BACKGROUND

Comedogenicity is the potential to promote follicular blockage leading to the formation of microcomedones and cosmetic acne. Mills and Kligman compared the established rabbit ear assay (REA) ratings with studies in human participants using the skin surface biopsy. They concluded that some materials considered comedogenic on REA were non-comedogenic in human skin.

Using a modification of the Mills and Kligman skin surface biopsy, this study aimed to determine the comedogenic potential of ten commonly used cosmetic oils: almond oil, argan oil, avocado oil, castor oil, coconut oil, grape seed oil, mineral oil, olive oil, safflower oil, and sunflower oil.

Each participant received a test patch with twelve chambers on the skin of the back, with each chamber containing filter paper saturated with each of the respective oils, the positive control (octyl palmitate), and the negative control (unsaturated filter paper). These patches were changed 3 times weekly for 4 weeks. Cyanoacrylate skin surface biopsies were done to determine the number of follicles and microcomedones at baseline and after 4 weeks of exposure.

Thirty individuals were enrolled in the study. All participants underwent baseline and final skin surface biopsies. Almond oil showed a significant increase with a 112.9% increase in the number of comedones from baseline.

The results of this study show that certain oils commonly used as ingredients in cosmetic products, such as almond oil, are comedogenic.

Desmos chinensis is a climber tree. Branches brown pubescent, leaves glaucous underneath, petals yellow. This tree distributes in many provinces of Viet Nam, mostly in Yen Bai, Ha Giang, Thai Nguyen, Bac Giang, Vinh Phuc, Quang Ninh, Hoa Binh, Ninh Binh, Quang Binh, Ha Tinh, Thua Thien Hue, Kontum, Dong Nai. The oil yield was 0.2% from air-dried flowers. The essential oil of Desmos chinensis was analysed using GS and RMN. 13 constituents have been identified, including beta-caryophyllene (28.9%), bicyclogermacren (11.5%), alpha-humullene (7.2%), D-germacren (7.2%), beta-elemene (6.4%)
chemistry ; Flowers ; Oils ; Oils, Volatile

Chemical components of essential oil of rhizoma (Alpinia pinnanensis T. L. Wu & Senjen) were analysed by capillary GC and GC/MS methods. Antimicrobiological activities were tested. Results showed principal components of essential oil are sesquitecpenoid and their derivatives (nearly 70%). The antibacteria spectrums of essential oil were broad, especially it has strong activities for negative gram bacteria, E. coli and S. aureus
Oils, Volatile ; Chemistry ; Oils ; Medicine, Traditional

Chemical components of essential oil of Piper nigrum L. and essential oil of Piper betle L. were identified by GC/MS method. The main constituents in essential oil of Piper nigrum L. are D-limonene, alpha-pinene, beta-pinene and D3-carene. The main components of essential oil of Piper betle L. are eugenyl acetate or isoeugenyl acetate, alylpyrocatechol diacetate, eugenol or isoeugenol, caryophylen
Oils, Volatile ; Chemistry ; Oils ; Medicine, Traditional

This paper presented a study on the dynamic of essential oil accumulation in Japanese mint SK33 (M. arrvensis L.) and the influence of storage time on its quantity and quality. This mint was cultivated at Co Nhue experimental station, Tu Liem district, Ha Noi City between 2000 and 2002. The results showed that during the vegetation and development process, the essential oil content in the plant gradually increased and achieved maximum at first branch flowering stage and reduced to minimum at the end of flowering stage. The menthol content in essential oil of Japanese mint SK33 reached the highest value at full flowering stage (81.79%). The best harvest time for this mint is from the beginning flowering stage to full flowering period. After harvesting the whole plants can be stored during 20 days without the change in content and quality of essential oil
oils ; Conservation of Natural Resources ; Oils, Volatile

Materials and methods: Wild growing Adenosma caeruleum R.Br. (Scrophulariaceae) was collected at Dak Mil district (Dak Lak province) in July 2002 for oil preparation. The oil analysis was carried out by a combination of capillary gas chromatography and mass spectrometry. Results: The essential oil was obtained from the aerial part of the plant at the yield of 0.5% compared with dried materials. 38 chemical compounds were identified. The major components were thymol (24.67%), alpha-humulene (16.44%), thymyl methylether (12.59%), gamma-terpinene (12.26%), beta-caryophyllene (5.82%), beta-bisabolene (5.67%), p-cymene (4.58%), humulene oxide (3.59%) and caryophyllene oxide (2.76%).
Scrophulariaceae ; Oils ; Oils, Volatile ; Plants ; Medicine, Traditional

Limnophyla rugosa is an erect-semi aquatic, fragrant, annual herb, up to 50 cm tall. Stem simple or branch, glabrous to hirsute, rooting from the lower nodes, leaves decussate, ovate-lanceolate to oval elliptical 2-8cmx1-5 cm, flowers solitary in axillary; sometimes in axillary pendunculate clusters with up to 7 sessile. Limnophyla rogusa occurs in moist along treams,pools and rice field from sea-level up to 1500 m attitude. Yield of essential oil from aerial parts of Limnophyla rogusa was 0.18 percent by air-dry material, 23 constituents of the essential oil were identified by GC/MS. Major constituent of essential oil was anethol (89.4%)
Oils, Volatile ; oils ; Chemistry ; Plants ; Medicine, Traditional

In Vietnam and Bulgaria, accumulation of essential oils of Artemisia annua L. depending on the period of it's growth, was investigated. The content change of compound is significant with 3 phases: Phase 1 - From tree began growth to first 6 months, phase 2 - from second month to fourth month, phase 3 - from fifth month to sixth month (the tree is in flower). Concentration of artemisia annua L. is highest at phase 3 when the tree is in flower
Oils, Volatile ; Artemisia ; plants

Mentha piperita L.Mentha piperita L. was collected from Sapa, Lao Cai province and cultivated at Co Nhue – Tu Liem – Ha Noi. The content of the essential oil in fresh branches of this peppermint was about 0.16%. Its green yield is 1.85-2.10 Kg/m2. First time in Vietnam, the chemical composition of peppermint oil was analyzed by GC/MS and 43 constituents were identified. The main constituents were L-menthol (47.60%), menthol (24.10%), menthofuran (6.07%) and 1.8 cineol (5.55%), pulegone (4.22%). Base on these data. The quality of Sa Pa peppermint oil is good as one from native origin. Peppermint collected from Sa Pa enrich the gene source of medicinal plant in general and particularly the gene source of essential oil plant group of Vietnam
Oils, Volatile ; Chemistry ; Plants

The material is seeds of Delavaya toxocarpa French harvested in Cao Bang province in 1999, 2000 and 2001. Fatty oil was quantified by weighing method. The indices of fatty oil were identified in relation to Vietnamese Pharmacopoeia. The fatty acid ingredients were analysed by gas chromatography (GC). The results showed that the fatty oil content in Delavaya toxocarpa French seeds was high (39.63+/-0.836), acidic index was 37.651+/-0.836, iodine index was 69.615+/-1.076, soap index was 180.762+/-3.382. The fatty oil included palmitic, oleic, linoleic, stearic, gadoleic and arachidic acids. Among these, oleic and gadoleic acids had the highest content
Oils ; Seeds ; Pharmacopoeias