Content uploaded by Bhagavathi Sundaram Sivamaruthi
Author content
All content in this area was uploaded by Bhagavathi Sundaram Sivamaruthi on Sep 30, 2020
Content may be subject to copyright.
applied
sciences
Article
Effect of Phyllanthus emblica Linn. on Tensile
Strength of Virgin and Bleached Hairs
Pratya Tiampasook 1, Chaiyavat Chaiyasut 2,* , Bhagavathi Sundaram Sivamaruthi 2,
Thanaroat Timudom 1and Duangporn Nacapunchai 3,*
1Faculty of Applied Thai Traditional Medicine, Suansunandha Rajabhat University,
Bangkok 10300, Thailand; s59562807009@ssru.ac.th (P.T.); s59562807008@ssru.ac.th (T.T.)
2Innovation Center for Holistic Health, Nutraceuticals and Cosmeceuticals, Faculty of Pharmacy,
Chiangmai University, Chiang Mai 50200, Thailand; sivamaruthi.b@cmu.ac.th
3College of Allied Health Science, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand
*Correspondence: chaiyavat@gmail.com (C.C.); duangporn.na@ssru.ac.th (D.N.)
Received: 15 August 2020; Accepted: 8 September 2020; Published: 10 September 2020
Abstract:
In Ayurveda medicine, Phyllanthus emblica Linn. (emblica) has been used as a hair
nourisher for more than a decade by soaking it overnight, but no study has proved the effect
of emblica on hair. This research aims to determine the effect of emblica solution on the tensile
strength of three types of hair: virgin hair (VH), bleached hair (BH), and twice bleached hair (TH).
The investigated active substances were deionized water (DI water) as a control, 3% emblica extract
solution (3% EXS), 6% emblica extract solution (6% EXS), and 9% emblica extract solution (9% EXS).
Black Virgin Asian hair was measured and analyzed before bleaching with a 12% bleaching agent
once (BH) and twice (TH). Three treatments and the control were applied to each type of hair under a
controlled condition. The tensile characteristics and surface morphology of all treated hairs were
measured and analyzed by texture analysis (TA.XT Plus Texture Analyzer, Stable Micro Systems),
Aramo (
Aramo-SG Skin & Hair analysis system
), and scanning electron microscopy (SEM model
JSM-5410LV JEOL). The results of the nanoindentation test proved that the tensile strength and
extensibility of all three types of hair increased in all concentrations (DI water, 3% EXS, 6% EXS,
and 9% EXS). High magnification SEM images were taken from the cuticle surfaces and cross-sections.
Emblica extracted solution (EXS) formed a coating around the hair, especially cuticle damaged by
bleaching (BH and TH). The breaking pattern from the cross-section images showed that emblica
extract solution reinforced all hair types. In conclusion, the emblica extract solution has a significant
positive effect on the tensile strength and extensibility of VH, BH, and TH. The result has proved
the ancient intelligence that the emblica nourishes the hair. In addition, our results show additional
benefit by strengthening virgin hair and bleached hair.
Keywords: emblica extract solution; tensile strength; extensibility; virgin hair; bleached hair
1. Introduction
Human hair is a keratin fiber with various properties, such as water absorbable, water-insoluble,
physically durable, chemically inert, flexible, and recoverable from physical deformation. Hair consists
of three concentric areas: the cuticle, cortex, and medulla. The cuticle is the outer layer (3.5–4.5
µ
m)
that helps to protect the hair and reduce physical impacts. The cortex is the middle layer and the main
part of the hair, which is essential for hair stability, cohesion, stiffness, and suppleness; there is melanin
in this layer. The medulla is the core of the hair, which is transparent. The fundamental chemical
composition of hair is keratin, up to 95%, which is contained in the cortex and medulla [1].
Appl. Sci. 2020,10, 6305; doi:10.3390/app10186305 www.mdpi.com/journal/applsci
Appl. Sci. 2020,10, 6305 2 of 16
Hair bleaching is a chemical reaction that oxidizes melanin, damages keratin in the hair structure,
and changes the appearance of the hair, such as color, smoothness, and endurance, which cause most
of the hair to become brittle and fall out problems [2,3]. The chemical agent in the bleaching solution
dramatically causes peeling and inflammation on the scalp, erythema, and pain on the skin nearby [
4
].
These problems have increased the need to use hair coloring products, via hair dyeing, in the senior
population, and the popularity of hair color change fashion in juniors [
5
]. There are numerous studies
on hair treatment before and after bleaching to reduce hair troubles and promote hair strengthening
and growth such as green tea [6], Eclipta alba [7], or Hibiscus rosa-sinensis Linn [8].
Phyllanthus emblica Linn. (syn. Emblica officinalis), commonly known as emblica, amla, or Indian
gooseberry, is highly nutritious; it contains vitamin C, amino acids, and minerals [
9
]. It is one of the
well-known and valuable medicinal herbs in ancient medicine, such as Thai Traditional Medicine,
Ayurveda (Indian Traditional Medicine), and Traditional Chinese Medicine. Based on studies in
many countries, emblica helps to boost the immune system and has anti-cancer [
10
], antimicrobial,
analgesic [
11
], and anti-oxidant activities [
12
]. It has been used as an ingredient to cure human illnesses,
such as diarrhea, injuries, fever, cold, malaria, gout, tumor, etc. The chemical components of emblica
include alkaloids, flavonoids, saponins, terpenoids, glycosides, and tannins. Among the more than
100 phenolic compounds in emblica, tannins are the main content with astringent properties [
13
,
14
].
They shrink the hair surface as well as tighten and make the hair stronger and healthier by coating
the hair cuticle [
15
]. Emblica also helps to promote hair growth, length, density, health [
16
,
17
] and
reduces hair loss by inhibiting 5
α
-reductase [
18
]. However, its effect on hair tensile strength has never
been studied. In ancient Ayurveda, emblica has been used as a traditional hair tonic for hair growth
(density and volume) and hair treatment (nourishment and pigmentation) by rinsing hair during the
last wash with a tonic prepared by soaking emblica in water overnight [19].
Strength is one of the fundamental properties of a material. It is determined by measuring
the amount of stress that makes a material deform or the maximum stress that breaks it. Material
strength is related to elastic and plastic properties (the ability of a material to resist distortion) [
20
].
One of the popular strength testing methods is tensile testing. The test was placed on stretching a
specific length of material at a fixed strain rate. The result would change the conditions and properties.
The most common testing machine is a comprehensive and extensive tester that can test tension,
compression, and bending in any material by changing grip [
21
]. In recent decades, tensile testing has
been developed to test micro/nanomaterials and measure their properties precisely. The metrological
and experimental techniques of material testing in micro size have become accessible and convenient in
many fields of research, including hair and cosmetic industries [
22
]. Some studies that have used these
techniques in the hair treatment field include Effects of Hard Water on Hair [
23
] and Tensile Strength of
Bleached Hair [
24
]. Studies have shown that in the hair structure, the hair cortex has the highest effect
on hair tensile properties [
25
]. The melanin causes the hair’s color is in the hair cortex. The effect of the
bleaching agent destroys hair structure through the cortex and makes hair color fading [
26
]. As the
Ancient know-how, emblica is a natural hair treatment. There is no previous study on the effect of
emblica on the tensile strength of hair. In this study, three concentrations of emblica extract solution
(3%, 6%, and 9%) were selected according to the result of a previous study on the effect of butterfly pea
and emblica hair spray [27]. The best concentration of emblica was 6.66%.
The objective of this study is, therefore, to evaluate the effect of emblica extract solution on the
tensile strength of virgin hair (VH), bleached hair (BH), and twice bleached hair (TH). The results of
this study would prove the know-how of ancient herbal medicine and the effect of emblica on the
tensile strength and extensibility of hair. The outcome would lead to further research in hair cosmetic
product formulation.
Appl. Sci. 2020,10, 6305 3 of 16
2. Materials and Methods
2.1. Emblica Extract Solution and Dye Solution
Fresh emblica samples were purchased from Chiang Mai province, Thailand, and dried at 60 ◦C
for three days. One hundred grams (100 g) of dried emblica was mixed with 1 L of water, boiled for
1 h, and the liquid collected. A filter (Whatman filter paper No.41) was used to separate the liquid.
The emblica extract solution was kept (in a refrigerator) at 8
◦
C; 3%, 6%, and 9% emblica extract
solutions were prepared by diluting emblica extract solution with deionized water based on each
concentration, and they were kept at room temperature.
As per the manufacturer’s instruction, 15 g of Berina hair bleaching powder was mixed with
60 mL of Berina developer (12% w/whydrogen peroxide). The mixture was stirred until becoming
homogenous, and it was put on the hair immediately after mixing for 60 min and rinse water.
2.2. Tannin Assay Kit
Tannin Microplate Assay Kit (Catalog # CAK1060) was purchased from Cohesion Biosciences
(London, UK). Tannin can react with phosphomolybdic acid, and this Assay Kit can be measured at a
colorimetric readout at 650 nm. Emblica extract was a liquid sample which can be detected by the
assay directly. The procedure from Cohesion Biosciences was to warm the reaction buffer, dye reagent
to room temperature before use and add sample, standard, distilled water, reaction buffer, and dye
reagent into the microplate. Mix the sample with the reagent and stay at room temperature for 10 min
before measured at 650 nm and record the absorbance.
2.3. Total Iron Testing
Emblic extract sample was sent to Central Laboratory Co., Ltd. (Chiang Mai, Thailand) for
total iron testing by ICP-OES technique. ICP- OES or Inductively coupled plasma- optical emission
spectroscopy is one of the suitable element analytical techniques that can be quickly and simply
measured most of the elements at trace levels that the plasma energy is given to analyze the element
with high sensitivity.
2.4. Hair Preparation
The hair samples used in this experiment were purchased from U And I Cut And Beauty (beauty
supply store) (Bangkok, Thailand); the samples were black, straight, and virgin hair (never been
bleached or dyed before). All samples were washed with room temperature water (22–25
◦
C) for 2 min
and dried at room temperature before been measured and cut to 10 cm length. Thirty hair samples
were randomly chosen and weighted in the preliminary analysis, and their weights were sorted in
ascending order. The ten medium weights were chosen as the representative weight range to select
360 samples to be used in the study (0.00063–0.00095 g). The hair diameters were measured with the
Aramo-SG Skin & Hair analysis system with a 200
×
magnifying camera. Each hair was measured three
times, at both ends of the hair and in the middle. The average diameter from the three measurements
is shown on the monitor by “Hair Pro X” analysis program, as shown in Figure 1. The measured
hairs were separated into 12 groups: (1) VH with DI water (B
0
E
0
), (2) VH with 3% EXS (B
0
E
3
), (3) VH
with 6% EXS (B
0
E
6
), (4) VH with 9% EXS (B
0
E
9
), (5) BH with DI water (B
1
E
0
), (6) BH with 3% EXS
(B
1
E
3
), (7) BH with 6% EXS (B
1
E
6
), (8) BH with 9% EXS (B
1
E
9
), (9) TH with DI water (B
2
E
0
), (10) TH
with 3% EXS (B
2
E
3
), (11) TH with 6EXS (B
2
E
6
), and (12) TH with 9% EXS(B
2
E
9
), as shown in Table 1.
The purpose of using the bleached hair was to compare the strength of VH, BH, and TH before and
after treatments. Various concentrations of emblica solution (3%, 6%, 9% w/w) were used to treat each
type of hair (virgin, bleached, and twice bleached). The processing parameters include temperature:
22–25
◦
C, relative humidity: 52–57%, and pH of solutions: 3.41–6.54. All hairs were immersed in
the solutions for 3 h, dried at room temperature and kept in zip-lock plastic bags. Then, as per the
manual (Hair and Hair Product testing: Texture analysis application overview, Stable Micro System),
Appl. Sci. 2020,10, 6305 4 of 16
square-hole papers (87
×
52 mm with 55
×
30 mm hole) were prepared for each hair, as shown in
Figure 2a. One hair shaft was put in the middle of the paper and glued at both ends of the hair before
putting another prepared square-hole paper on it, as shown in Figure 2b. The hair-attached paper was
mounted on Tensile Testing Grip (A/TG) with a 5 kg load cell, and both sides of the paper were cut,
as shown in Figure 2c.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 4 of 17
attached paper was mounted on Tensile Testing Grip (A/TG) with a 5 kg load cell, and both sides of
the paper were cut, as shown in Figure 2c.
Figure 1. Hair diameter measurement by the Aramo-SG Skin & Hair analysis system with 200×
magnification, which is shown on the Hair Pro X analysis program.
Table 1. The 12 groups of hair after measurement before bleaching and treatment.
Number of Bleaching Times (B)
Emblica Extract Solution Concentration (E)
0%
(E
0
)
3%
(E
3
)
6%
(E
6
)
9%
(E
9
)
1. VH (
No bleaching
) (B
0
)
B
0
E
0
B
0
E
3
B
0
E
6
B
0
E
9
2
.
One time bleaching hair
(
B
1
)
B
1
E
0
B
1
E
3
B
1
E
6
B
1
E
9
3
.
Twice bleaching hair
(
B
2
)
B
2
E
0
B
2
E
3
B
2
E
6
B
2
E
9
Figure 1.
Hair diameter measurement by the Aramo-SG Skin & Hair analysis system with 200
×
magnification, which is shown on the Hair Pro X analysis program.
Table 1. The 12 groups of hair after measurement before bleaching and treatment.
Number of Bleaching Times (B)
Emblica Extract Solution Concentration (E)
0%
(E0)
3%
(E3)
6%
(E6)
9%
(E9)
1. VH (No bleaching) (B0) B0E0B0E3B0E6B0E9
2.One time bleaching hair (B1) B1E0B1E3B1E6B1E9
3.Twice bleaching hair (B2) B2E0B2E3B2E6B2E9
Appl. Sci. 2020, 10, x FOR PEER REVIEW 5 of 17
Figure 2. (a) Prepared square-hole paper (87 × 52 mm with 55 × 30 mm hole); (b) one hair glued in the
middle of the paper before being attached to another paper; (c) cut both sides of the paper after
mounting it on the Tensile Testing Grip (A/TG).
2.5. Tensile Testing
Tensile strength and the corresponding failure strain of all 360 samples were tested on the
TA.XTplus Texture Analyser and Exponent Texture Analyser software. Tensile strength force (N)
and extensibility (mm) were measured by “Hair Mono Filaments” product, and force was measured
in “Tension” mode, 0.5 mm/s test-speed, 200 mm distance, and 20 g break detect. The machine was
calibrated before the experiment. All hair samples were prepared and tested under ambient
laboratory conditions (temperature 22–25 °C and 52–57% relative humidity). The test results are
shown on the monitor in the “Texture Exponent” program, as shown in Figure 3. Tensile strength
force (N) and time(s) were plotted continuously until hair breaking.
Figure 3. “Texture Exponent” program showing a graph of test result involving Tensile strength force
(g) and time(s).
2.6. SEM Analysis
Figure 2.
(
a
) Prepared square-hole paper (87
×
52 mm with 55
×
30 mm hole); (
b
) one hair glued in
the middle of the paper before being attached to another paper; (
c
) cut both sides of the paper after
mounting it on the Tensile Testing Grip (A/TG).
Appl. Sci. 2020,10, 6305 5 of 16
2.5. Tensile Testing
Tensile strength and the corresponding failure strain of all 360 samples were tested on the
TA.XTplus Texture Analyser and Exponent Texture Analyser software. Tensile strength force (N) and
extensibility (mm) were measured by “Hair Mono Filaments” product, and force was measured in
“Tension” mode, 0.5 mm/s test-speed, 200 mm distance, and 20 g break detect. The machine was
calibrated before the experiment. All hair samples were prepared and tested under ambient laboratory
conditions (temperature 22–25
◦
C and 52–57% relative humidity). The test results are shown on the
monitor in the “Texture Exponent” program, as shown in Figure 3. Tensile strength force (N) and
time(s) were plotted continuously until hair breaking.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 5 of 17
Figure 2. (a) Prepared square-hole paper (87 × 52 mm with 55 × 30 mm hole); (b) one hair glued in the
middle of the paper before being attached to another paper; (c) cut both sides of the paper after
mounting it on the Tensile Testing Grip (A/TG).
2.5. Tensile Testing
Tensile strength and the corresponding failure strain of all 360 samples were tested on the
TA.XTplus Texture Analyser and Exponent Texture Analyser software. Tensile strength force (N)
and extensibility (mm) were measured by “Hair Mono Filaments” product, and force was measured
in “Tension” mode, 0.5 mm/s test-speed, 200 mm distance, and 20 g break detect. The machine was
calibrated before the experiment. All hair samples were prepared and tested under ambient
laboratory conditions (temperature 22–25 °C and 52–57% relative humidity). The test results are
shown on the monitor in the “Texture Exponent” program, as shown in Figure 3. Tensile strength
force (N) and time(s) were plotted continuously until hair breaking.
Figure 3. “Texture Exponent” program showing a graph of test result involving Tensile strength force
(g) and time(s).
2.6. SEM Analysis
Figure 3.
“Texture Exponent” program showing a graph of test result involving Tensile strength force
(g) and time(s).
2.6. SEM Analysis
After tensile testing, a hair sample was randomly chosen from each group and cut at 0.5 cm from
the hair breaking terminal. The prepared samples were mounted on metal aluminum to be coated with
gold under vacuum. Multiple sections were scanned and analyzed by scanning electron microscopy
(SEM) to check hair surface and hair cross-section to check the breaking texture at the hair terminal by
SEM model JSM-5410LV JEOL, Japanat Tarabusiness Co., Ltd. (Bangkok, Thailand).
2.7. Statistic Analysis
After testing, all data were collected and checked for validation before being processed using
SPSS. t-test was used to compare the means of data. One-way ANOVA was used to check all hair
samples before bleaching or treatment with emblica extract solution. One-way ANOVA was used to
compare the tensile strength/extensibility of VH, BH, and TH before treatment with EXS to check the
effect of bleaching on hair. One-way ANOVA with LSD comparison was also used to compare the
tensile strength/extensibility of the12 groups of hair (B
0
E
0
, B
0
E
3
, B
0
E
6
, B
0
E
9
, B
1
E
0
, B
1
E
3
, B
1
E
6
, B
1
E
9
,
B
2
E
0
, B
2
E
3
, B
2
E
6
, and B
2
E
9
). The Spearman’s correlation was used to check the mutual relationship
and to find the correlation coefficient (R) between emblica extract solution concentration and tensile
strength/extensibility.
Appl. Sci. 2020,10, 6305 6 of 16
3. Results
3.1. Hair Data
The results showed in Table 2displays the means, Standard error of the mean (SE), and
p-values of hair weight, diameter, and density of the groups (30 hairs per group). All hairs
were measured before bleaching or treatment with emblica extract solution. The p-value showed
non-significant differences (p>0.05) between each group. The prepared hairs had the same size
(10 cm), and non-significant differences of weight and diameter. The measurement in this table aimed
to compare all hair in each group before the experiment to normalize and choose the virgin hairs that
were non-significant differences.
Table 2.
Hair weight, diameter, and density before bleaching or treatment with emblica extract solution.
Hair Group Label Emblica
(%w/w)
Weight
(×10−4g)
Diameter
(µm)
Density
(g/cm3)
Virgin hair (B0)
0 8.21 ±0.13 114.7 ±1.34 0.0079
3 8.14 ±0.12 115.7 ±1.67 0.0078
6 8.16 ±0.13 112.9 ±1.08 0.0082
9 8.04 ±0.11 114.3 ±1.26 0.0079
BH (B1)
0 8.02 ±0.14 111.4 ±2.13 0.0084
3 8.04 ±0.14 113.5 ±1.51 0.0079
6 8.18 ±0.13 113.9 ±1.97 0.0082
9 8.07 ±0.14 114.7 ±1.62 0.0078
TH (B2)
0 8.15 ±0.12 113.5 ±2.14 0.0083
3 8.10 ±0.14 114.0 ±1.75 0.0081
6 7.89 ±0.12 112.0 ±2.31 0.0084
9 8.10 ±0.12 111.6 ±1.47 0.0083
Means 8.095 113.52 0.0081
SE 0.037 0.495 0.00007
p-value * 0.936 0.834 0.511
* One-Way ANOVA compares data in the same column with LSD comparison.
3.2. Effect of Bleaching Agent on Hair
Table 3shows the effect of bleaching agents on hair tensile strength and extensibility before
emblica extract solution treatment. The tensile strength) N (of VH was significantly higher than those
of BH and TH) p<0.01. (The tensile strength of BH was also significantly higher than that of TH)
p<0.01). The extensibility) mm (of VH was significantly lower than those of BH and TH) p<0.01.
(The extensibility of BH was insignificantly lower than that of TH) p<0.01). We found that the
bleaching agent) 12% H2O2) affects the tensile strength and extensibility of hair.
Table 3. Effect of bleaching agent on tensile strength and extensibility.
Strength No of Bleaching (Times) p-Value *
0 1 2
Tensile strength (N)
0.958 ±0.019 a,b 0.884 ±0.023 a,c 0.810 ±0.032 b,c 0.000
Extensibility (mm) 22.79 ±0.497 a,b 31.05 ±0.787 a32.41 ±1.202 b0.000
Mean
±
S.E * One-way ANOVA with LSD comparison.
a,b,c.
There are no statistically significant differences between
means with the same alphabet in the same row. (p<0.01).
Appl. Sci. 2020,10, 6305 7 of 16
3.3. Effect of Emblic Extract Solution on Hair
Emblica extract solution has been tested for tannin content (1.25 g tannin/1000 g emblica extract
solution) and iron content (6.01 mg iron/1000 g emblica extract solution). Then it was used in
the experiment.
3.3.1. Effect of Emblica Extract Solution on Tensile Strength
Figure 4demonstrates the effect of emblica extract solution on the tensile strength of three types
of hair: The tensile strength of VH (0.958
±
0.102, 1.020
±
0.086, 1.13
±
0.165, and 1.124
±
0.123N)
was higher than those of BH (0.884
±
0.126, 0.927
±
0.188, 0.951
±
0.141, and 0.981
±
0.147N) and TH
(0.810
±
0.175, 0.874
±
0.177, 0.801
±
0.170, and 0.881
±
0.241 N). Emblica extract solution extremely
affected VH. The tensile strength of hair treated with 9% EXS was higher than those of 6% EXS, 3% EXS,
and DI water, respectively. Only the increase in the tensile strength of VH caused by 3% EXS was
statistically insignificant. The tensile strength of BH and TH were statistically insignificantly increased
by all concentrations of emblica extract except for the tensile strength increase of BH by 9% EXS,
which was statistically significant. The hair with the highest tensile strength was VH treated with 9%
EXS, while that with the lowest tensile strength was TH treated with DI water. Emblica extract solution
increased the tensile strength of VH by 14.76% and that of BH by 9.88%. The result showed that the
more the concentration of emblica extract solution, the more the tensile strength for VH and BH.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 8 of 17
Figure 4. Mean of tensile force (N) of 3 groups of hair samples treated with DI water, 3%, 6%, 9%
emblica extract solution using a texture analyzer (n = 30 each, p < 0.05); error bars represent standard
error of the mean. (3 groups: virgin, bleached, and twice bleached).
Analysis of correlation was conducted on the result with Spearman’s correlation coefficient to
measure the statistical relationship. Regarding VH, the degree of correlation between the
concentration of emblica solution and tensile strength was “moderate positive association” (0.656) (p
< 0.01), that of BH was “low positive association” (0.234) (p < 0.01), and that of TH was “no linear
association” (0.050) (p > 0.05).
3.3.2. Effect of Emblica Extract Solution on Extensibility
Figure 5 demonstrates the extensibility effect of emblica extract solution on three hair groups.
The extensibility of VH (22.79 ± 2.72, 25.24 ± 4.76, 32.20 ± 3.22, and 37.14 ± 5.95%) was lower than those
of BH (31.05 ± 4.31, 35.54 ± 4.59, 39.46 ± 5.32, and 39.78 ± 3.50%) and TH (32.41 ± 6.59, 33.98 ± 6.69,
30.18 ± 6.22, and 31.60 ± 7.40%). Emblica extract solution increased the extensibility of VH by 38.63%
and that of BH by 21.94%. For VH and BH, the extensibility of hair treated with 9% EXS was higher
than those of 6%, 3%, and DI water, respectively. The extensibility of VH and BH were statistically
significantly increased by all concentrations of EXS except for the increase in the extensibility of BH
caused by an increase from 6% EXS to 9% EXS, which was statistically insignificant. The hair with the
highest extensibility was BH treated with 6% EXS, while that with the lowest extensibility was VH
treated with DI water. The result showed that the more the concentration of emblica extract solution,
the more the extensibility for VH and BH. For TH result, the tensile strength and extensibility showed
fluctuations and inconclusive results.
Figure 4.
Mean of tensile force (N) of 3 groups of hair samples treated with DI water, 3%, 6%, 9%
emblica extract solution using a texture analyzer (n=30 each, p<0.05); error bars represent standard
error of the mean. (3 groups: virgin, bleached, and twice bleached).
Analysis of correlation was conducted on the result with Spearman’s correlation coefficient to
measure the statistical relationship. Regarding VH, the degree of correlation between the concentration
of emblica solution and tensile strength was “moderate positive association” (0.656) (p<0.01), that of
BH was “low positive association” (0.234) (p<0.01), and that of TH was “no linear association” (0.050)
(p>0.05).
Appl. Sci. 2020,10, 6305 8 of 16
3.3.2. Effect of Emblica Extract Solution on Extensibility
Figure 5demonstrates the extensibility effect of emblica extract solution on three hair groups.
The extensibility of VH (22.79
±
2.72, 25.24
±
4.76, 32.20
±
3.22, and 37.14
±
5.95%) was lower than those
of BH (31.05
±
4.31, 35.54
±
4.59, 39.46
±
5.32, and 39.78
±
3.50%) and TH (32.41
±
6.59, 33.98
±
6.69,
30.18
±
6.22, and 31.60
±
7.40%). Emblica extract solution increased the extensibility of VH by 38.63%
and that of BH by 21.94%. For VH and BH, the extensibility of hair treated with 9% EXS was higher
than those of 6%, 3%, and DI water, respectively. The extensibility of VH and BH were statistically
significantly increased by all concentrations of EXS except for the increase in the extensibility of BH
caused by an increase from 6% EXS to 9% EXS, which was statistically insignificant. The hair with the
highest extensibility was BH treated with 6% EXS, while that with the lowest extensibility was VH
treated with DI water. The result showed that the more the concentration of emblica extract solution,
the more the extensibility for VH and BH. For TH result, the tensile strength and extensibility showed
fluctuations and inconclusive results.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 9 of 17
Figure 5. Mean extensibility (mm) of 3 groups of hair samples treated with DI water, 3%, 6%, 9%
emblica extract solution using a texture analyzer (n = 30 each, p < 0.05); error bars represent standard
error of the mean. (3 groups: virgin, bleached, and twice bleached).
The analysis of correlation was also conducted on the result with Spearman’s correlation
coefficient. Regarding VH, the degree of correlation between the concentration of emblica solution
and extensibility was “moderate positive association” (0.656) (p < 0.01), that of BH was “moderate
positive association” (0.608) (p < 0.01), and that of TH was “no linear association” (−0.091) (p > 0.05).
All images in Figures 6 and 7 were taken from a group hair sample; thus about 50 SEM images
were obtained in each group. Representative SEM images were chosen when >80% of electron
micrographs showed a similar pattern of damage [28].
Figure 5.
Mean extensibility (mm) of 3 groups of hair samples treated with DI water, 3%, 6%, 9%
emblica extract solution using a texture analyzer (n=30 each, p<0.05); error bars represent standard
error of the mean. (3 groups: virgin, bleached, and twice bleached).
The analysis of correlation was also conducted on the result with Spearman’s correlation coefficient.
Regarding VH, the degree of correlation between the concentration of emblica solution and extensibility
was “moderate positive association” (0.656) (p<0.01), that of BH was “moderate positive association”
(0.608) (p<0.01), and that of TH was “no linear association” (−0.091) (p>0.05).
All images in Figures 6and 7were taken from a grouphair sample; thus about 50 SEM images were
obtained in each group. Representative SEM images were chosen when >80% of electron micrographs
showed a similar pattern of damage [28].
Figure 6illustrates the magnified Scanning Electron Microscope (SEM) images of hair surface in
the cuticle scales. All VH surfaces treated with DI water (a), 3% EXS (b), 6% EXS (c), and 9% EXS (d)
were normally smooth.
The VH surface in Figure 6a was flat compared with the BH surface in Figure 6e, which was slightly
damaged, and the TH surface in Figure 6i, which was dramatically damaged. On precise inspection,
Appl. Sci. 2020,10, 6305 9 of 16
the surfaces of BH and TH were damaged and lifted as much as the number of bleaching times.
The damage of bleaching remains on treated TH (Figure 6i–l) more than on treated BH (Figure 6e–h).
By comparing the pictures in the horizontal direction, emblica treated BH and TH (Figure 6e–l)
showed that the higher the concentration of emblica extract solution, the smoother the surface.
From the illustrations of BH (Figure 6e–h), 9% EXS could coat BH surface as smooth as VH, but the
cuticle was more damaged and fractured.
From the illustrations of TH (Figure 6i–l), 9% EXS could coat TH surface, but the cuticle was much
more fractured and lost than VH and BH. Emblica extract could recover some parts of damaged hair.
It could cover VH, BH, and TH and treated hair cuticle as confirmed by SEM analyses. From previous
studies, emblica extract solution composed of gallic acid, tannic acid, and iron [
20
,
21
] therefore,
it could imply that the emblica extract solution could coat VH, BH, and TH firmly, as shown in
Figure 6b–d,f–h,j–l.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 10 of 17
Figure 6. SEM images of damaged cuticle scale of VH/BH/TH after treatment with DI water and
different concentrations of emblica extract solution: (a) VH+ DI water, (b) VH+ 3%EXS, (c) VH+
6%EXS, (d) VH + 9%EXS, (e) BH+ DI water, (f) BH + 3%EXS, (g) BH + 6%EXS, (h) BH + 9%EXS, (i) TH
+ DI water, (j) TH + 3%EXS, (k) TH + 6%EXS, and (l) TH + 9%EXS.
Figure 6 illustrates the magnified Scanning Electron Microscope (SEM) images of hair surface in
the cuticle scales. All VH surfaces treated with DI water (a), 3% EXS (b), 6% EXS (c), and 9% EXS (d)
were normally smooth.
The VH surface in Figure 6a was flat compared with the BH surface in Figure 6e, which was
slightly damaged, and the TH surface in Figure 6i, which was dramatically damaged. On precise
inspection, the surfaces of BH and TH were damaged and lifted as much as the number of bleaching
times. The damage of bleaching remains on treated TH (Figure 6i–l) more than on treated BH (Figure
6e–h).
By comparing the pictures in the horizontal direction, emblica treated BH and TH (Figure 6e–l)
showed that the higher the concentration of emblica extract solution, the smoother the surface.
From the illustrations of BH (Figure 6e–h), 9% EXS could coat BH surface as smooth as VH, but
the cuticle was more damaged and fractured.
From the illustrations of TH (Figure 6i–l), 9% EXS could coat TH surface, but the cuticle was
much more fractured and lost than VH and BH. Emblica extract could recover some parts of damaged
hair. It could cover VH, BH, and TH and treated hair cuticle as confirmed by SEM analyses. From
previous studies, emblica extract solution composed of gallic acid, tannic acid, and iron [20,21]
therefore, it could imply that the emblica extract solution could coat VH, BH, and TH firmly, as shown
in Figure 6b–d,f–h,j–l.
Figure 6.
SEM images of damaged cuticle scale of VH/BH/TH after treatment with DI water and
different concentrations of emblica extract solution: (
a
) VH+DI water, (
b
) VH+3%EXS, (
c
) VH+6%EXS,
(
d
) VH +9%EXS, (
e
) BH+DI water, (
f
) BH +3%EXS, (
g
) BH +6%EXS, (
h
) BH +9%EXS, (
i
) TH +DI
water, (j) TH +3%EXS, (k) TH +6%EXS, and (l) TH +9%EXS.
Appl. Sci. 2020,10, 6305 10 of 16
Appl. Sci. 2020, 10, x FOR PEER REVIEW 11 of 17
Figure 7. Cross-sectional SEM images of VH/BH/TH after treatment with DI water and 9%
concentration of emblica extract solution: (a) VH + DI water, (b) VH + 9%, (c) BH + DI water, (d) BH +
9%, (e) TH + DI water, and (f) TH + 9%.
The high magnification SEM images were taken from cross-sections of VH, BH, and TH. Figure
7a,c,e, (left column) shows that the bleaching agents cause hair structure damaged based on the
number of bleaching times. By comparing the breaking pattern of VH between Figure 7a,b, 9% EXS
made hair more rigid and harder to break than DI water.
In Figure 7d, it is shown that 9% EXS consolidated the damaged hair than in Figure 7c, and the
breaking pattern of BH showed more durability than when treated with DI water; however, it was
inadequate for it to recover as well as VH. The breaking pattern of TH treated with 9% EXS (Figure
7f) was more rigid than when treated with DI water (Figure 7e); however, the damage of 2-times
bleaching was too severe for 9% EXS to recover.
Figure 7.
Cross-sectional SEM images of VH/BH/TH after treatment with DI water and 9% concentration
of emblica extract solution: (
a
) VH +DI water, (
b
) VH +9%, (
c
) BH +DI water, (
d
) BH +9%, (
e
) TH +DI
water, and (f) TH +9%.
The high magnification SEM images were taken from cross-sections of VH, BH, and TH.
Figure 7a,c,e, (left column) shows that the bleaching agents cause hair structure damaged based
on the number of bleaching times. By comparing the breaking pattern of VH between Figure 7a,b,
9% EXS made hair more rigid and harder to break than DI water.
In Figure 7d, it is shown that 9% EXS consolidated the damaged hair than in Figure 7c, and the
breaking pattern of BH showed more durability than when treated with DI water; however, it was
inadequate for it to recover as well as VH. The breaking pattern of TH treated with 9% EXS (Figure 7f)
was more rigid than when treated with DI water (Figure 7e); however, the damage of 2-times bleaching
was too severe for 9% EXS to recover.
4. Discussion
Hairs in this experiment were black and straight. They were bought from a beauty supply store
that sells Thai healthy hair in Thailand. The hair diameters, which were measured by ARAMO,
were used to find the hair cross-sectional area. The SEM images of VH show that all hairs were
Appl. Sci. 2020,10, 6305 11 of 16
almost circular in cross-section, which is confirmed and consistent with previous studies on hair from
subjects of different ethnic origins (Caucasian, Asian, and African). African hair tended to be flat oval,
while Asian hair tended to be round [
29
]. The hair diameters, which were measured by ARAMO,
were 101–132
µ
m, consistent with a previous study on 2249 healthy subjects from 24 ethnic groups.
The hair diameters from Thailand and China were 73–136
µ
m [
30
] and consistent with a previous study
about ethnic variation in hair. The hair diameter of people who are referred to as Oriental or Asian hair
were generally ranging from 100–130 µm. [31].
The damage of bleaching agents regarding one-time bleaching and twice bleaching is consistent
with previous studies on morphological and histological bleached hair. Even though the percentage of
hydrogen peroxide solution of bleaching agent and bleaching time were different, SEM images showed
hair damage and lifted cuticle [
32
]. In accordance with studies on hair dying [
33
], hair color was also
lighter from black to brown and light brown as the concentration of bleaching agent and the number
of bleaching time increased. The bleaching agent oxidizes hair melanin in the cortex and medulla
through the cuticle. The more the cuticle damage is, the less the hair color left and the less the tensile
strength but with increased extensibility.
The effect of bleaching on hair decreased the tensile strength from 0.958
±
0.019 to 0.884
±
0.023 N,
or about 7.72% decrease, which is consistent with previous studies on the tensile strength of bleached
hair. Tensile strength was decreased from 14.66 g/cm
2
to 12.95 g/cm
2
, or about 11.66% decrease [
27
].
The extensibility of bleached hair increased from 22.79
±
0.497 to 31.05
±
0.787%, or about 36.24%
increase, which is consistent with previous studies on the effect of bleaching time and hydrogen
peroxide concentration on hair damage. The extensibility increased by about 35.71% [
31
]. The bleaching
agent was dramatically affected both the tensile strength and extensibility of twice bleached hair.
The tensile strength decreased to 0.810
±
0.032 N, or about 15.44% decrease, and the extensibility
increased to 32.41
±
1.202%, or about 42.17%, which is consistent with previous studies on the damage
of hair bleaching. The result of the previous study showed that the more times of bleaching agent the
more tensile strength decreased and the more extensibility increased [34].
Test-speed in the tensile testing was 0.5 mm/s, which made a strain rate of 0.05/s, the stress of
74.49–123.3 MPa, and strain of 0.198–0.299, which is consistent with previous studies on female hair of
about the same age. The hair diameter was about 90
µ
m, the strain rate was 0.1–0.01/s, the stress was
100–160 MPa, and the strain was 0.2–0.3 [25].
After three concentrations of emblic extract treatment, the best and only one concentration
that statically significantly effect on BH was 9%EXS treatment. It was a 10.97% increase, which is
better than the previous study on a novel leave-on technology combination (caffeine, niacinamide,
panthenol, dimethicone, and an acrylate polymer (CNPDA)). The tensile stress effect between bleached
untreated and bleached CNPDA treated hair had a 5.00% increase [
35
] and consistent with another
previous studies on Glycolipid Biosurfactants, Mannosylerythritol Lipids, Repair the Damaged Hair.
The tensile strength effect on MEL-A treatment had a 22.00% increase and on MEL-B there was a 19.40%
increase [36].
Tannins are influential chemical components for emblica extract to coat hair. In this study,
9% EXS [
37
] treated VH caused tensile strength of 1.29 times and extensibility of 1.63 times more than
DI water treated VH. This is consistent with previous studies on the effect of eucalyptus ash on hair,
which caused tensile strength to increase by 1.17 times and extensibility by 1.38 times. The tannin in
the ash, which is bonded (s-bond) with iron (Fe), made hair stronger and darker [38].
The result of tannin testing is 1.25 g tannin/1000 g emblica extract solution, or 12.0 mg tannin/1 g
dried emblica weight which is calculated according to 960 mL emblica extract solution was obtained
from 100 g dried emblica. Compare with the tannin from the previous studies, “Acute and chronic
oral toxicity of standardized water extract from the fruit of Phyllanthus emblica Linn.” [
39
], the tannin
content of Amla (Phyllanthus emblica) fruit was 24.32% w/wor 41.32 mg tannin/1 g dried emblica weight,
which is higher than tannin in our study. The higher tannin content may be due to two times the
Appl. Sci. 2020,10, 6305 12 of 16
extraction process of emblica (boil for one hour two times compared to boil for one hour one time in
our experiment).
The total iron was 6.01 mg iron/1000 g emblica extract solution or 0.0576 mg iron/1 g dried emblica.
Another study of the iron content from the nutritional value of Phyllanthus emblica fruit, “Indian
gooseberry (Emblica officinalis): Complete pharmacognosy review” [
40
] found that the total iron was
0.0150 mg iron/1 g dried emblica, which is lower than in our study.
Another consistent study involves tannic acid, gallic acid, and iron bonded with protein [
41
],
and they were all found in emblica [
37
,
42
]. The study was conducted on the chemical bond in
dyed hair [
42
]. The ingredients used in their formulation included tannic acid, gallic acid, and Fe
2+
(D-gluconate). The formulation is oxidized upon exposure to air and coats hair firmly as blackish
tannin nano molecule, as shown in Figure 8. Among the numerous emblica chemical component
studies, there are pieces of evidence that emblica extract has a lot of phytochemical compounds,
such as gallic acid, tannic acid, iron (Fe), ascorbic acid, ellagitannin, ellagic acid along with flavonoids
and kaempferol [
43
,
44
]. Emblica extract solution could be able to coat hair like a chemical bond in
hair dyeing.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 13 of 17
weight, which is higher than tannin in our study. The higher tannin content may be due to two times
the extraction process of emblica (boil for one hour two times compared to boil for one hour one time
in our experiment).
The total iron was 6.01 mg iron/1000 g emblica extract solution or 0.0576 mg iron/1 g dried
emblica. Another study of the iron content from the nutritional value of Phyllanthus emblica fruit,
“Indian gooseberry (Emblica officinalis): Complete pharmacognosy review” [40] found that the total
iron was 0.0150 mg iron/1 g dried emblica, which is lower than in our study.
Another consistent study involves tannic acid, gallic acid, and iron bonded with protein [41],
and they were all found in emblica [37,42]. The study was conducted on the chemical bond in dyed
hair [42]. The ingredients used in their formulation included tannic acid, gallic acid, and Fe2+ (D-
gluconate). The formulation is oxidized upon exposure to air and coats hair firmly as blackish tannin
nano molecule, as shown in Figure 8. Among the numerous emblica chemical component studies,
there are pieces of evidence that emblica extract has a lot of phytochemical compounds, such as gallic
acid, tannic acid, iron (Fe), ascorbic acid, ellagitannin, ellagic acid along with flavonoids and
kaempferol [43,44]. Emblica extract solution could be able to coat hair like a chemical bond in hair
dyeing.
Figure 8. The air oxidation of soluble ferrous during hair dyeing and the possible binding of tannic
acid, gallic acid, and ferrous. This image was modified with permission from Han, S.Y.; Hong, S.P.;
Kang, E.K.; Kim, B.J.; Lee, H.; Kim, W.I.; Choi, I.S. Iron, Gall Ink Revisited: Natural Formulation for
Black Hair-Dyeing; published by Cosmetics, 2019 [41].
The SEM images selection method is consistent with a previous study of the comparison of hair
shaft damage after chemical treatment in Asian, White European, and African hair [28].
The bleaching agent concentration and bleaching time were the major cause of hair damage. As
the manufacturing instruction, 12% of Hydrogen peroxide for 1 h causes the cuticle lifted and
damaged on bleached hair more than previous studies on 6% of Hydrogen peroxide for 0.5 h. After
treated with polyquaternium 7® solution, the SEM images showed a roughness caused by the solution
on the hair surface which similar to the SEM in this study that EXS were coated on the hair surface.
[45].
Comparing the breaking patterns of cross-sectional images of DI water treated hair in Figure 9
(left column) (m, o, q) and 9% EXS treated hair in Figure 9 (right column) (n, p, r) indicates that 9%
EXS improved the condition of hair and made it more rigid and harder to break compared with DI
water. This experiment is consistent with a previous study on the breaking pattern of hair. There
usually are four types of hair fracture patterns, as shown in Figure 9. Fibrillation and splitting tend
to occur more in hair in poor condition than smooth and step patterns [46].
Figure 8.
The air oxidation of soluble ferrous during hair dyeing and the possible binding of tannic
acid, gallic acid, and ferrous. This image was modified with permission from Han, S.Y.; Hong, S.P.;
Kang, E.K.; Kim, B.J.; Lee, H.; Kim, W.I.; Choi, I.S. Iron, Gall Ink Revisited: Natural Formulation for
Black Hair-Dyeing; published by Cosmetics, 2019 [41].
The SEM images selection method is consistent with a previous study of the comparison of hair
shaft damage after chemical treatment in Asian, White European, and African hair [28].
The bleaching agent concentration and bleaching time were the major cause of hair damage. As the
manufacturing instruction, 12% of Hydrogen peroxide for 1 h causes the cuticle lifted and damaged on
bleached hair more than previous studies on 6% of Hydrogen peroxide for 0.5 h. After treated with
polyquaternium 7
®
solution, the SEM images showed a roughness caused by the solution on the hair
surface which similar to the SEM in this study that EXS were coated on the hair surface. [45].
Comparing the breaking patterns of cross-sectional images of DI water treated hair in Figure 9
(left column) (m, o, q) and 9% EXS treated hair in Figure 9(right column) (n, p, r) indicates that 9% EXS
improved the condition of hair and made it more rigid and harder to break compared with DI water.
This experiment is consistent with a previous study on the breaking pattern of hair. There usually are
four types of hair fracture patterns, as shown in Figure 9. Fibrillation and splitting tend to occur more
in hair in poor condition than smooth and step patterns [46].
Appl. Sci. 2020,10, 6305 13 of 16
Appl. Sci. 2020, 10, x FOR PEER REVIEW 14 of 17
Figure 9. Schematic depicting some of the fracture patterns of human hair modify from Chemical and
Physical Behavior of Human Hair [46].
5. Conclusions
Emblica has been ubiquitously used in Ayurvedic medicine for nourishing hair since ancient
times. The results of this experiment show that emblica extract solution promoted hair strength
(tensile strength and extensibility). Among all treatments (DI water, 3%EXS, 6%EXS, and 9%EXS), the
results showed that tensile strength/extensibility of VH and BH and concentration of emblica extract
solution are directly related; 9% EXS was the best concentration that could achieve the maximum
tensile strength (1.124 ± 0.123 N) and extensibility (37.14 ± 5.95%) for VH. Only the effect of 3% EXS
on VH led to a statistically insignificant increase, which means that the emblica extract solution can
increase the tensile strength of VH when the concentration is more than 3%. All concentrations of
emblica extract solution increased the tensile strength of BH and TH in a statistically insignificant
manner except for the increase of the tensile strength of BH by 9% EXS, which was statistically
significant; this means that emblica extract solution can increase the tensile strength on BH when the
concentration is more than 9%.
The extensibility of VH and BH were statistically significantly increased by all concentrations of
EXS except for the increase in the extensibility of BH caused by an increase from 6% EXS to 9% EXS,
which was statistically insignificant; this means that 6% EXS was the minimum concentration that
could cause the maximum extensibility for BH (0.40 ± 0.05%).
The extensibility of TH fluctuated with statistically insignificant changes. The microscopical
surface and cross-sectional images of SEM showed the morphological attachment of emblica on VH,
BH, and TH. As an extract solution, emblica has potential as a hair strengthening treatment for virgin
hair and 12% of hydrogen peroxide on BH.
Author Contributions: Conceptualization, and methodology, P.T., T.T., C.C., and D.N.; formal analysis, data
curation, P.T.; writing—original draft preparation, P.T.; writing—review and editing, B.S.S., C.C., D.N.;
supervision, project investigator, C.C., D.N. All authors have read and agreed to the published version of the
manuscript.
Funding: This project was partially supported by Suan Sunandha Rajabhat University, Bangkok, Thailand. This
project was partially supported by Chiang Mai University, Thailand.
Acknowledgments: BSS would like to acknowledge postdoctoral grant of Chiang Mai University.
Conflicts of Interest: The authors declare no conflict of interest in this work.
Figure 9.
Schematic depicting some of the fracture patterns of human hair modify from Chemical and
Physical Behavior of Human Hair [46].
5. Conclusions
Emblica has been ubiquitously used in Ayurvedic medicine for nourishing hair since ancient
times. The results of this experiment show that emblica extract solution promoted hair strength (tensile
strength and extensibility). Among all treatments (DI water, 3%EXS, 6%EXS, and 9%EXS), the results
showed that tensile strength/extensibility of VH and BH and concentration of emblica extract solution
are directly related; 9% EXS was the best concentration that could achieve the maximum tensile strength
(1.124
±
0.123 N) and extensibility (37.14
±
5.95%) for VH. Only the effect of 3% EXS on VH led to
a statistically insignificant increase, which means that the emblica extract solution can increase the
tensile strength of VH when the concentration is more than 3%. All concentrations of emblica extract
solution increased the tensile strength of BH and TH in a statistically insignificant manner except for
the increase of the tensile strength of BH by 9% EXS, which was statistically significant; this means
that emblica extract solution can increase the tensile strength on BH when the concentration is more
than 9%.
The extensibility of VH and BH were statistically significantly increased by all concentrations of
EXS except for the increase in the extensibility of BH caused by an increase from 6% EXS to 9% EXS,
which was statistically insignificant; this means that 6% EXS was the minimum concentration that
could cause the maximum extensibility for BH (0.40 ±0.05%).
The extensibility of TH fluctuated with statistically insignificant changes. The microscopical
surface and cross-sectional images of SEM showed the morphological attachment of emblica on VH,
BH, and TH. As an extract solution, emblica has potential as a hair strengthening treatment for virgin
hair and 12% of hydrogen peroxide on BH.
Author Contributions:
Conceptualization, and methodology, P.T., T.T., C.C., and D.N.; formal analysis,
data curation, P.T.; writing—original draft preparation, P.T.; writing—review and editing, B.S.S., C.C., D.N.;
supervision, project investigator, C.C., D.N. All authors have read and agreed to the published version of
the manuscript.
Funding:
This project was partially supported by Suan Sunandha Rajabhat University, Bangkok, Thailand.
This project was partially supported by Chiang Mai University, Thailand.
Acknowledgments: BSS would like to acknowledge postdoctoral grant of Chiang Mai University.
Conflicts of Interest: The authors declare no conflict of interest in this work.
Appl. Sci. 2020,10, 6305 14 of 16
References
1.
Leszek, J.W. Human hair: A unique physicochemical composite. J. Am. Acad. Dermatol.
2003
,48, S106–S114.
[CrossRef]
2.
Clara, B.; Sonya, S.; Alisa, R.L.; Rob, K.; Albert, M.M.; Jose, L.P.; Luisa, C. Restoring important hair properties
with wool keratin proteins and peptides. Fibers Polym. 2010,11, 1055–1061. [CrossRef]
3.
Oh, K.; Park, M.; Kang, T. Effect of mordant bleaching on the optical and mechanical properties of black
human hair. J. Soc. Dye. Colorists 1997,113, 243–249. [CrossRef]
4.
Deprez, P. Textbook of Chemical Peels: Superficial, Medium, and Deep Peels in Cosmetic Practice; CRC Press:
Florida, OH, USA, 2018; p. 63. ISBN 978-1482223934.
5.
Krishnaswamy, S.; Sooraj, S.Y. Hair dye poison and the developing world. J. Emerg. Trauma Shock
2009
,2,
129–131. [CrossRef]
6.
Kwon, O.S.; Han, J.H.; Yoo, H.G.; Chung, J.H.; Cho, K.H.; Eun, H.C.; Kim, K.H. Human hair growth
enhancement
in vitro
by green tea epigallocatechin-3-gallate (EGCG). Phytomedicine
2007
,14, 551–555.
[CrossRef]
7.
Datta, K.; Singh, A.T.; Mukherjee, A.; Bhat, B.; Ramesh, B.; Burman, A.C. Eclipta alba extract with potential
for hair growth promoting activity. J. Ethnopharmacol. 2009,124, 450–456. [CrossRef] [PubMed]
8.
Adhirajan, N.; Kumar, T.R.; Shanmugasundaram, N.; Babu, M.
In vivo
and
in vitro
evaluation of hair growth
potential of Hibiscus rosa-sinensis Linn.J. Ethnopharmacol. 2003,88, 235–239. [CrossRef]
9.
Barthakur, N.N.; Arnold, N.P. Chemical analysis of the emblic (Phyllanthus emblica L.) and its potential as a
food source. Sci. Hortic. 1991,47, 99–105. [CrossRef]
10.
Liu, X.; Zhao, M.; Wu, K.; Chai, X.; Yu, H.; Tao, Z.; Wang, J. Immunomodulatory and anti-cancer activities of
phenolics from emblica fruit (Phyllanthus emblica L.). Food Chem. 2012,131, 685–690. [CrossRef]
11.
Haque, T.; Muhsin, M.; Akhter, T.; Haq, E.; Begum, R.; Chowdhury, F.U.A. Antimicrobial and analgesic
activity of leaf extracts of Phyllanthus reticulatus Poir. (Family- Euphorbiaceae). Jahangirnagar Univ. J. Biol. Sci.
2016,5, 81–85. [CrossRef]
12.
Scartezzini, P.; Antognoni, F.; Raggi, M.A.; Poli, F.; Sabbioni, C. Vitamin C content and antioxidant activity of
the fruit and of the Ayurvedic preparation of Emblica officinalis Gaertn.J. Ethnopharmacol.
2006
,104, 113–118.
[CrossRef] [PubMed]
13.
Nisar, M.F.; He, J.; Ahmed, A.; Yang, Y.; Li, M.; Wan, C. Chemical Components and Biological Activities of
the Genus Phyllanthus: A Review of the Recent Literature. Molecules 2018,23, 2567. [CrossRef]
14.
Priya, F.F.; Islam, M.S. Phyllanthus emblica Linn. (Amla)—A Natural Gift to Humans: An Overview. J. Dis.
Med. Plants 2019,5, 1–9. [CrossRef]
15.
Archana, A.B.; Varsha, M.J.; Kadam, V.J. Potential of Tannins: A Review. Asian J. Plant Sci.
2010
,9, 209–214.
[CrossRef]
16.
Jain, P.K.; Dass, D. Evaluating hair growth potential of some traditional herbs. Asian J. Pharm. Clin. Res.
2015,8, 150–152.
17.
Yu, J.Y.; Gupt, B.; Park, H.G.; Son, M.; Jun, J.; Yong, C.S.; Kim, J.A.; Kim, J.O. Preclinical and Clinical Studies
Demonstrate That the Proprietary Herbal Extract DA-5512 Effectively Stimulates Hair Growth and Promotes
Hair Health. Evid. Based Complementary Altern. Med. 2017, 4395638. [CrossRef]
18.
Kumar, N.; Rungseevijitprapa, W.; Narkkhong, N.; Suttajit, M.; Chaiyasut, C. 5
α
-reductase inhibition and
hair growth promotion of some Thai plants traditionally used for hair treatment. J. Ethnopharmacol.
2012
,
139, 765–771. [CrossRef]
19.
Kumar, A.; Singh, A.; Dora, J. Review Article Essentials Perspectives for Emblica officinalis.Medicine
2012
,1,
11–18.
20.
Houwink, R.; de Decker, H.K. Elasticity, Plasticity, and Structure of Matter, 3rd ed.; Cambridge University
Press: London, UK, 1971; pp. 1–10. ISBN 9780521112765.
21. Davis, J.R. Tensile Testing, 2nd ed.; ASM International: Novelty, OH, USA, 2004; ISBN 978-0-87170-806-9.
22.
Gianola, D.S.; Eberl, C. Micro-and nanoscale tensile testing of materials. J. Oper. Manag.
2009
,61, 24–35.
[CrossRef]
Appl. Sci. 2020,10, 6305 15 of 16
23.
Srinivasan, G.; Srinivas, C.R.; Mathew, A.C.; Duraiswami, D. Effects of Hard Water on Hair. Int. J. Trichol.
2013,5, 137–139. [CrossRef]
24.
Gui-Young, L.; Byung-Soo, C. Study on the Tensile Strength of Bleached Hair. Appl. Microsc.
2008
,38,
251–257.
25.
Yu, Y.; Yang, W.; Wang, B.; Meyers, M.A. Structure and mechanical behavior of human hair. Mater. Sci. Eng. C
2017,73, 152–163. [CrossRef] [PubMed]
26.
Hall
é
got, P.; Peteranderl, R.; Lechene, C. Philippe In-Situ Imaging Mass Spectrometry Analysis of Melanin
Granules in the Human Hair Shaft Ralph Peteranderl Claude Lechene. Dermatology
2004
,122, 381–386.
[CrossRef]
27.
Tangvijitthiporn, T. The Effect of Hair Spray Containing Butterfly Pea and Malacca Extract on Coloring of
Hair Pieces. Master Thesis, Khonkaen University, Khonkaen, Thailand, 2007.
28.
Lee, Y.; Kim, Y.; Pi, L.; Lee, S.; Hong, H.; Lee, W. Comparison of hair shaft damage after chemical treatment
in Asian, White European, and African hair. Int. J. Dermtol. 2014,53, 1103–1110. [CrossRef]
29.
Franbourg, A.; Hallegot, P.; Baltenneck, F.; Toutain, C.; Leroy, F. Current research on ethnic hair. J. Am. Acad.
Dermtol. 2003,48, 115–119. [CrossRef]
30.
Loussouarn, G.; Lozano, I.; Panhard, S.; Collaudin, C.; Rawadi, C.E.; Genain, G. Diversity in human hair
growth, diameter, colour and shape. An
in vivo
study on young adults from 24 different ethnic groups
observed in the five continents. Eur. J. Dermtol. 2016,26, 144–154. [CrossRef]
31.
Baran, R.; Maibach, H.I. Textbook of Cosmetic Dermatology, 5th ed.; CRC Press: San Francisco, CA, USA, 2017;
p. 390. ISBN 13: 978-1-4822-5734-2.
32.
Jeong, M.S.; Lee, C.M.; Jeong, W.J.; Kim, S.J.; Lee, K.Y. Significant damage of the skin and hair following hair
bleaching. J. Dermatol. 2010,37, 882–887. [CrossRef]
33.
Tapia, A.G.; Guerra, E.G. Hair Cosmetics: Dyes. Dep. Med. Actas Actas Dermo-Sifiliogr
á
ficas
2014
,105, 833–839.
[CrossRef]
34.
Kim, C.; Chun, H. Effects of bleaching time and hydrogen peroxide concentration on hair damage. Korean J.
Hum. Ecol. 2005,14, 433–439.
35.
Davis, M.G.; Thomas, J.H.; van de Velde, S.; Boissy, Y.; Dawson, T.L., Jr.; Iveson, R.; Sutton, K. A novel
cosmetic approach to treat thinning hair. Br. J. Dermtol. 2011,165, 24–30. [CrossRef]
36.
Morita, T.; Kitagawa, M.; Yamamoto, S.; Sogabe, A.; Imura, T.; Fukuoka, T.; Kitamoto, D. Glycolipid
biosurfactants, mannosylerythritol lipids, repair the damaged hair. J. Oleo Sci.
2010
,59, 267–272. [CrossRef]
[PubMed]
37. Khan, K.H. Roles of Emblica officinalis in Medicine—A Review. Bot. Res. Int. 2009,2, 218–228.
38.
Priprem, A.; Lee, Y.C.; Limphirat, W.; Tiyaworanant, S.; Saodaeng, K.; Chotitumnavee, J.; Kowtragoon, N.
Eucalyptus ash alters secondary protein conformation of human grey hair and facilitates anthocyanin dyeing.
PLoS ONE 2018,13, e0199696. [CrossRef]
39.
Jaijoy, K.; Soonthornchareonnon, N.; Lertprasertsuke, N.; Panthong, A.; Sireeratawong, S. Acute and chronic
oral toxicity of standardized water extract from the fruit of Phyllanthus emblica Linn.Int. J. Appl. Res. Nat. Prod.
2010,3, 48–58.
40.
Kaushik, V.K.; Shrishail, M.G. Indian gooseberry (Emblica officinalis): Complete pharmacognosy review. Int. J.
Chem. Stud. 2018,2, 5–11.
41.
Han, S.Y.; Hong, S.P.; Kang, E.K.; Kim, B.J.; Lee, H.; Kim, W.I.; Choi, I.S. Iron Gall Ink Revisited: Natural
Formulation for Black Hair-Dyeing. Cosmetics 2019,6, 23. [CrossRef]
42.
Catherine, U. Natural Standard Medical Conditions Reference E-Book: An Integrative Approach; Natural Standard
Research Collaboration: Somerville, MA, USA, 2009; p. 150. ISBN 978-0-323-06405.
43.
Evgeny, P.; Alexander, S.; Damien, D.; Olga, P.; Valery, M.; Vladimir, T.; Raimo, H. Chemical and antioxidant
evaluation of Indian gooseberry (Emblica officinalis Gaertn., syn. Phyllanthus emblica L.) supplements.
Phytother. Res. 2009,23, 1309–1315. [CrossRef]
44.
Kaleem, Q.M.; Akhtar, M.; Awais, M.M.; Saleem, M.; Zafar, M.; Iqbal, Z.; Muhammad, F.; Anwar, M.I.
Studies on Emblica officinalis Derived Tannins for Their Immunostimulatory and Protective Activities against
Coccidiosis in Industrial Broiler Chickens. Sci. World J. 2014,2014, 378473. [CrossRef]
Appl. Sci. 2020,10, 6305 16 of 16
45.
Fernandes, M.V.; Duboc, N.A.M.; Bastos, S.L.E.; Longo, E. Morphological analysis of polymers on hair fibers
by SEM and AFM. Mater. Res. 2003,6. [CrossRef]
46.
Robbins, C.R. Chemical and Physical Behavior of Human Hair; Springer: Berlin, Germany, 2012; pp. 388–395.
[CrossRef]
©
2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).