SUMMARY FOR PRESENTATION
A large number of herbs are used in perfumery, beauty and cosmetics since the ancient ages. The toiletries and their allied industries utilize herbs and their fragrant oil extractions in the manufacture of toothpastes, soaps, freshness sachets, face packs, lotions, hair oils and toilet papers. Herbs are essential ingredients in the manufacture of beauty care agents, moisturizers, infusions, skin toners, bathing oils, shampoos, eye lotions, hair conditioners, antiseptic and anti-tanning lotions and creams, cosmetic creams, blood purifiers and for the improvement of complexions.
Essential oils extracted from leaves, fruits or flowers of Camomile, Salvie, Timian and Rosmarin exhibit a wide range of bioactivities. Most of these extracts or their formulations such as creams lotions or herbal water interact with the intended surfaces through oral ingestion or topical applications. The degree of usefulness of these essential oils in meeting the cosmetic objective is largely dependent on the level of bioactive substances present in the extract. Apart from the direct effects of these herbs on the skin such as cleansing, soothing and softening of the skin, these oils also offer U-V radiation protection and aid in the treatment of a variety of dermatological conditions.
As cosmetology continues to scale new heights of innovation and effectiveness in achieving the beauty standards as prescribed by our generation, it should never be forgotten that health and beauty must be mutually co-existent. The finest and most expensive herbal cosmetics in the world cannot and will never succeed in disguising the effects of lack of exercise, lack of sleep, poor nutrition and too much stress. Owing to the interrelatedness of the application and practice of cosmetology with regard to the promotion of health, it is fundamental that extreme care be taken in the application of herbs in cosmetics so as to avoid the potential negative effects of inappropriate or overdose usage of herbs.
Introduction
The quest for and the desire for an aesthetic appearance and beauty have been with humanity as long as civilization has lasted. Just like philosophy where every new generation develops and espouses a novel arena of generative ideas constitutive of the philosophical epoch, the dynamic and intergenerational quest for aestheticity as cosmetology, trails mankind as civilization progresses from one era to another. At the basic, cosmetology is both an art and a science of beautifying of the skin, nails and hair. It is a study of cosmetics and their application.
Cosmetology is derived from the Greek word “cosmestikos”, a word descriptive of the art or science of being skilled in the use of cosmetics. The most common forms of cosmetology are haircutting and hairstyling. Archaeological studies reveal that as early as the glacial age hairstyling and haircutting was done using instruments like oyster shells, sharpened flints, and bones. To tie the hair or to serve as an additional adornment, strips of hide or animal sinew was used.
The first records of the extravagance of fashion can be traced to the Egyptians who were well versed with the art of hairstyling and makeup. Ancient records dating over 6000 years ago confirm that barbers were a necessity in the servicing of the nobility and priesthood. Ancient Egyptians were the first community to use cosmetics as a constituent of their personal beautification habits, in preparing the dead for burial and in religious ceremonies (Alpert et al 2002).
Some records opine that the use of cosmetics originated from China about 4000 years ago. In 3000 B.C, Emperor Shen Nung collected, collated and recorded information about a wide variety of herbs and their uses. In the second century A.D it is reported that a Greek physician; Galen carried out the first experimentation in the field of herbal cosmetics. Galen discovered that when you mixed vegetable oil with water and meted bees wax, the resultant cream could be used in the smoothening and soothing of the skin. The mixture not only achieved the softening of the skin but also made the skin supple. Galen christened his mixture, the “cold cream”(Bakhru 1995).
These same ancient records report that coloring matter made from minerals, insects, backs of trees, berries, leaves, nuts and herbs, were used on the skin hair and nails. Of these forms of cosmetics, the eye paint: henna was a dye extracted from the leaves of ornamental herbs. Henna was and is still used today in many cultures to impart a reddish stint on the nails or the hair.
As early as 1500 B.C, the use of henna had been popularized among the ancient Egyptian communities as a hair coloring agent. Archaeological findings from excavations of ancient tombs have revealed that even in these early ages’ relics such as mirrors, combs, razors that were made from tempered copper and bronze as well as cosmetics existed(Alpert et al 2002). These early attestations of the use of herbs in cosmetology not only confirm the natural dispositions that make the herbs wonderful for use in cosmetics but also serve to increase the variety of species that have currently been proved to be beneficial to the skin hair and nails.
In the modern world, cosmetology is a licensed profession at the state level. Practicing cosmetologists must thus be holders of a cosmetologist’s license. Even though cosmetologists operate in a practically non medical field they are by nature of their profession made to continually interact with those in the medical profession. Cosmetology is a health care discipline hence it must as well operate under a holistic approach. Current herbal cosmetics are products of the chemical manufacturing process.
As such they contain substances that may be deleterious to the body if used at levels or through routes that are not recommended. Cosmetology shares a commonality with medicine in that it is also a healing art. Through topical application of herb based creams and lotions, skin conditions can be treated. When used independently or in combination of essential oils, these cosmetics cleanse the skin and remove blemishes(Gambino 1992).
As aforementioned, modern cosmetology are both an art and a science. As a science it requires it decrees that cosmetologists must be in possession of knowledge and understanding of the principles of physical sciences. As an art, cosmetology must succeed in creating the perfect canvas to showcase the radiant glow of beauty.
Herbs in Cosmetics: Camomile, Salvie, Timian and Rosmarin
A large number of herbs have been used in perfumery, beauty and cosmetics since the ancient ages. The toiletries and their allied industries utilize herbs and spices as well as their fragrant oil extractions in the manufacture of toothpastes, soaps, freshness sachets, face packs, lotions, hair oils and toilet papers. Herbs are essential ingredients in the manufacture of beauty care agents, moisturizers, infusions, skin toners, bathing oils, shampoos, eye lotions, hair conditioners, antiseptic and anti-tanning lotions and creams, cosmetic creams, blood purifiers and for the improvement of complexions(Peter 2004). To fully understand the benefits of these herbs based on the specificity of the herbals species that form these essential ingredients of cosmetics, the paper offers a succinct analysis of four major herbs; Camomile, Salvie, Timian and Rosmarin.
Camomile/ Chamomile
The camomile, sometimes referred to as German chamomile, wild chamomile, pig heads matricaria, Hungarian chamomile, Flos chamomile vulgaris or blue chamomile belongs to the family Asteraceae(Compositae). In the genus Chamomilla, most common species, chamomilla recutia is widely distributed in vast waste lands in Europe especially Hungary and Croatia. Many plants are often referred to as chamomile or alternatively designated the common reference “camomile”.
The German chamomile(C. Recrutia) is the most common wild variety of the variety of species of plans referred to as camomile and distributed in North Africa, Europe and the temperate regions of Asia. Other wild varieties common in Europe are the foetid or stinking may weed(Athemis arvensis), Roman chamomile(C. recutita), yellow chamomile and the corn chamomile(Anthemis cotula).
The English herbals more frequently refer to the Roman chamomile also called Chamomaemelum nobile as the “chamomile”. However, with reference to cosmetic functions both the Roman chamomile and the Roman chamomile have similar uses.
Chamomile is chemically composed of about 0.24-1.9% essential oils, flavonoids, apigenin, apigetrin, apigenin-7-acetylglucoside, apiin, rutin, luteolin, quercimeritrin and isorhamnetin. Chamomile is also constitutive of cuemarins, proazulenes and plant acids. With regard to cosmetic purposes essential oils are the most useful components of chamomile extracts. Essential oils are produced when the yellow chamomile extracts produced by cold extraction is subjected to steam distillation procedures to yield a blue essential oil(Braun & Cohen 2007).
The blue essential oil is a derivative of matricin which is sometimes referred to as prochamazulene or proazulene and is the precursor of chamazulene. The proportion of chamazulene in the essential oil is largely dependent on chemeotype. Difference in chemotypes also determines the differences in the content of bisabolol oxide in the chamomile essential oils(Braun & Cohen 2007).
The two most widely used species of camomile in cosmetology are the German chamomile and the Roman chamomile. While it is possible to use the two interchangeably Roman chamomile produces a characteristic essential oil that is yellow in color. The plant is a perennial herb hence limiting its availability for cosmetic purposes.
On the other hand, the German chamomile is an annual shrub and this explains why it is the most common chamomile herb used for cosmetic purposes. Its essential oil is characteristically deep blue in color as a result of the presence of azulenes in its composition. Due to these differences in the content of azulenes in the Roman chamomile and the German chamomile, the deep blue essential oil is more preferable as it possesses more anti inflammatory properties necessary for its increased activity and compatibility with skin troubled skin conditions and sensitive skin.
In normal circumstances at the home environment, chamomile based creams or lotions can be made by simply purchasing beeswax from the local shopkeeper and mixing the two to desired proportion. However, care should be taken to ensure that the small dark materials characteristic of the dark spots in beeswax is removed by basic beeswax purification procedures.
Since cosmetology is also a health care discipline that operates in commonality with a holistic approach, it is prudent to briefly describe the antimicrobial properties of chamomile. In vitro studies have shown that chamomile possesses active substances that exhibit fungicidal and bactericidal activities against Gram positive bacteria like Staphylococcus aureas and Bacillus subtilis as well as the fungi Candida albicans when concentrations above 0.05%v/v are administered in the clinic.
In vitro studies no effect has been exhibited on Pseudomonas aeruginosa, Escherichia coli and Salmonella typhimurium. Topical applications of chamomile extracts have been demonstrated to have antimicrobial activity against Escherichia coli, Staphylococcus aureas and Staphylococcus mutans (Braun & Cohen 2007). Given that these are the most common commensal organisms on the skin, the use of chamomile for cosmetic purposes increases the additive effect in preventing diseases of bacterial and fungal aetiology.
Chamomile extracts decrease Ultra-Violet induced pigmentation and also hyperpigmentation that is usually found in people with lentigo senilis; commonly called aged liver spots. Hyperpigmentation is caused by Endothin-1 cytokine which stimulates melanocyte function hence leading to hyperpigmentation. Chamomile interrupts the endothin-1 induced signaling of melanocyte function hence leading to the reduction of the ability of melanocyte proliferation and the consequent synthesis of melanin.
Chamomile is ideal for all complexion types inclusive of sensitive, puffy and inflamed conditions. In current clinical practice, chamomile is administered orally in a concentrated extract form so as to produce stronger therapeutic effects. For a variety of dermatological conditions, chamomile is used as topical applications. Kamillosan is the most widely known form of commercial chamomile preparation that is used in the treatment of dermatological conditions. The variety of skin conditions that are can be treated or managed with chamomile topical applications such as creams or lotions include wound, eczema, and dermatitis. For patients with breast cancer, chamomile cream can be used to protect patients against skin radiation damage.
Just like any substance that is used for either cosmetic or medicinal purposes, chamomile use may present with cases of allergic skin reactions, especially when such applications are based on extracts from Chamomilla recutita or Anthemis(Braun & Cohen 2007). Chamomile is also contraindicated in hypersensitivity or in cases where there are historical accounts of allergy to chamomile.
Therefore, in cases of allergic reactions it should be noted that either the cosmetic cream or lotion is adulterated with other species like Chamomilla recutita or Anthemis or the individual is allergic to the active components of chamomile. Thus for cosmetology, the German chamomile is the best option as it exhibits comparatively higher beautifying effects and therapeutic effects with respect to the other camomiles. It is also a very safe herb as there are no reports of negative effects after use.
Salvia/Salvie/Sage
Salvia is a genus in the family, Laminaceae. Salvia is one of the three genera that constitute what is commonly called sage. The term sage usually refers to Salvia officialis. Salvia is composed of ornamental species that sum up to approximately seven hundred to nine hundred plant species of herbaceous, shrubs, perennials and annuals. Due to the existence of many species under the genus, Salvia, these plants have an almost global distribution. However, they are more diversely distributed in South Western Asia and Central Western Asia. This region has been cited as the probable origin of the genus Salvia. More than five hundred species are found in South America, Central America and Mexico(Kintzios 2000).
The Salvia genera can be descriptively be said to be composed of plants that are either perennial, annual or biennial and may also contain woody based sub shrubs, penicles and racemes. These plants have flower colors that range from blue to red or while and yellow. The latter two are less common. Their calyx is characteristically tubular and bell shaped but the bearded throats are absent. The corollas are claw shaped while the stamens normally reduced to two structures having anthers that are two celled. Their fruits are smooth nutlets and a large number of species in this genera have a mucilaginous coating.
There about five species that are commonly used for various cosmetic and therapeutic purposes. They include Salvia officialis which is widely used as a herbal medicine as well as in cooking. Several studies have also demonstrated that this species could be important in the treatment of Alzheimer’s disease. Salvia miltiorrhiza, sometimes called the Red sage has been used for centuries as traditional Chinese medicine. Salvia splendens or the Scarlet sage is a pot plant or an ornamental bedding. Te white sage or the Salvia apiana is utilized as smudge sticks among many Native Americans while the species the Diviners sage or Salvia divinorum is a poplar hallucinogenic agent that is classified as an illegal drug in the United States.
Salvia officialis has anhidrotic, antifungal, antibiotic, astringent, estrogenic, antiplasmodic, hyperglyceamic and tonic activity. The strongest bioactive constituents are found in its essential oils which is composed of borneol, cineole and thujone. Leaf extracts contain tannic acid, ursonic acid, oleic acid, cornsole, cornsolic acid, chlorgenic acid, fumaric acid, caffeinic acide, falavones, falvonoid glycosides, niacin, nicotinamide and estrogenic substances(Kintzios 2000).
The diversity of the constituents of the leaf extracts give Salvia officialis its wide berth of activity in cosmetology as well as medicine. Salvia apiana is native to the South Western United States and the North Western Mexico. The Leaves of the White sage can be crushed and mixed with water to produce a hair dye, straightener or a hair shampoo. Medically, it is also used as tea to decrease salivation, sweating and mucus secretions to the throat, sinuses and lungs.
In cosmetology sage is used in skin care. For individuals with large pores, sage benefits as an infusion or as a compress. It can also be used as a face pack. Sage based creams have wide usage in the treatment of cold sores adjacent to the mouth. In Michigan, where Salvia apiana is native Black adults crush fresh leaves and use the resultant past to get rid of warts in the arms, hands, neck, throat and on the face. A herbal wash of the same leaves offer relief from bumps, wounds, sores, cuts and a multitude of other skin injuries. Both Sage and Rosemary are considered “soul cosmetics” among Black Americans resident in the Southern States.
The variety of bioactive constituents confer the exhibition of antifungal activity by sage extracts. When mixed with water, the mixture can be used for bathing and washing to treat dermatological conditions. When these therapeutic properties are coupled to other external properties that advance skin objectives like antirheumatic in baths, antiseptic, and tonic effects, then it becomes simple to understand the connection and interrelatedness of the field and application of cosmetology and medical practice. Sound skin health and the quest for beauty must go hand in hand.
Sage is also used in darkening and toning of hair. For this cosmetic procedure, an infusion of the fresh Salvia leaves or the tops are used. When sage is applied on the scalp, hair darkening is achieved. An additive effect is in cases of allopecia where application of sage extracts on the scalp has the capability of reducing hair loss. As a good hair tonic and hair lotion it is rubbed on the scalp on a daily basis to ensure the growth and maintenance of healthy shining hair(Kintzios 2000). it can also be taken in small doses as an anti-inflammatory.
Products of Salvia in the market such as Salvia(Clary sage) water have been praised for gently cleansing, moisturizing and calming the skin. The tannins in the product re-stabilize and improve hair condition. These products are recommended for irritating and puffy skins where they are used as lotions to improve the general condition of the upper levels of skin so as to promote friction in oily hair. For best results, Salvia lotions and creams as well as Salvia water are applied by damp compression for a period of between ten to fifteen minutes in the mornings and the evenings using a cotton wool.
Plant Salvia Hot Oil & Hair Care Shampoo is a natural formulation for normal hair and oily hair. These combinations provide an effective action against oily hair due owing to their antiseptic properties. When combined with the extracts of Olive and Lavender, they promote deep and thorough cleansing of hair while aiding in the removal of the oiliness. Apart from Salvia water and the air oils there are several other cosmetics and personal care products formulated with constituents derived from Salvia officialis. They range from bath products, shampoos, fragrance products, shaving creams and cleansing products.
Timian/ Thyme
This is a commonly known shrub. The common usage of the word Thyme/ Timian is in reference to all plant species under the genus, Thymus. In this genus the most common species is the Thymus vulgaris. There are historical records showing that the Ancient Egyptians used thyme for embalming since they believed that thyme was a source of courage.
As a consequence of Roman conquests, the plant spread to Europe where it gained popular usage in purifying rooms and to confer aromatic flavor to liqueurs and cheese. During the middler ages in Europe, the plant was used in wadding off nightmares during sleep by putting it under the pillow. During hospitals, thyme was placed on coffins to assure the dead of a safe and courageous passage to the next life. In modern times, thyme is cultivated for the exploitation of its strong flavor which is derived from the high content of thymol. Since aestheticity is but a fraction of cosmetology, thymus has for centuries been used to create an aesthetic feeling particularly inside the house.
As mentioned in the preceding paragraph, the major constituent of the essential oil of thymus is the thymol(it makes up between 20-54% of the essential oil extract). Thymol is an antiseptic and it has been commercially exploited in the manufacture of Listerine mouthwash. The same antibiotic activity was exploited in the medication of bandages just before the advent of modern forms of antibiotics. As an antifungal, thymus extracts are applied on the nails as a shiner(cosmetic purpose) and to eradicate fungus(medicinal purpose).
The most important species of thyme include Thymus vulgaris or Garden Thyme which is basically a culinary herb but it can also be used for medicinal purposes, Thymus herba-barona also known as the Caraway Thyme is used as a ground cover and a culinary herb. Thymus herba-barona has a strong caraway scent due to high content of carvone. Thymus pseudolanuginosus or Woolly Thyme is commonly grown for the purposes of ground cover. Thymus zigis is the main source of thyme essential oils.
On a wider scale, the commercial products that are manufactured from ingredients extracted from the genus Thymus include essential oils, landscape plants, fresh and dried herbs. The Genus is estimated to be composed of approximately 350 species. However, only the common species listed above are of economic importance.
In the early years of the 20th century thymus essential oils mainly originated from plants cultivated from Germany or from wild plants which could be collected from the mountains of Southern France but as it became more and more inviable to cultivate and distill thyme from cultivated sources. As a consequence, harvesting of wild plants(especially T. zigis and T. vulgaris) became popular in France then in Spain. Extracts from these harvests are distilled to produce either red or white thyme oil.
With the production of thyme oil from Spain stabilized at between 1-3 tonnes annually coupled to the synthetic production of thyme oil other uses which had hitherto been deemed as miscellaneous uses are rapidly expanding. Natural cosmetics or rather phyto-cosmetics is a rapidly growing niche market for thyme oil in North America and Europe.
Even though these products were initially concentrated in health food stores owing to their wide culinary potentials, they are currently getting their way into wider distribution channels such as boutiques, departmental stores, discount stores and salons. Thyme oil are now even being sold over the Internet for cosmetic purposes(Lawrence & Tucker). These novel products which are basically thyme essential oils are purported to possess the same efficacy as the active bioactive components found within them.
Currently there are a wide range of thyme oil products that promote the potentials of thyme essential oils to tone the skin, act as a great antioxidant while at the same time provide the skin with better astringent qualities. As a powerful antiviral and anti fungal agent it protects the skin from viral and fungal infections thus keeping the skin in a tip-top condition.
Face wash gels containing arnica and thyme extracts have been launched in the market as a creation for individuals with skins prone to stress and unfavorable atmospheric conditions such aw smoke rooms, air conditioned rooms, urban environment as well as the frequent exposure to cold and wind. These products cleanse and moisturize the skin without interfering with the skins protective barrier. Just as it soothes the impacts of using chlorinated water, this combination also assures a feeling of relaxation.
Rosmarin/ Rosemary
Rosmarin or Rosemary(Rosmarinus officinalis) can be described as a woody perennial herb having fragrant evergreen needle like leaves. This species has its origins in the Mediterranean region and just like Salvia, it is also a member of the mint family called Lamiaceae. The name Rosemary is derived from the Latin word rosmarinus.
Rosmarinus is derived from ros meaning dew and marinus meaning sea hence dew of the sea. The name is descriptive as the plant frequently grows near the sea. Descriptively the forms of Rosemary range from upright forms which can reach a height ranging from 1.5-2 meters. Rosemary can also be found as trailing. The leaves are evergreen and have woolly hair. Their flower which change with the seasons range from white, pink, purple and blue(Sasikumar 2004).
Due to its attractiveness and tolerance to dry conditions, it is mainly used in landscaping with particular successes in geographical locations with a Mediterranean climate. Additionally, it is pest resistant and can be pruned into desirable shapes hence its popularity in topiary. In cases where it is grown in pots, it has to be routinely pruned to prevent in from becoming shaggy and unsightly. Though it can also be left to grow big and still be attractive.
The most common usage of Rosemary is in culinary where the fresh or the dried leaves are used in Mediterranean cuisine. Their bitter astringent taste complements with a wide variety of foods. When burned they give a distinct mustard smell that can be used in flavoring during barbecuing. The high concentration of calcium, iron and Vitamin B6 increases their desirability as traditional cuisine.
Rosemary oil is chemically composed of camphor, 1,8-cineol, bornyl acetate, alpha-pinene, beta-pinene, camphene, linalool, myrcene, subinene, limonene, copalene, terpinolene, thymol, methylchavicol and caryophyllene. These active substances found in oil extracted from flowering tops and leaves account for the cosmetic potentialities of the Rosemary plant(Sasikumar 2004).
On the cosmetic and aromatherapy front, essential oils of Rosemary are increasingly becoming extremely important. Several cosmetologists have reported that when a massage cocktail of essential oils derived from thyme, rosemary, cedar wood and lavender is used for massaging scalp patients with Alopecia areata for a period of seven months progress in treatment can be attained.
Rosemary oil functions in stimulating the hair follicles and the circulation efficiency in the scalp hence helping in cases of premature baldness. With regard to cosmetics, rosemary oil is used in promoting hair growth, controlling dandruff and also controlling greasy hair. It can also be used as a shampoo and it also achieves darkening of hair. As a flower distillate in water, it can be used as a soothing eye lotion(Sasikumar 2004).
To maintain the integrity of the skin, rosemary is active in the treatment of acne. Rosemary has gained a wide usage as a major component of room fresheners, soaps, perfumes, skin lotions and deodorants. In such cases it is either existent in the formulation in combination with other cosmetic herbs or it may exist singly. The calyx from the flowers are used in tussie-mussies, in potpouri and as herb pillows(Sasikumar 2004).
For those prone to epileptic seizures care should be taken when administering Rosemary either in culinary or therapeutic uses as the essential oils have strong epileptogenic properties. These essential oils should never be ingested since they are potentially toxic. Large amounts of cosmetic purposes can cause adverse reactions like spasm, vomiting, pulmonary edema or coma. Pregnant mother are advised to desist from the consumption of large quantities of Rosemary because potential negative side impacts to the unborn. Owing to these risks, dosages of Rosemary should be limited whether for culinary, therapeutic of cosmetic purposes.
To understand just how much these plants have been exploited for their cosmetic potentials one only needs to Google “Rosemary” and a whole lot of product choices are run before the eyes. For example Alen Mak’s Rose Mary Cosmetic Line showcases the latest developments in herbal cosmetology where researchers, cosmetologists and manufacturers have teamed up to use the wisdom of traditional medicine in creating formulations of herbs, fruits, healing natural concentrates, vitamins and minerals. These mixtures are skillfully blended to satisfy consumer satisfaction, inspire self confidence and promote health(http://www.alenmak.com/rosemary.phtml).
A case in point is the cosmetic series Rose Mary which consists of products that are especially blended for dry, sensitive and delicate skin. With no additional fragrance added to the natural fragrance of Rosemary, the cosmetic line is a testament of the changing patterns in herbal cosmetology.
Conclusion
As cosmetology continues to scale new heights of innovation and effectiveness in achieving the beauty standards as prescribed by our generation, it should never be forgotten that health and beauty must be mutually co-existent. The finest and most expensive herbal cosmetics in the world cannot and will never succeed in disguising the effects of lack of exercise, lack of sleep, poor nutrition and too much stress. Ideally, beauty comes from within ourselves, the external appearance that cosmetics serve should thus be exploited only for an additive effect on the overall beauty. That is when reflections of a clear skin, glossy hair, sparkling eyes and a trim body can truly attest to the far reaching influence of herbal cosmetology.
References
- Alpert, A., Altenburg, M., Bailey, D., Barnes, L., Beatty, D., Bruneti, M., Halal, J., Crawford, J., Evirs, A., Frangie, M. Catherine., Milady. (2002). Milady’s Standard Cosmetology: Cosmetology. Cengage Learning. p. 6-15
- Braun, L., & Cohen, M. (2007). Herbs & Natural Supplements: An Evidence-Based Guide. Elsevier Australia. p. 215-217
- Bakhru, H. K. (1995). Handbook of Natural Beauty. Jaico Publishing House. p. 123-130
- Gambino, J. H. (1992). Modern Esthetics: A Scientific Source for Estheticians. Cengage Learning. p. 4-7
- Kintzios, E. S. (2000). Sage: The Genus Salvia. CRC Press. p. 1-20
- Peter, K. V. (2004). Handbook of herbs and spices. Woodhead Publishing. p. 4
- Lawrence, M. B., & Tucker, O. A. (2002). The Genus Thymus as a Source of Commercial Products. In, Thyme: The Genus Thymus, Elisabeth Stahl-Biskup, Francisco Sáez. CRC Press. p. 247-255
- Sasikumar, B. (2004). Rosemary. In, Handbook of herbs and spices, K. V. Peter, Knovel (Firm). Edition: 2, Woodhead Publishing. p. 243-260
