367
responsible for the production of collagen and elastin fibers reducing skin wrinkles.
In addition, amino acids in Aloe soften dry skin cells and increase its zinc content,
and decrease pores sizes through its astringent effect (West and Zhu 2003).
Topical application of Aloe vera gel on the skin, yield to the production of the
antioxidant protein metallothionein which scavenges hydroxyl radicals (OH
•
),
inhibits superoxide dismutase (SOD) suppression and glutathione peroxidase
(GSHx) in skin with subsequent reduction in interleukin-10 (IL-10) production
(Byeon et al. 1988). Accordingly, Aloe vera gel can also prevent the UV and gamma
rays-induced skin damages (Roberts and Travis 1995). Aloesin can act as a potential
as a pigmentation-altering component for cosmetic uses through inhibition of the
tyrosinase enzyme (Yagi et al. 2003).
Cho et al. 2009 studied the effect of 90 days dietary intake of Aloe vera gel
supplementation at 2 different doses (1200 and 3600 mg/day) on thirty healthy
female subjects over the age of 45. Their facial wrinkles measured using a skin
replica were improved significantly in at the two doses, and facial elasticity determined by an in vivo suction skin elasticity meter were improved in the lower-dose
group compared to their baseline status which was used as a control. In the
photoprotected skin, the type I procollagen mRNA levels were insignificantly,
increased at the two dose levels, the matrix metalloproteinase 1 (MMP-1) mRNA
levels expression determined using real-time RT-PCR was significantly decreased
in the higher-dose group. Type I procollagen immunostaining was substantially
increased throughout the dermis in both groups. So, the gel significantly improved
wrinkles and elasticity in photoaged human skin, with an increase in collagen production in the photoprotected skin and a decrease in the collagen- degrading MMP-1
gene expression. However, no dose- response relationship was found between the
low- dose and high-dose groups.
Tanaka et al. (2015) investigated the capability of Aloe sterols (cycloartenol and
lophenol) to stimulate human dermal fibroblasts in vitro. After 48-h co-culture with
Aloe sterols, the production of collagen and hyaluronic acid increased in a
concentration- dependent manner. Treatment of the human dermal fibroblasts with
2 μM Aloe sterols increased collagen and hyaluronic acid production by approximately twofold and 1.5-fold The gene expression levels of the enzymes responsible
for the synthesis of collagen (COL1A1 and COL3A1) and hyaluronic acid (HAS2
and HAS3) was associated with a dose-dependent increase in their mRNA level
after A 6-h incubation period with 0.02–2.0 μM cycloartenol and lophenol in human
dermal fibroblasts.
The authors also investigated the effect of intake of A. vera gel powder containing 40 μg Aloe sterols on the skin conditions in 54 Japanese women with dry skin in
a randomized, double-blind, placebo-controlled trial. An increase in arm skin hydration was observed at 8 weeks in the A. vera gel powder treated group, whereas a
slight decrease in arm skin hydration was noted in the placebo group. However,
there was no statistical difference between A. vera gel powder and placebo groups
in skin moisture. In subgroup analysis, the change in the mean wrinkle depth was
significantly lower in the A. vera gel powder group than in the control group. No
observed harmful phenomenon during the treatment period. The study confirmed
18 Aloe Species as Valuable Sources of Functional Bioactives
responsible for the production of collagen and elastin fibers reducing skin wrinkles.
In addition, amino acids in Aloe soften dry skin cells and increase its zinc content,
and decrease pores sizes through its astringent effect (West and Zhu 2003).
Topical application of Aloe vera gel on the skin, yield to the production of the
antioxidant protein metallothionein which scavenges hydroxyl radicals (OH
•
),
inhibits superoxide dismutase (SOD) suppression and glutathione peroxidase
(GSHx) in skin with subsequent reduction in interleukin-10 (IL-10) production
(Byeon et al. 1988). Accordingly, Aloe vera gel can also prevent the UV and gamma
rays-induced skin damages (Roberts and Travis 1995). Aloesin can act as a potential
as a pigmentation-altering component for cosmetic uses through inhibition of the
tyrosinase enzyme (Yagi et al. 2003).
Cho et al. 2009 studied the effect of 90 days dietary intake of Aloe vera gel
supplementation at 2 different doses (1200 and 3600 mg/day) on thirty healthy
female subjects over the age of 45. Their facial wrinkles measured using a skin
replica were improved significantly in at the two doses, and facial elasticity determined by an in vivo suction skin elasticity meter were improved in the lower-dose
group compared to their baseline status which was used as a control. In the
photoprotected skin, the type I procollagen mRNA levels were insignificantly,
increased at the two dose levels, the matrix metalloproteinase 1 (MMP-1) mRNA
levels expression determined using real-time RT-PCR was significantly decreased
in the higher-dose group. Type I procollagen immunostaining was substantially
increased throughout the dermis in both groups. So, the gel significantly improved
wrinkles and elasticity in photoaged human skin, with an increase in collagen production in the photoprotected skin and a decrease in the collagen- degrading MMP-1
gene expression. However, no dose- response relationship was found between the
low- dose and high-dose groups.
Tanaka et al. (2015) investigated the capability of Aloe sterols (cycloartenol and
lophenol) to stimulate human dermal fibroblasts in vitro. After 48-h co-culture with
Aloe sterols, the production of collagen and hyaluronic acid increased in a
concentration- dependent manner. Treatment of the human dermal fibroblasts with
2 μM Aloe sterols increased collagen and hyaluronic acid production by approximately twofold and 1.5-fold The gene expression levels of the enzymes responsible
for the synthesis of collagen (COL1A1 and COL3A1) and hyaluronic acid (HAS2
and HAS3) was associated with a dose-dependent increase in their mRNA level
after A 6-h incubation period with 0.02–2.0 μM cycloartenol and lophenol in human
dermal fibroblasts.
The authors also investigated the effect of intake of A. vera gel powder containing 40 μg Aloe sterols on the skin conditions in 54 Japanese women with dry skin in
a randomized, double-blind, placebo-controlled trial. An increase in arm skin hydration was observed at 8 weeks in the A. vera gel powder treated group, whereas a
slight decrease in arm skin hydration was noted in the placebo group. However,
there was no statistical difference between A. vera gel powder and placebo groups
in skin moisture. In subgroup analysis, the change in the mean wrinkle depth was
significantly lower in the A. vera gel powder group than in the control group. No
observed harmful phenomenon during the treatment period. The study confirmed
18 Aloe Species as Valuable Sources of Functional Bioactives