Table 1.

Characteristics of the studies included in this review (changes in parameters compared to the normal control).

Type of Plant Used	Sample/ Population	Methodology	Parameters Increased	Parameters Decreased	Parameters Unchanged	Conclusion
Green tea polyphenol (GTP) [19]	In vivo study Female SKH-1 hairless mice (6–7 weeks old).	GTP was given to SKH-1 hairless mice as drinking water (0.2%, wt/vol) before they were repeatedly exposed to UVB (90 mJ/cm2) for two months on alternate days. (a) H&E staining for microscopic histological evaluation (b) Skin biopsies were collected to determine protein carbonyl following DNPH analytical assay (c) Western blot analysis was done to assess the protein oxidation & MMP analysis		epidermal hyperplasia protein oxidation protein carbonylation expression of MMP-2, MMP-3, MMP-7, and MMP-9		GTP exerts photoprotective effects by preventing oxidative damage and inhibition of MMP expression.
	In vitro study Human fibroblast HS68.	Human fibroblast HS68 were cultured and treated with GTP before being exposed to UVB radiation (30 mJ per cm2) (a) Western blot analysis to access protein oxidation
Green tea [20]	Double blind, placebo controlled clinicaltrial	(a) UV irradiation sensitivity was tested at weeks 0, 6, and 12 where dorsal skin at the back and scapular region was exposed to radiation. Skin tone was assessed before and after 24 h. (b) Skin elasticity was assessed using the Cutometer SEM 474 suction method on the inner forearm skin. (d) Skin density, thickness, structure and texture were examined using a high-frequency Ultrasound B-Scan. (e) Tewameter and Corneometer were used to measure transepidermal water loss (TEWL) and skin hydration in inner forearm. (f) The O2C-system (Lea Instruments) to assess peripheral blood flow and oxygen was used.	Skin elasticity and density hydration dermal blood flow oxygen saturation	roughness, volume, and scaling skin redness	skin thinning	Regular intake of tea flavonoid in beverage was able to protect skin against UV radiation and improve skin quality and function
Bog blueberry extract (BBe) [21]	Human dermal fibroblast	Human dermal fibroblasts were pretreated with 1–10 mg/L ATH-BBe. Then, 100 mJ/cm2 UV-B was used to expose the pre-treated cell culture. (a) The MTT assay was used to assess cellular viability following UVB exposure. (b) Procollagen and collagenolytic MMP secretion expression levels were assessed using Western blot. (c) ELISA was used to measure the cytokine secretion from UV-B-irradiated fibroblasts. (d) Immunoblot analysis was used to assess NF-kB activation and MAPK signalling.	Cell viability Procollagen expression	Expression of MMP-1, MMP-8, and MMP-13 Cytokine releaseꓽ IL-1b, IL-6, IL-8, TNF-a. Phosphorylation of IkB		Anthocyanins were able to alleviate UV radiation injury via anti-inflammatory action and inhibition of NF-kB activation and MAPK signalling.
Rosemary extract, citrus bioflavonoid extract [22]	In vitro study The human keratinocytes cell (HaCaT cells)	Human keratinocyte cells were cultured and treated with rosemary extract and citrus bioflavonoid extract before exposure to UVB. (a) Cell protection level was estimated as the percentage of cell viability recovered using the MTT assay, which was used to determine cellular viability. (b) The Folin-Ciocalteu technique was used to calculate the total phenolic compound (TPC). (c) The Comet assay was used to measure DNA damage. (d) A CBMN technique was used to conduct micronucleus assays on the irradiated lymphocytes.	Cell survival MED	Abnormalities of lymphocytes chromosomal Intracellular ROS DNA damage		Synergistic effect of both polyphenols in photoprotection by reducing oxidative damage.
	Human study Double blind, placebo controlled clinical trial	MED was measured pre and post-treatment.
Luteolin from carrots [23]	In vitro study HaCaT human keratinocyte cell line	Before being exposed to UVB (0.01 J/cm2), HaCaT cells were treated for 1 h with luteolin (5 and 10 lM) and then incubated for 5 or 3 h, respectively. (a) The expression of MMP-1, JNK, c-Jun, ERK, and RSK phosphorylation were measured by Western blot analysis. (b) Using the luciferase assay, AP-1 transactivation and c-Fos promoter activation were quantified. (c) The expression of JNK1, JNK2, ERK2, and p90RSK was assessed using kinase assay. (d) JNK1, JNK2, and RSK2 expressions were analysed using pull-down assay.		MMP-1 expression Inhibit AP-1 transactivation C-FOS gene expression Activity of JNK1 and p90RSK Expression of MMp-13 Wrinkles formation	Activation of JNK2 and ERK	Luteolin was able to provide protection by inhibiting UVB-induced signal transduction
	In vivo study SKH-1 hairless mice (5 weeks of age; mean body weight, 25 g)	For 15 weeks, luteolin (10 and 40 nmol) dissolved in 200L acetone was applied topically to the backs of SKH-1 hairless mice. This treatment began 1 h before UVB exposure (0.18 J/cm2). (a) Western blot analysis was done to assess MMP-13 expression (b) Grading of wrinkle formation.
Tomato and rosemary extract [24]	Double blind, placebo controlled clinical trial	149 participants were randomly assigned to carotenoid-rich tomato nutrient complex (TNC) or placebo for a 12-week period (a) A dose of 1.25 MED with Dermalight® 80 MED was administered to an additional field (12 × 12 mm) of the buttock to take biopsies and to determine the skin’s colour using chromametry. A change in skin tone quantified the development of erythema. (b) Blood samples were taken, and serum was evaluated for the presence of carotenoids at random intervals during a 5-week washout phase, after four weeks of therapy, and after the study. Two colourless carotenoids (phytofluene and phytoene), were also measured. (c) Biopsies were taken after 24 h following chromametry using 1.25 MED in order to evaluate UV-induced gene expression.	Carotenoid plasma level	Erythema formation IL6	MED	The carotenoid-rich supplement significantly prevented UVB-induced erythema and cytokine upregulation.
Tomato [25]	Single blind, placebo controlled clinical trial.	Volunteers received either tomato paste and olive oil or just olive oil. Their skin was exposed to UVB and they were assessed for erythema at baseline and week 12. (a) Immunohistochemical analysis was done to identify a panel of ECM molecules or remodelling enzymes in frozen sections. (b) A five-point semiquantitative scale was used to evaluate the level of immunostaining for procollagen and fibrillin-1, (c) MMP-1-positive dermal cell counts were calculated with high-power field (×400)	Mean SD erythemal D30 Procollagen deposition	MMP-1 expression	Fibrillin-1 expression	Lycopene-rich tomato paste offers defense against both immediate and possible long-term effects of photodamage.
Grape peel extract (GPE) [26]	In vitro study HaCaT cells In vivo study: ICR six-week-old male mice	HaCaT cells were treated for 24 h with GPE or resveratrol (RES). Then, HaCaT cells were subsequently exposed to UVB radiation at a dose of 25 mJ/cm2. (a) Assessment of fractionation of nuclear and cytoplasmic proteins using Western blot analysis. Before receiving UVB (280–315 nm) radiation treatment, the dorsal skin of mice was shaved and they were given GPE orally three times per week for seven weeks. (a) Histological analysis of the skin tissue from mice (b) Western blot analysis	Expression of nuclear Nrf2 Expression of cytoplasmic HO-1	Wrinkles Epidermis thickening		Resveratrol exhibits photoprotection and photoageing effects via regulation of nuclear Nrf2.
Grape seed proanthocyanidin extract (GSPE) [27]	Double blind, placebo controlled clinical trial.	Cutaneous areas on the backs of volunteers were untreated or treated with GSPE solutions, 30 min before exposure to two minimal erythema doses (MED) of solar simulated radiation. (a) Cutaneous regions at various sites were examined histologically for the number of sunburn cells. (b) Mutant p53-positive cells and CD1a+ Langerhans cells were identified using immunohistochemistry.	Langerhans cells exhibit more dendrites	Sunburn cells Fewer mutant p53-positive cells		Topical GSPE prevents formation of sunburn cells, mutant p53 epidermal cells.