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Torres et al. Plast Aesthet Res 2020;7:57 I http://dx.doi.org/10.20517/2347-9264.2020.87 Page 7 of 9

Table 2. Other botanicals with photoprotective effects
Botanical agent Spectrum Mechanism of photoprotection Routes Models Ref.
Cocoa extract UVB Increases MED; decreases erythema and Oral Mouse, Human [7]
skin wrinkling
Rosemary plus grapefruit UVA, UVB Increases MED, skin elasticity; decreases Oral Human [37]
extract erythema, lipoperoxides, and skin wrinkling
Strawberry extract UVA Increases cell viability NA In vitro [38]
Blueberry extract UVA, UVB and Increases cell viability NA In vitro [39]
UVC
Melon concentrate UVA, UVB Increases MED and endogenous antioxidants; Topical, oral Human, In vitro [40]
decreases sunburn cells
Sechium edule (chayote) UVA Increases DNA repair; decreases apoptosis, NA In vitro [41]
extract ROS, DNA damage, and CPDs
Oenanthe javanica (water UVB Increases collagen type I and III; decreases Topical Mouse [42]
celery) extract MMP-1, MMP-3, TNF, and COX-2 expression
UVB: ultraviolet B; UVA: ultraviolet A; UVC: ultraviolet C; MMP: matrix metalloproteinase; TNF: tumor necrosis factor; COX-2:
cyclooxygenase 2; MED: minimal erythema dose; DNA: deoxyribonucleic acid; ROS: reactive oxygen species; CPD: cyclobutane
pyrimidine dimers; NA: Not applicable

dependent manner (i.e., less viable cells with higher silymarin doses). In addition, silymarin pre-treated
keratinocytes produced higher amounts of CPDs following UVA exposure compared to non-pre-treated
keratinocytes. The mechanism for this silymarin-induced phototoxicity is still poorly understood.

Table 1 summarizes the mechanism of photoprotection and spectrum coverage of the botanical agents
discussed above.

Others
Other botanicals that have been reported to have photoprotective effects, albeit have not been as rigorously
studied, are summarized in Table 2.

CONCLUSION
Botanical-based photoprotection is likely to increase in popularity as consumer trends worldwide continue
to place an emphasis on naturally occurring compounds used solely or in conjunction with synthetic
products. The botanicals reviewed above currently have the most evidence available and can serve as
options for providers to recommend to patients. These oral and topical botanical products act through a
variety of biologic mechanisms to confer protection against the adverse effects of UVR. However, unlike
sunscreens, botanical products are not subject to FDA regulations and so rigorous efficacy and safety
testing through large-scale controlled therapeutic trials are lacking for many of these agents. As such, their
true photoprotective benefit compared to established measures like seeking shade, donning UV-blocking
garments, or organic or inorganic topical sunscreens remains to be verified. In addition, the stability of
botanical ingredients as well as the optimal concentration of their constituents is unregulated. Therefore,
while evidence on their use as an adjunctive means of photoprotection appears favorable, they should be
used in conjunction with, and not as a replacement of, pre-existing photoprotection recommendations.
Finally, as the biologic effects of other wavelengths of electromagnetic radiation such as visible and infrared
ranges continue to be elucidated, it will be critical for future research to evaluate the potential applicability
of botanicals for protection in that realm as well.

DECLARATIONS
Authors’ contributions
Made substantial contributions to literature search and writing of initial manuscript: Torres AE, Luk KM
Contributed to writing and editing of manuscript: Lim HW