the present invention discloses a method for preventing uv - induced skin - cellular injury by providing a green algae extract as a skin - cell protector to inhibit interaction between apoptosis pathway molecules fas / fasl so as to inhibit caspase - 3 activation and polymerase ( parp ) cleavage , such that unrecoverable damage to dna can be prevented . the green algae extract may be made through any commercially available method and mainly achieved by extracting an aqueous liquid extract from fresh water grown unicellular algae . from the ir spectrums of fig5 , 6 and 7 , wherein the wave numbers are ranging form 4000 cm - 1 - 400 cm - 1 , it is learned that the green algae extract is substantially an organic compound and the major elements therein are carbon , hydrogen , as well as nitrogen . the concentrations of the elements are : nitrogen ( n ) 7 . 06 %˜ 7 . 66 %, hydrogen ( h ) 5 . 9 %˜ 6 . 51 %, and carbon ( c ) 35 . 67 %˜ 38 . 1 %. for demonstrating the protective effects of the green algae extract on uv - induced skin injury , the results of some experiments are provided for further illustration . fig1 shows the results of experiment ( n ≧ 6 ) that demonstrates the protective effects of the green algae extract of the present invention on uv - induced cytotoxicity , namely the ability of the green algae extract to prevent uv - induced skin - cellular injury . green algae extracts ( 20 mg / ml and 10 mg / ml ), vitamin c , and vitamin e treated fibroblasts are taken as subjects of the present experiment . the fibroblast survival rates are analyzed after 24 , 48 and 72 hours of uv exposure and the results are quantified in the histogram . in the histogram , rectangles ( 1 ), ( 6 ) and ( 11 ) belong to a comparison group , and the resultant data exhibit that the fibroblast survival rates of the fibroblasts after 24 , 48 and 72 hours of uv exposure are respectively about 63 %, 35 %, and 37 % of the fibroblast survival rates of a control group ( 100 %) which is not exposed in uv . thus , it is revealed that uv exposure is responsible for the decreased fibroblast survival rates and thus the fact is proven that uv - induced cytotoxicity significantly affects the fibroblast survival rates . in the histogram , rectangles ( 2 ), ( 7 ) and ( 12 ) belong to an experimental group , and the resultant data exhibit that the fibroblast survival rates in the green algae extract of 20 mg / ml after 24 , 48 and 72 hours of uv exposure are respectively about 92 %, 101 %, and 149 % of the fibroblast survival rates of the control group which is not exposed in w . as compared with the comparison group , the fibroblast survival rates of the experimental group are much higher . thus , the fact is proven that an effective dose of the green algae extract facilitates reducing uv - induced cytotoxicity so as to provide protection to cells and in turn increase the cell survival rates . in the histogram , rectangles ( 3 ), ( 8 ) and ( 13 ) belong to another experimental group , and the resultant data exhibit that the fibroblast survival rates in the green algae extract of 10 mg / ml after 24 , 48 and 72 hours of uv exposure are respectively about 85 %, 82 %, and 104 % of the fibroblast survival rates of the control group which is not exposed in uv . as compared with the comparison group , the fibroblast survival rates of the experimental group are higher . thus , the fact is proven that an effective dose of the green algae extract facilitates reducing uv - induced cytotoxicity so as to provide protection to cells and in turn increase the cell survival rates . in the histogram , rectangles ( 4 ), ( 9 ) and ( 14 ) belong to another experimental group , and the resultant data exhibit that the fibroblast survival rates in vitamin c of 0 . 15 mm after 24 , 48 and 72 hours of uv exposure are respectively about 53 %, 29 %, and 22 % of the fibroblast survival rates of the control group which is not exposed in u . as compared with the comparison group , the present experimental group fails to sustain fibroblast survival rates . thus , the fact is proven that vitamin c does not facilitate reducing uv - induced cytotoxicity and fails to provide protection to cells . in the histogram , rectangles ( 5 ), ( 10 ) and ( 15 ) belong to another experimental group , and the resultant data exhibit that the fibroblast survival rates in vitamin e of 25 μm after 24 , 48 and 72 hours of uv exposure are respectively about 49 %, 27 %, and 23 % of the fibroblast survival rates of the control group which is not exposed in u . as compared with the comparison group , the present experimental group fails to sustain fibroblast survival rates . thus , the fact is proven that vitamin e does not facilitate reducing uv - induced cytotoxicity and fails to provide protection to cells . as mentioned previously , caspases play an important role in the actuation and completion of apoptosis . thus , the present experiment activates caspase - 3 by uv to analyze the inhibitory effects of the green algae extract of the present invention on caspase - 3 activity . the green algae extract of 20 mg / ml containing fibroblasts is taken as a subject of the present experiment . the concentrations of caspase - 3 are tested after 1 , 24 , 48 and 72 hours of uv exposure and the results are quantified in the histogram of fig2 . in the histogram , rectangle ( 1 ) belongs to a non - ux exposed control group and exhibits that the caspase - 3 concentration in fibroblasts is normally 0 . 7 mmol / 0 . 1 ml . rectangle ( 2 ) belongs to a comparison group and exhibits that after one hour of uv exposure , caspase - 3 in fibroblasts is activated and the concentration thereof is increased to about 1 . 1 mmol / 0 . 1 ml . this result proves that uv exposure substantially induces caspase - 3 activation . in the histogram , rectangle ( 3 ) belongs to an experimental group and exhibits that the caspase - 3 concentration in fibroblasts in green algae extract of 20 mg / ml after one hour of uv exposure is increased to about 1 . 4 mmol / 0 . 1 ml . this result proves that caspase - 3 currently has been activated in a higher rate . this early activation of apoptotic enzyme may indicate that green algae extract accelerates uv - induced cell death in order to maintain normal cell population which is evidence in cell survival rate in experiment 1 . in the histogram , rectangle ( 4 ) belongs to an experimental group and exhibits that the caspase - 3 activity in fibroblasts in the green algae extract of 20 mg / ml after 24 hours of uv exposure is reduced to about 1 . 1 mmol / 0 . 1 ml from about 1 . 4 mmol / 0 . 1 ml that measured after one - hour uv exposure . inhibition of caspase - 3 is kept proceeding . as shown by rectangles ( 5 ) and ( 6 ), after 48 hours and 72 hours of uv exposure , the green algae extract of the present invention still works on restraining caspase - 3 activity , and the caspase - 3 concentrations is reduced to respectively 0 . 6 mmol / 0 . 1 ml and 0 . 4 mmol / 0 . 1 ml . experiment 2 thus proves that an effective dose of the green algae extract of the present invention performs evident effect on inhibiting caspase - 3 so as to protect fibroblasts from premature apoptosis . it is known that caspase activation is achieved by the death - inducing signaling complex ( disc ) which is a product of the interaction between apoptosis pathway molecules fas / fasl . as described above , fas - associated death domain ( fadd ) is one of the death - inducing signaling complex ( disc ) and phosphorylated fadd is in the form of an activated fadd protein . only such phosphorylated fadd can act as the bridge between fas and procaspase 8 , which is the precursor of the caspase , and lead to oligomerization of caspase - 8 to activate the downstream caspase - 3 . thereupon , the present experiment activates fadd by uv or phosphorylates fadd , to form phosphorylated fadd ( po4 - fadd ), to analyze the inhibitory effects of the green algae extract of the present invention on po4 - fadd by the western blotting method . the results are shown in fig3 . in fig3 , column ( 1 ) belongs to a control group and exhibits the fadd and po4 - fadd expressions in fibroblasts under basal condition . columns ( 2 ) and ( 3 ) belong to a comparison group , and exhibit fadd and po - 4 fadd expressions at the 12 th hour and 16 th hour after uv exposure . as compared with the control group shown by column ( 1 ), fadd and po4 - fadd of the comparison group are increased . columns ( 4 ) and ( 5 ) belong to an experimental group wherein the green algae extract of 20 mg / ml is added in fibroblasts before the fibroblasts are exposed to uv irradiation . fadd and po - 4 . fadd expressions are observed at the 12 th hour and 16 th hour after uv exposure . as compared with the comparison group shown by rectangles ( 2 ) and ( 3 ), po4 - fadd of the experimental group are decreased . columns ( 6 ) and ( 7 ) belong to another experimental group wherein the green algae extract of 20 mg / ml is added in fibroblasts that have be exposed in uv . fadd and po - 4 fadd expressions are observed at the 12 th hour and 16 th hour after uv exposure . as compared with the comparison group shown by columns ( 2 ) and ( 3 ), po4 - fadd of the experimental group are decreased . experiment 3 proves the fact that the effective dose of the green algae extract added in fibroblasts , no matter before or after uv exposure , facilitates inhibiting po4 - fadd expressions so as to reduce the bridges between apoptosis pathway molecule fas and procaspase 8 , the precursor of the caspase , and in turn reduce oligomerization of caspase - 8 , resulting in reduction of caspase - 3 . consequently , uv - induced premature apoptosis in fibroblasts is prevented . it is known that uv - induced fibroblast apoptosis stems to caspase activation and causes polymerase ( parp ) cleavage that renders irreparable damage to dna . experiments 1 , 2 and 3 have proven that the green algae extract of the present invention facilitates inhibiting po4 - fadd and caspase - 3 activities so that parp cleavage is expectably reduced . thereupon , the present experiment uses uv to cause cleaved parp and analyzes the inhibitory effects of the green algae extract of the present invention on cleaved parp by the western blotting method . the results are shown in fig4 . in fig4 , column ( 1 ) belongs to a control group and exhibits cleaved parp expression in fibroblasts under basal condition . columns ( 2 ) and ( 3 ) belong to a comparison group , and exhibit cleaved parp expressions at the 12 th hour and 16 th hour after uv exposure . as compared with the control group shown by column ( 1 ), both cases show increased amounts of cleaved parp . columns ( 4 ) and ( 5 ) belong to an experimental group wherein the green algae extract of 20 mg / ml is added in fibroblasts before the fibroblasts are exposed in v . the expression of cleaved parp is observed at the 12 th hour and the 16 th hour after uv exposure . as compared with the comparison group shown by columns ( 2 ) and ( 3 ), the amounts of cleaved parp in the present experimental group are decreased . columns ( 6 ) and ( 7 ) belong to another experimental group wherein the green algae extract of 20 mg / ml is added into fibroblasts that have been exposed in uv . then the expression of cleaved parp is observed at the 12 th hour and 16 th hour . as compared with the comparison group shown by columns ( 2 ) and ( 3 ), the amounts of cleaved parp in the present experimental group are decreased . experiment 4 therefore proves the fact that the effective dose of the green algae extract added in fibroblasts , no matter before or after uv exposure , facilitates inhibiting the expression of parp cleavage so as to protect fibroblasts from uv - induced premature apoptosis . the aforementioned experiments are for purposes of illustration and demonstration and not limitations to the practice of the present invention .
a method for preventing uv - induced skin - cellular injury by using a green algae extract and a cosmetic composition containing the green algae extract are disclosed . an effective dose of the green algae extract is used to protect fibroblasts from uv - induced apoptosis . the mechanism of the disclosed method is using the green algae extract to inhibit interaction between apoptosis pathway molecules fas / fasl so as to inhibit an adapter protein in a death - inducing signaling complex and in turn to inhibit caspase - 3 activation and cleaved polymerase such that irreparable damage to dna can be prevented . the green algae extract can be mixed with a skin permeable cosmetic composition so that the cosmetic composition possesses the function of preventing skin from uv - induced injury .