Abstract:
Dermal aging is characterized by states of oxidative stress, chronic inflammation, and
abnormal proteolytic degradation due to the action of hydrogen peroxide, superoxide, 5-
lipoxygenase, and elastase, respectively. Noteworthy elastase inhibition has previously
been reported, and so this study aimed to investigate the ability of Myrsine africana and
myrsinoside B to reduce the activity of hydrogen peroxide, superoxide, and 5-
lipoxygenase as supplementary mechanisms of action by which M. africana may
reduce the appearance of wrinkles. The use of maltose microneedles were also
investigated as a means to enhance the delivery of myrsinoside B into the skin as this
is a crucial aspect to investigate when characterizing the efficacy of an active ingredient.
Myrsine africana has traditionally been used for skin allergies, boils, and to purify blood (as
an astringent) and was selected for this study based on it use in skincare. The crude
extract exhibited IC50’s of 56.08 ± 2.88 and 132.74 ± 1.64 μg/ml against the hydrogen
peroxide and superoxide radicals, while myrsinoside B exhibited IC50’s of 52.19 ± 4.16
and 192.14 ± 3.52 μg/ml, respectively. The IC50 of the extract and compound against 5-
lipoxygenase was 29.65 ± 2.92 and 29.33 ± 3.08 μg/ml, respectively. No toxicity was
observed in vitro at the highest concentration tested. Microneedle treatment increased the
permeation of the active through the skin after 24 h to 12.46 ± 5.14 μg/cm2 compared to
the passive group (1.30± 0.85 μg/cm2). The amount of active retained in the epidermis
and dermis was 8.97 ± 0.90 and 6.98 ± 0.73 μg/cm2 respectively, greater than the
retention observed in the passive group (3.24 ± 1.41 and 3.27 ± 1.47 μg/cm2, respectively). M. africana and myrsinoside B showed promising antioxidant and antiinflammatory
activity thus supporting the potential of M. africana and myrsinoside B as
anti-wrinkle agents. Further, treatment of dermatomed human skin with maltose
microneedles facilitated topical delivery of myrsinoside B and provided an effective
means for compound delivery to ensure maximum effect.
