Effect of a peptide in cosmetic formulations for hair volume control

OBJECTIVE

The capacity of hair to absorb water causes changes in its physical and cosmetic properties under different environmental conditions. Hence, the control of hair volume in variable relative humidity settings is an important topic in cosmetics. The behaviour of two types of hair, Caucasian and Asian, was studied regarding their volume change in different relative humidity conditions. The ability of a peptide as a hair volume treatment was evaluated in two climate control formulations.

METHODS

Tresses of the two types of hair were tested in two relative humidity (RH) conditions: (A) variable relative humidity (2 h 40% RH, followed by 2 h 90% RH and 2 h of 40% RH), and (B) continuous high relative humidity (90% RH for 6 h). Changes in the hair tress volume were assessed throughout time. Hair treated with two climate control formulations, with and without a peptide (KP peptide), were tested under the two relative humidity conditions.

RESULTS

Caucasian hair had a higher change in volume compared to the Asian hair in variable and high relative humidity conditions. The hair volume increase when subject to high air humidity, and it was lower with the incorporation of a peptide into climate control formulations.

CONCLUSION

Caucasian hair showed higher volume than Asian hair when submitted to both relative humidity conditions. The incorporation of the peptide into the climate control formulations, a base (mostly composed of water ≈ 94%) and an ethanolic, was found to reduce the volume of Caucasian hair tresses. The presence of the peptide improved the hair volume change more than 60% in high relative humidity conditions.

Changing the shape of hair with keratin peptides

Here we propose a solution which will replace harsh reducing agents at alkaline pH by peptide formulations acting at neutral pH to change hair shape through the re-conformation of disulphide bonds.

A note on the infection of Scomberomorus brasiliensis (Osteichthyes, Scombridae) by Kudoa sp. (Myxozoa: Multivalvulida)

The infection of Scomberomorus brasiliensis by the myxozoan Kudoa sp. is reported. The parasites formed plasmodiae inside the skeletal muscle fibres. The spores were quadrate in apical view and bell-like shaped in lateral view, containing four equally sized more or less rounded polar capsules. No detrimental effects were observed in the host, namely muscle liquefaction. The importance of these parasites is discussed.

Potential of human γD-crystallin for hair damage repair: insights into the mechanical properties and biocompatibility

OBJECTIVES

The objective of this work was to develop a new strategy to physically 'repair' chemically damaged hair. Hence the human eye γD-crystallin, a protein from the superfamily characterized structurally by the Greek key motif, was studied. The human γD-crystallin was chosen based on the ability of proteins belonging to this superfamily to be involved in the coating of specific structures. Two crystallins were used on the study, the wild type (Protein Data Bank ID: 1HK0) and the mutant protein. The mutant form was intended to induce a strong and quick protein polymerization as well to have new possible points of anchorage to hair.

METHODS

The ability of both crystallins to bind to damaged hair and even penetrate into its cortex was checked by fluorescence microscopy, confocal microscopy and scanning electron microscopy. Furthermore the reinforcement of hair mechanical resistance, the potential cytotoxic/inflammatory effect of crystallins were studied in order to have a fully comprehension about the protein based formulation.

RESULTS

Although the chemical over-bleaching treatment induced a decrease of 20% on the resistance of the hair, the crystallins which bind and penetrate the hair fibre were able to recover and even to improve its mechanical properties when compared to the virgin hair. Moreover none of the crystallins displayed a toxic effect in fibroblasts for all the range of tested concentrations upon 72 h of exposure. The active aggregation process of mutant crystallin induced an inflammatory response in fibroblasts in the first 24 h of contact, measured by the amount of released pro-inflammatory cytokine IL-6 to the medium. In contrast contact with wild type crystallin did not lead to significant inflammation.

CONCLUSION

Outcome from protein formulation characterization supports the hypothesis that the γD-crystallin it is able to recover and improve the mechanical properties of chemical damaged hair. Therefore it can be considered as a very promising strengthening agent for the development of new restorative hair care products.

Electromyography in cycling: difference between clipless pedal and toe clip pedal

The purpose of this study was to verify if there is electromyographic difference in biceps femoris (long portion), semitendinous, semimembranous and gastrocnemius (lateralis and medialis) muscles, using clipless pedal and toe clip pedal. Thirty seven triathletes answered a questionnaire about their preferred type of pedal, which showed that 5.4% used toe clip pedal and 94.6% used clipless pedal. Four male triathletes (age: 21.75 +/- 2.50 years old; cycling experience: 5.00 +/- 2.45 years; preferred cadence: 83.75 +/- 7.5 rpm) rode their own bicycles on a stationary roller at 100 rpm. The subjects performed one trial with each type of pedal. Bipolar surface electrodes placed on right lower limb picked up the EMG signal during 6 s. A band-pass filter (10-600 Hz) was used. Two muscles (semitendinous and semimembranous) presented lower activity with clipless pedal for all subjects. Biceps femoris and gastrocnemius lateralis presented lower activity with clipless pedal for three subjects. This led us to conclude that there is less electromyographic activity with the use of clipless pedal.