Table 6.

Selected flavonoids of S. littoralis Hassk. in cosmetic properties based on clinical activity.

Cosmetic properties	The main mechanism	Selected flavonoids	Clinical activity	Reference(s)
Antioxidant activity	▪Increasing the radical scavenging activity in human skin.	Catechin	Catechin-rich Yabukita and Benifuuki teas increased radical scavenging activity in human skin by 28 and 29%, respectively. For two weeks, each participant drank 600 mL of tea every day.	(Megow et al., 2017)
		Daidzein	Tofu containing daidzein has been shown to reduce coronary heart disease in both men and women in the United States, assuming that daidzein is an excellent antioxidant.In six healthy women between the ages of 18 and 35, consumption of isoflavones containing glycitein (1.0 and 2.0 mg total isoflavones/kg bw/day for 3 weeks) was performed as an effective antioxidant.	(Ma et al., 2020) (Fritz et al., 2003)
		Glycitein	Consumption of isoflavones containing glycitein (1.0 and 2.0 mg total isoflavones/kg bw/day for 3 weeks) acted as a good antioxidant in 6 healthy women 18-35 years old.	(Fritz et al., 2003)
		Luteolin	The antioxidant effects of luteolin and palmitoylethanolamide on olfactory function recovery in corona virus (COVID-19) patients.	(D’Ascanio et al., 2021)
		Apigenin	Consuming 40 mg of apigenin is less than 1% of what is required for a significant therapeutic result on cancer cell behavior, including free radical scavenging.	(DeRango-Adem and Blay, 2021)
		Hesperetin	Hesperetin was quickly absorbed when taken orally and acted as an antioxidant in six healthy volunteers.	(Kanaze et al., 2007)
		Naringenin	In patients with level I hypertension, consumption of naringenin glycoside 677 mg/L for 5 weeks in sweet juice decreased diastolic blood pressure and was related to higher plasma antioxidant levels. In six healthy volunteers, naringenin was promptly absorbed when administered orally and worked as an antioxidant.	(Reshef et al., 2005) (Kanaze et al., 2007)
Anti-inflammatory activity	▪Protecting human skin from sunburn inflammation and inflammation associated with many diseases ▪Reducing IL-18 levels in postmenopausal women	Catechin	In a 12-week open oral intervention research, 16 healthy people were given low-dose green tea catechin (540 mg) and vitamin C (50 mg) daily. The results in human skin contributed to protecting against sunburn inflammation.	(Rhodes et al., 2013)
		Daidzein	In the United States, it has been demonstrated that tofu containing daidzein lowers inflammation related to coronary heart disease in both men and women.	(Ma et al., 2020)
		Formononetin	When compared to the control diet, consuming soy nuts with formononetin (an isoflavone) reduced IL-18 levels in postmenopausal women over eight weeks.	(Azadbakht et al., 2007)
		Glycitein	For eight weeks, postmenopausal women who consumed soy nuts together with glycitein (an isoflavone) had lower IL-18 levels than those who had a control diet.	(Azadbakht et al., 2007)
		Luteolin	37 children between the ages of 4 and 14 years ingested 2 capsules/20 kg (each capsule containing 200 mg of total luteolin and quercetin) over 4 weeks, which demonstrated a significant reduction in inflammation-related disorders in humans.	(Theoharides et al., 2012)
Photoprotective activity	▪To protect skin from UV radiation containing UVA and UVB rays.	Catechin	Consuming green tea polyphenols with a total catechin content of 1402 mg per day for 12 weeks in a group of 60 female volunteers showed that it might protect skin from damaging UV rays and enhance women's overall skin quality.	(Heinrich et al., 2011)
		Daidzein	Daidzein-containing soy products were consumed orally by thirty healthy women over eight weeks, and the results demonstrated significant photoprotection with minimum erythema dosage to UVA increased by 60% and to UVB increased by 87%.	(Haron et al., 2020)
		Glycitein	Over eight weeks, thirty healthy women consumed soy products containing glycitein orally, and the results showed considerable photoprotection with minimum erythema dosage to UVA increased by 60% and to UVB increased by 87%.	(Haron et al., 2020)
		Hesperetin	Hesperetin formulations with enhancers (D-limonene and lecithin) were effective as topical photoprotective agents on six volunteers (25-35 years old).	(Saija et al., 1998)
		Naringenin	As topical photoprotective agents in six participants (25-35 years old), naringenin formulations with enhancers (D-limonene and lecithin) proved successful.	(Saija et al., 1998)
Tyrosinase inhibitor	▪Reducing melanin formation ▪Suppressing the tyrosinase activity ▪Making the skin brighter ▪Reducing dark circles under the eyes	Daidzein, Formononetin, Glycitein	For two months, the stabilized soy extracts reduced melanin production or suppressed the expression of tyrosinase in 50 South-East Asian women.	(Petit and Piérard, 2002)
		Apigenin	After 28 days of treatment with an apigenin-based regimen, the skin was brighter (81%) and dark circles under the eyes were minimized (53%) in 25 healthy females.	(Arterbery and Gupta, 2018)
Elastase inhibitor	▪Improving the skin elasticity ▪Increasing the elastic fibers ▪Reducing skin wrinkles	Daidzein, Formononetin, Glycitein	After eight weeks of oral intake of 10 mg of isoflavone aglycones, Japanese women (30-40 years old) in the test food group showed considerably greater skin elasticity recovery than those in the control group. For six months, 100 mg/day of an isoflavone-rich supplement enhanced the number of elastic fibers in 22 postmenopausal women (75.8%).	(Izumi et al., 2007) (Accorsi-Neto et al., 2009)
		Luteolin	The cream containing luteolin extracted from Artemisia iwayomogi showed effective anti-wrinkle results.	(Kim et al., 2019)
		Apigenin	Apigenin-based regimen enhanced skin elasticity (81%) after 56 days of treatment on healthy 25 females. The cream contained apigenin increased skin elasticity (43.4%) and dermal density (24.75%) in 40 women (30 years old) for 4 weeks of treatment	(Arterbery and Gupta, 2018) (Choi et al., 2016)
		Hesperetin	A topical formulation containing 0.1% hesperetin and 0.1% sodium cyclic lysophosphatidic acid (NcPA) used for 12 weeks could enhance skin elasticity in 35 females.	(Sheen et al., 2021)
Collagenase inhibitor	▪Increasing the number of collagens in the dermis ▪Preventing collagen degradation .	Daidzein, Formononetin, Glycitein	During six months, 100 mg/day of an isoflavone-rich supplement enhanced the amount of collagen in the dermis in 25 postmenopausal women (86.2%).	(Accorsi-Neto et al., 2009)
		Luteolin	The cream containing luteolin extracted from Artemisia iwayomogi showed effective anti-wrinkle results.	(Kim et al., 2019)
		Apigenin	On healthy 25 females, an apigenin-based regimen resulted in skin that was younger (67%) and softer (90%) after 28 days of treatment.	(Arterbery and Gupta, 2018)
		Hesperetin	On 35 females, a topical composition containing 0.1% hesperetin and 0.1% NcPA used for 12 weeks could prevent collagen degradation and keep the structure of the dermal extracellular matrix.	(Sheen et al., 2021)
Hyaluronidase inhibitor	▪Making skin hydrated ▪Enhancing skin moisture	Apigenin	Throughout 28 days of treatment, the skin of 25 healthy females was moisturized because of an apigenin-based regimen. During a 4-week treatment period, apigenin cream enhanced skin moisture (51.38%), skin texture evenness (19.65%), and transepidermal water loss (TEWL) (27.61%) in 40 women (30 years old).	(Arterbery and Gupta, 2018) (Choi et al., 2016)
		Hesperetin	Over 12 weeks, a topical composition combining 0.1% hesperetin and 0.1% NcPA might enhance stratum corneum hydration and make skin moisturized in 35 females.	(Sheen et al., 2021)