The key phytochemistry of rosemary (Salvia rosmarinus) contributing to hair protection against UV

Extracts from rosemary (Salvia Rosmarinus) are analysed for their phytochemistry using LC-MS and the phytochemistry identified. The same extracts were tested for their efficacy to act as antioxidants by both hydrogen-atom transfer (ORAC) and single electron transfer (FRAP). A correlation analysis was performed to identify the key phytochemistry responsible for antioxidant efficacy. The top performing extracts were then tested in a peptide model and in hair with the presence of UV to measure ability to protect against UV-induced peptide and protein damage. Polyphenols (e.g. rosmarinic acid, glycosides of selgin) and abietane diterpenes (e.g. carnosic acid) in rosemary were identified as the principal compounds which enables the extracts to protect hair from UV.

OBJECTIVE

The objective of this work was to correlate the phytochemistry of rosemary (Salvia rosmarinus), a botanical with known antioxidant properties, to a UV protection benefit in hair. These data will give insights into mechanisms of UV damage, the ROS formed and their reactivity.

METHODS

LC-MS was used to compare the compounds in 10 commercial extracts of rosemary. ORAC (oxygen radical antioxidant capacity) and FRAP (ferric reducing antioxidant power) were used to measure the antioxidant capacity of the rosemary extracts. The ORAC assay measures ability of an antioxidant to react with a peroxyl radical via hydrogen atom extraction and FRAP measures electron transfer through reduction of ferric iron (Fe3+ ) to ferrous iron (Fe2+ ) by antioxidants present in the samples. Correlation of extract composition with antioxidant measures was performed using principal component analysis. Selected extracts were assessed for their ability to protect hair from UV damage in a model peptide system and on hair. In addition, the same methods were used to test rosmarinic acid and carnosic acid, key phytochemistries in the rosemary extracts. The model system was a peptide and its decomposition on exposure to UV was monitored by LC-MS in the absence and presence of the rosemary extracts. Hair degradation in the presence of UV was measured by exposure of UV in an Atlas weatherometer followed by extraction of degraded protein in water. A fragment of the S100A3 protein was used as a marker of UV damage (m/z = 1278) and quantified via LC-MS.

RESULTS

Ten rosemary extracts were assessed for antioxidant performance and correlated with their compositions. The phytochemistry in each extract varied widely with a total of 33 individual compounds identified. The differences were most likely driven by the solvent and extraction method used by the supplier with extracts varying in the proportion of polar or non-polar compounds. This did influence their reactivity in the ORAC and FRAP assays and their efficacy in preventing protein damage. Two of the key compounds identified were rosmarinic acid and carnosic acid, with rosmarinic acid dominating in extracts with mainly polar compounds and carnosic acid dominating in extracts with mainly nonpolar compounds. Extracts with higher rosmarinic acid correlated with ORAC and FRAP scores, with UV protection on hair and in the peptide model system. The extracts chosen for hair experiments showed hair protection. UV protection was also measured for rosmarinic and carnosic acid.

CONCLUSIONS

Despite the variation in the profile of phytochemistries in the 10 rosemary extracts, likely driven by the chosen extraction method, all rosemary extracts had antioxidant activity measured. This study suggests that the polyphenols (e.g. rosmarinic acid, glycosides of selgin) and abietane diterpenes (e.g. carnosic acid) are the principal compounds which enables the extracts to protect hair from UV.

Hair surface interactions against different chemical functional groups as a function of environment and hair condition

OBJECTIVE

The nature and magnitude of molecular interactions on hair surfaces underpin the design of formulated products, of which the application involves a competitive adsorption process between cationic surfactants, fatty alcohols and surface actives such as silicone. The knowledge of molecular interaction with hair surface will not only provide insight on the surface binding affinity but also offer an effective methodology in characterizing surface deposits.

METHODS

Untreated and chemically treated hair samples were treated with either conditioner chassis alone (gel network) or conditioner chassis plus silicone (chassis/TAS). Hair surface interactions against four different chemical functional groups, namely methyl (-CH3 ), acid (-COOH), amine (-NH2 ) and hydroxyl (-OH), were quantified in both ambient and aqueous environment using Chemical Force Microscopy, a method based on atomic force microscopy (AFM).

RESULTS

Surface adhesion on hair in ambient is dominated by capillary force that is determined by both the wettability of hair fibre (hydrophobic vs. hydrophilic), presence of any deposits and the chemical functionality of the AFM cantilever. Capillary force is diminished and replaced by electrostatic interaction when polar groups are present on both hair and AFM cantilever. A distinctively different force, hydrophobic interaction, plays a major role when virgin hair and hydrophobic functionalized AFM cantilever make contact in water.

CONCLUSION

Results acquired by AFM cantilevers of different functional groups show that hydrophobic interaction is a key driver for deposition on virgin hair, whilst electrostatic interaction is the most important one for bleached hair. Interfacial conformation of chassis components upon deposition is determined by the hair surface properties. Our study highlights the possibility of a range of polar groups, not necessarily negatively charged, on the damaged hair. Unlike conventional surface chemical analysis method, it is possible to quantitatively evaluate the interfacial conformation of deposited surface actives on hair, which identifies the target moieties for conditioning products on different types of hair.

UV and visible light exposure to hair leads to widespread changes in the hair lipidome

OBJECTIVE

Scalp hair is among the most exposed parts of the human body, yet the impact of visible and UV light on hair lipids, an important structural component of hair, is poorly researched. We have used lipidomics, a broad-based approach to measure lipids in samples, which has hitherto not been applied to UV-exposed hair in the published literature, and could allow for a wider understanding of how UV light impacts on specific hair lipids.

METHODS

Mixed blonde Caucasian hair switches were divided into two groups of five, with half of the hair switches exposed to UV and visible light mimicking normal daytime exposure and half left unexposed. LC-MS lipidomics was used to profile the lipids in the hair samples.

RESULTS

A total of 791 lipids and 32 lipid classes with tentative identifications were detected in the hair samples. Nineteen lipid classes and 397 lipids differed between UV-treated and non-treated hair. The main lipid classes that differed were vitamin A fatty acid esters, sterol esters, several ceramides, mono-, di- and triglycerides, phosphatidylethanolamines (all decreased in UV-exposed hair) and bismonoacylglycerolphosphates, acylcarnitines and acylglycines (all increased in UV-exposed hair). Most detected lipids were decreased in UV-exposed hair, supporting earlier work that has found that UV exposure causes oxidation of lipids which would result in a decrease in most lipid classes.

CONCLUSION

Light exposure to hair has a widespread impact on the hair lipidome. This study also adds to the emerging literature on the hair lipidome, broadening the range of lipid classes reported in hair.

Molecular interaction and partitioning in α-keratin using 1H NMR spin-lattice (T1) relaxation times

The interactions between small molecules and keratins are poorly understood. In this paper, a nuclear magnetic resonance method is presented to measure changes in the ¹H T₁ relaxation times of small molecules in human hair keratin to quantify their interaction with the fibre. Two populations of small-molecule compounds were identified with distinct relaxation times, demonstrating the partitioning of the compounds into different keratin environments. The changes in relaxation time for solvent in hair compared with bulk solvent were shown to be related to the molecular weight (MW) and the partition coefficient, LogP, of the solvent investigated. Compounds with low MWs and high hydrophilicities had greater reductions in their T₁ relaxation times and therefore experienced increased interactions with the hair fibre. The relative population sizes were also calculated. This is a significant step towards modelling the behaviour of small molecules in keratinous materials and other large insoluble fibrous proteins.

Redox proteomics analysis of hair shaft proteins upon hydrothermal and alkaline insult

OBJECTIVE

Human hair is regularly subjected to chemical and physical insults, such as heat, UV-irradiation and alkaline hair care products. These insults result in molecular modifications at the hair protein level that underpin mechanical and sensory property changes in the fibres. These changes can manifest itself in reduced hair quality and performance attributes observable to the consumer. In this work, changes in protein modification as a result of heat and alkaline treatments are determined.

METHODS

Redox proteomic profiling using high-resolution mass spectrometry was applied to map and evaluate amino acid residue modifications in human hair exposed to a combination of thermal treatments and alkali exposure with the aim to understand the underlying chemical processes.

RESULTS

Our results show that an increase in redox-related modifications is associated with exposure to higher levels of hydrothermal and alkaline insult. Post-translational modification profiling at the protein primary structural level delivered some further insights into the site-specificity of these modifications, with a clear increase in the number of cysteic acid modifications noticed in samples subjected to more extreme insults.

CONCLUSION

Pinpointing modification sides within proteins and the hair shaft proteome can be used as a basis for employing mitigation or repair strategies of hair protein damage caused by environmental or hair treatment-related insults.

Protection of hair from damage induced by ultraviolet irradiation using tea (Camellia sinensis) extracts

BACKGROUND

Damage to hair by UV is relevant to most people, and for many, it is a major source of hair damage. Prevention of UV damage is of high interest to cosmetic companies.

OBJECTIVES

Describe UV damage mechanisms and link these mechanisms to measurable changes in hair protein composition and color changes resulting from breakdown of yellow-colored kynurenines. Test the power of botanical antioxidants, specifically Camellia sinensis (tea) extracts to prevent this protein damage and color change. Link specific phytochemistry of extract samples to hair performance.

METHODS

Camellia sinensis (tea) extracts were analyzed by LC-MS to identify the key composition chemistries. ORAC (Oxygen Radical Antioxidant Capacity) was used to measure ability of the extract to react with a peroxyl radical via a hydrogen abstraction mechanism. Hair protein structural damage was measured by quantification of a biomarker peptide that is specific to UV-induced damage and hair color changes were measured with a spectrophotometer.

RESULTS

Levels of key phytochemistry in the extracts, specifically the catechins, correlated with prevention of UV-induced protein damage and prevention of color changes due to kynurenine breakdown. Extracts with higher phytochemistry levels also had higher ORAC scores indicating that they were more effective antioxidants.

CONCLUSIONS

Camellia sinensis (tea) extracts can be used as effective protective treatments for hair protection but this efficacy is linked to extract concentrations of key chemistries (catechins).

Role of Redox Metals in Color Formation in a Hair Colorant

The objective of this work was to identify if low levels of redox metals such as copper would accelerate color formation on hair and to understand the consequent impact on initial color formation and color fade. Kinetics of color formation with oxidative dyes in solution in the presence of varying concentrations of copper ions were assessed via imaging and color measurements. Color uptake on hair and color fade were measured with a spectrophotometer, and copper levels in hair were measured with inductively coupled plasma atomic spectroscopy after hair digestion. In this work, the role of redox metal ions such as copper and iron on accelerating rates of oxidative dye formation was demonstrated. Kinetics of dye formation were measured in solution for three dye couples-p-phenylene diamine (PPD) plus resorcinol, PPD plus 5-amino-2-methylphenol (AHT), and 4,5-diamino-1-(2-hydroxyethyl) pyrazole sulfate (HDAP) plus AHT- in a solution that also contained ammonium hydroxide and hydrogen peroxide at pH 10. Low levels of copper were added at a concentration range from 0.01 μg/g to 0.1 μg/g and the rate of color formation measured over 2 h. All th ree dye couples showed signifi cant color acceleration that increased with increasing levels of copper. A mechanism where initial oxidation of primary intermediate PPD or HDAP is accelerated is proposed. This mechanism is demonstrated to become important when trace levels of copper are in hair and a hair colorant added. Color formation is accelerated outside versus inside hair, and ultimately, color uptake is reduced after the colorant is rinsed off hair. Noticeable color fade versus the starting hair color is also increased. This work provides evidence for the role of copper ions in color formation in hair and strategies to reduce copper levels in hair using a chelant such as histidine in a shampoo or conditioner before coloring.

Nanoscale Mass Spectrometry Multimodal Imaging via Tip-Enhanced Photothermal Desorption

Materials ranging from adhesives, pharmaceuticals, lubricants, and personal care products are traditionally studied using macroscopic characterization techniques. However, their functionality is in reality defined by details of chemical organization on often noncrystalline matter with characteristic length scales on the order of microns to nanometers. Additionally, these materials are traditionally difficult to analyze using standard vacuum-based approaches that provide nanoscale chemical characterization due to their volatile and beam-sensitive nature. Therefore, approaches that operate under ambient conditions need to be developed that allow probing of nanoscale chemical phenomena and correlated functionality. Here, we demonstrate a tool for probing and visualizing local chemical environments and correlating them to material structure and functionality using advanced multimodal chemical imaging on a combined atomic force microscopy (AFM) and mass spectrometry (MS) system using tip-enhanced photothermal desorption with atmospheric pressure chemical ionization (APCI). We demonstrate enhanced performance metrics of the technique for correlated imaging and point sampling and illustrate the applicability for the analysis of trace chemicals on a human hair, additives in adhesives on paper, and pharmaceuticals samples notoriously difficult to analyze in a vacuum environment. Overall, this approach of correlating local chemical environments to structure and functionality is key to advancing research in many fields ranging from biology, to medicine, to material science.

UV damage to hair and the effect of antioxidants and metal chelators

OBJECTIVE

To study the effects of addition of a redox metal, copper, antioxidants and metal chelators on the formation of free radicals in natural white Caucasian hair subsequently exposed to UV light. Three different methods, electron paramagnetic resonance (EPR), a fluorescent probe for hydroxyl radical formation (terephthalate) and free radical photoyellowing, were used. These methods utilized different UV sources and reaction conditions, and so can give insights into the different mechanisms of action occurring during UV oxidation of hair. In addition, this study demonstrates how antioxidants and chelators can be screened to determine whether they can protect hair from UV damage.

RESULTS

The three methods gave somewhat different results, illustrating the importance of reaction conditions and wavelength on the photochemical mechanisms, and the efficacy of additives to influence these reactions. EPR results showed that N-acetylcysteine (NAC) pre-treatment eliminated the intensity of the signal because of sulphur and carbon free radicals in white hair both before and after exposure to UVB radiation. Doping the hair with copper ions had no effect on the intensity of the EPR signal under dry conditions. Terephthalate fluorescent probe data showed that under wet conditions, irradiation of white hair with UVA produced significant amounts of hydroxyl radicals. Pre-treatment of hair with NAC reduced the number of •OH radicals produced by natural white hair compared to an untreated control. In contrast to the EPR result, white hair doped with copper ions produced significantly higher levels of •OH radicals under wet conditions. It appears that the ability of copper ions to catalyse the photogeneration free radicals in hair is highly dependent on water content. Photoyellowing data showed a benefit for oxalic acid but no difference for NAC and an increase in yellowing for EDTA.

CONCLUSION

The micro-EPR and terephthalate fluorescent probe methods are both effective techniques to study production of free radicals by hair exposed to UV light under wet and dry conditions, respectively. Both assays are simple methods for determining the effectiveness of potential protective hair treatments against UV damage, but because they assess free radical damage under dry vs wet conditions, the chemistry created on UV exposure is different. This gives insights into mechanism of action, but results may not be consistent between the two methods for actives added for reduction of UV damage. NAC pre-treatment did reduce free radical generation in UV-exposed hair under both wet and dry conditions. Photoyellowing data are more complicated as it is a less direct measure of UV damage and is highly dependent on irradiation source. Using UVB irradiation is experimentally convenient but may not be appropriate, because UVB wavelengths comprise only 0.3% of terrestrial sunlight. The photochemistry of hair exposed to sunlight involves concurrent photobleaching and photoyellowing processes and is far more complex. Under UVB irradiation conditions, oxalic acid showed a yellowing benefit.

Anomalous Fluorescence of White Hair Compared to Other Unpigmented Keratin Fibres

OBJECTIVE

To demonstrate that the tryptophan (Trp) fluorescence of natural white hair is much weaker than other unpigmented keratin fibres such as wool, cashmere, rabbit hair and mink fur, and to explore possible reasons for this behaviour. The origin of the blue visible fluorescence (~450 nm) excited by UVA radiation in the range 360-380 nm, often associated with Trp degradation products, is also discussed and compared to other fibrous and globular proteins.

METHODS

As the fluorescence spectrum of keratin fibres usually contains at least two major features, a visual comparison is more effectively demonstrated by creating a 3D contour plot of excitation versus emission wavelength, which is sometimes referred to as an excitation emission matrix (EEM).

RESULTS

The Trp fluorescence from white hair is very much weaker than for wool, cashmere, rabbit hair and mink fur, but its visible fluorescence emission is stronger. Oxidation and reduction have little effect on the Trp intensity, which suggests quenching by cystine is not a major factor. Decuticulation of hair fibres had no effect on the Trp intensity showing that the increased number of cuticle scales surrounding the fibre cortex is not responsible. Trp fluorescence is very sensitive to exposure to UVB wavelengths, so possibly its low intensity in hair is due to greater levels of environmental exposure to sunlight than the other fibres examined.

CONCLUSION

Trp fluorescence from natural white hair is either extremely weak or completely absent, in contrast to the four other keratin fibres examined. It is possible that environmental exposure to UV wavelengths present in sunlight contributes to a reduction in the Trp fluorescence intensity of white hair. However another explanation is that Trp is quenched, by either an unknown substance introduced into hair during keratinisation, or as a result of regular exposure to personal care products, which may interact with Trp or tyrosine residues and disrupt the energy transfer process involved in keratin fluorescence. Further studies will be required to definitively determine the cause.

Effect of humidity on photoinduced radicals in human hair

EPR spectroscopy was used to monitor formation of free radicals in human hair upon UV irradiation. While the EPR spectra of brown hair were dominated by melanin signal, those of white hair were keratin-derived. The decay of UV induced keratin radicals was enhanced at increased ambient humidity. We argue that at higher humidity the swollen hair provides a more liquid-like environment, and higher molecular mobility in this environment leads to faster radical reactions. This interpretation is consistent with the increased UV-triggered protein damage in hair at high humidity as demonstrated by the protein loss, MALDI-TOF and FT-IR data.

Role of Internal Lipids in Hair Health

Saturated and unsaturated fatty acids make up 85% of the total hair lipid content and are found in the cuticle and cortical cell membrane complex. Although these lipids only make up 2-6% of the hair's overall weight, they play a crucial role in keeping hair healthy, influencing shine, feel, manageability, and strength. The objective of this work was to understand the mechanisms of how these lipids are lost on exposure to external stressors, such as chemical treatments, washing, and UV exposure and to understand how their loss impacts hair strength. The experimental approach was to measure these lipids and oxidation products, lipid peroxides (LPOs) and correlate their loss with fatigue strength measurements. The results show lipids are lost over time by washing, exposure to chemical treatments, such as coloring, and environmental insults, such as UV, and it was confirmed that a mechanism of degradation is via oxidation of unsaturated lipids to form LPOs. In addition, it was shown that replenishment of these lipids is possible by incorporating lipids, such as fatty alcohols (FaOHs), into a gel network with anionic surfactants to create a delivery system that can efficiently penetrate FaOHs into hair and increase internal strength as measured by fatigue.

Mechanistic insights into the bleaching of melanin by alkaline hydrogen peroxide

This work aims to determine the roles of reactive oxygen species HO∙ and HO₂^- in the bleaching of melanins by alkaline hydrogen peroxide. Experiments using melanosomes isolated from human hair indicated that the HO∙ radical generated in the outside solution does not contribute significantly to bleaching. However, studies using soluble Sepia melanin demonstrated that both HO₂^- and HO∙ will individually bleach melanin. Additionally, when both oxidants are present, bleaching is increased dramatically in both rate and extent. Careful experimental design enabled the separation of the roles and effects of these key reactive species, HO∙ and HO₂^-. Rationalisation of the results presented, and review of previous literature, allowed the postulation of a simplified general scheme whereby the strong oxidant HO∙ is able to pre-oxidise melanin units to o-quinones enabling more facile ring opening by the more nucleophilic HO₂^-. In this manner the efficiency of the roles of both species is maximised.

Preserving fibre health: reducing oxidative stress throughout the life of the hair fibre

Hair health is an important attribute to women globally--specifically attributes such as shine, healthy tips, frizz-free and strength. However, many women will claim to have at least moderate hair damage caused by habits and practices such as washing, combing and brushing, use of heated implements and regular use of chemical treatments. The objective of this work was to investigate two mechanisms of damage--hair colouring and UV exposure--where oxidative processes are involved. The role of copper in these oxidative processes was then investigated: its presence in hair and its consequent impact on hair damage via free radical formation. Finally, the role of chelants N,N'-ethylene diamine disuccinic acid (EDDS) and histidine in preventing free radical formation was investigated and shown to improve hair health.

Advanced hair damage model from ultra-violet radiation in the presence of copper

OBJECTIVE

Damage to hair from UV exposure has been well reported in the literature and is known to be a highly complex process involving initiation via absorption of UV light followed by formation and propagation of reactive oxygen species (ROS). The objective of this work was to understand these mechanisms, explain the role of copper in accelerating the formation of ROS and identify strategies to reduce the hair damage caused by these reactive species.

METHODS

The location of copper in hair was measured by Transmission electron microscopy-(TEM) X-ray energy dispersive spectroscopy (XEDS) and levels measured by ICP-OES. Protein changes were measured as total protein loss via the Lowry assay, and MALDI ToF was used to identify the biomarker protein fragments. TBARS assay was used to measure lipid peroxide formation. Sensory methods and dry combing friction were used to measure hair damage due to copper and UV exposure and to demonstrate the efficacy of N,N' ethylenediamine disuccinic acid (EDDS) and histidine chelants to reduce this damage.

RESULTS

In this work, a biomarker protein fragment formed during UV exposure is identified using mass spectrometry. This fragment originates from the calcium-binding protein S100A3. Also shown is the accelerated formation of this peptide fragment in hair containing low levels of copper absorbed from hair during washing with tap water containing copper ions. Transmission electron microscopy (TEM) X-ray energy dispersive spectroscopy (XEDS) studies indicate copper is located in the sulphur-poor endo-cuticle region, a region where the S100A3 protein is concentrated. A mechanism for formation of this peptide fragment is proposed in addition to the possible role of lipids in UV oxidation. A shampoo and conditioner containing chelants (EDDS in shampoo and histidine in conditioner) is shown to reduce copper uptake from tap water and reduce protein loss and formation of S100A3 protein fragment. In addition, the long-term consequences of UV oxidation and additional damage induced by copper are illustrated in a four-month wear study where hair was treated with a consumer relevant protocol of hair colouring treatments, UV exposure and regular shampoo and conditioning.

CONCLUSIONS

The role of copper in accelerating UV damage to hair has been demonstrated as well as the ability of chelants such as EDDS and histidine in shampoo and conditioner products to reduce this damage.

Role of copper in photochemical damage to hair

OBJECTIVE

The objective of this work was to identify whether low levels of redox metals such as copper will accelerate damage to hair on exposure to UV irradiation and whether this damage can be prevented.

METHODS

The methods used were proteomics to measure the protein damage via protein loss after different periods of exposure and mass spectroscopy methods to identify specific marker peptides that are specifically created by this type of damage.

RESULTS

In this work, we have developed new insights into the mechanism of UV damage using these proteomic methods. A marker fragment in the hair protein loss extract was identified (m/z = 1279) that is unique to UV exposure and increases with time of UV exposure. We have also identified for the first time in hair the role of exogenous copper in increasing UV damage both in terms of total protein degradation and also increased formation of the marker fragment and proposed a mechanism of action. It has been demonstrated that shampoo treatment containing a chelant such as N,N'-ethylenediamine disuccinic acid (EDDS) reduced copper accumulation in hair.

CONCLUSION

This work provides evidence for the role of copper in UV-induced damage to hair and strategies to reduce copper levels in hair using a chelant such as EDDS.

The uptake of water hardness metals by human hair

The objective of this work was to examine the variables that influence the interaction between water hardness metals and human hair. Hair extracts various constituents from the tap water used during daily hygiene practices and chemical treatments. Calcium and magnesium metal ions are the most prevalent and give water "hardness." Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was employed to quantify the metal content of hair, which was studied as a function of the following variables: hair condition (oxidative damage), level of water hardness, and water pH. We have demonstrated that these variables impact water hardness metal uptake to varying extents, and the effects are driven primarily by the binding capacity (available anionic sites) of the hair. The condition of the hair, a key representation of the binding capacity, was most influential. Interestingly, water hardness levels had only a small effect on uptake; hair became saturated with notable amounts of water hardness metals even after repeated exposure to soft water. Water pH influenced metal uptake since side chains of hair proteins deprotonate with increasing alkalinity. These insights highlight the importance to the hair care industry of understanding the interaction between water hardness metals and hair.

Quantitative detection of chemical compounds in human hair with coherent anti-Stokes Raman scattering microscopy

Coherent anti-Stokes Raman scattering (CARS) microscopy is used to determine the distribution and concentration of selected compounds in intact human hair. By generating images based on ratiometric CARS contrast, quantitative concentration maps of both water and externally applied d-glycine are produced in the cortex of human hair fibers. Both water and d-glycine are found to homogeneously distribute throughout the cortical regions of the hair. The ability to selectively detect molecular agents in hair fibers is of direct relevance to understanding the chemical and physical mechanisms that underlie the performance of hair-care products.

Copper and calcium uptake in colored hair

During hair coloring a number of disulfide bonds in cystine are oxidized (1) to create cysteic acid, forming binding sites for metal ions such as Ca(2+ )and Cu(2+ )from tap water (2). The increased uptake of these metals can have a detrimental impact on fiber properties-for example, reducing shine and causing a poor wet and dry feel (3). In addition, the increased uptake of copper can also contribute to further fiber damage during subsequent coloring due to its ability to take part in metal-induced radical chemistry (4). It is important to know where in the fibers these metals are located in order to either effectively remove these metals or control their chemistry. Nanoscale secondary ion mass spectrometry (NanoSIMS) has been used to locate the calcium and copper within hair that has been treated with a colorant and washed multiple times in tap water containing these ions. Untreated hair is used as a baseline standard material. Images with up to 50-nm spatial resolution of the preferential locations of calcium uptake were obtained, showing a high concentration of calcium in the cuticle region of colored hair, specifically in the sulfur-rich regions (A-layer and exocuticle).

High-pressure differential scanning calorimetry of colorant products

High-pressure differential scanning calorimetry (HPDSC) can be used to gain information on both the degree of crystallinity in the intermediate filaments (IFs) and the structural rigidity of the surrounding matrix or intermediate filament associated proteins (IFAP) of the hair cortex (1-3). We have used HPDSC to measure changes in the denaturation temperature (T(D)) and enthalpy (DeltaH(D)) of the crystalline components after multiple treatments with permanent hair colorant products. We have observed that after three repeat treatments both the denaturation enthalpy and peak temperature are significantly decreased vs the untreated starting substrate. However, on dialysis of the fibers in deionized water this decrease is shown to be completely reversible, returning the enthalpy and temperature to that of the untreated hair. It is proposed that the decrease is due to the incorporation of formulation components such as the alkalizer and surfactants etc. and metal ions such as calcium and magnesium from the tap wash water. These components are predicted to have a non-permanent effect on the salt bridges and hydrogen bonds and hence the rigidity or viscosity of the matrix. We have compared the denaturation temperature with the tensile properties of the fiber after treatment both before and after removal of actives from the fiber.

Hair coloring systems delivering color with reduced fiber damage

The possible metal-induced formation of free radical species such as the hydroxyl radical (HO*) during the use of permanent hair coloring products has been demonstrated. These highly reactive species are formed from the reaction of hydrogen peroxide with redox metals such as copper, which are thought to be absorbed by the hair from the from-the-tap wash water. Formation of such radical species has been shown to lead to measurable keratin fiber damage. The incorporation of chelants such as N,N'-ethylenediamine disuccinic acid (EDDS) has been demonstrated to prevent this metal-induced radical formation and thus significantly reduce the fiber damage. This chelant is highly effective due to its ability to specifically bind low levels of copper in the presence of relatively high levels of calcium, as is found in hair.

Investigations of cosmetic treatments on high-pressure differential scanning calorimetry

High Pressure Differential Scanning Calorimetry (HPDSC) can be used to gain information on both the degree of crystallinity in the intermediate filaments (IFs) and the structural rigidity of the surrounding matrix or intermediate filament associated proteins (IFAP) of the hair cortex. We have used HPDSC to measure changes in denaturation temperature (T(D)) and enthalpy (deltaH(D)) of the crystalline components after treatment with bleach products. Literature reports suggest that a decrease in peak denaturation temperature is indicative of permanent damage to the hair. However, changing the rigidity of the matrix surrounding the IFs, by temporarily changing electrostatic interactions, should also result in a similar decrease in peak temperature. The complex nature of bleach formulations including oxidants, alkalizers and salts suggests that several of the components could have a non-permanent affect on salt bridges and hydrogen bonds and hence rigidity or viscosity of the matrix. We have compared the denaturation temperature with levels of lightening (dL) and tensile properties of the fiber after treatment both before and after removal of actives from the fiber. It is evident that the HPDSC results are strongly influenced by formulation components and that these changes are reversible with extensive washing or dialysis. Combined with tensile data, it is proposed that a decrease in T(D) and deltaH(D) following treatment with bleach products can be due to both permanent and reversible changes to either the intermediate filaments or intermediate filament associated proteins of the hair fiber.

Collagen, collagenase and collagenolytic activity in rat Graafian follicles during follicular growth and ovulation

Follicles were dissected from the ovaries of immature rats at intervals after subcutaneous injection of 20 IU of pregnant mare's serum gonadotropin. A surge of luteinizing hormone was observed at 54 h and ovulation occurred at 64-66 h. The follicular volume between 36 and 48 h, then doubled again shortly before ovulation. The collagen content of the follicles increased 3-fold from 35 to 56 h, but decreased significantly (25%) from 61 to 66 h. Follicle homogenates, activated with trypsin or aminophenylmercuric acetate, digested Type I collagen at 28 degrees C to produce typical of a true collagenase. Collagenolytic activity assayed against endogenous collagen at 37 degrees C did not change significantly between 38 and 66 h.

In vitro conditions affecting the synthesis of sulfated proteoglycans by normal and rheumatoid synovial cells in culture

In vitro conditions affecting synthesis of sulfated proteoglycans by cell suspensions derived from monolayer cell cultures of normal and rheumatoid synovial tissue were examined. The capacity of cells to synthesize proteoglycans was estimated by the incorporation of 35S--sulfate into cetylpyridinium chloride--precipitable material. Synthesis of sulfated proteoglycans was maximal during log phase, and after 2--3 hours of recovery from disaggregation. Normal synovial cells appeared to be more sensitive to changes in serum concentration than were rheumatoid synovial cells, but rheumatoid synovial cells were more sensitive to changes in cell density. The proportion of newly synthesized extracellular proteoglycans increased with the duration of incubation in 35S--sulfate.

Costs of managing patients at a Canadian rheumatic disease unit

Financial and other costs of managing 194 inpatients and 433 outpatients referred to the rheumatology service of a Canadian general teaching hospital during 1978 were assessed. The tax financed institutional cost/outpatient visit was $102, compared to $112/inpatient day, which was 62% of the hospital's $180 cost/inpatient day. Hospital financial costs represent 78% of RDU outpatient costs and 85% of substantially lower than per diem rates. Our findings caution against relying solely on hospital data in assessing total economic costs of any diagnostic subset of patients.

Uridine diphosphate glucose dehydrogenase in rheumatoid synovial cells in culture

Extracts containing uridine diphosphate (UDP) glucose dehydrogenase (EC 1.1.1.22) activity were prepared from rheumatoid and from normal human synovial cell lines using previously standardized techniques. Although no significant differences in the enzyme from the 2 sources were detected with respect to activity, substrate affinities, or responses to temperature and pH, these determinations have demonstrated that the enzyme is very sensitive to alterations in these parameters. The ultimate activity of the enzyme in vivo will be dependent upon the extent of the increased temperature, acidity, and altered glucose metabolism in the rheumatoid joint.

Stimulation of phospholipid labeling and steroidogenesis by luteinizing hormone in isolated bovine luteal cells

The present study was conducted to examine the effect of LH on phospholipid metabolism in corpora luteal tissue. Collagenase-dispersed cells obtained from bovine corpora lutea of early pregnancy were incubated with 32PO4 in the presence or absence of LH and examined for their ability to incorporate this label into phospholipids. LH (1 microgram/ml) significantly increased 32P incorporation into total lipid extracts, with a time course similar to that of progesterone synthesis. This stimulation of 32P incorporation was dependent on the concentrations of LH, and this dose-response relationship correlated well with the dose response of LH-induced progesterone production. Bovine serum albumin and ACTH had no apparent effect on 32P incorporation into phospholipids or progesterone production. Separation of luteal cell phospholipid extracts by thin layer chromatography revealed that LH stimulated the incorporation 32PO4, mainly into phosphatidic acid and phosphatidylinositol, with small increases occurring in the polyphosphoinositide fraction. The LH-induced labeling of these individual phospholipids also appeared to be temporally and dose-related to the LH-induced increases in progesterone synthesis. LH had no effect on the labeling of phosphatidylcholine, phosphatidylserine, sphingomyelin, or cardiolipin. These results indicate that LH has selective effects on phospholipid metabolism in bovine luteal cells which may be a part of the mechanism of action of LH on steroidogenesis.

Effect of indomethacin on preovulatory changes in the ultrastructure of rabbit Graafian follicles

This investigation uses electron microscopy to examine the effect of prostaglandins on follicular tissue during the ovulatory process. The ultrastructure of follicles from indomethacin-treated rabbits was compared to the ultrastructure of normal ovulatory follicles in order to determine the morphological differences between follicles with negligible and normal prostaglandin synthesis, respectively. The most obvious difference between the two groups of follicles was that the tissue at the apex of normal follicles began to thin out significantly by 9 h post coitus (near the time of ovulation), whereas the follicles from indomethacin-treated animals showed no signs of thinning, even as late as 12 h post coitus. It appeared that the fibroblasts in the follicles with limited prostaglandin synthesis failed to undergo the normal ovulatory transformation from a quiescent to a proliferative state. Otherwise, the prostaglandin-deficient follicles had a number of morphological features similar to those which usually occur in ovulatory tissue. There was detectable loosening of the connective tissue elements and some indication of edema at the apex of the mature follicles. Also, granulocytes became localized in the vascular compartment of these follicles. In addition, there tended to be an increase in the multivesicular structures which protrude from the fibroblasts, as well as an increase in the dense granules which accumulate in the cytoplasm of the surface epithelial cells. Collectively, these data suggest that normal prostaglandin synthesis in ovulatory follicles may be important in the connective tissue decomposition and ultimate thinning of the follicle wall.

Stimulation of prostaglandin accumulation by luteinizing hormone-releasing hormone (LHRH) and LHRH analogs in rat granulosa cells in vitro

LHRH and LHRH agonists have been reported to exhibit somewhat paradoxical antireproductive effects. The current studies were undertaken to examine the actions of these substances on one parameter of ovarian function which is required for ovulation, i.e. prostaglandin production. Granulosa cells were obtained from immature rats 48 h after injection of 20 IU PMSG and incubated for up to 5 h in vitro. LHRH, [D-Ala6, des-Gly-NH2(10)]LHRH-ethylamide (Analog I) and [D-Leu6, des-Gly-NH2(10)]LHRH-ethylamide (Analog II) were observed to stimulate prostaglandin accumulation by granulosa cells. Analog I, for example, at 100 ng/ml increased PGE from 0.19 +/- 0.06 in the control to 7.7 +/- 2.01 ng/2 x 10(6) cells (n = 7; P less than 0.01) after 5 h. TRH, on the other hand, had no effect on prostaglandin accumulation. When added with LH or FSH, the stimulation by maximal concentrations of Analog I and the gonadotropins appeared additive. Although the stimulation of prostaglandin accumulation by LH appears to be mediated by cAMP, no effect of Analog I on the amount of cAMP could be detected. cAMP was determined in cells plus medium at times of 1.5 min to 5 h and at concentrations of 10-2000 ng/ml Analog I, but did not change from the control. LHRH and LHRH agonists, therefore, stimulate the accumulation of ovarian granulosa cell prostaglandins and do so in a manner apparently distinct from that of LH or FSH.

Correlation of cyclic AMP and cyclic GMP accumulation and steroidogenesis during stimulation of bovine luteal cells with luteinizing hormone

The relationship between LH-induced steroidogenesis and the production of cyclic AMP and cyclic GMP was studied as a function of LH dose and time in isolated luteal cells from pregnant cows. Submaximal steroidogenic concentrations of LH caused a transient but significant rise in cyclic AMP that peaked after incubation for 5 min. A consequent rise in progesterone occurred at 30 min even though cyclic AMP had returned to the basal level at that time. Higher steroidogenic doses of LH elicited a maximum increase of cyclic AMP at 5 min and this was sustained for up to 1 h; the related progesterone production was significantly raised at 15 min and reached a maximum plateau at 30 min. The corresponding levels of cyclic GMP did not appear to be altered by any of the LH concentrations used. The present study has provided direct evidence that even at very low doses of LH, cyclic AMP plays an intermediary role in the stimulation of steroidogenesis in a mixed population of cells isolated from the bovine corpus luteum. Cyclic GMP, on the other hand, did not appear to play a role in the action of LH on the same population of luteal cells.

Inhibition by estradiol of human chorionic gonadotropin-induced progesterone accumulation in isolated human luteal cells: lack of mediation by prostaglandin F

Estradiol has been previously reported to be a potent inhibitor of hCG-stimulated progesterone accumulation in isolated cells from human corpora lutea of the menstrual cycle. We assessed the role of prostaglandin (PG) in this in vitro estradiol-induced inhibition by measuring PGF and adding a blocker of PG synthesis (indomethacin) to the incubation medium. The inhibition by estradiol of hCG-stimulated progesterone accumulation occurred without any increase in PGF accumulation in the incubations. Furthermore, PGF accumulation was markedly reduced (P less than 0.05) at all concentrations of indomethacin testes (0.1, 1, and 10 microgram/ml), but the inhibitory effect of estradiol on hCG-stimulated progesterone accumulation was not prevented. These data suggest that the inhibitory effect of estradiol observed in vitro is not mediated by PGs.

Uridine diphosphate glucose dehydrogenase in normal human synovial cells in culture

Extracts containing uridine diphosphate (UDP) glucose dehydrogenase (EC 1.1.1.22) activity were prepared from 5 normal human synovial cell lines and sources of variation in the method determined. The mean catalytic activity of UDP-glucose dehydrogenase from the 5 extracts was 12.0 +/- 2.4 x 10(-3) International Units/mg protein. The KmUDP-glucose was estimated as 3.90 +/- 1.56 x 10(-5) M and the KmNAD+ was estimated as 1.72 +/- 0.60 x 10(-4) M. Maximum catalytic activity occurred in a temperature range of 55 degrees C-68 degrees C and in a pH range of 8.1-8.4. The mechanistic implications of these data in the normal human diarthrodial joint are discussed.

Synthesis of sulphated proteoglycans by rheumatoid and normal synovial tissue in culture

Synthesis of sulphated proteoglycans by cell lines derived from explants of 7 rheumatoid and 9 normal specimens of synovial tissue, as well as by 7 lines of skin fibroblasts from non-rheumatoid patients, was examined. Cells of all 3 types were cultured as monolayers. They were then disaggregated and their capacity to synthesise proteoglycan estimated in cell suspensions by the incorporation of [35S]-sulphate into CPC-precipitable material during 2 hours of incubation. Cell suspensions incorporated somewhat more [35S]-sulphate than corresponding duplicate monolayers. Synovial cells from rheumatoid patients incorporated 2 to 3 times as much [35S]-sulphate as synovial cells from normals. Skin fibroblasts, however, incorporated less [35S]-sulphate than rheumatoid or normal synovial cells up to the fifth passage. Thereafter their incorporation gradually increased to overtake that of synovial cells. About one-half to one-third of the total [35S]-sulphate labelled material was closely associated with cells from synovial tissues and fibroblasts respectively.

An ultraviolet spectrophotometric procedure for the routine determination of naproxen

1. A procedure for the routine assay of Naproxen in serum by ultraviolet spectrophotometry is presented. The absorption coefficient (A1 1% cm) of Naproxen in methanol at 261 nm was found to be 216. 2. The Naproxen procedure appears to be relatively free from interferences of commonly coadministered medications. Salicylate interference is eliminated by a modified procedure. 3. Concentrations of Naproxen in a limited number (40) of clinical samples ranged from non-detected to 12.5 mg/dl. The therapeutic concentration appears to be 4 to 6 mg/dl (174-260 mumol/L).

Inhibition of human chorionic gonadotropin-induced progesterone synthesis by estradiol in isolated human luteal cells

The purpose of this study was to determine whether estrogens exerted a direct inhibitory effect on progesterone synthesis in isolated human luteal cells in vitro. It was found that hCG stimulated progesterone synthesis by luteal cells, obtained from corpora lutea of the menstrual cycle, whereas cells isolated from corpora lutea of pregnancy were unresponsive to exogenous hCG. Estradiol markedly inhibited (P less than 0.001) this hCG effect in luteal cells of the menstrual cycle, and this inhibition was dose dependent. Estradiol did not block the stimulation of cAMP accumulated by hCG in the luteal cells of the cycle but did inhibit the stimulatory effect of dibutyryl cAMP on progesterone synthesis. These data suggest that estrogens may directly cause functional luteolysis in the human and that its site of action may be after the accumulation of cAMP.

Mechanism of luteinizing hormone regulation of prostaglandin synthesis in rat granulosa cells

The present study was undertaken to examine the mechanism by which luteinizing hormone (LH) stimulates prostaglandin (PG) synthesis in rat granulosa cells. Immature rats were injected with 20 IU of pregnant mare's serum gonadotropin and granulosa cells isolated 48 h later. LH (5 microgram/ml) stimulated PGE synthesis markedly over the control with no additions in 6-h incubations (1.98 +/- 0.24 and 0.24 +/- 0.05 ng/2 X 10(6) cells, respectively, n = 6). When arachidonic acid (100 microgram/ml) was included during the last hour of incubation, further increases to 15.4 +/- 2.9 and 2.48 +/- 0.48 ng of PGE/2 X 10(6) cells in LH and control incubations were observed. The cause of the increased response to a 1-h incubation with arachidonic acid in the LH-treated cells did not appear to be a stimulation of fatty acid uptake. In addition, when cellular lipids were labeled by a 2-h incubation with radioactive arachidonic acid, LH did not stimulate intra- or extracellular release of arachidonic acid. A 5-fold stimulation of prostaglandin synthetase activity, however, was observed in cells incubated with LH for 5 h. Our results, therefore, indicate that LH acts at a step in the prostaglandin pathway after hydrolysis of arachidonic acid esters and produces an increase in prostaglandin synthetase activity.

Estradiol inhibition of luteinizing hormone-stimulated progesterone synthesis in isolated bovine luteal cells

The effects of several steroid hormones on progesterone synthesis and cAMP accumulation in isolated bovine corpora luteal cells were investigated in an attempt to determine if any of the steroids would affect the basal level of these processes or their response to gonadotropin. Isolated bovine corpora luteal cells responded to LH with a significant (P less than 0.05) increase in progesterone synthesis and cAMP accumulation when incubated at 37 C for up to 1 h. Exogenous cAMP and analogs of cAMP also significantly stimulated steroidogenesis in these incubated cells. Stimulation of progesterone synthesis by 1 microgram/ml LH was significantly suppressed (P less than 0.05) in the presence of 5--10 microgram/ml estradiol. This inhibition appeared to be largely specific for 17beta-estradiol, in that other steroids such as estrone, estriol, 17alpha-estradiol, cortisol, and dihydrotestosterone were not inhibitory. Testosterone was found to be inhibitory, but it is uncertain if this effect was due to the androgen itself or to its conversion to estradiol. Estradiol did not affect the increase in endogenous cAMP caused by LH in these cells, but did inhibit the effect of exogenous dibutyryl cAMP on progesterone synthesis. The magnitude of this inhibition of the effect of dibutyryl cAMP was not, however, equal to the estradiol inhibition of the stimulation of progesterone synthesis by LH. These data indicate that estradiol, a possible physiological luteolytic agent, has a direct inhibitory action on the corpus luteum and produces its suppression by blocking the stimulatory effect of LH at a step after cAMP.

Localization and in vitro synthesis of prostaglandins in components of rabbit preovulatory graafian follicles

Graafian follicles obtained 9 hours after the injection of human chorionic gonadotropin (hCG) into mature rabbits were dissected into a follicular fluid component, a granulosa cell-oocyte component, and a residual wall component, (the latter containing mostly theca tissue with a small and variable amount of adhering granulosa cells). The amounts of PGE and PGF were determined for each component. The follicular fluid contained approximately 4-10 times more PGE and PGF than either the granulosa cell-oocyte component or the residual wall component. The latter two components contained approximately equal amounts of these prostaglandins. The in vitro biosynthesis of PGE and PGF was also studied and it was found that the granulosa cell-oocyte component had about 4 fold the capacity of the residual wall, and that the follicular fluid synthesized no prostaglandins. There was no significant effect of LH on either PGE or PGF synthesis in any of the components.

Stimulation of prostaglandin accumulation in preovulatory rat follicles by adenosine 3',5'-monophosphate

LH stimulates an increase in prostaglandins in vitro in preovulatory follicles from rats pretreated with PMS gonadotropin. The role of cAMP in this action of LH was examined by incubating preovulatory follicles with various substances and determining the resultant prostaglandin (PG) E accumulation by radioimmunoassay. LH (5 microgram/ml) increased PGE accumulation to approximately 4 times the control (181 +/- 23 to 886 +/- 83 pg/follicle). The addition of 20 mM cAMP also stimulated PGE accumulation, and the addition of 20 mM cAMP in the presence of 0.5 mM 1-methyl-3-isobutylxanthine was as effective as LH. Other nucleotides such as ATP, ADP, 3'-AMP, 5'-AMP, cGMP, and O2'-monobutyryl-cAMP did not stimulate PGE accumulation. On the other hand, (Bu)2cAMP, 8-bromo-cAMP, and N6-monobutyryl-cAMP produced an increase in PGE accumulation similar to that observed with LH. In addition, 10 microgram/ml cholera toxin was shown to increase both cAMP and PGE accumulation in preovulatory follicles. These results indicate that the prostaglandin response of follicles is specific for cAMP-like nucleotides or substances capable of increasing intracellular cAMP. The data support the concept that cAMP mediates the effect of LH on PGE accumulation in preovulatory follicles in the rat.