Investigation of the antiobesity and antioxidant properties of wild Plumbago europaea and Plumbago auriculata from North Palestine
© The Author(s) 2016
Received: 21 October 2016
Accepted: 17 November 2016
Published: 2 December 2016
Historically, plants have proven their value as a source of phytochemicals with therapeutic potentials and recently they play an important role in the discovery of novel drugs.
The current study aimed to investigate new antiobesity drugs from Plumbago europaea and Plumbago auriculata through the inhibition of the adsorption of dietary lipids. In vitro porcine pancreatic lipase inhibitory tests were conducted with weight reduction property as well as this study aimed to explore the antioxidant potential and to estimate total phenolic, flavonoid, and tannin contents in both of the studied species.
Antioxidant capacity was evaluated using ferric reducing antioxidant power and DPPH assays, and porcine pancreatic lipase inhibitory tests were conducted using the UV spectrophotometric method, while total flavonoid, phenol, and tannin contents were estimated using standard phytochemical analytical methods.
Antioxidant potential and total flavonoid, phenol, and tannin contents of P. europaea were significantly higher than those of P. auriculata, and both of the studied species have potential antiobesity activity in comparison with orlistat.
KeywordsAnti-lipase Antioxidant Flavonoids Plumbago europaea Plumbago auriculata
For millennia, the plant kingdom has been a valuable source of therapeutic agents and till now many modern drugs are semi-synthesized or isolated from these natural sources .
In the past decades, the major focus of pharmaceutical companies was mainly on synthetic molecules as a source of drug discovery due to their effectiveness, ease of production, and supply. For all these reasons, synthetic medications spread globally, while drug discovery from natural sources was associated with some intrinsic difficulties, and the pharmaceutical industry has shifted its main focus to synthetic molecules [2–4]. Unfortunately, many side effects and adverse reactions were associated with these synthetic drugs, and the world has witnessed an increase in the use of plants to treat diseases and to promote better health [5, 6].
One of the most important challenges that are still facing humanity is weight gain and obesity. This problem is drawing the attention of both the cosmetic and the pharmaceutical industries. In fact, many countries consider a slim body as a factor of beauty. In addition, obesity is currently considered a worrying epidemic disorder. In fact, it touches adults, as well as children and teenagers. It was estimated that about 300,000 people die each year from obesity and related causes, which puts this disorder as the second leading cause of death. In fact, being both overweight and obese increases the risk of several diseases and health conditions such as high triglycerides, cholesterol, diabetes, heart disease, high blood pressure, tumors (breast, colon, and endometrial), sleep disorders, and respiratory problems [7–9].
Previous studies showed that some medicinal plants contain mixtures of antioxidant phytochemical compounds such as flavonoids, tannins, and polyphenols that can inhibit or reduce oxidative deterioration of lipids, proteins, and DNA, consequently preventing neurodegenerative diseases, radiation damage, atherosclerosis, chronic inflammatory diseases, carcinogenesis, arthritis, aging, liver injury, and other pathological disorders [10–12].
Both of the studied plants species Plumbago europaea and Plumbago auriculata (Fig. 1) belonged to the Plumbaginaceae family. Plumbago europaea L., also known as the common leadwort, is a perennial plant which is native to the Central Asia and Mediterranean regions. The plant is well known to contain europetin flavonol and plumbagin naphthoquinones [13–15]. The P. europaea plant is used for the treatment of respiratory disorders, hepatitis, edema, leprosy, inflammations, scabies, toothache, warts, blisters, injury, calluses, and skin hardness in traditional Palestinian, Jordanian, Italian, and Turkish folkloric ethno-medicines [16–22].
Plumbago auriculata Lam. (Cape Leadwort) is a species of the perennial flowering plants which are found in South Africa, subtropical gardens in Florida, and in all the warm winter climate regions across the world . In South African and Arabian folk medicines, P. auriculata is used for the treatment of malaria, wounds, gastro-esophageal reflux disease, broken bones, and to remove warts [24–27]. Sitosterol steroids, plumbagin naphthoquinones, epi-isoshinanolone, 3-O-glucosylsitosterol, palmitic acid, and plumbagic acid were isolated from P. auriculata .
The current study aimed to investigate new antiobesity drugs from the leaves of P. europaea and P. auriculata through the inhibition of the adsorption of dietary lipids. In vitro porcine pancreatic lipase inhibitory with weight-reducing properties were conducted for this purpose. In addition, this study aimed to explore the antioxidant potential and to estimate total phenolic, flavonoid, and tannin contents in both of the studied Plumbago species.
Shaker device (Memmert shaking incubator, Germany), rotary evaporator (Heidolph OB2000 Heidolph VV2000, Germany), UV–visible spectrophotometer (Jenway 7135, England), grinder (Moulinex model, Uno, China), and balance (Rad wag, AS 220/c/2, Poland) were used in this study.
Chemicals and reagents
Methanol (Loba Chemie, India), acetone (Alzahraa, Palestine), Millon’s reagent (Gadot, Israel), ninhydrin solution (Alfa Agar, England), Benedict’s reagent (Gadot, Israel), Molisch’s reagent, H2SO4, iodine solution (Alfa-Aesar, England), NaOH (Gadot, Israel), chloroform, HCl (Sigma-Aldrich, Germany), magnesium ribbon, acetic acid (Frutarom Ltd., Israel), FeCl3 (Riedel–de–haen, Germany), Folin–Ciocalteu reagent (Sigma-Aldrich, Germany), NaHCO3 (Merck, Germany), trichloroacetic acid (Sigma-Aldrich, Germany), (s)-(-)-6-hydroxy-2,5,7,8–tetramethylchroman-2 carboxylic acid (Trolox) (Sigma-Aldrich, Denmark), 2,2-diphenyl-1-picrylhydrazyl (DPPH) (Sigma-Aldrich, Germany), dimethyl sulfoxide (DMSO) (Riedel–de–haen, Germany), acetonitrile (Sigma-Aldrich, Germany), porcine pancreatic lipase type II (Sigma, USA), p-nitrophenol (PNP) (Sigma-Aldrich, Germany), orlistat, quercetin (Sigma, USA), gallic acid, AlCl3, sodium nitrite, vanillin, catechin (Sigma- Aldrich, Germany), and potassium ferricyanide (Riedel–de–haen, Germany) were used in this study.
The leaves of P. europaea and P. auriculata were collected in June, 2015 from the Jericho and Tubas regions of Palestine. Botanical identification was carried out in the Pharmacognosy and Herbal Products Laboratory at An-Najah National University by the Pharmacognosist Dr. Nidal Jaradat, and the voucher specimen codes were Pharm-PCT-1899 and Pharm-PCT-1900, respectively.
The leaves were washed and then dried in the shade at room temperature until all the plant parts became well dried. After drying, the plant materials were ground well into a fine powder using a mechanical blender and transferred into airtight containers with proper labeling for future use.
Preparation of different extracts of plants
About 10 g of the grounded leaves of P. europaea and P. auriculata plants were soaked separately in 1 l of three different solvents (water, methanol, and acetone), and each of the extracts was placed in a shaker device at 100 rounds per minute for 72 h at room temperature and then stored in a refrigerator for 4 days. After that, the extract was filtered using Whatman filter paper No. 1 and concentrated under vacuum on a rotary evaporator at 35 °C. The crude extracts were then stored at 4 °C in the refrigerator for further use .
Qualitative phytochemical analysis
Qualitative preliminary phytochemical screening of primary and secondary metabolic compounds such as starch, phenols, cardiac glycosides, flavonoids, saponin glycosides, alkaloids, steroids, volatile oils, and tannins was carried out according to the standard common phytochemical methods described by Trease and Evans  and Harborne .
Screening of antioxidant activity
Ferric reducing assay
Methanolic extracts were subjected to this assay by preparing methanolic solutions of different concentrations (100, 200, 300, 400, and 500 µg/ml), and 1 ml from each dilution was mixed with 2.5 ml of phosphate buffer (200 mM, pH 6.6) and 2.5 ml of 1% potassium ferricyanide in a separate tube.
The tubes were placed in a boiling water bath for 20 min at 50 °C, cooled rapidly, and then mixed with 2.5 ml of 10% trichloroacetic acid and 0.5 ml of 0.1% ferric chloride. The amount of iron (II)–ferricyanide complex formed was determined by measuring the formation of Perl’s Prussian blue at 700 nm after 10 min, and the presence of antioxidants (reductants) in the sample would result in the reduction of Fe3+ to Fe2+ by donating an electron. The amount of Fe2+ complex formed by the reduction of Fe3+ can be monitored by measuring the formation of color complex at 700 nm. An increase in absorbance indicates an increase in reduction ability. The reducing capacity of the compound may serve as a significant indicator of its potential antioxidant activity. This would have the effect of converting free radicals to more stable products and thus terminating free radical-initiated chain reactions .
The antioxidant half maximal inhibitory concentration (IC50) for the plant samples and the standard were calculated using BioDataFit edition 1.02 (data fit for biologist).
Pancreatic lipase inhibition
Preparation of lipase stock solution and plant extract dilution series
The porcine pancreatic lipase inhibitory assay was adapted from Zheng et al.  and Bustanji et al.  with some modifications. From the prepared 1 mg/ml plant extract stock solution in 10% DMSO, solutions of five different concentrations (200, 400, 600, 800, and 1000 μg/ml) were prepared, while 1 mg/ml stock solution of pancreatic lipase enzyme was prepared immediately before use, which was suspended in Tris–HCl buffer.
Preparation of lipase substrate stock solution
The stock solution of PNPB (p-nitrophenyl butyrate) was prepared by dissolving 20.9 mg of PNPB in 2 ml of acetonitrile. For each working test tube, 0.1 ml of porcine pancreatic lipase (1 mg/ml) was added to a test tube containing 0.2 ml plant extract from each diluted solution series for each studied plant. The resulting mixture was then made up to 1 ml by adding Tris–HCL solution and incubated at 37 °C for 15 min. After the incubation period, 0.1 ml of PNPB (p-nitrophenyl butyrate) solution was added to each test tube. The mixture was again incubated for 30 min at 37 °C. Pancreatic lipase activity was determined by measuring the hydrolysis of p-nitrophenolate to p-nitrophenol at 405 nm using a spectrophotometer. The same procedure was repeated for Orlistat which was used as a reference compound .
Determination of total tannin content in the different extracts
Total tannin content (proanthocyanidins) was determined according to the method of Sun et al. , with some modification. To 0.5 ml of each of the diluted catechin solutions of different concentrations (0.1, 0.4, 0.5, 0.7, and 1 mg/ml), 3 ml of 4% vanillin solution in methanol and 1.5 ml of concentrated HCl were added. The mixture was allowed to stand for 15 min, and absorption was measured at 500 nm against methanol as a blank. The amount of total tannins is expressed as mg (+)-catechin/g plant extract (mg CAE/g). All samples were analyzed in triplicate. The same procedure was repeated for methanolic extracts of the two plants .
Determination of total phenolic content
Total phenolic content in the plant methanolic extract was determined using spectrophotometric method with some modifications . 1 mg/ml stock aqueous solutions of methanolic extracts were prepared. The reaction mixture was prepared by mixing 0.5 ml of plant extract solution, 2.5 ml of 10% Folin–Ciocalteu reagent dissolved in water, and 2.5 ml of 7.5% of NaHCO3 aqueous solution. The samples were incubated in a thermostat at 45 °C for 45 min. The absorbance was determined using a spectrophotometer at the wavelength of 765 nm. The samples were prepared in triplicate for each analysis and the mean value of absorbance was calculated. The same procedure was repeated for the standard solution of gallic acid and the calibration line was construed. Based on the measured absorbance, the concentration was expressed in terms of gallic acid equivalent (mg of GAE/g of extract), and this procedure was repeated three times for both of the studied Plumbago species.
Determination of total flavonoid content
Total flavonoid content was measured with the aluminum chloride colorimetric assay . 10 mg of quercetin was dissolved in 100 ml of methanol and then diluted to 10, 30, 50, 70, and 100 µg/ml using methanol. The stock solution of plant extract was prepared by dissolving 100 mg of the methanolic extract in 5 ml methanol and transferred to a 10-ml volumetric flask and made up to the volume with methanol. 0.3 ml of 5% sodium nitrite solution was added into each working test tube. After 5 min, 0.3 ml of 10% aluminum chloride was added. At the 6th minute, 2 ml of 1 M sodium hydroxide was added. Finally, the volume was made up to 10 ml with distilled water and mixed well. The absorbance was measured at 510 nm using a UV–visible spectrophotometer. A blank test was performed using distilled water. Quercetin was used as the standard. The samples were analyzed in triplicate. The calibration curve was plotted using standard quercetin. The total flavonoid content of the extract was expressed as mg of quercetin equivalents/g (mg of QUE/g) of plant extract, and this procedure was repeated three times for both of the studied plants species.
Phytochemical classes identified in the aqueous, acetone, and methanolic extracts of both plumbago studied species
Total tannin content
Total phenolic content
Total flavonoid content
Total phenolic, flavonoid, and tannin contents of methanolic extracts for P. auriculata and P. europaea
Studied species of Plumbago plants
Total phenolic content (mg GAE/g) ± SD
Total flavonoid content (mg QUE/g) ± SD
Total Tannin content (mg CAE/g) ± SD
24.3 ± 0.22
87.12 ± 0.15
9.55 ± 0.80
41.5 ± 0.20
94.66 ± 0.08
29.58 ± 0.20
Antioxidant screening assay
Using ferric reducing power assay, IC50 value for the methanolic extract of P. europaea was 69.18 µg/ml and that for the methanolic extract of P. auriculata was 70.79 µg/ml, whereas the IC50 value for Trolox was 50.12 µg/ml. This result indicates the relatively high ferric reducing activity of these two extracts compared to pure standard Trolox.
Pancreatic lipase enzyme inhibition activity
The methanol extracts anti-lipase IC50 value of P. europaea and P. auriculata was 134.29 and 130.32 µg/ml, respectively, as shown in Fig. 8. This result showed that both the studied Plumbago species possess relatively the same inhibitory action against lipase enzyme.
Recently, the focus on medicinal plants research has increased considerably, especially for those plants that were used in folk medicines. This increasing interest is due to the scarcity of therapeutic agents available to treat chronic diseases, increasing of bacterial resistance and the harmful side effects of chemical compounds [39, 40]. Natural plant products containing polyphenolic compounds such as phenolic acids, tannins, anthocyanins, and flavonoids were demonstrated to have potential health benefits for the treatment of metabolic disorders such as diabetes mellitus, hypercholesterolemia, overweight, and obesity . Several studies were conducted on natural products in order to assess their pharmacological activities including antioxidant and anti-lipase effects [42–44].
In this context, P. europaea and P. auriculata exhibited high flavonoid contents of 94.66 mg QUE/g and 87.12 mg QUE/g, respectively, which may explain their anti-lipase activity.
In addition, P. europaea and P. auriculata showed a promising antioxidant activity in both of the utilized DPPH and ferric reducing assays.
On the other hand, total phenolic content was higher in P. europaea, which was 41.5 mg GAE/g, while in P. auriculata the total phenolic content was 24.3 mg GAE/g. At the same time, the total tannin content was also higher in P. europaea than in P. auriculata, which were 29.58 mg CAE/g and 9.55 mg CAE/g, respectively.
In another investigation conducted by Amoo et al.  in South Africa, the total phenolic and flavonoid contents in P. auriculata were 15.0 mg GAE/g and 5.5 mg QUE/g, respectively. This means that wild-growing P. auriculata used in our study had much better total phenolic and flavonoid contents than South African P. auriculata .
Using ferric reducing power assay, the IC50 values were 69.18 and 70.79 µg/ml for the methanolic extracts of P. europaea and P. auriculata, respectively, whereas the IC50 value for Trolox was 50.12 µg/ml. This result indicates the relatively high ferric reducing activity of these two extracts compared to Trolox.
Moreover, using DPPH assay the IC50 values for P. europaea and P. auriculata were 21.38 and 89.12 µg/ml, respectively, while the IC50 value for Trolox was 1.85 µg/ml. This indicates the high potential antioxidant activity of P. europaea versus P. auriculata.
Moreover, there was a significant linear correlation between the antioxidant activity determined using the DPPH and ferric reducing assays and the total phenolic, tannin, and flavonoid contents in both of the studied Plumbago species. However, no significant relationship was observed between the antioxidant activity and the total tannin, phenolic, and flavonoid contents in both of the studied Plumbago species and the anti-lipase activity because both of the studied species had almost the same potential as anti-lipase drugs.
A study conducted by Bircan and Kirbag  evaluated the antioxidant activity of P. europaea growing in Turkey using DPPH assay and found that it was 83.62 µg/ml, while in the studied P. europaea growing in Palestine it was 21.38 µg/ml which exhibited an antioxidant activity four times better than that of the Turkish P. europaea . In fact, the impact of the flavonoid content on anti-aging and anti-lipase activities was documented.
On the other hand, both of the studied species had more powerful antioxidant activity than Plumbago zeylanica that had an antioxidant activity of 88.45 µg/ml which was studied by Sini et al.  and which is almost equal to the antioxidant activity of P. auriculata which was 89.12 µg/ml.
In fact, overweight and obesity have become epidemics and are increasing at an alarming rate in both the developed and developing countries [51, 52]. Pancreatic lipase is considered the principal lipolytic enzyme which plays an essential role in the efficient digestion of lipids and is responsible for the hydrolysis of about 70% of total ingested fats .
The IC50 value showed potent inhibitory action against lipase enzyme when comparing with Arum palaestinum which was previously reported by Bustanji et al.  to have potent lipase inhibitory action with an IC50 value of 107.7 µg/ml.
For the studied Plumbago plant species, the potential activity against pancreatic lipase enzyme can be attributed to the high content of flavonoids which are well known to exhibit potential activity against pancreas and liver enzymes.
In the present study, the total contents of phytochemical compounds including flavonoids, phenols, and tannins as well as their antioxidant and antiobesity activities of the two species, P. europaea and P. auriculata, were evaluated and compared. The obtained results suggested that these plants have moderate to potent antioxidant activity and both of them had high contents of flavonoids. In addition, they could be used as a source of lead drugs for developing new antiobesity agents. However, further isolation, identification, and characterization of phyto-active compounds responsible for anti-lipase action are required to evaluate the full therapeutic potentials of these plants.
All research has been done by the authors. All authors read and approved the final manuscript.
The authors acknowledge the assistance of the technicians Mohamad Arar and Linda Esa, and a special thanks to Jonathan Wright (English Center—An-Najah National University) for English language editing and proofing.
The authors declare that they have no competing interests.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Rischer H, Hakkinen ST, Ritala A, Seppanen-Laakso T, Miralpeix B, Capell T, et al. Plant cells as pharmaceutical factories. Curr Pharm Des. 2013;19(31):5640–60.View ArticlePubMedGoogle Scholar
- Kinghorn AD, Pan L, Fletcher JN, Chai H. The relevance of higher plants in lead compound discovery programs. J Nat Prod. 2011;74(6):1539–55.View ArticlePubMedPubMed CentralGoogle Scholar
- Newman DJ, Cragg GM. Natural products as sources of new drugs over the 30 years from 1981 to 2010. J Nat Prod. 2012;75(3):311–35.View ArticlePubMedPubMed CentralGoogle Scholar
- David B, Wolfender J-L, Dias DA. The pharmaceutical industry and natural products: historical status and new trends. Phytochem Rev. 2015;14(2):299–315.View ArticleGoogle Scholar
- Schuster D, Laggner C, Langer T. Why drugs fail-a study on side effects in new chemical entities. Curr Pharm Des. 2005;11(27):3545–59.View ArticlePubMedGoogle Scholar
- Alqahtani S, Mohamed LA, Kaddoumi A. Experimental models for predicting drug absorption and metabolism. Expert Opinion Drug Metab Toxicol. 2013;9(10):1241–54.View ArticleGoogle Scholar
- Hopkins M, Finlayson G, Duarte C. Modelling the associations between fat-free mass, resting metabolic rate and energy intake in the context of total energy balance. Int J Obes. 2016;40(2):312–8.View ArticleGoogle Scholar
- Kusminski CM, Bickel PE, Scherer PE. Targeting adipose tissue in the treatment of obesity-associated diabetes. Nat Rev Drug Discov. 2016;3:1033–8.Google Scholar
- Baillie-Hamilton PF. Chemical toxins: a hypothesis to explain the global obesity epidemic. J Altern Complement Med. 2002;8(2):185–92.View ArticlePubMedGoogle Scholar
- Turati F, Rossi M, Pelucchi C, Levi F, La Vecchia C. Fruit and vegetables and cancer risk: a review of southern European studies. Br J Nutr. 2015;113(S2):102–10.View ArticleGoogle Scholar
- Kaefer CM, Milner JA. The role of herbs and spices in cancer prevention. J Nutr Biochem. 2008;19(6):347–61.View ArticlePubMedPubMed CentralGoogle Scholar
- Karbach S, Wenzel P, Waisman A, Munzel T, Daiber A. eNOS uncoupling in cardiovascular diseases-the role of oxidative stress and inflammation. Curr Pharm Des. 2014;20(22):3579–94.View ArticlePubMedGoogle Scholar
- Iwashina T. Flavonoid properties of five Families newly incorporated into the Order Caryophyllales (Review). Bull Natl Sci Mus Ser B. 2013;39(1):25–51.Google Scholar
- Al-Nuri MA, Hannoun MA, Zatar NA, Abu-Eid MA, Al-Jondi WJ, Hussein AI, et al. Plumbagin, a naturally occurring naphthoquinone: its isolation, spectrophotometric determination in roots, stems, and leaves in Plumbago europaea L. Spectrosc Lett. 1994;27(4):409–16.View ArticleGoogle Scholar
- Muhammad HM, Saour KY, Naqishbandi AM. Quantitative and qualitative analysis of Plumbagin in the leaf and root of Plumbago europaea growing naturally in Kurdistan by HPLC. Iraqi J Pharm Sci. 2009;18:54–60.Google Scholar
- Sezik E, Yeşilada E, Honda G, Takaishi Y, Takeda Y, Tanaka T. Traditional medicine in Turkey X. Folk medicine in central Anatolia. J Ethnopharmacol. 2001;75(2):95–115.View ArticlePubMedGoogle Scholar
- Jaradat NA, Al-Ramahi R, Zaid AN, Ayesh OI, Eid AM. Ethnopharmacological survey of herbal remedies used for treatment of various types of cancer and their methods of preparations in the West Bank-Palestine. BMC Complement Altern Med. 2016;16(1):1–12.Google Scholar
- Ali-Shtayeh MS, Yaniv Z, Mahajna J. Ethnobotanical survey in the Palestinian area: a classification of the healing potential of medicinal plants. J Ethnopharmacol. 2000;73(1):221–32.View ArticlePubMedGoogle Scholar
- Benítez G, González-Tejero M, Molero-Mesa J. Pharmaceutical ethnobotany in the western part of Granada province (southern Spain): Ethnopharmacological synthesis. J Ethnopharmacol. 2010;129(1):87–105.View ArticlePubMedGoogle Scholar
- Passalacqua N, Guarrera P, De Fine G. Contribution to the knowledge of the folk plant medicine in Calabria region (Southern Italy). Fitoterapia. 2007;78(1):52–68.View ArticlePubMedGoogle Scholar
- Palmese MT, Manganelli REU, Tomei PE. An ethno-pharmacobotanical survey in the Sarrabus district (South–East Sardinia). Fitoterapia. 2001;72(6):619–43.View ArticlePubMedGoogle Scholar
- Oran S, Al-Eisawi D. Ethnobotanical survey of the medicinal plants in the central mountains (North–South) in Jordan. J Biodivers Environ Sci. 2015;6(30):381–400.Google Scholar
- Dorling K. RHS AZ Encyclopedia of garden plants. London: The Royal Horticultural Society; 2008.Google Scholar
- de Paiva SR, Figueiredo MR, Kaplan MAC. Isolation of secondary metabolites from roots of Plumbago auriculata Lam. by countercurrent chromatography. Phytochem Anal. 2005;16(4):278–81.View ArticlePubMedGoogle Scholar
- Motsei M, Lindsey K, Van Staden J, Jäger A. Screening of traditionally used South African plants for antifungal activity against Candida albicans. J Ethnopharmacol. 2003;86(2):235–41.View ArticlePubMedGoogle Scholar
- De Paiva SR, De AFontoura L, Figueiredo MR, Mazzei JL, Kaplan MAC. Perfil cromatográfico de duas espécies de Plumbaginaceae: Plumbago scandens L. e Plumbago auriculata Lam. Química Nova. 2002;25(5):717–21.View ArticleGoogle Scholar
- Sharma P, Mujundar A. Traditional knowledge on plants from Toranmal Plateau of Maharastra. Indian J Tradit Knowl. 2003;2:292–6.Google Scholar
- Jaradat N, Eid A, Abdelwahab F, Isa L, Abdulrahman A, Abualhasan M, et al. Phytochemical analysis, quantitative estimations of total phenols and free radical scavenging activity of Bupleurum subovatum from Jerusalem. Pharm Sci. 2015;21(4):205–10.View ArticleGoogle Scholar
- Trease G, Evans W. A textbook of Pharmacognosy, London. BailliareTindall. 1983;12(193):336.Google Scholar
- Harborne A. Phytochemical methods a guide to modern techniques of plant analysis. Berlin: Springer Science & Business Media; 1998.Google Scholar
- Wong C-C, Li H-B, Cheng K-W, Chen F. A systematic survey of antioxidant activity of 30 Chinese medicinal plants using the ferric reducing antioxidant power assay. Food Chem. 2006;97(4):705–11.View ArticleGoogle Scholar
- Jaradat NA, Damiri B, Abualhasan MN. Antioxidant evaluation for Urtica urens, Rumex cyprius and Borago officinalis edible wild plants in Palestine. Pakistan J Pharm Sci. 2016;29(1):325–30.Google Scholar
- Zheng C-D, Duan Y-Q, Gao J-M, Ruan Z-G. Screening for anti-lipase properties of 37 traditional Chinese medicinal herbs. J Chin Med Assoc. 2010;73(6):319–24.View ArticlePubMedGoogle Scholar
- Bustanji Y, Issa A, Mohammad M, Hudaib M, Tawah K, Alkhatib H, et al. Inhibition of hormone sensitive lipase and pancreatic lipase by Rosmarinus officinalis extract and selected phenolic constituents. J Med Plants Res. 2010;4(21):2235–42.Google Scholar
- Drent M, Larsson I, William-Olsson T, Quaade F, Czubayko F, Von Bergmann K, et al. Orlistat (Ro 18-0647), a lipase inhibitor, in the treatment of human obesity: a multiple dose study. Int J Obes Relat Metab Disord. 1995;19(4):221–6.PubMedGoogle Scholar
- Sun B, Ricardo-da-Silva JM, Spranger I. Critical factors of vanillin assay for catechins and proanthocyanidins. J Agric Food Chem. 1998;46(10):4267–74.View ArticleGoogle Scholar
- Waterhouse AL. Determination of total phenolics. New York: Wiley; 2002.Google Scholar
- Jaradat N, Hussen F, Al Ali A. Preliminary phytochemical screening, quantitative estimation of total flavonoids, total phenols and antioxidant activity of Ephedra alata Decne. J Mater Environ Sci. 2015;6(6):1771–8.Google Scholar
- Pan S-Y, Litscher G, Gao S-H, Zhou S-F, Yu Z-L, Chen H-Q, et al. Historical perspective of traditional indigenous medical practices: the current renaissance and conservation of herbal resources. Evid Based Complement Altern Med. 2014;2014:1–20.Google Scholar
- Aguiar JJ, Sousa CP, Araruna MK, Silva MK, Portelo AC, Lopes JC, et al. Antibacterial and modifying-antibiotic activities of the essential oils of Ocimum gratissimum L. and Plectranthus amboinicus L. Eur J Integr Med. 2015;7(2):151–6.View ArticleGoogle Scholar
- Martin K, Appel C. Polyphenols as dietary supplements: a double-edged sword. Nutr Diet Suppl. 2010;2:1–12.Google Scholar
- Mulvihill EE, Assini JM, Sutherland BG, DiMattia AS, Khami M, Koppes JB, et al. Naringenin decreases progression of atherosclerosis by improving dyslipidemia in high-fat–fed low-density lipoprotein receptor–null mice. Arterioscler Thromb Vasc Biol. 2010;30(4):742–8.View ArticlePubMedGoogle Scholar
- Ado MA, Abas F, Mohammed AS, Ghazali HM. Anti-and pro-lipase activity of selected medicinal, herbal and aquatic plants, and structure elucidation of an anti-lipase compound. Molecules. 2013;18(12):14651–69.View ArticlePubMedGoogle Scholar
- Dzomba P, Musekiwa C. Anti-obesity and antioxidant activity of dietary flavonoids from Dioscorea steriscus tubers. JCLM. 2014;2:465–70.Google Scholar
- Kim S, Kim Y, Hong M, Rhee H. Studies on the inhibitory effect of Eugenia aromaticum extract on pancreatic lipase. Agric Chem Biotechnol. 2005;48(2):84–93.Google Scholar
- Stahl W. Prevention of age-related diseases: effects of antioxidant supplements. Studies on experimental toxicology and pharmacology. Berlin: Springer; 2015. p. 397–412.Google Scholar
- Martín MA, Goya L, Ramos S. Preventive effects of cocoa and cocoa antioxidants in colon cancer. Diseases. 2016;4(1):6–20.View ArticleGoogle Scholar
- Amoo SO, Aremu AO, Moyo M, Van Staden J. Antioxidant and acetylcholinesterase-inhibitory properties of long-term stored medicinal plants. BMC Complement Altern Med. 2012;12(1):1.View ArticleGoogle Scholar
- Bircan B, Kirbag S. Plumbago europaea L.’nın besinsel, antioksidan ve antimikrobiyal aktivitesinin belirlenmesi. J Forest Fac. 2015;16(1):30–6.Google Scholar
- Sini K, Sinha B, Karpagavalli M. Determining the antioxidant activity of certain medicinal plants of Attapady (Palakkad), India using DPPH assay. Current Bot. 2011;1(1):13–6.Google Scholar
- AlBlooshi A, Shaban S, AlTunaiji M, Fares N, AlShehhi L, AlShehhi H, et al. Increasing obesity rates in school children in United Arab Emirates. Obes Sci Pract. 2016;2(2):196–202.View ArticlePubMedPubMed CentralGoogle Scholar
- Molarius A, Lindén-Boström M, Granström F, Karlsson J. Obesity continues to increase in the majority of the population in mid-Sweden—a 12-year follow-up. Eur J Public Health. 2016. doi:10.1093/eurpub/ckw042.PubMedGoogle Scholar
- Zhang J, Xiao L, Yang Y, Wang Z, Li G. Lignin binding to pancreatic lipase and its influence on enzymatic activity. Food Chem. 2014;149:99–106.View ArticlePubMedGoogle Scholar
- Bustanji Y, Mohammad M, Hudaib M, Tawaha K, Al-Masri IM, AlKhatib HS, et al. Screening of some medicinal plants for their pancreatic lipase inhibitory potential. Jordan J Pharm Sci. 2011;4(2):81–8.Google Scholar