ANTIOXIDANT ACTIVITY POTENCY OF CHITOSAN FROM HARUAN (CHANNA STRIATA) SCALES

ABSTRACTBackground: Stimulation of inflammatory cells such as polymorphonuclear cells (PMN) will initiate to release free radicals in destroying bacteria. Excessive free radicals can damage cells in the body. Antioxidants as one of the body's defense systems will neutralize existing free radicals. Chitosan from Haruan scales in addition to being antimicrobial turned out to also be antioxidants. Objective: To know the antioxidant potential of chitosan from haruan (Channa striata) scales. Methods: This study is a pure experimental (true experimental design) with a post-test only with control group design using two treatment groups, with quantitative tests to calculate the amount of antioxidant activity of chitosan from fish scales using DPPH radical reduction method. The first treatment is 4, 6, 8 and 10 ppm standard ascorbic acid concentration with DPPH solution as positive control, and the second treatment is 200, 250, 300 and 350 ppm chitosan from Haruan scales concentration with DPPH solution. Results: The results showed that chitosan from Haruan fish scales have antioxidant activity with 50.513% percentage of inhibition at a maximum concentration of 350 ppm with an IC50 value of 356.98 ppm. The results of the independent T-test showed that there was a significant difference between the inhibition percentage of chitosan from haruan fish scales and the inhibition percentage of ascorbic acid (p = 0,000) (p <0.05). Conclusion: Chitosan from Haruan fish scales proved to have antioxidant activity.Keywords: Antioxidants, Chitosan, Haruan fish scalesABSTRACTBackground: Stimulation of inflammatory cells such as polymorphonuclear cells (PMN) will initiate to release free radicals in destroying bacteria. Excessive free radicals can damage cells in the body. Antioxidants as one of the body's defense systems will neutralize existing free radicals. Chitosan from Haruan scales in addition to being antimicrobial turned out to also be antioxidants. Objective: To know the antioxidant potential of chitosan from haruan (Channa striata) scales. Methods: This study is a pure experimental (true experimental design) with a post-test only with control group design using two treatment groups, with quantitative tests to calculate the amount of antioxidant activity of chitosan from fish scales using DPPH radical reduction method. The first treatment is 4, 6, 8 and 10 ppm standard ascorbic acid concentration with DPPH solution as positive control, and the second treatment is 200, 250, 300 and 350 ppm chitosan from Haruan scales concentration with DPPH solution. Results: The results showed that chitosan from Haruan fish scales have antioxidant activity with 50.513% percentage of inhibition at a maximum concentration of 350 ppm with an IC50 value of 356.98 ppm. The results of the independent T-test showed that there was a significant difference between the inhibition percentage of chitosan from haruan fish scales and the inhibition percentage of ascorbic acid (p = 0,000) (p <0.05). Conclusion: Chitosan from Haruan fish scales proved to have antioxidant activity. Keywords: Antioxidants, Chitosan, Haruan fish scales.

Revisiting DPPH (2,2-diphenyl-1-picrylhydrazyl) assay as a useful tool in antioxidant evaluation: A new IC100 concept to address its limitations

The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay has been widely used in antioxidant evaluation. However, it suffers from certain limitations that are addressed in this contribution. The limitations discussed in this work were the ratio of DPPH radicals to antioxidants and the presence of pigments in the reaction medium which interferes with absorbance readings. To do so, we used eight different concentrations of DPPH solution. The modified DPPH assay proposes a new concept, IC100, that is defined as the amount of DPPH radical required to oxidize all antioxidants present in the reaction medium. The modified DPPH assay does not suffer from an underestimation of antioxidant activity found in the original DPPH procedure due to the decrease in the ratio of DPPH radicals to antioxidants. Moreover, the modified method was not influenced by interference from coexisting pigments in the measurement of radical scavenging potential of extracts. To the best of our knowledge, this is the first attempt to effectively resolve the above-mentioned limitations of the DPPH assay.

Skrining Fitokimia dan Uji Aktivitas Antioksidan dari Daun Nasi (Phrynium capitatum) dengan Metode DPPH (1,1-difenil-2-pikrilhidrazil)

Telah dilakukan penelitian tentang skrining fitokimia dan uji aktivitas antioksidan dari daun nasi (Phrynium capitatum) dengan metode DPPH (1,1-difenil-2-pikrilhidrazil). Skrining fitokimia meliputi pengujian alkaloid, flavonoid, saponin, steroid, triterpenoid dan fenolik. Uji aktivitas antioksidan dilakukan dengan penambahan 2 mL larutan DPPH dengan 0,5 mL larutan ekstrak dengan konsentrasi masing-masing 1000, 750, 500 dan 250 µg/mL. Data yang diproleh kemudian digunakan untuk menghitung nilai IC50 dari ekstrak etanol daun nasi. Hasil pengujian menunjukan bahwa ekstrak etanol daun nasi mengandung senyawa alkaloid, flavonoid, saponin, steroid dan fenolik. Ekstrak etanol daun nasi memiliki aktivitas antioksidan trrtinggi pada konsentrasi 1000 µg/mL sebesar 65,77 % dan semakin menurun aktivitasnya dengan berkurangnya konsentrasi ekstrak, konsentrasi 750, 500 dan 250 µg/mL masing-masing sebesar 53,96 %, 43,8 % dan 19,58 % dengan nilai IC50 pada konsentrasi 701,78 µg/mL.A research on phytochemicals screening and antioxidant activity test of daun nasi (Phrynium capitatum) using DPPH (1,1-diphenyl-2-picrylhydrazyl) method had been conducted. Test for alkaloids, flavonoids, saponins, steroids, triterpenoids and phenolic were included in phytochemical screening. Antioxidant activity was tested through the addition of 2 mL DPPH solution into 0.5 mL of the extract having a concentration of 1000, 750, 500 and 250 µg/mL respectively. The data obtained was used to calculate the IC50 value for the ethanol extract of daun nasi. The results showed that the ethanol extract of daun nasi contains alkaloids, flavonoids, saponins, steroids and phenolic. Ethanol extract of daun nasi has the highest antioxidant activity of 65.77% at concentration of 1000 µg/mL. Its activity decreased with decreasing concentration of the extract, which were 53.96 %, 43.8 % and 19.58 % at concentration of 750, 500 and 250 µg/mL respectively. IC50 values was found at a concentration of 701.78 µg/mL.