Bioprospecting of non-timber forest products of selected flora in Baluran National Park, East Java, Indonesia for phytochemicals, anti-diabetic, anti-tyrosinase, and antioxidants

##plugins.themes.bootstrap3.article.sidebar##

PDF
DOI https://doi.org/10.13057/biodiv/d251042
Issue
Vol. 25 No. 10 (2024)
Section
Articles
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

##plugins.themes.bootstrap3.article.main##

RICO RAMADHAN ♥
Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
NI’MATUZAHROH
Department of Biology, Faculty of Science and Technology, Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
DINDA AYU LESTARI
Division of Exploration and Synthesis of Bioactive Compounds (ESBC), University CoE-Research Center for Bio-Molecule Engineering (BIOME), Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
NOVA ALFIAN HARIYANTO
Division of Exploration and Synthesis of Bioactive Compounds (ESBC), University CoE-Research Center for Bio-Molecule Engineering (BIOME), Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
SUHARTINI SUWANDARI
Division of Exploration and Synthesis of Bioactive Compounds (ESBC), University CoE-Research Center for Bio-Molecule Engineering (BIOME), Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
IRMAYANTI TRI KURNIA
Division of Exploration and Synthesis of Bioactive Compounds (ESBC), University CoE-Research Center for Bio-Molecule Engineering (BIOME), Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
PREECHA PHUWAPRAISIRISAN
Center of Excellent in Natural Products, Department of Chemistry, Faculty of Science, ¬Chulalongkorn University. 254 Phaya Thai Rd, Wang Mai, Pathum Wan, Thailand
MUHAMMAD IQBAL HASAN
Division of Exploration and Synthesis of Bioactive Compounds (ESBC), University CoE-Research Center for Bio-Molecule Engineering (BIOME), Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
KIETTIPUM PHONTREE
Division of Pharmacognosy and Toxicology, Faculty of Pharmaceutical Sciences, Khon Kaen University. 123 Mittrapap Rd, Khon Kaen 40002, Thailand
JOHAN SETIAWAN
Baluran National Park. Wonorejo, Banyuputih, Situbondo, East Java, Indonesia
SALAMUN
Department of Biology, Faculty of Science and Technology, Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
NANANG DWI WAHONO
Baluran National Park. Wonorejo, Banyuputih, Situbondo, East Java, Indonesia
AGUS SUPRIYANTO
Department of Biology, Faculty of Science and Technology, Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia
MOCH. AFFANDI
Department of Biology, Faculty of Science and Technology, Universitas Airlangga. Jl. Dr. Ir. H. Soekarno, Surabaya 60115, East Java, Indonesia

Abstract

Abstract. Ramadhan R, Ni’matuzahroh, Lestari DA, Hariyanto NA, Suwandari S, Kurnia IT, Phuwapraisirisan PP, Hasan MI, Phontree K, Setiawan J, Salamun, Wahono ND, Supriyanto A, Affandi M. 2024. Bioprospecting of non-timber forest products of selected flora in Baluran National Park, East Java, Indonesia for phytochemicals, anti-diabetic, anti-tyrosinase, and antioxidants. Biodiversitas 25: 3803-3815. The ecosystem within Baluran National Park comprises elements that exhibit varying degrees of sensitivity to environmental influences, encompassing both biotic and abiotic factors. It has been observed that identical plant species may display significant variations in their secondary metabolite content across different habitats. The primary objective of this investigation is to analyze the phytochemical composition, antioxidant properties, anti-tyrosinase effects, and anti-diabetic potential of specific flora species found in Baluran National Park. Furthermore, the research aims to identify novel natural resources with anti-diabetic and antioxidant properties among the selected flora from Baluran National Park, East Java, using chemotaxonomic and ethnopharmacological data. The study involved the qualitative and quantitative analysis of phytochemicals, along with assessing their in vitro anti-diabetic, anti-tyrosinase, and antioxidant activities through various assays such as ?-glucosidase inhibition, tyrosinase inhibition, and free radical scavenging tests (DPPH, ABTS, CUPRAC, and FRAP). The findings reveal that ethanol extracts of Euphorbia atoto demonstrated potent ?-glucosidase inhibitory activity with a percent inhibition (PI) value of 92.07±1.43%, surpassing the inhibitory effects of acarbose (25.92±1.61%) and quercetin (84.79±1.18%). Additionally, the antioxidant assessments indicated that the selected flora from Baluran National Park exhibited substantial antioxidant properties, as evidenced by their percent inhibition (PI) values. These results provide a scientific basis for considering the flora of Baluran National Park as a potential source of natural medicinal compounds.

##plugins.themes.bootstrap3.article.details##

References
Abeysinghe DT, Kumara KAH, Kaushalya KAD, Chandrika UG, Alwis DDDH. 2021. Phytochemical screening, total polyphenol, flavonoid content, in vitro antioxidant and antibacterial activities of Sri Lankan varieties of Murraya koenigii and Micromelum minutum leaves. Heliyon 7 (7): e07449. DOI: 10.1016/j.heliyon.2021.e07449.
Ahad MF, Zilani MNH, Akter A, Nasrullah ASM, Karmakar UK, Biswas NN, Anisuzzman M, Bokshi B. 2021. Comparative pharmacological potential of Ceriops decandra (Griff.) and Ceriops tagal Linn: Medicinal plants of the Sundarbans. J Med Plants Stud 9 (4): 14-23. DOI: 10.22271/plants.2021.v9.i4a.1306.
Akyuz M, Yabo-Dambagi L, Kilic T, Cakir A. 2022. Anti-diabetic, neuroprotective and antioxidant potentials of different parts of Pistacia terebinthus fruits. S Afr J Bot 147: 443-456. DOI: 10.1016/j.sajb.2022.01.040.
Al-Owamri FSN, Sibay LSAA, Reddy SH, Hussain SA, Gangireddygari VSR. 2023. Phytochemical, antioxidant, hair growth and wound healing property of Juniperus excelsa, Olea oleaster and Olea europaea. J King Saud Univ Sci 35: 102446. DOI: 10.1016/j.jksus.2022.102446.
Al-Robai SA, Zabin SA, Ahmed AA, Mohamed HA, Alghamdi AAA, Ahmed AAE. 2022. Phenolic contents, anticancer, antioxidant, and antimicrobial capacities of MeOH extract from the aerial parts of Trema orientalis plant. Open Chem 20 (1): 666-678. DOI: 10.1515/chem-2022-0183.
Andriani Y, Ramli NM, Syamsumir DF, Kassim MNI, Jaafar J, Aziz NA, Marlina L, Musa NS, Mohamad H. 2019. Phytochemical analysis, antioxidant, antibacterial and cytotoxicity properties of keys and cores part of Pandanus tectorius fruits. Arab J Chem 12 (8): 3555-3564. DOI: 10.1016/j.arabjc.2015.11.003.
Banothu V, Neelagri C, Adepally U, Lingam J, Bommareddy K. 2017. Phytochemical screening and evaluation of in vitro antioxidant and antimicrobial activities of the indigenous medicinal plant Albizia odoratissima. Pharm Biol 55 (1): 1155-1161. DOI: 10.1080/13880209.2017.1291694.
Barbieri R, Coppo E, Marchese A, Daglia M, Sobarzo-Sanchez E, Nabavi SF, Nabavi SM. 2017. Phytochemicals for human disease: An update on plant-derived compounds antibacterial activity. Microbiol Res 196: 44-68. DOI: 10.1016/j.micres.2016.12.003.
Busari IO, Soetan KO, Aiyelaagbe OO, Babayemi OJ. 2021. Phytochemical screening and in vitro anthelmintic activity of methanolic extract of Terminalia glaucescens leaf on Haemonchus contortus eggs. Acta Trop 223: 106091. DOI: 10.1016/j.actatropica.2021.106091.
Chaturvedi SK. 2010. A New Sponin From the Leaves of Streblus asper. Asian J Chem 22: 5579-5780.
Chaudhury A, Duvoor C, Dendi VSR, Kraleti S, Chada A, Ravilla R, Marco A, Shekhawat NS, Montales MT, Kuriakose K, Sasapu A, Beebe A, Patil N, Musham CK, Lohani GP, Mirza W. 2017. Clinical review of anti-diabetic drugs: Implications for type 2 diabetes mellitus management. Front Endocrinol 8: 6. DOI: 10.3389/fendo.2017.00006.
Chohra D, Ferchichi L, Cakmak YS, Zengin G, Alsheikh SM. 2020. Phenolic profiles, antioxidant activities and enzyme inhibitory effects of an Algerian medicinal plant (Clematis cirrhosa L.). S Afr J Bot 132: 164-170. DOI: 10.1016/j.sajb.2020.04.026.
de Araújo KM, de Lima A, Silva JN, Rodrigues LL, Amorim AGN, Quelemes PV, dos Santos RC, Rocha JA, de Andrades EO, Leite JRSA, Mancini-Filho J, da Trindade RA. 2014. Identification of phenolic compounds and evaluation of antioxidant and antimicrobial properties of Euphorbia tirucalli L. Antioxidant 3 (1): 159-175. DOI: 10.3390/antiox3010159.
Fernandes RPP, Trindade MA, Tonin FG, Lima CG, Pugine SMP, Munekata PES, Lorenzo JM, de Melo MP. 2016. Evaluation of antioxidant capacity of 13 plant extracts by three different methods: Cluster analyses applied for selection of the natural extracts with higher antioxidant capacity to replace synthetic antioxidant in lamb burgers. J Food Sci Technol 53: 451-460. DOI: 10.1007/s13197-015-1994-x.
Ghasemzadeh A, Jaafar HZE, Rahmat A. 2010. Antioxidant activities, total phenolics and ?avonoids content in two varieties of Malaysia young ginger (Zingiber of?cinale Roscoe). Molecules 15 (6): 4324-4333. DOI: 10.3390/molecules15064324.
Gumisiriza H, Birungi G, Olet EA, Sesaazi CD. 2019. Medicinal plant species used by local communities around Queen Elizabeth National Park, Maramagambo Central Forest Reserve and Ihimbo Central Forest Reserve, South western Uganda. J Ethnopharmacol 239: 111296. DOI: 10.1016/j.jep.2019.111926.
Hassan A, Akmal Z, Khan N. 2020. The phytochemical screening and antioxidants potential of Schoenoplectus triqueter L. Palla. J Chem 2020 (1): 3865139. DOI: 10.1155/2020/3865139.
Haqqin F, Arkan F, Ibriza NM, Fadhilah RN, Safira RN, Dewangga A, Kusumaningrum L, Thenya T, Setyawan AD. 2024. Diversity, composition, and role of woody Non-Timber Forest Products in Tawangmangu, Central Java, Indonesia. Asian J Ethnobiol 7: 68-78. DOI: 10.13057/asianjethnobiol/y070108.
Hossen MM, Hossain ML, Mitra K, Hossain B, Bithi UH, Uddin MN. 2022. Phytochemicals and in-vitro antioxidant activity analysis of Aloe vera by-products (skin) in different solvent extract. J Agric Food Res 10: 100460. DOI: 10.1016/j.jafr.2022.100460.
Ibrahim NM, Mat I, Lim V, Ahmad R. 2013. Antioxidant activity and phenolic content of Streblus asper leaves from various drying methods. Antioxidant 2 (3): 156-166. DOI: 10.3390/antiox2030156.
Indriaty, Djufri, Ginting B, Hasballah K. 2023. Phytochemical screening, phenolic and flavonoid content, and antioxidant activity of Rhizophoraceae methanol extract from Langsa, Aceh, Indonesia. Biodiversitas 24 (3): 2865-2876. DOI: 10.13057/biodiv/d240541.
Ji Y, Liu D, Jin Y, Zhaou J, Zhao J, Li H, Li L, Zhang H, Wang H. 2021. In vitro and in vivo inhibitory effect of anthocyanin-rich bilberry extract on ?-glucosidase and ?-amylase. LWT 145: 111484. DOI: 10.1016/j.lwt.2021.111484.
Kalasuba K, Miranti M, Rahayuningsih SR, Safriansyah W, Syamsuri RRP, Farabi K, Oktavia D, Alhasnawi AN, Doni F. 2023. Red Mangrove (Rhizophora stylosa Griff.)-a review of its botany, phytochemistry, pharmacological activities, and prospects. Plants 12 (11): 2196. DOI: 10.3390/plants12112196.
Khatun A, Rahman M, Kabir S, Akter MN, Chowdhury SA. 2013. Phytochemical and pharmacological properties of methanolic extracts of Ardisia humilis Vahl. Intl J Res Ayurveda Pharm 4 (1): 38-41. DOI: 10.7897/2277-4343.04120.
Khongkarat P, Ramadhan R, Phuwapraisirisan P, Chanchao C. 2020. Safflospermidines from the bee pollen of Helianthus annuus L. exhibit a higher in vitro antityrosinase activity than kojic acid. Heliyon 6 (3): e03638. DOI: 10.1016/j.heliyon.2020.e03638.
Kumar N, Goel N. 2019. Phenolic acids: Natural versatile molecules with promising therapeutic applications. Biotechnol Rep 24: e00370. DOI: 10.1016/j.btre.2019.e00370.
Liu S, Yu Z, Zhu H, Zhang W, Chen Y. 2016. In vitro ?-glucosidase inhibitory activity of isolated fractions from water extract of Qingzhuan dark tea. BMC Complement Altern Med 16: 378. DOI: 10.1186/s12906-016-1361-0.
Moukette BM, Pieme CA, Njimou JR, Biapa CPN, Marco B, Ngogang JY. 2015. In vitro antioxidant properties, free radicals scavenging activities of extracts and polyphenol composition of a non-timber forest product used as spice: Monodora myristica. Biol Res 48: 15. DOI: 10.1186/s40659-015-0003-1.
Munteanu I, Apetrei C. 2021. Analytical methods used in determining antioxidant activity: A review. Intl J Mol Sci 22 (7): 3380. DOI: 10.3390/ijms22073380.
Ndam LM, Mih AM, Tening AS, Fongod, AGN, Temenu NA, Fujii Y. 2016. Phytochemical analysis, antimicrobial and antioxidant activities of Euphorbia golondrina L.C. Wheeler (Euphorbiaceae Juss.): An unexplored medicinal herb reported from Cameroon. SpringerPlus 5: 264. DOI: 10.1186/s40064-016-1928-8.
Nipun TS, Khatib A, Ahmed QU, Nasir MHM, Supandi F, Taher M, Saiman MZ. 2021. Preliminary phytochemical screening, in vitro anti-diabetic, antioxidant activities, and toxicity of leaf extracts of Psychotria malayana Jack. Plants 10: 2688. DOI: 10.3390/plants10122688.
Owusu-Ansah P, Alhassan AR, Ayamgama AA, Adzaworlu EG, Afoakwah NA, Mahunu GK, Amagloh FK. 2023. Phytochemical analysis, enumeration, isolation, and antimicrobial activity of lemongrass and Moringa leaves extracts. J Agric Food Res 12: 100579. DOI: 10.1016/j.jafr.2023.100579.
Pandey MM, Rastogi S. 2022. Streblus asper: A phytochemical, ethnopharmacological and pharmacological research update. J Pharm Phytochem 11 (3): 7-18. DOI: 10.22271/phyto.2022.v11.i3a.14402.
Pasaribu G, Winari I, Gusti REP, Maharani R, Fernandes A, Harianja AH, Saragih GS, Turjaman M, Tampubolon AP, Kuspradini H, Lukmandaru G, Njurumana GN, Sukito A, Aswandi, Kholibrina CR. 2021. Current challenges and prospects of Indonesian Non-Timber Forest Products (NTFPs): A review. Forests 12 (12): 1743. DOI: 10.3390/f12121743.
Pawlowicz K, Ludowicz D, Lada MK, Wdowiak K, Piontek JC. 2021. Analysis of the composition of lyophilisates obtained from Aloe arborescens gel of leaves of different ages from controlled crops. Molecules 26 (1): 3204. DOI: 10.3390/molecules26113204.
Paula PL, Lemos ASO, Campos LM, Ferreira TG, de Souza TF, Queiroz LS, Guedes MCMR, Martins MM, Filho LRG, Macedo GC, Tavares GD, Rocha VN, Denadai AML, Fabri RL. 2021. Pharmacological investigation of antioxidant and anti-inflammatory activities of leaves and branches extracts from Plinia cauliflora (Jaboticaba). J Ethnopharmacol 280: 114463. DOI: 10.1016/j.jep.2021.114463.
Payne AC, Mazzer A, Clarkson GJJ, Taylor G. 2013. Antioxidant assays-consistent ?ndings from FRAP and ORAC reveal a negative impact of organic cultivation on antioxidant potential in spinach but not watercress or rocket leaves. Food Sci Nutr 1 (6): 439-444. DOI: 10.1002/fsn3.71.
Ramadhan R, Kristanti AN, Amirta R, Kusuma IW, Phuwapraisirisan P, Haqiqi MT, Saparwadi. 2019. Screening for potential anti-diabetes and antioxidant activities of selected plants from East Kalimantan, Indonesia. Biodiversitas 20: 1820-1826. DOI: 10.13057/biodiv/d200705.
Rozirwan, Nugroho RY, Hendri M, Fauziyah, Putri WYE, Agussalim A. 2022. Phytochemical pro?le and toxicity of extracts from the leaf of Avicennia marina (Forssk.) Vierh. collected in mangrove areas affected by port activities. S Afr J Bot 150: 903-919. DOI: 10.1016/j.sajb.2022.08.037.
Samad MA, Hossain MJ, Zahan MS, Islam MM, Rashid MA. 2024. A comprehensive account on ethnobotany, phytochemistry and pharmacological insights of genus Celtis. Heliyon 10: e29707. DOI: 10.1016/j.heliyon.2024.e29707.
Sarmento NC, Worachartheewan A, Pingaew R, Prachayasittikul S, Ruchirawat S, Prachayasittikul V. 2015. Antimicrobial, antioxidant and anticancer activities of Strychnos lucida R. Br. Afr J Tradit Compl Altern Med 12 (4): 122-127. DOI: 10.4314/ajtcam.v12i4.18.
Seal T. 2016. Quantitative HPLC analysis of phenolic acids, flavonoids and ascorbic acid in four different solvent extracts of two wild edible leaves, Sonchus arvensis and Oenanthe linearis of North-Eastern region in India. J Appl Pharm Sci 6: 155-166.
Seck I, Hosu A, Cimpoiu C, Ndoye SF, Ba LA, Sall C, Seck M. 2021. Phytochemicals content, screening and antioxidant/pro-oxidant activities of Carapa procera (barks) (Meliaceae). S Afr J Bot 137: 369-376. DOI: 10.1016/j.sajb.2020.11.019.
Sekeroglu N, Urlu E, Kulak M, Gezici S, Dang R. 2017. Variation in total polyphenolic contents, DNA protective potential and antioxidant capacity from aqueous and ethanol extracts in different plant parts of Hypericum perforatum L. Indian J Pharm Educ Res 51 (2): S1-S7. DOI: 10.5530/ijper.51.2s.43.0.7324/JAPS.2016.60225.
Shackleton CM, Ticktin T, Cunningham AB. 2018. Non-timber forest products as ecological and biocultural keystone species. Ecol Soc 23 (4): 22. DOI: 10.5751/ES-10469-230422.
Silva TC, Araujo ECG, Lins TRS, Reis CA, Sanquetta CR, da Rocha MP. 2020. Non-timber forest products in Brazil: A bibliometric and a state-of-the-art review. Sustainability 12: 7151. DOI: 10.3390/su12177151.
Singh M, Pandey N, Agnihotri V, Singh VV, Pandey A. 2017. Antioxidant, antimicrobial activity and bioactive compounds of Bergenia ciliata Sternb.: A valuable medicinal herb of Sikkim Himalaya. J Tradit Complement Med 7 (2): 152-157. DOI: 10.1016/j.jtcme.2016.04.002.
Spiegel M, Kapusta K, Kolodziejczyk W, Saloni J, Zbikowska B, Hill GA, Sroka Z. 2020. Antioxidant activity of selected phenolic acids-ferric reducing antioxidant power assay and QSAR analysis of the structural features. Molecules 25 (13): 3088. DOI: 10.3390/molecules25133088.
Sridhar K, Charles AL. 2019. In vitro antioxidant activity of Kyoho grape extracts in DPPH assays: Estimation methods for EC50 and ABTS using advanced statistical programs. Food Chem 275: 41-49. DOI: 10.1016/j.foodchem.2018.09.040.
Suh SS, Hwang J, Park M, Park HS, Lee TK. 2014. Phenol content, antioxidant and tyrosinase inhibitory activity of mangrove plants in Micronesia. Asian Pac J Trop Med 7 (7): 531-535. DOI: 10.1016/S1995-7645(14)60089-4.
Sulasmi ES, Wuriana ZF, Sari RS, Rohmawati U. 2019. Flavonoid characterization in ferns from Baluran National Park. IOP Conf Ser: Earth Environ Sci 276: 012033. DOI: 10.1088/1755-1315/276/1/012033.
Sundari MS, Sornalakshmi V, Tresina PS, Mohan VR. 2022. Evaluation of phytochemical screening and in vitro anti-inflammatory activity of mangrove associate plant Pemphis acidula J.R. Forst and G. Forst (Lythraceae). Intl J Health Sci 6 (S6): 10691-10702. DOI: 10.53730/ijhs.v6nS6.12879.
Trinh BTD, Staerk D, Jäger AK. 2016. Screening for potential ?-glucosidase and ?-amylase inhibitory constituents from selected Vietnamese plants used to treat type 2 diabetes. J Ethnopharmacol 186: 189-195. DOI: 10.1016/j.jep.2016.03.060.
Tungmunnithum D, Thongboonyou A, Pholboon A, Yangsabai A. 2018. Flavonoids and other phenolic compounds from medicinal plants for pharmaceutical and medical aspects: An overview. Medicines 5 (3): 93. DOI: 10.3390/medicines5030093.
Wairata J, Fadlan A, Purnomo AS, Taher M, Ersam T. 2022. Total phenolic and flavonoid contents, antioxidant, anti-diabetic and antiplasmodial activities of Garcinia forbesii King: A correlation study. Arab J Chem 15: 103541. DOI: 10.1016/j.arabjc.2021.103541.
Wirasisya DG, Kinces A, Vidács L, Szemeredi N, Spengler G, Barta A, Mertha IG, Hohmann J. 2023. Indonesian Euphorbiaceae: Ethnobotanical survey, in vitro antibacterial, anti-tumour screening and phytochemical analysis of Euphorbia atoto. Plants 12 (22): 3836. DOI: 10.3390/plants12223836.
Xu R, Bu YG, Zhao ML, Tao R, Luo J, Li Y. 2020. Studies on antioxidant and ?-glucosidase inhibitory constituents of Chinese toon bud (Toona sinensis). J Funct Foods 73: 104108. DOI: 10.1016/j.j?.2020.104108.
Zahra S, Hofstetter RW, Waring KM, Gehring C. 2020. The invasion of Acacia nilotica in Baluran National Park, Indonesia, and potential future control strategies. Biodiversitas 21 (1): 104-116. DOI: 10.13057/biodiv/d210115.
Zhao H, Duan RJ, Kong CH, Dai HF, Mei WL, Xu FQ, Huang SZ. 2024. Two new anti-inflammatory trachylobane diterpenoids from Euphorbia atoto. J Asian Nat Prod Res 26 (3): 313-319. DOI: 10.1080/10286020.2023.2224232.
Zhao H, Wu SY, Duan RJ, Zeng J, Dai HF, Mei WL, Xu FQ, Huang SZ. 2022. Chemical constituents of Euphorbia atoto from Xisha Islands. Tianran Chanwu Yanjiu yu Kaifa 34 (11): 1883-1891. DOI: 10.16333/j.1001-6880.2022.11.009.

Most read articles by the same author(s)

<< < 1 2 3 > >>