331 Topical Apple Derivatives
shown by Yang et al. and Chang et al.), and this was further demonstrated through studies
with HaCaT keratinocytes.17 This study allowed for the macroscopic evaluation of the effects
of phloretin 3’3-disulfonate. Another human clinical study demonstrated the effects of
Annurca polyphenolic extract, an industrial procyanidinic extract, on wrinkles and reduced
skin density, elasticity, and hydration in women. The study found an overall increase in dermal
density, skin elasticity, and skin hydration among subjects along with reduction of crow’s
feet and skin roughness.18 The study found that the apple extracts optimized metabolism
in senescent fibroblasts by increasing cellular oxygen consumption and ATP level while also
reducing extracellular lactate levels, restoring full cell function, which resulted in the anti-
aging properties of the serum. However, the serum also contained pro-collagen lipopeptide,
creatine, and urea which are also known for having cosmetic anti-aging effects.27-29 Any of
these ingredients could be responsible for the metabolic optimization, hydration, or cosmetic
effects observed in this study.18 Further studies are indicated for testing the lone effects of
Annurca polyphenolic extract for the reversal of skin wrinkles and increased dermal density.
The evidence that apple derivatives work for chemotherapy-induced alopecia is poor, since
most of the current information is tested only in mice. Chemotherapy-induced alopecia is
a common side-effect of chemotherapy which can be distressing for the patient, can lead
to social and sexual dysfunction, as well as anxiety and depression. Furthermore, typical
treatments for alopecia usually involve hormones and growth factors which could provide
unwanted protection of tumor cells or worse, could induce cancer cell proliferation, and thus
are not an option for patients undergoing chemotherapy. Annurca polyphenolic extract was
found to have a hair promoting effect that resulted in metabolic reprogramming of hair
follicles.20 This reprogramming increases β-oxidation and reduces metabolism through
NADPH dependent pathways, allowing more amino acids to be present for keratin
formation and more prostaglandin F2α intracellularly, which also promotes hair growth.
Due to its mechanism of action, DNA replication and mitosis are not affected by Annurca
polyphenolic extract, making it a potential treatment option for those experiencing
chemotherapy-induced alopecia. However, it is uncertain if the mechanism of action of
Annurca polyphenolic extract is the same in human hair follicles as in mice hair follicles.
Therefore, further studies are indicated in humans and in the efficacy of this extract against
chemotherapeutic regimens, other than Paclitaxel and Docetaxel.
Apple derivatives were found to be ineffective in molluscum contagiosum, TEWL, and
atopic dermatitis, and often lead to more irritation or skin damage. The presence of a
damaged skin barrier seems to predispose further inflammation due to the skin’s inability
to protect itself against the potentially corrosive effects of acidic apple derivatives, such as
apple cider vinegar.
Molluscum contagiosum is a self-limiting skin condition resulting from a molluscum
contagiosum virus infection that is marked by pink umbilicated papules.30 In the reviewed
case report, the topical application of apple cider vinegar to treat Mollusca contagiosum
resulted in chemical burns similar to that of a stronger acid, despite vinegar being a weak
acid.19 The severity of the tissue damage by a weak acid may be attributed to the extended
contact the acid had to the skin (t =8 hours), the preexisting molluscum contagiosum
lesions that could have weakened the skin barrier, or some component in apple cider vinegar
that adds to the causticity of the acid. However, to determine the true effects of the apple-
derived acid on the lesions, there needs to be further studies investigating the effect of the
length of topical contact, molluscum contagiosum lesions, and components of apple cider
vinegar on the skin barrier. As this is a case report based on a single subject, the studies
would need to also involve more subjects to reduce the chances of error and other variables
from affecting the results.
TEWL is commonly evaluated in various dermatologic diseases that present with skin
barrier dysfunction, but there is little current evidence that supports apple derivatives’
efficacy in reducing TEWL.13,31,32 A study evaluating the effectiveness of apple-derived 3%
anthocyanin extract cream on 12 subjects revealed a significant decrease in TEWL after
application for 12 weeks, but there was no significant difference between the treatment
and placebo group.12 The protection from TEWL in both treatment and placebo groups
in this study could be explained by the beeswax present in the topical vehicle. Beeswax is
found to have hydrating properties due to its richness in vitamin A and its ability to form
a hydrophobic barrier over the skin.33
Atopic dermatitis is a chronic skin condition and involves a strong genetic predisposition,
multiple immune pathways, T-cell inflammation, and epidermal dysfunction.34 Two studies
tested the efficacy of apple cider vinegar as a treatment option for atopic dermatitis. One
study found an unsustained reduction in skin pH immediately after treatment with apple
cider vinegar, mild discomfort of the treated area treated, and one subject had a severe
reaction to apple cider vinegar resulting in their discontinuation from the study.21 The
second study found that apple cider vinegar had no altering effects on skin microbiome in
atopic dermatitis patients and no adverse effects to the daily 10-minute soaks.1 The limited
sustainability of skin pH reduction and ineffectiveness in altering skin microbiome could
be due to the dilution of apple cider vinegar to perform soaks (as instructed in the study),
or the short time of contact with dilute apple cider vinegar. Furthermore, a significant
number of subjects with atopic dermatitis in one study showed mild adverse effects to the
treatment with only 10 minutes of contact, and one subject experienced severe pruritus.
The irritating effects of apple derivatives were further supported by a case report, where
topical applications of apple extract resulted in contact urticaria in a 16-year-old male with
atopy, which cleared with removal of contact with the extract.11 This case could indicate
that patients with atopy might have increased risk of reaction or increased sensitivity to
apple extract and could potentially explain the subject’s skin discomfort resulting from
contact with apple cider vinegar. If proven, this could eliminate apple cider vinegar as a
potential therapeutic for patients with atopic dermatitis. To determine the true effect of
apple cider vinegar, further studies should investigate the concentration and duration of
contact with the weak acid with a larger treatment population.
There are a few limitations within these studies that require further study before apple
derivatives can be established as a therapy or used in commercial or drug products. Each
study involved less than 100 subjects, and with such a small sample size, confounding
variables can misrepresent the true effectiveness of the apple derivatives. Adverse effects
can also be overlooked if there is not a wider range of subject ages, gender, and skin types
involved when testing for safety. Also, the effectiveness of different dosages is still yet to be
investigated. In addition, some apple derivatives, such as apple cider vinegar, are found to
be corrosive for the skin and should be warned against use by the public.
Even with these limitations, apple derivatives, most notably 1% phloretin 3’,3-disulfonate
and procyanidin oligomers, show promise in increasing hair growth and decreasing
Previous Page Next Page