Document Type : Original Article


1 Medicinal Chemistry Research Group, Organic Chemistry Unit, Department of Chemistry, University of Ibadan, Ibadan, Nigeria

2 Marine and Biodiversity Center, Chemistry Department, Meston Building, University of Aberdeen, Scotland, United Kingdom


Diabetes mellitus is a critical clinical condition characterized by hyperglycemia in which an accelerated amount of glucose circulates in the blood plasma. This work attempts to evaluate the α-amylase and α-glucosidase inhibitory activities of hexane, ethyl acetate and methanol fractions of Pterocarpus soyauxii at varying concentrations. 1.0 kg of milled leaf sample was first soaked in 5 L of methanol to obtain a percentage yield of 12%. The assay was carried out using standard procedures. The following IC50 values were obtained in the α-amylase inhibition: 0.0395, 0.05995, and 0.0509 mg/mL for hexane, ethyl acetate, and methanol, respectively compared to the standard drug acarbos (0.00812 mg/mL). A dose-dependent increase in percentage inhibition was obtained for α-glucosidase with IC50 values of 0.052, 0.059, and 0.065 mg/mL for respective fractions compared to the standard drug used (0.0017 mg/mL). The hexane fraction showed the greatest percentage inhibition for both α-amylase and α-glucosidase, while appreciable inhibition activity was observed in other fractions. The Nigerian Pterocarpus soyauxii has been identified for the first time as a very potent anti-diabetic agent useful in management of postprandial hyperglycemia and related therapeutic interventions.

Graphical Abstract

In-vitro alpha amylase and alpha glucosidase inhibitory potential of leaf hexane, ethyl acetate and methanol fractions of Pterocarpus soyauxii Taub


Aidi-Wannes, W., Mhamdi, B., Saidani-Tounsi, M., Marzouk, B., 2017. Lipid and volatile composition of borage (Borago officinalis L.) leaf. Trends Phytochem. Res. 1(3), 143-148.
Arnone, A., Camarda, L., Merlini, L., Nasini G., Taylor, D.A.H., 1977. Coloring matters of the West African red woods Pterocarpus osun and P. soyauxii. Structures of santarubins A and B. J. Chem. Soc. Perkin Trans 1(19), 2116-2118.
Assanta, M.A., Robert, C., 2011. Gnetum africanum, a wild food plant from the African forest with many nutritional and medicinal purposes. Afr. J. Herb. Med. 14, 1289-1297.
Ayat, A., Mohamad, E.A., Mohamad, J.K., Foroogh, N., 2015. In vitro α-amylase and α- glucosidases inhibitory effects of some plant extracts. Int. J. Pharmacogn. Phytochem. Res.
7(2), 315-318.
Balkan, B., Charles, M.A., Eschwege, E., 2000. Discussion epidemiolgique des nouveaux criteres du diabete Mt. Endocrinologie 2, 229-234.
Barend, C.B., Brandt, B.E.V., 1987. Flavonoid analogs from Pterocarpus species. Phytochemistry 26, 531-535.
Boutati, E.I., Raptis, S.A., 2004. Post prandial hyperglycemia in type 2 diabetes: Pathophysiological aspect, teleogical notions and flags for clinical practice. Diabetes Res. Rev. 20(2), S13-S23.
Bremaud, I., Amusant, N., Minato, K., Gril, J., Thibaut, B., 2011. Effect of extractives on vibrational properties of African Padauk (Pterocarpus soyauxii Taub). Wood Sci. Tech. 45, 461-472.
Camilo, C.J., Alves Nonato, C.d.F., Galvão-Rodrigues, F.F., Costa, W.D., Clemente, G.G., Sobreira Macedo, M.A.C., Galvão Rodrigues, F.F., da Costa, J.G.M., 2017. Acaricidal activity of essential oils: a review. Trends in Phytochem. Res. 1(4), 183-198.
Cheng, A.Y., Fantus, I.G., 2005. Oral antihyperglycemic therapy for type 2 diabetes mellitus. Can. Med. Assoc. J. 172, 213-226.
de Sales, P.M., Simeoni, L.A., Magalhães, P.O., Silveira, D., 2012. α-Amylase inhibitors: A review of raw material and isolated compounds from plant source. J. Pharm. Pharm Sci. 15, 141-183.
DeFronzo, R.A., 1999. Pharmacologic therapy for type 2 diabetes mellitus. Ann. Intern. Med.
131(4), 281-303.
Devesh, KK., Manjulika, Y., Sanjukta, C., Amrita, KS., Geeta, W., 2016. α-Amylase and α-glucosidase inhibitory activity assessment of Cucurbita maxima seeds-A LIBS based study. Int. Phytomedicine 8, 312-318.
Dike, M.C., 2010. Proximate and nutrient composition of some fruits, seeds and leaves of some plant species at Umudike, Nigeria. ARPN J. Agric. Biol. Sci. 5, 7-16.
Ganesan, K., Xu, B., 2017. Ethnobotanical studies on folkloric medicinal plants in Nainamalai, Namakkal District, Tamil Nadu, India. Trends Phytochem. Res. 1(3), 153-168.
Hanefeld, M., Schmechel, H., Julius, U., Schwanebeck, U. 1996. Determinants for coronary heart disease in non-insulin dependent diabetes mellitus: lessons from the diabetes intervention study. Diabetes Res. Clin. Pract. 30, 67-70.
Hasani-Ranjbar, S., Larijani, B., Abdollah, M., 2008. A systematic review of Iranian medicinal plants useful in diabetes mellitus. Arch. Med. Sci. 4, 285-292.
Hind, L., Nabila, B., Sara, A., Rabah, D., 2007. In vitro α-amylase and α-glucosidase inhibitory activity of Ononis angustissima extracts. J. App. Pharm. Sci. 7(2), 191-198.
Kim, Y.M., Jeong, M.H., Wang, W.Y., Lee, H.I., 2005. Inhibitory effect of pine extract on alpha-glucosidase activity and postprandial hyperglycemia. Nutrition 21, 756-761.
King, F.E., Cotterill, C.B., Godson, D.H., Jurd, L., King, T.J., 1953. The chemistry of extractives from hardwoods. XIII. Colorless constituents of Pterocarpus species. J. Chem. Soc. 3693-3697.
Kneen, E., Sandstedt, R.M., Hollenbeck, C.M.,1943. Amylase and diastatic activity. Cereal Chem. 2(4), 399.
Kwon, Y.I., Apostolidis, E., Kim, Y.C., Shetty, K., 2007. Health benefits of traditional corn, beans and pumpkin: In vitro studies for hyperglycemia and hypertension management. J. Med. Food 10, 266-275.
Kwon, YI., Apostolidis, E., Shetty, K., 2007. Evaluation of pepper (Capsicum annuum) for management of diabetes and hypertension. J. Food Biochem. 31(3), 370-385.
Lavin, M., Pennigton, R.T., 2001. Delimitation of a pantropic legumes. J. Bot. Sci. 8, 503-511.
Matsuda, H., Nishida, N., Yoshikawa, M., 2002. Antidiabetic principles of natural medicines. V. Aldose reductase inhibitors from Myrcia multiflora DC. (2): Structures of myrciacitrins III, IV, and V. Chem. Pharm. Bull. 50(14), 429-431.
McCue, P.P., Shetty., K., 2004. Inhibitory effects of rosmarinic acid extracts on porcine pancreatic amylase. Asia Pac. J. Clin. Nutr. 13(1), 101-106.
Mohammadhosseini, M., 2017. The ethnobotanical, phytochemical and pharmacological properties and medicinal applications of essential oils and extracts of different Ziziphora species. Ind. Crop Prod. 105, 164-192.
Mohammadhosseini, M., Akbarzadeh, A., Hashemi- Moghaddam, H., Mohammadi Nafchi, A., Mashayekhi, H.A., Aryanpour, A., 2016. Chemical composition of the essential oils from
the aerial parts of Artemisia sieberi by using conventional hydrodistillation and microwave assisted hydrodistillation: A comparative study. J. Essent. Oil-Bear. Plants 19(1), 32-45.
Mohammadhosseini, M., Sarker, S.D., Akbarzadeh, A., 2017. Chemical composition of the essential oils and extracts of Achillea species and their biological activities: A review. J. Ethnopharmacol. 199, 257-315.
Mohammadhosseini, M., Venditti, A., Sarker, S.D., Nahar, L., Akbarzadeh, A., 2019. The genus Ferula: Ethnobotany, phytochemistry and bioactivities - A review. Ind. Crops Prod. 129, 350-394.
Nunes, H.S., Miguel, M.G., 2017. Rosa damascena essential oils: a brief review about chemical composition and biological properties. Trends Phytochem. Res. 1(3), 111-128.
Okerulu I. O., Onyema C.T., Onwukeme V. I., Ezeh C.M., 2017. Assessment of phytochemicals, proximate and elemental composition of Pterocarpus soyauxii (Oha) leaves Am. J. Anal. Chem. 8, 406-415.
Ortiz-Andrade, R.R., Garcia-Jimenez, S., Castillo-Espana, P., Ramirez-Avila, G., Villalobos-Molina, R., EstradaSoto, S. 2007. Alpha-glucosidase inhibitory activity of the methanolic extract from Tournefortia hartwegiana: an antihyperglycemic agent. J. Ethnopharmacol. 109, 48-53.
Oteng-Gang, K., Mbachu, J.I., 1990. Changes in the ascorbic acid content of some tropical leafy vegetables during traditional cooking and local processing. Food Chem. 23, 9-17.
Oteng-Gyang, K., Mbachu, J.I., 1987. Changes in the ascorbic acid content of some tropical leafy vegetables during traditional cooking and local processing. Food Chem. 23, 9-17.
Pavunraj, M., Ramasubbu, G., Baskar, K., 2017. Leucas aspera (Willd.) L.: Antibacterial, antifungal and mosquitocidal activities. Trends Phytochem. Res. 1(3), 135-142.
Rai, R., Nath, V., 2003. Use of medicinal plants by traditional herbal healers in central India. XII World Forestry Congress.
Saha, J.B.T., Abia, D., Dumarcay, S., Ndikontar, M.K., Gerardin, P., Ngamveng, N.J., Perrin, D., 2013. Antioxidant activities, total phenolic contents and chemical compositions of extracts from four Cameroonian woods: Padouk (Pterocarpus soyauxii Taub), tali (Erythrophleum suaveolens), moabi (Baillonella toxisperma), and movingui (Distemonanthus benthamianus). Ind. Crop Prod. 41, 71-77.
Saha, M.R., Rai, R., Kar, P., Sen, A., Sarker, D.D., 2015. Ethnobotany, traditional knowledge and socioeconomic importance of native drink among the Oraon tribe of Malda district in India. J. Intercult. Ethnopharmacol. 4(1), 34-39.
Santhakumari, P., Prakasam, A., Pugalendi, K.V., 2006. Pugalendi antihyperglycemic activity of piper betle leaf on Streptozotocin-induced diabetic rats. J. Med. Food 9(1), 108-112.
Savithramma, N., Yugandhar, P., Prasad, K.S., Ankanna, S., Chetty, K.M., 2016. Ethnomedicinal studies on plants used by Yanadi tribe of Chandragiri reserve forest area, Chittoor District, Andhra Pradesh, India. J. Intercult. Ethnopharmacol. 5(1), 49-56.
Shaw, J.E., Sicree, R.A., Zimmet, P.Z., 2010. Global estimates of the prevalence of diabetes for 2010 and 2030. Diabetes Res. Clin. Pract. 87(1), 4-14.
Shihabudeen, M.S., Hansi, P., Kavitha, T., 2011. Cinnamon extract inhibits a-glucosidase activity and dampens postprandial glucose excursion in diabetic rats. Nutr. Metab. 8, 46-51.
Tanko, Y., Eze, E.D., Jimoh, A., Yusuf, K., Mohammed, K.A., Balarabe, F., Mohammed, A., 2012. Haemostatic effect of aqueous extract of mushroom (Ganoderma lucidum). Eur. J. Exp. Biol. 2(6), 2015-2018.
Tchamadeu, M.C., Dzeufiet, P.D., Nana, P., Kouambou, N.C., Ngueguim, T.F., Allard, J., Blaes, N., Siagat, R., Zapfack, L., Girolami, J.P., Tack, I., Kamtchouing, P., Dimo, T., 2011. Acute and sub-chronic oral toxicity studies of an aqueous stem bark extract of Pterocarpus soyauxii Taub (Papilionaceae) in rodents. J. Ethnopharmacol. 133, 329 -335.
Wansi, J.D., Sewald, N., Nahar, L., Martin, C., Sarker, S.D., 2019. Bioactive essential oils from the Cameroonian rain forest: A review - Part II. Trends in Phytochem. Res. 3(1), 3-52.