Potential of Frangipani (Plumeria alba) Leaves Extract as Ultra Violet Protection

Sunscreen is a substance or material that can protect the skin against ultra violet (UV) radiation's harmful effects by absorbing, diffusing, or reflecting the rays, reducing the energy that affects the skin (Eff et al., 2018; Latha et al., 2013). Cosmetic preparation that contains sunscreen is usually labeled with a specific Sun Protection Factor (SPF) strength. The SPF value is in 2-60 range, this figure shows how long the product can protect or block UV ray that causes sunburn, pigmentation, wrinkles, dermatitis, and skin cancer (Geoffrey et al., 2019; Ngoc et al., 2019; Surdu et al., 2013). In general, sunscreens with an SPF 15 value are used to protect the skin from the adverse effects of UVA and UVB (Paul, 2019). A user can determine the duration of effectiveness only by multiplying the SPF number by the length of time it takes to burn his skin when not wearing sunscreen (Wacker & Holick, 2013). Sunscreen cosmetic preparations on the market come in various forms such as creams, lotions, ointments, gels, or sprays applied to the skin (Perugini et al., 2019). The ingredients of this sunscreen are varied, ranging from synthetic to natural ingredients. Recently, people prefer to use natural sunscreens. This is because the natural ingredients have a less negative impact (Mishra et al., 2011). Natural sunscreen ingredients often added to sunscreens cosmetic products, e.g., carrot, soy, avocado, aloe vera, walnut, citrus fruits, lemon, marigold, sesame seeds, jojoba, and other extracts (Korać & Khambholka, 2011; Geoffrey et al., 2019; Shanbhag et al., 2019). Frangipani (Plumeria alba) plants are a relatively abundant plant in Indonesia, especially in Bali. This plant, originating from America, is straightforward to find in Bali, where almost every Balinese household has this plant because it is easy to grow, and it is rich in benefits. Potential of Frangipani (Plumeria alba) Leaves Extract as Ultra Violet Protection


INTRODUCTION
Sunscreen is a substance or material that can protect the skin against ultra violet (UV) radiation's harmful effects by absorbing, diffusing, or reflecting the rays, reducing the energy that affects the skin (Eff et al., 2018;Latha et al., 2013). Cosmetic preparation that contains sunscreen is usually labeled with a specific Sun Protection Factor (SPF) strength. The SPF value is in 2-60 range, this figure shows how long the product can protect or block UV ray that causes sunburn, pigmentation, wrinkles, dermatitis, and skin cancer (Geoffrey et al., 2019;Ngoc et al., 2019;Surdu et al., 2013). In general, sunscreens with an SPF 15 value are used to protect the skin from the adverse effects of UVA and UVB (Paul, 2019). A user can determine the duration of effectiveness only by multiplying the SPF number by the length of time it takes to burn his skin when not wearing sunscreen (Wacker & Holick, 2013).
Sunscreen cosmetic preparations on the market come in various forms such as creams, lotions, ointments, gels, or sprays applied to the skin (Perugini et al., 2019). The ingredients of this sunscreen are varied, ranging from synthetic to natural ingredients. Recently, people prefer to use natural sunscreens. This is because the natural ingredients have a less negative impact (Mishra et al., 2011). Natural sunscreen ingredients often added to sunscreens cosmetic products, e.g., carrot, soy, avocado, aloe vera, walnut, citrus fruits, lemon, marigold, sesame seeds, jojoba, and other extracts (Korać & Khambholka, 2011;Geoffrey et al., 2019;Shanbhag et al., 2019).
Frangipani (Plumeria alba) plants are a relatively abundant plant in Indonesia, especially in Bali. This plant, originating from America, is straightforward to find in Bali, where almost every Balinese household has this plant because it is easy to grow, and it is rich in benefits.
To grow this plant, people only need to cut the branching of the stem and stick it into the soil or fertile land, and without the need for over care, this plant will thrive.
These plants have many benefits, ranging from being used as herbal medicines with various properties such as treating swelling, diarrhea, tinea versicolor, toothache, and consuming such as making vegetables (Wrasiati et al., 2011;Ningsih et al., 2014). The Balinese Hindu community uses many flowers from this plant for prayer ceremonies.
Plumeria alba offers many benefits, but the use of its leaves for sunscreen is still unknown. Various studies on P. alba leaves show that these leaves contain secondary metabolites such as flavonoids, alkaloids, phenolic compounds (Gupta et al., 2016). These secondary metabolites are compound capable of absorbing UV rays because it has a conjugated aromatic benzene group (Panche et al., 2016). Therefore, this study aimed to determine P. alba leaves' potential as a sunscreen by calculating the SPF value.

Sample sources and determination
Plumeria alba leaves were collected from Tibubeneng village, Badung Bali, in March 2020. Plant determination is carried out by the Eka Karya Botanical Garden Conservation Center, Indonesian Institute of Sciences with specimen number B154-2 to ensure that the sample used is P. alba from the Apocynaceae family.

Sample preparation
The samples were green P. alba leaves 15-30 cm long.
Samples were washed with flowing water and cut into small pieces. Then the samples were drained and dried by using an oven at 45°C for 24 hours. The samples were blended until achieving a certain degree of smoothness, and afterward, it was sieved by using an 80 mesh siever to obtain the P. alba leaves powder (Ersalina et al., 2020).

Sample extraction
Plumeria alba leaves powder weighed for 750 g was dissolved with ethanol solvents (materials : ethanol ratio = 1 : 7 b/v). Extraction of the sample was filtered with fine filter paper. The filtrate obtained was evaporated using a rotary vacuum evaporator at 40°C and 40 rpm until extract was obtained in the paste form (Ersalina et al., 2020).

Qualitative test of flavonoids compounds
As much as 2 mL of extract was added with 1 mL of 2 N NaOH. The presence of yellow color indicates the presence of flavonoids (Altemimi et al., 2017).

Qualitative test of alkaloids compounds
As much as 1 mL of extract was stirred with 5 mL of 1% aqueous HCl. Then a few drops of Dragendorff's reagent were added. The presence of green color or white precipitate indicates alkaloids' presence (Altemimi et al., 2017).

Qualitative test of phenolic compounds
As much as 0.05 g of the P. alba extract was put in the test tube, then mixed with 2 mL ethanol. The mixture was then added with two drops of 5% FeCl3. Positive reactions were indicated by black-green or blue color (Altemimi et al., 2017).

Determination of SPF value
The P. alba extract sample was weighed at 0.1 g and was dissolved in 10 mL ethanol p.a. Sample testing was conducted by measuring its absorbance using a spectrophotometer at λ 290-320 nm with a measurement interval of 5 mm. The SPF value was performed by using a constant set (Fonseca & Rafaela, 2013). The sample SPF value is calculated using the formula below (Cefali et

Preliminary phytochemical screening
Preliminary phytochemical screening was conducted to determine secondary metabolites content in P. alba extract. The test results can be seen in Table I, where P.
alba extract is positive for flavonoids, alkaloids, and phenolics. This is in line with research conducted by (Gupta et al., 2016), where the P. alba extract tested also contained these secondary metabolites.

SPF value
The SPF values of the P. alba extract obtained are presented in Table II. The sunscreen ability is categorized as classified by Wasitaatmadja (1997). From Table II, P. alba extract with 2500 ppm concentration can potentially be a sunscreen with an extra protection category. Plumeria alba extract with a concentration of 10000 ppm can potentially be a sunscreen with an ultra-protection category (Damogalad et al., 2013). Plumeria alba leaves extract has an SPF value due to its flavonoids, alkaloids, and phenolic contained in the extract. Phenol compounds have conjugated double bonds in the benzene ring. If it is exposed to UV light, the resonance will occur in the form of electron transfer. Flavonoids and alkaloids have UV protective properties because of the presence of a chromophore group, which is considered as a conjugated aromatic system having the ability to absorb light rays in the UV wavelength range in both UV A and B (Becker et al., 2013;Costa et al., 2015;Laeliocattleya, 2019). The SPF value is then used to construct the regression curve, as shown in Figure 1.
From Figure 1, a regression equation that serves to predict the resulting SPF value with a specific concentration can be obtained. The higher the concentration extract used, the higher the SPF value would be.  Yulianti et al. (2015) showed an SPF value of 35.12 from the extract at a concentration of 5000 ppm. Another study by Widyastuti et al. (2016) reported that the ethanol extract of

ACKNOWLEDGMENT
This project is fully supported by the 2020 Universitas Bali Internasional Internal Research Grant.