been more
`extensively studied for their medicinal properties including
`antioxidant activity (22, 26-28).
`Vanillin (4-hydroxy-3-methoxybenzaldehyde) is one of
`the most widely used flavoring agents for sweet foods.
`Vanillin is reported to suppress protein oxidation and lipid
`
`OCH3
`
`OH
`
`/
`
`~
`
`/CH2
`
`Eugenol
`
`H3C
`
`CH,
`
`H3C
`
`CH3
`
`Carvacrol
`Thymol
`Fig. 1. Structures of natural flavor compounds with anti-
`oxidant properties.
`
`329
`
`Introduction
`Food is a complex mixture of biochemicals essential for
`the metabolic processes of life. Many natural food
`components have been reported to possess various health
`promoting properties (1, 2). Consequently, the study of
`health promoting and disease preventing compounds in
`food or the food itself, so called nutraceuticals and
`functional foods, respectively, has become a major field in
`food science.
`Flavor
`the
`influencing
`is a major characteristic
`desirability of food, together with color, texture and
`nutrition, and it forms the cornerstone of contemporary
`food industries throughout the world (3). Flavor compounds
`are usually present in food materials, especially in spices
`and herbs. It was found that small amounts of spices and
`herbs could be used to enhance the flavor of a food and
`also serve to help preserve the food ( 4). Today, however,
`the health promoting properties of spices, rather than their
`flavoring properties, are of great interest. In this review,
`we discuss
`representative natural
`flavor substances
`including volatile flavor compounds, spices and herbs that
`are known to possess properties that are beneficial for
`health.
`
`Antioxidant properties of natural flavor substances
`Free radicals and/or reactive oxygen species (ROS) play
`an important role in over a hundred disease conditions in
`humans, including arthritis, hemorrhagic shock, athero-
`sclerosis, aging, Alzheimer's disease, Parkinson's disease,
`gastrointestinal dysfunctions, tumor promotion, carcino-
`genesis, and acquired
`immune deficiency syndrome
`(AIDS) (5, 6). An antioxidant can be defined as a
`substance
`that, when present at
`low concentrations
`compared with
`those of an oxidizable
`substrate,
`
`*Corresponding author: Tel: 82-55-320-3238; Fax: 82-55-321-0691
`E-mail: jeongws@inje.ac.kr
`Received February 6, 2006; accepted May 8, 2006
`
`0:--._
`"CH
`
`OCH3
`
`OH
`Vanillin
`
`OH
`
`H2c~,....s~
`IT
`CH,
`0
`
`Allicin
`
`OH
`
`/
`
`9'
`7CH3 7CH,
`
`Ex. 1186
`
`

`

`330
`
`M Jun eta!.
`
`autoxidation in lard and sunflower oil (19, 22). However,
`these compounds differ
`in the mechanism of their
`inhibition, which depends on the character of the lipid
`medium. Thymol is a better antioxidant in sunflower oil
`than in lard, whereas the antioxidant activity of carvacrol
`in the two lipid systems does not differ significantly. The
`inhibition of oxidation by essential oils from plants of the
`oregano species depends highly on the content of
`carvacrol and thymol.
`Eugenol is found in several volatile oils such as clove
`oil, laurel, and cinnamon leaf oil (3). It possesses a strong
`antioxidant activity with regard
`to hydroxy radical
`formation (17, 18, 34). Nagababu and Lakshmaiah (34)
`reported that eugenol inhibits hydroxy radical formation
`through its inhibitory effect on OH-mediated deoxyribose
`degradation. Eugenol also inhibited lipid peroxidation of
`human erythrocyte membranes catalyzed by hydrogen
`peroxide (H20 2) or benzoyl peroxide in the presence of
`copper ions (17). Eugenol also suppressed enzymatic lipid
`peroxidation catalyzed by soybean lipoxygenase, not by
`inactivating the enzyme directly, but by interfering with
`fatty acid radical intermediates due to its hydroxy radical
`scavenging ability, and thus plays a role in inhibiting the
`propagation of lipid peroxidation. (18)
`The antioxidant properties of spices and their compounds
`have been widely studied. The total antioxidant activities
`of 12 common spice extracts are summarized in Fig. 2.
`The term 'total antioxidant activity' involves the 'ability'
`of an antioxidant substance to scavenge 2,2'-azino-bis(3-
`ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radicals,
`which can be derived from the enzymatic oxidation of
`metmyoglobin (35). Trolox (6-hydroxy-2,5,7,8-tetramethyl-
`chroman-2-carboxylic acid), a synthetic water soluble
`tocopherol analog, is commonly used as a standard
`antioxidant in this assay. Any material having a Trolox
`equivalent number of more than one is considered to have
`superior free radical scavenging activity compared to
`Trolox. As shown in Fig. 2, seven out of the twelve spice
`extracts
`tested have better free
`radical scavenging
`capabilities than Trolox. These spices include oregano,
`thyme, sage, mint, huajiao, cinnamon, and rosemary.
`However,
`it should be noted that the free radical
`scavenging assay is not the only antioxidant test. There are
`many other antioxidant assays, and frequently, one assay
`does not necessarily correlate with another.
`Rosemary (Rosemarinus officinalis L.) extracts are good
`sources of various antioxidant compounds such as carnosol,
`
`oregano
`
`thyme
`sage
`
`mint
`huajiao
`cinnamon
`rosemary
`
`(J
`
`.l!l
`.... ><
`Cl)
`Cl)
`(J
`"ii
`u,
`
`basil
`cumin
`dill weed
`nutmeg
`. black pepper
`
`peroxidation induced by photosensitization in rat liver
`mitochondria (9). It also scavenges peroxynitrite and
`inhibits peroxynitrite-mediated reactions ( 10).
`Garlic (Allium sativum) has several flavor compounds
`and has been widely studied for its medicinal effects, such
`as antioxidant and anticancer activities,
`for several
`decades. Allicin (thio-2-propene-1-sulfinic acid S-allyl
`ester) is a known antioxidant in garlic and is produced by
`an enzymatic reaction when fresh garlic is crushed or
`injured. Allicin inhibits the formation of hydroxy radical
`adducts by more than 90% in liver homogenate (cone. 36
`µg/mL) (11). Allicin and its precursor, alliin (S-allyl-L-
`cysteine sulfoxide ), exhibit significant antioxidant activity
`against lipid hydroperoxide (LOOH) formation in human
`low-density lipoprotein (LDL) (13) and in the Fenton
`oxygen-radical generating system. The biological activity
`of allicin is attributed to either antioxidant activity or thiol
`disulfide exchange. Allicin displays inhibitory activity
`against three thiol-containing enzymes which possess very
`reactive or unshielded SH-groups: SH-protease papain,
`NADP+-dependent alcohol dehydrogenase, and the NAD+-
`dependent alcohol dehydrogenase from horse liver (12).
`Thiosulfinates including allicin seem to be primarily
`responsible for the antioxidant activity of garlic whereas
`they seem to have little or inverse effect on metal chelating
`ability of garlic (29).
`The antioxidant activities of S-allyl cysteine (SAC), an
`organosulfur compound of aged garlic, and a commercial
`garlic tablet, Kyolic (Wakunaga Phann. Co., Ltd., CA,
`USA), were demonstrated by using three different antioxidant
`assay systems involving the 1,1-diphenyl-2-picrylhydrazyl
`(DPPH) radical, superoxide-mediated autoxidation of
`pyrogallol and 2,2' -azobis(2-amidinopropane) dihydrochloride
`(AAPH) induced lipid peroxidation (14). In addition to its
`radical scavenging ability, SAC has been shown to
`regulate oxidative stress in cells. SAC suppressed nitric
`oxide formation by inhibiting inducible nitric oxide
`(iNOS) mRNA and protein expression
`in murine
`macrophage RAW264.7 cells induced with lipopoly-
`saccharides (LPS) and interferon-gamma (IFN-y) (15).
`Diallyl polysulfides such as diallyl trisulfide (OATS),
`diallyl
`tetrasulfide, diallyl pentasulfide, and diallyl
`hexasulfide, are also strong antioxidants found in garlic
`(28). Diallyl polysulfides from aged garlic extract protect
`biological membranes from lipid peroxidation both in vitro
`and in vivo (30). Diallyl sulfide (DAS) and diallyl
`disulfide (DADS) seem to have significantly greater
`oxidative-delaying properties
`than cysteine-containing
`compounds (SAC; S-ethyl cysteine, SEC; S-methyl
`cysteine, SMC; S-propyl cysteine, SPC) in both oxidized
`LDL and plasma samples (16).
`Thymol is present in quantities of up to 50% in the
`essential oils of Monarda punctata, Satureia thymera,
`viride, Ocimum
`Origanum
`floribundum, Ocimum
`gratissimum, and particularly in thyme (Thymus vulgaris
`L., T. capitatus, T. serpillum L., T. zygis L. subsp.
`Sylvestris, T. herba barona L.) (3, 31-33). In Lamiaceae
`plants, thymol is always accompanied by its isomer
`carvacrol (22). An early study showed that thymol and
`carvacrol inhibited peroxidation of liposome phospholipids
`in the presence of iron (III) and ascorbate (20). Thymol
`and carvacrol are also effective
`inhibitors of lipid
`
`0
`
`2.5
`
`1.5
`0.5
`2
`Trolox equivalent. mmol/L
`Fig. 2. Antioxidant activities of spice methanol extracts against
`ABTS·+ free radicals.
`
`3
`
`3.5
`
`Ex. 1186
`
`

`

`Health Promoting Properties of Flavor Substances
`
`331
`
`isorosmanol,
`rosmanol, epirosmanol,
`carnosic acid,
`rosmaridiphenol, rosmadial, miltirone, and ursolic acid
`(36-41 ). The structures of the representative compounds in
`rosemary extracts are presented in Fig. 3. Hexane, acetone,
`and methanol extracts from rosemary leaves have been
`reported to contain strong antioxidants ( 42). Rosemary
`extracts seem to strongly inhibit lipid oxidation as well as
`soybean lipoxygenase activity. Carnosol and carnosic acid
`are responsible for over 90% of the antioxidant activity of
`rosemary (43). The antioxidant activities of camosol and
`carnosic acid were reported as early as the 1960s (44).
`Studies by Nakatani et al. (37, 45) showed that rosmanol,
`epirosmanol, isorosmanol, and carnosol all have remarkably
`high antioxidant capabilities when evaluated in lard using
`the Active Oxygen Method. Among these, rosmanol,
`epirosmanol, and isorosmanol were more than four times
`as effective as butylated hydroxytoluene (BHT), and
`carnosol was twice as active. A number of the compounds
`in rosemary have been found in the closely related sage
`(Salvia officinalis L.) and summer savory (Satureja
`hortenis L.) plants
`(46). Carnosol, carnosic acid,
`rosmadial, rosmanol, epirosmanol, and methyl carnosate
`were also identified from sage leaves and shown to have
`antioxidant activity ( 42, 4 7).
`The antioxidant effect of capsanthin on the chlorophyll-
`
`sensitized photooxidation of soybean oil and several flavor
`compounds has also been reported ( 48). Capsanthin is the
`most abundant carotenoid
`in paprika spice and its
`concentration is about 1590 mg/kg of dry matter. In other
`spices, flavonoids, alone or together with other phenolic
`compounds, have been found to contribute to antioxidant
`activity. For example, the antioxidant activity of pepper
`(Piper nigrum L.) can be ascribed to the presence of
`glycosides of the flavonoids kaempferol, rhamnetin, and
`quercetin and at least five different phenolic amides ( 46).
`[ 6]-Gingerol (1-[ 4' -hydroxy-3 '-methoxyphenyl]-5-hydroxy-
`3-decanone ), a major pungent flavor component of ginger
`(Zingiber officinale Roscoe), has been shown in numerous
`assays
`to possess substantial antioxidant properties
`including 1) DPPH radical scavenging activity, 2)
`oxidation of methyl linoleate by the Oil Stability Index
`(OSI) method, 3) liposome oxidation induced by AAPH,
`4) oxidation of ROS detecting comopound, dichloro-
`fluorescin, and 5) phospholipid peroxidation induced by
`FeCh-ascorbate (20, 23, 25). Gingerol is also known to
`suppress xanthine oxidase activity and decrease 12-O-
`tetradecanoylphorbol-13-acetate (TPA)-induced superoxide
`formation in human promyelocytic leukemia (HL-60) cells
`(25, 49).
`
`r,
`CH
`\H,
`
`CH3
`
`CH3
`
`WOH
`
`Camosol
`
`Rosmanol
`
`Ursolic acid
`
`0
`
`OH
`
`H
`
`CH,
`
`CH,
`
`/CH,
`CH
`"-cH,
`
`CH:,
`
`CH3
`
`Camosic acid
`Fig. 3. Structures of major components in rosemary extracts.
`
`Rosmaridiphenol
`
`Table 1. Active phytochemicals found in herbs
`Herbal source
`Allium sp. (Garlic, onions, leeks, and chives)
`Labiatae family (Basil, dill, fennel, marjoram,
`mint, rosemary, oregano, sage, and thyme)
`
`Umbellifereae family (Anise, caraway, celery seed,
`cilantro, coriander, cumin, dill, fennel, and parsley)
`Zingiberaceae family (Turneric and ginger)
`Table adapted from Craig (2).
`
`Active phytochemicals
`Diallyl sulfide, disulfides, and trisulfides
`Monoterpenes, sesquiterpenes, and flavonoids. Rosemary and sage contain
`diterpenoids (rosmanol, camosol, camosic acid, rosmarinic acid, epirosmanol, and
`isorosmanol), and ursolic acid (a triterpenoid)
`Cournarins, phthalides, polyacetylenes, and terpenoids
`
`Curcurnin, gingerols, and diarylheptanoids
`
`Ex. 1186
`
`

`

`M Jun et al.
`
`Nutmeg
`Cumin
`
`Huajiao
`
`3
`
`4
`
`2
`IC50 (ppm)
`Fig. 4. Anticarcinogenic activities of various spices methanol
`extracts. Pellets of hlllllan leukemia HL-60 cells after centrifugation
`were suspended in RPMI medilllll at a concentration of 5xl05
`cells/mL. Each I mL of the cell suspension was transferred to test
`tubes and treated with 2 µL of vehicle (DMSO) or various concen-
`trations of spice extracts. Three microliters of [3H]thymidine (50 µCi/
`mmol) was added to each tube followed by incubation at 37°C for
`2 hr. The reaction was terminated by the addition of I mL of ice
`cold phosphate buffer saline and centrifuged for 10 min at 1000 g.
`The precipitated cells were collected, lysed with I mL of ice cold
`deionized water and I mL of I 0% trichloroacetic acid (TCA)
`solution. After washing the macromolecular substances with TCA
`and acetone, the dry filtrates were transferred to scintillation vials
`with 5 mL of Scient Varse fluid (Fisher Scientific, Springfield, NJ,
`USA) and radioactive emissions from each vial were measured in
`a scintillation counter.
`
`I
`
`,e
`Cinnamon
`i;i
`Ill - - - - - - • Knotweed
`Thyme
`Oregano
`<II
`Dillweed
`<II
`u
`Blackpepper
`'ii
`Mint
`Sage
`ti)
`Rosemary
`----Basu
`0
`
`332
`
`Anticarcinogenic properties of natural flavor sub-
`stances
`identified several
`The National Cancer Institute has
`commonly used herbs as possessing cancer preventive
`properties (Table 1 ). These herbs include members of the
`Allium sp. (garlic, onions, and chives); members of the
`Labiatae (mint) family (basil, mints, oregano, rosemary,
`sage, and thyme); members of the Zingiberaceae family
`(turmeric and ginger), etc. (50). In addition to the
`antioxidant activities of the 12 spices extracts listed in Fig.
`2, the anticarcinogenic properties of these spice extracts
`have been demonstrated using HL-60 cells as well (Fig.
`4). HL-60 cells are genetically derived human leukemia
`cells that have lost reproductive control like other naturally
`occurring cancer cells. The anticancer properties of these
`spices were determined by measuring their inhibition of
`DNA synthesis in HL-60 cells. The extracts of basil,
`rosemary, sage, and mint exhibited very strong anticancer
`(Fig. 4). Beneficial
`activities
`in
`the HL-60 assay
`substances found in spices and herbs act as antioxidants
`and electrophile scavengers, stimulate the immune system,
`inhibit nitrosation and the formation of DNA adducts with
`carcinogens,
`inhibit hormonal actions and metabolic
`pathways associated with the development of cancer, and
`induce phase I or II detoxification enzymes (2).
`Some of the substances from spices and herbs are
`to stimulate Glutathione S-transferase (GST)
`known
`activity (2). GST is a detoxifying enzyme that catalyzes
`the reaction of glutathione with electrophiles to form
`compounds that are less toxic, more water-soluble, and
`therefore, more easily excreted. Beneficial substances that
`induce GST activity include phthalides in umbelliferous
`herbs; sulfides in garlic and onions, curcumin in turmeric
`i.e.
`limonene, geraniol,
`and ginger; and terpenoids,
`menthol, and carvone found in commonly used herbs
`(Table 2).
`Among terpenoids, monoterpenes are non-nutritive
`dietary compounds found in the essential oils of citrus
`fruits,
`including sweet orange, mandarin, grapefruit,
`lemon, lime, bitter orange, and many other plants (Fig. 5).
`The anticarcinogenic properties of monoterpenes have
`been systematically reviewed (51). d-Limonene comprises
`over 90% of orange peel oil and is used as a chemical
`intermediate in flavorings and fragrances. d-Limonene
`possesses
`chemopreventive
`activity
`against
`rodent
`
`mammary, skin, liver, lung, and forestomach cancers (52-
`54). Recently, limonene has been found as the most
`abundant volatile compound in Zanthoxylum piperitum
`(Chopi) (55). Perillyl alcohol (POH) and geraniol also
`display inhibitory properties against various cancers. POH
`suppresses the growth of breast and pancreatic cancer cells
`in vitro, and inhibits their growth and metastasis in vivo
`(56-59). POH also induces cell cycle arrest, causes
`in human
`apoptosis and
`inhibits cell proliferation
`carcinoma cell lines (BroTo and A549) in vitro (60).
`Geraniol suppresses MCF-7 human breast cancer cell
`proliferation and 3-hydroxy-3-methylglutaryl coenzyme A
`(HMG-CoA) reductase activity, which catalyzes
`the
`formation of mevalonate, a precursor of cholesterol that is
`required for cell proliferation (61). In addition, geraniol
`inhibits colon,
`lung, and prostate cancers
`( 62-65).
`Structurally diverse isoprenoids, such as d-limonene,
`
`Table 2. Terpenoids known to inhibit tumors
`Terpenoids
`Herbs that contain the active terpenoid
`Carvone
`Caraway, spearmint, and dill
`Cineole
`Coriander, lavender, rosemary, sage, and thyme
`Farnesol
`Lemongrass, chamomile, and lavender
`Gemiol
`Lemongrass, coriander, melissa, basil, and rosemary
`Limonene
`Caraway, mints, cardamom, dill, celery seed, coriander, and fennel
`Menthol
`Peppermint
`Perillyl alcohol
`Lavender, spearmint, sage
`a-Pinene
`Caraway, coriander, fennel, juniper berry, rosemary, and thyme
`Table adapted from Craig (2).
`
`Ex. 1186
`
`

`

`Health Promoting Properties of Flavor Substances
`
`333
`
`OH
`
`OH
`
`Lirnonene
`
`Perillyl alcohol
`
`Geraniol
`
`HO
`
`Carveol
`Carvone
`Fig. 5. Structures of anticarcinogenic monoterpenes.
`
`perillyl alcohol, cyclic monoterpenes (perillaldehyde,
`carvacrol, and
`thymol), and acyclic monoterpene
`(geraniol) decrease the proliferation of murine B16 (FlO)
`melanoma cells (66). Bioassay-guided fractionation of
`clove terpenes from the plant Eugenia caryophyllata
`revealed that eugenol significantly induces the detoxifying
`enzyme GST in mouse liver and small intestine ( 67).
`Essential oil of Chrysanthemum boreale Makino, which
`contains aromatic monoterpenes such as camphor, a-
`thujone, cis-cluysanthenol, 1,8-cineole, a-pinene, etc.,
`inhibits cell proliferation and induces apoptosis through the
`induction of poly-ADP-ribose polymerase (PARP) cleavage
`and caspase-3 activation in a human oral epidermal
`carcinoma KB cell line (68).
`The antitumor activities of monoterpenes may be
`explained by several mechanisms, which include 1) the
`induction of phase II carcinogen-metabolizing enzymes,
`resulting in carcinogen detoxification, 2) the induction of
`apoptosis and/or inhibition of the post-translational iso-
`prenylation of cell growth-regulating proteins, and 3)
`tumor
`redifferentiation
`concomitant with
`increased
`expression of the mannose-6-phosphate/insulin-like growth
`factor II receptor and transforming growth factor ~1 (51).
`Alcohol extract of rosemary and sage has also been
`shown to exhibit strong anti-tumorogenic properties (69).
`Application of rosemary extract to mice skin inhibited the
`covalent binding of benzo(a)pyrene [B(a)P] to epidermal
`DNA and inhibited tumor initiation by B(a)P and 7,12-
`dimethylbenz(a)anthracene (DMBA) (70). Camosol or
`ursolic acid from rosemary inhibited TPA-induced ear
`inflammation and omithine decarboxylase activity (70).
`When applied topically, sage oil, which has similar
`constituents to rosemary, not only delayed tumor appearance
`but also inhibited tumor incidence and the yield (19 and 61
`%, respectively) of DMBA-initiated and TPA-promoted
`SP-1 skin papillomas (1C50: 50 µg/mL) (71).
`Camosol was shown to prevent DMBA-induced DNA
`damage and tumor formation in rat mammary tissue (72).
`A recent study reported that camosol suppressed ~-catenin
`
`tyrosine phosphorylation and prevented intestinal tumor
`multiplicity by 46% in C57BL/6J/Min/+ (Min/+) mice
`(73). In addition, camosol inhibited the invasion of highly
`metastatic mouse melanoma B 16/F 10 cells in vitro by
`suppressing metalloproteinase-9 through down-regulation
`of nuclear factor kappa B (NF-KB) and c-Jun (74).
`Curcumin ( diferuloyl methane), a naturally occurring
`yellow pigment in turmeric and curry, is present in the
`rhizomes of the plant Curcuma longa Linn (75). Chemo-
`preventive properties of curcumin have been widely
`studied and reviewed in several previous publications (26,
`27, 76-79). Curcumin exhibits antimutagenic activity in
`the Ames assay and inhibits chemically induced preneo-
`plastic lesions in breast, colon, and neoplastic lesions in
`the skin, forestomach, duodenum, and colon of rodents
`(80, 81 ). Curcumin also modulates arachidonic acid
`metabolism by blocking phosphorylation of cytosolic
`phospholipase A2 ( cPLA2), decreasing the expression of
`cyclooxygenase-2 (COX-2) and inhibiting the catalytic
`activity of 5-lipoxygenase (5-LOX) (82). It also enhances
`glutathione content and GST activity in the liver and
`inhibited arachidonic acid metabolism in mouse skin,
`protein kinase C activity in TPA-treated NIH 3T3 cells,
`tyrosine protein kinase activity in rat colon, and 8-
`hydroxyguanosine formation in mouse fibroblasts (75).
`Curcumin
`enhances
`tumor necrosis
`factor-related
`apoptosis inducing ligand (TRAIL )-mediated apoptosis by
`ROS-mediated DRS up-regulation in human renal cancer
`cells (83). It inhibits the activity of specific receptor
`tyrosine kinases
`(RTKs) and
`the activity of the
`transcription factors activator protein-I (AP-1) and NF-
`KB,
`thus
`inhibiting cell proliferation and enhancing
`apoptosis (84).
`Many researchers have examined the anticarcinogenic
`potential of garlic and its components. Recent reports
`demonstrated
`that allylsulfide derivatives
`inhibit
`the
`growth of transplantable tumors and also inhibits a number
`of different tumor cell lines such as those derived from
`canine breast, human melanoma, human neuroblastoma,
`human prostate, and human breast (85). Oral administration
`of garlic extract inhibits two-stage chemical carcinogenesis
`induced by DMBA in mice transplanted intraperitoneally
`with Ehrlich ascites tumour (86). The inhibition of
`gastrointestinal cancer by organosulfur compounds in
`garlic has also been demonstrated (87). Onion and garlic
`oils have demonstrated abilities to inhibit tumor formation
`in mouse skin (88). Subsequently, diallyl sulfide and its
`analogues were shown to inhibit 1) 1,2-dimethylhydrazine
`(DMH)-induced colon tumorigenesis in mice and rats, 2)
`B(a)P-induced forestomach tumorigenesis in A/J mice, 3)
`nitrosomethylbenzylamine-induced formation of esophageal
`tumors in rats, 4) DMH-induced formation ofliver tumors
`in mice, 5) 3-methylcholanthrene-induced uterine cervix
`tumors in mice, and 6) benzoyl peroxide-induced tumor
`promotion
`in Sencar mice previously
`initiated with
`DMBA (89, 90). Hong et al. (91) indicated that diallyl
`sulfide inhibits the formation of lung tumors in mice by
`reducing the metabolic activation of tobacco-specific
`nitrosamine 4-(methylnitrosamino )-1-(3-pyridyl)-1-butanone
`(NNK). Other interesting compounds having biological
`activity in garlic are the cis and trans isomers of ajoene,
`which have been shown to be a potent inhibitor of platelet
`
`Ex. 1186
`
`

`

`334
`
`M Jun etal.
`
`aggregation (92).
`Organosulfur compounds, including DAS, N-acetyl-
`cysteine, and SAC present in garlic and onion oil, have
`been shown to inhibit colon, forestomach, esophagus,
`mammary gland, and lung carcinogenesis in experimental
`animals (93-96). As previously stated, these compounds
`are known to induce phase II enzymes including GST,
`NAD(P)H-dependent quinone reductase 1 (NQOl), and
`UDP-glucuronosyl transferase, in the liver and colonic
`mucosa of experimental animals (26, 28). A recent study
`revealed that garlic organosulfur compounds induce phase
`II detoxifying enzymes such as NQOl and heme
`oxygenase 1 (HO-1 ), through transcription factor Nrf2 and
`the antioxidant response element (ARE) (97).
`the major
`induction of apoptosis may be
`The
`contributing factor for the anti-tumorigenic properties of
`diallyl sulfide (98). S-Allylmercaptocysteine (SAMC) has
`been evaluated for its inhibitory effects on the proliferation
`and viability of two erythroleuk:emia cell lines, HEL and
`OCIM-1, two hormone-responsive breast and prostate
`cancer cell lines, MCF-7 and CRL-1740, and normal
`human umbilical vein endothelial cells (99). Although
`there were variations in sensitivity to this organosulfur
`compound in the different cell lines examined, the two
`hormone-responsive cancer cell lines of breast and prostate
`were clearly much more susceptible to the thioallyl
`compound. SAC and raw garlic also have been reported to
`reduce B(a)P-DNA adduct formation in stimulated human
`peripheral blood lymphocytes in vitro (100).
`COX-2, a major enzyme catalyzing the production of
`prostaglandins in response to inflammatory stimuli, has
`been recognized as a target of chemopreventive as well as
`anti-inflammatory agents. Extensive studies demonstrated
`that COX-2 is positively regulated by euk:aryotic nuclear
`transcription factor NF-KB. Natural compounds derived
`from spices that can inhibit NF-KB pathways include
`curcumin, gingerol, capsaicin, eugenol, gingerol, ursolic
`acid, and diallyl sulfide, etc (27, 76, 101-103).
`
`Anti-inflammatory properties of natural flavor sub-
`stances
`Inflammation is a necessary response of the host to
`counteract infectious agents and other foreign bodies
`(104). A number of mediators, including cytokines, ROS,
`and arachidonic acid metabolites produced by immune
`cells, play a key role in inflammatory responses. In chronic
`inflammation, cytokines induce the production of nitric
`oxide resulting in DNA damage and carcinogenic per-
`oxynitrite and nitrite production. Uncontrolled production of
`these mediators can exacerbate inflammatory responses (105).
`Salvia (Lamiaceae ), which comprises about 500 species,
`including sage, has been reported
`to possess anti-
`inflammatory activity (106). Ethanol extract of Salvia
`transsylvanica (Schur ex Griseb) significantly decreased
`the weight of edema induced by carrageenan in rat paw in
`a dose-dependent manner. Rosemary extract and compounds
`in rosemary, such as carnosol and ursolic acid, exhibited
`antiinflammatory effects on TPA-induced and arachidonic
`acid
`induced
`inflammation
`in mice (70). Carnosol
`inhibited nitrite formation induced by lipopoly-saccharide
`(LPS) and IFN-y in mouse peritoneal cells by more than
`50% (2.5-10 µM) (107).
`
`Oral administration of rosemary (Rosmarinus officinalis
`L.) prevents CCli-induced inflammation, necrosis, and
`vacuolation (108). It also enhances GST-dependent detoxifi-
`cation systems by increasing cytosolic GST activity and
`plasma GST activity in CCLi-induced acute liver in rat
`(108). Carnosol was recently reported to suppress iNOS
`through the down-regulation of NF-KB signaling pathways
`in mouse macrophage cells (109).
`Oral administration of curcumin from tumeric and
`capsaicin from red pepper is also known to inhibit paw
`inflammation in arthritic rats (110). The level of Gp A 72,
`which precedes the onset of paw inflammation in arthritic
`rats and persists in the chronic phase, was lowered by
`curcumin and capsaicin (88 and 73%, respectively). In
`addition, curcumin and capsaicin could control the release
`of inflammatory mediators such as eicosanoids and
`hydrolytic enzymes secreted by macrophages, and thereby
`(111 ). Curcumin
`exhibit anti-inflammatory properties
`suppresses ultraviolet B-irradiated COX-2 expression in
`human keratinocytes (HaCaT) by inhibiting the activation
`of the nuclear transcription factor AP-1, and mitogen-
`activated protein kinases (MAPKs) such as p38 and JNK
`(112). Curcumin reduces the respiratory burst of Chlamydia
`pneumoniae-primed THP-1 cells (113). It also inhibits the
`expression of cyclin D 1, which results in decreased cell
`growth (114). Topical application of curcumin significantly
`suppresses TPA-induced inflammation, hyperplasia, prolifera-
`tion, and papilloma formation in mouse skin (75, 78).
`ROS generated by activated macrophages play an
`important role in the initiation of inflammation. Capsaicin
`and curcumin at a concentration of 10 µM entirely
`inhibited ROS and nitrite radical production in vitro by
`activating rat peritoneal macrophages (110). Eugenol from
`clove and piperine from pepper required higher concen-
`trations (500 µM) to completely inhibit ROS release.
`Eugenol supplementation (0.17 wt%) lowers carrageenan-
`induced inflammation in rats (93). However, curcumin as a
`feed supplement does not affect inflammatory responses in
`rats but instead, due to its poor absorption, inhibits
`inflammation after parenteral application. According
`to
`Huang et al. (115), the topical application of commercial
`grade curcumin ( approximately 77% curcumin, 17%
`demethoxycurcumin, and 3% bisdemethoxy-curcumin)
`and
`pure
`curcumin,
`demethoxycurcumin
`and
`bisdemethoxy-curcumin has a similar potent inhibitory
`effect on TPA-induced inflammation of mouse ears, as
`well as TPA-induced transformation of cultured JB6 (P+)
`cells. Eugenol and thymol also display marked inhibitory
`activities against neutrophil chemotaxis (116).
`A terpene oxide, 1,8-cineole, possesses anti-inflammatory
`properties against paw edema induced by carrageenan and
`cotton pellet-induced granuloma (117). It is also known as
`eucalyptol or cajeputol, and is a major component of
`eucalyptus (up to 75%), rosemary (up to 40%), Psidium
`(40-60%), and many other essential oils. When tested on
`human blood monocytes in vitro, cineole was reported to
`inhibit cytokine production and arachidonic
`acid
`metabolism (118). Cineole also inhibits trinitrobenzene
`sulfonic acid (TNBS)-induced colitis in rats (119). Colonic
`damage is associated with an increase in myeloperoxidase
`activity and by a decrease
`in glutathione. It also
`significantly reduces the myeloperoxidase activity and
`
`Ex. 1186