Antioxidant Capacity of Some Selected Medicinal Plants in East Nusa Tenggara, Indonesia: The Potential of Sterculia quadrifida R.Br.

Kristoferson Lulan, Fatmawati, Santoso, and Ersam: Antioxidant Capacity of Some Selected Medicinal Plants in East Nusa Tenggara, Indonesia: The Potential of Sterculia quadrifida R.Br.

Authors

Key message

This study focus on in vitro antioxidant activity of twenty-four traditional medicinal plants, in order to explore the potential of medicinal plants of NTT.

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INTRODUCTION

Indonesia has abundant biodiversity which are thousands species of plants widely distributed in tropical rainforests including Timor island monsoon forest in East Nusa Tenggara (NTT) province. Dry soil structure and physicochemical properties with low rainfall intensities and water supplies led NTT to have a different biodiversity compare with another region of Indonesia.1 Plants have various benefits of meeting the human demand of clothing, food, and shelter. Moreover, those plants are essential for health care as medicinal resources. Plants have been used as medicine since the ancestral period in curing diseases.2-3 People in NTT only acquire their knowledge from their ancestors, without any scientific evidences before. Traditional medicinal plants are commonly used as an alternate treatment in order to cure the diseases until now. They still consume it because of their safety, effectiveness, and readily evaluable in rural area. This is because people are more concern about the side effects of several syntetic medicines which can be a toxic.4-5

The medicinal properties of traditional medicinal plants have been investigated in the recent scientific developments for treatment of many metabolic diseases. The extract of these plants from various places in the world are reported to possess several pharmacological activities including anti-inflammatory,6-7 antidiabetic,8-11 antimalarial,12 antimicrobial,13-14 anti TB,15 anthelmintic activity,16 anticancer,17-18 cylindroxanthones A-C (1-3 etc. Traditional medicinal plants derived natural product such as alkaloids, flavonoids and terpenes. These compounds are the most important common sources of potentially natural antioxidant that can be used for prevention of degenerative diseases. Antioxidants are molecules which can prevent oxidation in other molecules through interact with free radical and terminate the chain reaction.19 The primary characteristic of an antioxidant is its ability to trap free radicals. Free radicals are produced in human body as a by-products of body metabolism of an unhealthy life style. Free radicals do not only cause metabolism perturbation but also damage human tissue. Uncontrolled free radical leads to oxidative stress of tissue, ultimately cell death and subsequent diseases.20-21

The present study is directed towards discovering naturally effective antioxidant of plant origin from NTT. The traditional uses claim that medicinal plants of NTT are potential folk medicine but very little research has been conducted on these plants. The evaluation of twenty-four traditional medicinal plants endemic from NTT had been performed. The most active as antioxidant is Sterculia quadrifida R. Br. S. quadrifida is the most plant used in NTT traditional medicines. Traditionally, bark and roots extracts of S. quadrifida are commonly used to treat various diseases such as diabetic, liver and cancer. S. quadrifida locally known as Faloak is an endemic plant to NTT as shown in Figure 1. It grows wild throughout NTT including Timor, Sumba, Flores and Alor islands.22 To the best of our knowledge, this is the first report on the antioxidant potency of crude extract from NTT traditional medicines including S. quadrifida.

Figure 1

Sterculia quadrifida R. Br. a). plant b). flower c). fruit d). seed

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The aim of this research is to find out total flavonoid content (TFC), total phenolic content (TPC), and in vitro antioxidant activity of extracted medicinal plants from NTT by using free radical scavenging assays DPPH and ABTS, in order to explore the potential of medicinal plants of NTT. This research would give scientific knowledge on NTT medicinal plants which are potentially used as antioxidant for further development of antioxidant.

MATERIALS AND METHODS

Chemicals

1,1-diphenyl-2-picrylhydrazyl (DPPH), 2-2”-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), trolox, quercetin, gallic acid and dimethyl sulfoxide (DMSO) were purchased from sigma chemical company (St. Louis, MO-USA), Folin-Ciocalteu reagent, Na2CO3, NaNO2, AlCl3.6H2O, NaOH, ethanol 99.5 % and methanol were acquired from Merck (Darmstadt, Germany). Other chemicals used for the study were analytical grade.

Plant materials

Plants were collected from some areas around Kupang district, NTT province, Indonesia. The samples used were leaves, roots, and barks of the medicinal plants were shown in Table 1. Voucher specimens were identified at Purwodadi Botanical Garden, East Java. Specimens of the collected plants were deposited in the laboratory of Natural Product Chemistry and Synthesis, department of Chemistry, Institut Teknologi Sepuluh Nopember, Surabaya.

Table 1

Traditional uses of medicinal plants from East Nusa Tenggara (NTT).

Botanical Name of the PlantLocal Name of the PlantParts of PlantIndications
Acalypha indica L.Anting-antingleafDysentery, inflammation
Alstonia scholaris L.R.BrTadukleafMalarial, dermatitis
Artemisia vulgaris L.Baru cinaleafDysentery, vomiting
Azadirachta indica A.NimbaleafToothache, kidney
Bidens pilosa L.Rumput kudaleaf, barkDiabetic, inflammation
Calotropis gigantean L.Kolang susuleafDermatitis, wounds
Cassia siamea Lamk.JoharleafDiabetic, fever
Cassia tora L.PepoleafEye infections
Ceiba pentandra (L) Gaertn.KapukleafCough, inflammation
Elephantopus scaber L.Tapak limanleafInflammation, fever
Eugenia jambolana Lam.JamlangleafDiabetes, cancer
Euphorbia hirta L.Rumput KerbauleafAsthma, dysentery
Euphorbia tirucalli L.Patah Tulangleaf, barkRheumatism, dermatitis
Jatropha gossypifolia L.Jarak merahleafInflammation, fever
Lamea grandusKedondong HutanleafCough, dysentery
Mentha arvensis L.Bunga putihleafWounds, toothache
Moringa oleifera Lam.KelorleafRheumatism, eye infections
Phyllanthus niruri L.Cinta buahleaf, barkKidney stones
Plectranthus amboinicus Lour (L) Spreng.Retunu RoteLeafCough, fever, asthma
Sauropus giganteus (L.) Merr.KatukleafCholesterol, diabetic
Schleichera oleosaKesambileafEczema, dermatitis
Solanum tarvumTerong hutanfruitCough, boil
Sterculia quadrifida R. Br.FaloakrootDiabetes, cancer
Strychnos lucida R. Br.Kayu UlarleafMalarial, diabetic

Extraction

The plant sample was air-dried to eliminate the humidity. Then, it was pounded into a fine powder. Next, it was weighed for 100 g and was extracted by maceration with 400 mL methanol in 24 h at room temperature. Then the extract was filtered and evaporated under vacuum by using rotary evaporator to dryness.

Antioxidant assay

Producing DPPH dissolvent

The molecule formula of DPPH is C18H12N5O6 with molecular weight 394.32 g/mol. DPPH dissolvent is 6 x 10-5M made by dissolving 0.24 mg of DPPH in 10 mL methanol.

DPPH radical scavenging assay

DPPH assay was determined by the method of Brand Williams modified by Dudonn’e et al.23-24 About 3 mL of 6 x 10-5 M DPPH solution was mixed with 100 µL samples in a test tube. After being incubated for 20 min at 37°C of temperature, absorbance decrease of the mixture was determined at 515 nm in a UV-Visible Spectrophotometer (As). Radicals DPPH have maximum absorbance at about 515 nm (Ab). The absorbance of blank of DPPH solution was also measured at the same wavelength (Ab). Trolox was used as positive control. The experiment was performed in triplicate. Radical scavenging activity was calculated by using the following way.

Inhibition(%)=[AbAsAb]×100https://s3-us-west-2.amazonaws.com/jourdata/fra/FreeRadAntiox-8-2-96-g000.jpg

ABTS radical scavenging assay

ABTS radical scavenging assay were described by Re et al.25 About 5 mL of 7 mM ABTS ammonium aqueous solution was mixed with 88 µL of potassium peroxydisulfate (K2S2O6) 140 mM. The mixture was allowed to stand for 12-16 h at room temperature to yield a dark blue solution. Then it was mixed with 99.5 % of ethanol which gave 0.7 ± 0.02 units absorbance at 734 nm to get working solution. One mL of working solution was mixed with 10 µL of samples extract and shuffled for 10 sec, then incubated at 30°C of temperature for 4 min. Then, the absorbance of the mixture reaction was measured at 734 nm to produce As values. Ethanol 99.5% was used as a blank solution and its absorbance was measured to produce Ab value. Trolox was used as positive control. The inhibition rate was measured by the same formula as shown in DPPH assay.

Estimation of Total Flavonoid Content (TFC)

The TFC was determined using the Aluminum chloride colorimetric assay described by Zhishen et al.(1999)26 with some minor modifications. The extract was dissolved in methanol at a concentration of 100 μg/mL and distilled water was added to make 5 mL. A 0.3 mL 5% NaNO2 was added to the flask. After standing for 5 min at room temperature, 0.3 mL 10% AlCl3.6H2O was added to the flask and was allowed to stand for 6 min at room temperature. 2 mL 1 M NaOH was then added and the total volume was made up to 10 mL with distilled water. After a thorough mixing, the absorbance reading was recorded at 510 nm using a UV-visible spectrophotometer. Results were expressed as mg quercetin equivalents (QE)/100g of extract. All samples were analyzed in triplicate.

Estimation of Total Phenolic Content (TPC)

The TPC was determined using the Folin-Ciocalteu (FC reagent) assay following Singh et al. (2013).27 The extract was dissolved in methanol at a concentration of 100 μg/mL. Then, these sample solutions were mixed with 3.6 mL of water and 0.4 mL of FC reagent 10% (v/v) and were allowed to stand for 5 min at room temperature. 4 mL 7% Na2CO3 solution was then added. The solutions were made up to 10 mL with water mixed. After 90 min, the absorbance of each samples was recorded at 760 nm using a UV-visible spectrophotometer. Results were expressed as mg gallic acid equivalents (GAE)/100g of extract. All samples were analyzed in triplicate.

RESULTS

Antioxidant activity of traditional medicinal plants from NTT has been determined by using two measuring methods, DPPH and ABTS free radical scavenging assays. All the medicinal plants showed varying free radical scavenging activities as potent antioxidant when compared to trolox as a standard. There was a wide range of antioxidant capacities of medicinal plant extracts using DPPH assay. The DPPH inhibition rate varied from 0.8 to 90.06 %. The reduction capacity of DPPH radical shown by absorbance decrease at 515 nm induced by antioxidants. S. quadrifida was reported as a strong potential antioxidant plant with 80.13 % of radical scavenging capacity. Other antioxidant compound resource exists in Euphorbia hirta L. and Lamea grandu with 90.06 and 89.92 % of DPPH inhibition rate successfully. Trolox was taken as standard showed 97.89 % antioxidant activity. Whereas Solanum tarvum, Euphorbia tirucalli L. and Alstonia scholaris L.R. Br showed low level of antioxidant capacity with 0.80; 3.79 and 6.85 % of DPPH inhibition rate respectively from selected plants. The result of DPPH radical scavenging at 319.45 ppm of medicinal plant extracts is shown in Figure 2.

Figure 2

Free radical scavenging activity of 24 NTT medicinal plant extracts at a concentration of 319.45 μg/mL for DPPH and 99 μg/mL for ABTS; triplicate experiments.

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To confirm the antioxidant activities using DPPH radicals, we examined the IC50 values of six plant samples which had the highest activity in the screening result (Table 2).

Table 2

Antioxidant activity of potent NTT traditional medicinal plants using DPPH assay.

Botanical NameLocal NameIC50 (μg/mL)
Sterculia quadrifida R. Br.Faloak3.11
Schleichera oleosaKesambi10.05
Euphorbia hirta L.Rumput Kerbau10.09
Eugenia jambolana Lam.Jamblang16.22
Lamea grandusKedondong Hutan27.80
Phyllanthus niruri L.Cinta buah31.63

The experimental results showed the highest antioxidant activity by DPPH method was observed in S. quadrifida plant extract with IC50 value of 3.11 µg/mL. The low IC50 value indicate high antioxidant activity of the substrate. Figure 3 shows inhibition rate of S. quadrifida using DPPH radical scavenging assay.

Figure 3

DPPH radical scavenging activity of Sterculia quadrifida R. Br.

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The free radical scavenging has also determined using the ABTS scavenging assay. ABTS radical scavenging activities of medicinal plants varied from 2.78 to 99.66 %. The reduction of radical ABTS is shown by the decreasing of absorbance at 734 nm. The highest antioxidant capacity was observed in extract of S. quadrifida with 99.66 % of ABTS inhibition rate, followed by Cassia tora L. and E. jambolana with 99.49 and 99.42 % respectively. Whereas E. tirucalli, A. scholaris, and Bidens pilosa L. showed low antioxidant capacities values of 2.78; 4.69 and 6.50 % of inhibition rate successfully. Trolox was taken as standard showed 95.97 % antioxidant activity. The result of ABTS radical scavenging at 99 ppm of medicinal plant extracts is shown in Figure 2. Table 3 showed the IC50 value of NTT traditional medicinal plants from ABTS assay.

Table 3

Antioxidant activity of potent NTT traditional medicinal plants using ABTS assay.

Botanical NameLocal NameIC50 (μg/mL)
Sterculia quadrifida R. Br.Faloak7.29
Eugenia jambolana Lam.Jamblang9.15
Lamea grandusKedondong Hutan12.29
Schleichera oleosaKesambi18.27
Euphorbia hirta L.Rumput Kerbau18.35
Phyllanthus niruri L.Cinta buah37.39

In this study, the highest antioxidant activity by using ABTS is found in S. quadrifida with IC50 value of 7.29 µg/mL. The extracts of E. jambolana also have strong antioxidant capacity with IC50 values of 9.15 µg/mL followed by L. grandus with IC50 values of 12.29 µg/mL. ABTS radical scavenging activity of S. quadrifida is shown in Figure 4.

Figure 4

ABTS radical scavenging activity of Sterculia quadrifida R. Br.

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An extensive range of flavonoid and phenolic content were estimated in medicinal plant extracts. The highest total flavonoid content was observed in extract of S. quadrifida with 661.85 mg of quercetin equivalents (QE) per 100 g of extracts, followed by S. oleosa with 595.19 mg of QE per 100 g of extract. Quercetin is used as a standard for flavonoid content. S. quadrifida also showed a high total phenolic with 116.84 mg of gallic acid equivalents (GAE) per 100 g of extract as shown in Table 4. Gallic acid is used as a standard for phenolic content. In TPC test, it is considered that a complex is formed between extract and reagent indicated by colour changes from yellow to blue.

Table 4

Total flavonoid and phenolic content of potent NTT traditional medicinal plants.

Botanical NameLocal NameTotal Flavonoid Content (mg of QE/100g of extract)Total Phenolic Content (mg of GAE/100g of extract)
Sterculia quadrifida R. Br.Faloak661.85 ± 12.83116.84 ± 1.22
Schleichera oleosaKesambi595.19 ± 6.42176.84 ± 1.05
Phyllanthus niruri L.Cinta buah398.89 ± 11.119.47 ± 1.05
Eugenia jambolana Lam.Jamblang180.37 ± 12.8362.11 ± 1.61
Euphorbia hirta L.Rumput Kerbau84.07 ± 6.4275.79 ± 1.22
Lamea grandusKedondong Hutan24.81 ± 6.4220.0 ± 1.61

DISCUSSION

In the present study, twenty four traditional medicinal plant extracts from NTT were identified to have antioxidant activity. The experiments result showed there were six most active extracts among others, S. quadrifida, S. oleosa, P. niruri, E. jambolana, E. hirta, and L. grandus. It revealed the free radical scavenging capacities of the selected medicinal plant extracts using DPPH and ABTS assay. DPPH and ABTS radical scavenging are based on electron transfer, in which those methods measure the capacity of an antioxidant to reduce an oxidant, which changes colour when reduced.26-27

DPPH is a stable free radical which will accepts electron or hydrogen radical to form a more stable molecule. Interacted with DPPH, antioxidant will transfer electron or hydrogen atom to DPPH and thus neutralizing its free radical and convert it to 1, 1-diphenyl-2-picrylhydrazine. The determination of free radical scavenging activity by DPPH method was influenced by some important factors such as dissolving liquid, the length of reaction, the ratio of sample and reagent, and the wavelength for measuring the absorbance. Antioxidant capacities of extracts not only depend on extract composition, but also on the conditions of the test used.28-29 The reduction of the DPPH molecules by the molecules of the substrate was visually shown by a change in colour of purple DPPH solution turned to light yellow when mixed with plant extract by 20 min incubation period. This process shows that antioxidant compound reacted with radical DPPH for it was reduced to DPPH-H which is more stable and signed by the reduction of absorbance value of DPPH. The reduction degree of absorbance indicated the radical scavenging ability of the extract. Plants have high inhibition rate which shows them as strong antioxidant and vice versa.30

The phenolic and flavonoid content in plant extracts impacts significantly to their antioxidant potential which might be responsible for radical scavenging activity. Various study revealed that phenolic and flavonoid are the most important substance that present numerous biological activity and pharmacology properties.31 The results of this study support that medicinal plants in NTT is rich in phenolic and flavonoids that might contribute to potential antioxidant activities.

S. quadrifida is a well-known as NTT traditional medicinal plants. Traditionally bark and roots extracts of S. quadrifida have been proved to be useful for the treatment of diabetic, liver and cancer. In this work, S. quadrifida showed a highest antioxidant activity with DPPH and ABTS assays, and it also have a high total flavonoid and phenolic content. Free radical can diffuse throughout the body and attack important biomolecules including DNA leading to oxidative damage of DNA. The resulting damage is involved in mutagenesis, carcinogenesis and aging. Phytochemicals including flavonoid and phenolic can prevent damage by their radical scavenging ability.32

The secondary metabolites found in one species in a genus will be similar to another species in the same genus. Flavonoid, terpenoid, alkaloid, phenolic and steroid were reported to exist in other species of genus Sterculia, but there is no literature reports found on the chemistry of S. quadrifida. It offers a challenge in finding new constituent from S. quadrifida. Study of genus Sterculia plant extracts revealed some biological activity like anti-diabetic from S. villosa,5 anti-inflammatory and antifertility activity from S. foetida,33 larvacidal activity from S. guttata,34 and anti-proliferative activity from S. tavia.35 Some chemical constituents also reported from genus Sterculia plants such as sitosterol and betulinic acid were isolate from S. striata,36 sterculinine I and II were isolate from S. lychnophora,37 and 1,6-diferuloyl glucose was isolate from S. foetida.38 Although the genus Sterculia has been well investigated, S. quadrifida has not been explored for its chemical constituents and biological activity. Further investigation on isolation and identification of bioactive constituents derived from S. quadrifida is in progress.

CONCLUSION

The present study gives scientific evidences that twenty four samples of NTT plants have high free radical scavenging capacity. S. quadrifida is a promising candidate for antioxidant investigation for future studies.

Methanol extract of S. quadrifida root exhibited the highest DPPH and ABTS radical scavenging activity with IC50 value of 3.11 and 7.29 μg/mL, respectively. S. quadrifida extract also showed high flavonoid and phenolic content with 661.85 mg of GAE and 116.84 mg of QE per 100 g of extracts. The result is a valuable reference of antioxidant properties from NTT traditional medicinal plants, which is serve as scientific value of antioxidant source in Indonesia.

ACKNOWLEDGEMENT

The Authors would like to acknowledge to The Indonesian Directorate General of Higher Education (DIKTI) for Research Grant and Beasiswa Pendidikan Pascasarjana Dalam Negeri (BPPDN) Scholarship for financial support of TYKL. We also thank to Purwodadi Botanical Garden staffs for plant identification and deposition, Ms. Fitria, Ms. Mutia DH, and Ms. Wiwit DF for kindly sharing information of related experimental details.

CONFLICT OF INTEREST

We declare that we have no conflict of interest.

ABBREVIATIONS

NTT

Nusa Tenggara Timur

DPPH

1,1-diphenyl-2-picrylhydrazyl

ABTS

2-2”-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)

QE

Quercetin Equivalent

GAE

Gallic Acid Equivalent

TFC

Total Flavonoid Content

TPC

Total Phenolic Content

DIKTI

Direktorat Jenderal Pendidikan Tinggi

TYKL

Theodore Yehezkiel Kristoferson Lulan,

TB

Tubercle bacillus

FC

Folin-Ciocalteu

DMSO

dimethyl sulfoxide.

REFERENCES

1. 

Forest Watch Indonesia/Global Forest Watch. The state of the forest Indonesia. Bogor: Indonesia; 2002

2. 

Ayoola GA, Coker HA, Adesegun SA, Adepoju-bello AA, Obaweya K, Ezennia EC , authors. et al. Phytochemical screening and antioxidant activities of some selected medicinal plants used for malaria therapy in Southwestern Nigeria. Trop J Pharm Res. 2008;7(3):1019–24

3. 

Dey A, De JN , authors. Ethnobotanical survey of Purulia district, West Bengal, India for medicinal plants used against gastrointestinal disorders. J Ethnopharmacol. 2012;1439(1):68–80

4. 

Engel N, Oppermann C, Falodun A, Kragl U , authors. Proliferative effects of five traditional Nigerian medicinal plant extracts on human breast and bone cancer cell lines. J Ethnopharmacol. 2011;137(2):1003–10

5. 

Tarak D, Namsa ND, Tangjang S, Arya SC, Rajbonshi B, Samal PK , authors. et al. An inventory of the ethnobotanicals used as anti-diabetic by a rural community of Dhemaji district of Assam, Northeast India. J Ethnopharmacol. 2011;138(2):345–50

6. 

Tewtrakul S, Tansakul P, Daengrot C, Ponglimanont C, Karalai C , authors. Anti-inflammatory principles from Heritiera littoralis bark. Phytomedicine. 2010;17(11):851–5

7. 

Ntandou GF, Banzouzi JT, Mbatchi B, Elion-itou RD, Etou-ossibi AW, Ramos S , authors. et al. Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts. J Ethnopharmacol. 2010;127(1):108–11

8. 

Fatmawati S, Kondo R, Shimizu K , authors. Structure-activity relationships of lanostane-type triterpenoids from Ganoderma lingzhi as α-glucosidase inhibitors. Bioorganic Med Chem Lett. 2013;23(21):5900–3

9. 

Fatmawati S, Ersam T, Yu H, Zhang C, Jin F, Shimizu K , authors. 20(S)-ginsenoside Rh2 as aldose reductase inhibitor from Panax ginseng. Bioorg Med Chem Lett. 2014;24(18):4407–9

10. 

Fatmawati S, Ersam T, Shimizu K , authors. The inhibitory activity of aldose reductase in vitro by constituents of Garcinia mangostana Linn. Phytomedicine. 2015;22(1):49–51

11. 

Zahratunnisa N, Elya B, Noviani A , authors. Inhibition of Alpha-Glucosidase and Antioxidant Test of Stem Bark Extracts of Garcinia fruticosa Lauterb. Pharmacogn J. 2017;9(2):273–5

12. 

Widyawaruyanti A, Kalauni SK, Awale S, Nindatu M, Zaini NC , authors. et al. New prenylated flavones from Artocarpus champeden, and their antimalarial activity in vitro. J Nat Med. 2007;61(4):410–3

13. 

Koné WM, Atindehou KK, Terreaux C, Hostettmann K, Traoré D, Dosso M , authors. Traditional medicine in North Cote-d’Ivoire : Screening of 50 medicinal plants for antibacterial activity. J Ethnopharmacol. 2004;93(1):43–9

14. 

Ananth AD, Sivasudha T, Rameshkumar A, Jeyadevi R, Aseervatham SB , authors. Free Radicals and Antioxidants Chemical constituents, in vitro antioxidant and antimicrobial potential of Caryota urens L. Free Radicals Antioxidants. 2013;3:107–12

15. 

Babalola IT, Adelakun EA, Wang Y, Shode FO , authors. Anti-TB activity of Sterculia setigera Del, leaves (Sterculiaceae). J Pharmacogn Phytochem. 2012;1(3):17–23

16. 

Alam MR, Raton M, Hassan M, Kadir MF, Islam SM, Haque MA , authors. Anthelmintic and diuretic activity of bark extracts of Sterculia villosa. J Appl Pharm Sci. 2012;2:86–9

17. 

Sukandar ER, Ersam T, Fatmawati S, Siripong P, Aree T, Tip-Pyang S , authors. Cylindroxanthones A-C, three new xanthones and their cytotoxicity from the stem bark of Garcinia cylindrocarpa. Fitoterapia. 2016;108:62–5

18. 

Iqbal S, Sivaraj C, Gunasekaran K , authors. Antioxidant and Anticancer Activities of Methanol Extract of Seeds of Datura stramoniuml. Free Radicals Antioxidants. 2017;7(2):184–9

19. 

Bhatia H, Kaur J, Nandi S, Gurnani V, Chowdhury A, Reddy PH , authors. et al. A review on Schleichera oleosa : pharmacological and environmental aspects. J Pharm Res. 2013;6(1):224–9

20. 

Raghavendra M, Reddy AM, Yadav PR, Raju AS, Kumar S , authors. Comparative studies on the in vitro antioxidant properties of methanolic leafy extracts from six edible leafy vegetables of India. Asian J Pharm Clin Res. 2013;6(3):96–9

21. 

Sharma RA, Yadav A, Bhardwaj R , authors. DPPH free radical scavenging activity of phenolic compounds in argemone. Int J Pharm Pharm Sci. 2013;5(3):683–6

22. 

Saragih GS, Rainawati H , authors. Potential distribution and utilization of Faloak (Sterculia quadrifida R.Br 1844) on Timor Island, East Nusa Tenggara. Langi M, Tasirin J, Walangitan H, Masson G , authors. Forest and Biodiversity Manado: Manado Forestry Research Institute; 2013. p. 165–72

23. 

Brand-Williams W, Cuvelier ME, Berset C , authors. Use of a free radical method to evaluate antioxidant activity. Leb Wiss u-Technol. 1995;28(1):25–30

24. 

Dudonne S, Vitrac X, Coutiere P, Woillez M, Merillon JM , authors. Comparative study of antioxidant properties and total phenolic content of 30 plant extracts of industrial interest using DPPH, ABTS, FRAP, SOD, and ORAC assays. J Agric Food Chem. 2009;57(5):1768–74

25. 

Re R, Pellegrini N, Proteggente A, Pannala A, Yang M, Rice-Evans C , authors. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Biol Med. 1999;26(9-10):1231–7

26. 

Zhishen J, Mengcheng T, Jianming W , authors. Analytical, nutritional and clinical methods section: the determination of flavonoid contents in murberry and their scavenging effects on superoxide radicals. Food Chem. 1999;64(4):555–9

27. 

Singh RS, Negi PS, Radha C , authors. Phenolic composition, antioxidant and antimicrobial activities of free and bound phenolic extracts of Moringa oleifera seed flour. J Funct Foods. 2013;5(4):1883–91

28. 

Molyneux P , author. The use of the stable free radical diphenylpicryl- hydrazyl (DPPH) for estimating antioxidant activity. Songklanakarin J Sci Technol. 2004;26(2):211–9

29. 

Thaipong K, Boonprakob U, Crosby K, Cisneros-Zevallos L, Hawkins Byrne D , authors. Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts. J Food Compos Anal. 2006;19(6-7):669–75

30. 

Fitriana WD, Ersam T, Shimizu K, Fatmawati S , authors. Antioxidant activity of Moringa oleifera extracts. Indones J Chem. 2016;16(2):297–301

31. 

Annapandian VM, Rajagopal SS , authors. Phytochemical Evaluation and In vitro Antioxidant Activity of Various Solvent Extracts of Leucas aspera (Willd.) Link Leaves. Free Radicals Antioxidants. 2017;7(2):166–71

32. 

Harman D , author. Free radical theory of aging. Mutat Res. 1992;275:257–66

33. 

Prakash GY, Gopal V, Kaviarasan L , authors. Prominsing pharmaceutical prospective of Java olive’-Sterculia foetida Linn (Sterculiaceae). Int J Pharm Rev Res. 2012;2:93–6

34. 

Katade SR, Pawar PV, Wakharkar RD, Deshpande NR , authors. Sterculia guttata seeds extractives - an effective mosquito larvicide. Indian J Exp Biol. 2006;44:662–5

35. 

Dai Y, Harinantenaina L, Brodie PJ, Callmander MW, Randrianasolo S, Rakotobe E , authors. et al. Isolation and synthesis of two antiproliferative calamenene-type sesquiterpenoids from Sterculia tavia from the Madagascar rain forest. Bioorg Med Chem. 2012;20(24):6940–4

36. 

Costa DA, Chaves MH, Silva WCS, Costa CL , authors. Chemical constituents, total phenolics and antioxidant activity of Sterculia striata, St Hil. Et Naudin. Acta Amaz. 2010;40(1):207–12

37. 

Wang R, Yang X, Ma C, Shang M, Liang J, Wang X , authors. et al. Alkaloids from the seeds of Sterculia lychnophora (pangdahai). Phytochemistry. 2003;63(4):475–8

38. 

Xia P, Feng Z, Yang Y, Zhang P , authors. Two flavonoid glycosides and a phenylpropanoid glucose ester from the leaves of Sterculia foetida. J Asian Nat Prod Res. 2009;11(8):766–71

GRAPHICAL ABSTRACT

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SUMMARY

  • Twenty-four traditional medicinal plants collected from Kupang, East Nusa Tenggara (NTT) were determined for antioxidant activity by using the free radical scavenging assays DPPH and ABTS. The present study revealed that the methanol extract of Sterculia quadrifida R. Br. root exhibited the highest DPPH and ABTS radical scavenging activity. It also showed high flavonoid and phenolic content. Strong radical scavenging activity of these plants especially S. quadrifida could be considered as a potential source of natural antioxidants.

ABOUT AUTHORS

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Prof. Dr. Taslim Ersam: Lecturer at Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Sukolilo, Surabaya, East Java, 60111, INDONESIA.

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Prof. Mardi Santoso, Ph.D: Lecturer at Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Sukolilo, Surabaya, East Java, 60111, INDONESIA.

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Sri Fatmawati, M.Sc., Ph.D: Lecturer at Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Sukolilo, Surabaya, East Java, 60111, INDONESIA

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Theodore Y K Lulan, M.Sc.: Doctor Candidate at Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Sukolilo, Surabaya, East Java, 60111 Work at Organic Laboratory, Department of Chemistry, Faculty of Science and Engineering, Universitas Nusa Cendana, Penfui, Kupang, East Nusa Tenggara, 85000