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Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina a
a
a
a
Farhat Ullah , Muhammad Ayaz , Abdul Sadiq , Abid Hussain , a
a
a
Sajjad Ahmad , Muhammad Imran & Anwar Zeb a
Department of Pharmacy, University of Malakand, Chakdara, Dir Lower, Khyber Pakhtoonkhwa 18000, Pakistan Published online: 13 Jul 2015.
Click for updates To cite this article: Farhat Ullah, Muhammad Ayaz, Abdul Sadiq, Abid Hussain, Sajjad Ahmad, Muhammad Imran & Anwar Zeb (2015): Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina, Natural Product Research: Formerly Natural Product Letters, DOI: 10.1080/14786419.2015.1057585 To link to this article: http://dx.doi.org/10.1080/14786419.2015.1057585
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &
Downloaded by [University of Otago] at 09:13 20 July 2015
Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
NATURAL PRODUCT RESEARCH, 2015 http://dx.doi.org/10.1080/14786419.2015.1057585
SHORT COMMUNICATION
Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina Farhat Ullah, Muhammad Ayaz, Abdul Sadiq, Abid Hussain, Sajjad Ahmad, Muhammad Imran and Anwar Zeb Department of Pharmacy, University of Malakand, Chakdara, Dir Lower, Khyber Pakhtoonkhwa 18000, Pakistan ARTICLE HISTORY
Downloaded by [University of Otago] at 09:13 20 July 2015
ABSTRACT
This study was designed to investigate antioxidant and anticholinesterase potential of Iris germanica var; florentina. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential of plant samples were investigated by Ellman’s assay. Antioxidant activity was performed using DPPH, H2O2 and ABTS free radical scavenging assays. Total phenolics and flavonoids contents were expressed in mg GAE/g dry weight and mg RTE/g, respectively. In AChE inhibition assay, Ig.Fl, Ig.Sp and Ig.Cf fractions exhibited highest activity with IC50 values of < 0.1, 5.64 and 19 μg/mL, respectively. In BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Cf and Ig.Cr were most active with IC50 of < 0.1, < 0.1, 31 and 78 μg/mL, respectively. In DPPH assay, Ig.Fl and Ig.Cf exhibited highest inhibition of free radicals, 80.52% (IC50 = 9 μg/mL) and 78.30% (IC50 = 8 μg/mL), respectively. In ABTS assay Ig.Cr, Ig.Cf, Ig.Fl and Ig.Sp exhibited IC50 values of < 0.1, 2, 2 and 3 μg/mL, respectively.
Received 21 April 2015 Accepted 28 May 2015 KEYWORDS
Acetylcholinesterase (AChE); butyrylcholinesterase (BChE); DPPH; H2O2; ABTS; Ellman’s assay; Iris germanica
GRAPHICAL ABSTRACT
1. Introduction Low cholinergic function and disturbances in the level of neurotransmitters are amongst the key features involved in the pathology of central nervous system disorders. Acetylcholine (ACh), a vital neurotransmitter in human beings, has a functional role in signal transfer and CONTACT Muhammad Ayaz © 2015 Taylor & Francis
[email protected]
Downloaded by [University of Otago] at 09:13 20 July 2015
2
F. ULLAH ET AL.
cognitive functions including learning, memory, arousal and excitement processes (Gold 2003). Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the key enzymes involved in the breakdown of ACh, is the most useful strategy in the treatment of various neurological disorders including Alzheimer’s disease (AD), Parkinson’s disease, senile dementia, myasthenia gravis and ataxia (Mukherjee et al. 2007). Several cholinesterase inhibitors such as galanthamine, tacrine, rivastigmine and donepezil are used in the treatment of above-mentioned neurological disorders, but their use is limited due to the major side effects (Knapp et al. 1994; Schulz 2003) and less effectiveness (Schneider 2001). Therefore, a constant investigation for the discovery of new, safe and effective drug candidates is the interest of current researchers. Oxygen is vital for aerobic respiration and animal’s life on earth. The oxygen consumption leads to the production of a chain of reactive oxygen species (ROS), which play an important role in energy production, regulation of cell growth, intercellular signalling and phagocytosis (Verma et al. 2009). However, ROS may also be very injurious as they can readily attack biomolecules such as DNA, lipids, proteins, leading to genotoxicity, cancer, arthritis, arteriosclerosis, inflammation, diabetes and neurological disorders such as AD (Shah et al. 2013). Plants and their products, rich in antioxidant compounds, are known to retard progression of AD and neuronal degeneration (Houghton et al. 2007). Owing to their capacity of scavenging free radicals, these antioxidants attenuate inflammation pathways, decrease cancer progression, heart diseases and other degenerative problems associated with ageing (Henry et al. 2002; Ferreira et al. 2006). Nowadays, the use of antioxidants in the management of some disease states and as food supplements has tremendously increased. The health hazards associated with the toxicity of synthetic AChE and BChE inhibitors, and antioxidants have led to the continuous search for naturally occurring drugs especially of plant origin. Amongst the antioxidant compounds, significant attention has been given to flavonoids and phenolic compounds. Flavonoids are widely distributed in plant kingdom with more than 10,000 known compounds (Xiao, Mao, et al. 2011). Flavonoids are of major interest due to their bioactivities including anti-inflammatory, anti-genotoxic, anti-cancer, neuroprotective, anti-Alzheimer’s and antiglycative properties (Chidambara Murthy et al. 2012). All these properties are basically attributed to the antioxidant nature of flavonoids (Xiao, Chen, et al. 2011). IGF belongs to the family Iridaceae. Iris is a rhizomatous or bulbous herb. Iris genus is rich in isoflavonoids which have a wide range of biological activities including antioxidant, anti-inflammatory and cancer chemopreventive properties (Rahman et al. 2003). Iris rhizomes are also popular in cosmetic preparations, and its oil is regarded as one of the most precious ingredients in perfume industries (Schütz et al. 2011). Iris suaveolens, another specie of iridaceae family, has been reported for antioxidant and anticholinesterase activities and potential usefulness in neurological disorders (Hacıbekirog and Kolak 2011). In an effort to discover new sources which can potentially be used in the treatment of AD, this study was designed to evaluate the AChE, BChE inhibitory and diverse antioxidant potentials of IGF.
2. Results and discussion Development of novel- and mechanism-based cholinesterase inhibitors is amongst the most valuable approaches for the treatment of neurodegenerative diseases, due to their role in the breakdown of neurotransmitter ACh (Ayaz et al. 2014). Neurodegenerative disorders such as AD are characterised by reduced cholinergic activity in brain (Nunes-Tavares et al. 2012).
Downloaded by [University of Otago] at 09:13 20 July 2015
Natural Product Research
3
The enzymes AchE and BchE cause hydrolysis of ACh; therefore, inhibition of these enzymes plays a key role in enhancing cholinergic activity. Besides reduced cholinergic activity, oxidative stress has also been recognised as a key factor in the pathogenesis of AD (Lee et al. 2012). Oxidation is an integral process in the cellular metabolism. Generally, the free radicals generated during metabolic processes have unpaired electrons (Pietta 2000), are highly reactive and produce cellular injury by causing membrane lipid peroxidation and damage to enzymes and DNA (Rafat Husain et al. 1987). The cell injury and multiple hazardous effects of free radicals may lead to several nervous disorders and eventually may cause neuronal death. In this context, huge investigational studies demonstrate the efficacy of phenolic antioxidants from plant origin to reduce or block neuronal death occurring in the pathophysiology of AD. Flavonoids being a group of polyphenolic compounds have been reported to be responsible for antioxidant activity, as they can effectively scavenge the free radicals and protects the body cells especially the neuronal cells from injurious effect of free radicals (Valko et al. 2006). Furthermore, the hydrogen donating substituent (hydroxyl groups) attached to the aromatic ring structures of flavonoids enable them to undergo a redox reaction, which in turn, helps them scavenge free radicals (Robards et al. 1999). Similarly, another group of secondary metabolite, i.e. the saponins have also been reported to possess antioxidant and anticholinesterase potentials (Gülçin et al. 2004). Bacopa monniera and Ginkgo biloba have been traditionally used in dementia and cognitive disorders and as reported earlier that these plants are rich in saponins and possess strong anticholinesterase potentials (Das et al. 2002). In this study, we observed that Ig.Cf and Ig.Cr showed the highest phenolic contents which were 89.11 ± 1.07 mg and 83.46 ± 2.40 mg GAE/g, respectively. Whereas, Ig.Cf and Ig.Cr showed the highest flavonoids contents which were 100.27 ± 2.65 mg and 67.12 ± 2.37 mg RTE/g, respectively. Further, flavonoids, phenolics, saponins and fractions rich with these compounds exhibited high antioxidant and anticholinesterase activities. In AChE inhibitory assay, we found Ig.Fl, Ig.Sp, Ig.Chf and Ig.EtAc were most potent presenting IC50 of < 0.1, 5.64, 19 and 43 μg/mL, respectively (Table S1). Likewise in BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Chf, Ig.EtAc and Ig.Cr were found most effective fractions with IC50 values of
Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina a
a
a
a
Farhat Ullah , Muhammad Ayaz , Abdul Sadiq , Abid Hussain , a
a
a
Sajjad Ahmad , Muhammad Imran & Anwar Zeb a
Department of Pharmacy, University of Malakand, Chakdara, Dir Lower, Khyber Pakhtoonkhwa 18000, Pakistan Published online: 13 Jul 2015.
Click for updates To cite this article: Farhat Ullah, Muhammad Ayaz, Abdul Sadiq, Abid Hussain, Sajjad Ahmad, Muhammad Imran & Anwar Zeb (2015): Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina, Natural Product Research: Formerly Natural Product Letters, DOI: 10.1080/14786419.2015.1057585 To link to this article: http://dx.doi.org/10.1080/14786419.2015.1057585
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &
Downloaded by [University of Otago] at 09:13 20 July 2015
Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
NATURAL PRODUCT RESEARCH, 2015 http://dx.doi.org/10.1080/14786419.2015.1057585
SHORT COMMUNICATION
Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var; florentina Farhat Ullah, Muhammad Ayaz, Abdul Sadiq, Abid Hussain, Sajjad Ahmad, Muhammad Imran and Anwar Zeb Department of Pharmacy, University of Malakand, Chakdara, Dir Lower, Khyber Pakhtoonkhwa 18000, Pakistan ARTICLE HISTORY
Downloaded by [University of Otago] at 09:13 20 July 2015
ABSTRACT
This study was designed to investigate antioxidant and anticholinesterase potential of Iris germanica var; florentina. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential of plant samples were investigated by Ellman’s assay. Antioxidant activity was performed using DPPH, H2O2 and ABTS free radical scavenging assays. Total phenolics and flavonoids contents were expressed in mg GAE/g dry weight and mg RTE/g, respectively. In AChE inhibition assay, Ig.Fl, Ig.Sp and Ig.Cf fractions exhibited highest activity with IC50 values of < 0.1, 5.64 and 19 μg/mL, respectively. In BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Cf and Ig.Cr were most active with IC50 of < 0.1, < 0.1, 31 and 78 μg/mL, respectively. In DPPH assay, Ig.Fl and Ig.Cf exhibited highest inhibition of free radicals, 80.52% (IC50 = 9 μg/mL) and 78.30% (IC50 = 8 μg/mL), respectively. In ABTS assay Ig.Cr, Ig.Cf, Ig.Fl and Ig.Sp exhibited IC50 values of < 0.1, 2, 2 and 3 μg/mL, respectively.
Received 21 April 2015 Accepted 28 May 2015 KEYWORDS
Acetylcholinesterase (AChE); butyrylcholinesterase (BChE); DPPH; H2O2; ABTS; Ellman’s assay; Iris germanica
GRAPHICAL ABSTRACT
1. Introduction Low cholinergic function and disturbances in the level of neurotransmitters are amongst the key features involved in the pathology of central nervous system disorders. Acetylcholine (ACh), a vital neurotransmitter in human beings, has a functional role in signal transfer and CONTACT Muhammad Ayaz © 2015 Taylor & Francis
[email protected]
Downloaded by [University of Otago] at 09:13 20 July 2015
2
F. ULLAH ET AL.
cognitive functions including learning, memory, arousal and excitement processes (Gold 2003). Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the key enzymes involved in the breakdown of ACh, is the most useful strategy in the treatment of various neurological disorders including Alzheimer’s disease (AD), Parkinson’s disease, senile dementia, myasthenia gravis and ataxia (Mukherjee et al. 2007). Several cholinesterase inhibitors such as galanthamine, tacrine, rivastigmine and donepezil are used in the treatment of above-mentioned neurological disorders, but their use is limited due to the major side effects (Knapp et al. 1994; Schulz 2003) and less effectiveness (Schneider 2001). Therefore, a constant investigation for the discovery of new, safe and effective drug candidates is the interest of current researchers. Oxygen is vital for aerobic respiration and animal’s life on earth. The oxygen consumption leads to the production of a chain of reactive oxygen species (ROS), which play an important role in energy production, regulation of cell growth, intercellular signalling and phagocytosis (Verma et al. 2009). However, ROS may also be very injurious as they can readily attack biomolecules such as DNA, lipids, proteins, leading to genotoxicity, cancer, arthritis, arteriosclerosis, inflammation, diabetes and neurological disorders such as AD (Shah et al. 2013). Plants and their products, rich in antioxidant compounds, are known to retard progression of AD and neuronal degeneration (Houghton et al. 2007). Owing to their capacity of scavenging free radicals, these antioxidants attenuate inflammation pathways, decrease cancer progression, heart diseases and other degenerative problems associated with ageing (Henry et al. 2002; Ferreira et al. 2006). Nowadays, the use of antioxidants in the management of some disease states and as food supplements has tremendously increased. The health hazards associated with the toxicity of synthetic AChE and BChE inhibitors, and antioxidants have led to the continuous search for naturally occurring drugs especially of plant origin. Amongst the antioxidant compounds, significant attention has been given to flavonoids and phenolic compounds. Flavonoids are widely distributed in plant kingdom with more than 10,000 known compounds (Xiao, Mao, et al. 2011). Flavonoids are of major interest due to their bioactivities including anti-inflammatory, anti-genotoxic, anti-cancer, neuroprotective, anti-Alzheimer’s and antiglycative properties (Chidambara Murthy et al. 2012). All these properties are basically attributed to the antioxidant nature of flavonoids (Xiao, Chen, et al. 2011). IGF belongs to the family Iridaceae. Iris is a rhizomatous or bulbous herb. Iris genus is rich in isoflavonoids which have a wide range of biological activities including antioxidant, anti-inflammatory and cancer chemopreventive properties (Rahman et al. 2003). Iris rhizomes are also popular in cosmetic preparations, and its oil is regarded as one of the most precious ingredients in perfume industries (Schütz et al. 2011). Iris suaveolens, another specie of iridaceae family, has been reported for antioxidant and anticholinesterase activities and potential usefulness in neurological disorders (Hacıbekirog and Kolak 2011). In an effort to discover new sources which can potentially be used in the treatment of AD, this study was designed to evaluate the AChE, BChE inhibitory and diverse antioxidant potentials of IGF.
2. Results and discussion Development of novel- and mechanism-based cholinesterase inhibitors is amongst the most valuable approaches for the treatment of neurodegenerative diseases, due to their role in the breakdown of neurotransmitter ACh (Ayaz et al. 2014). Neurodegenerative disorders such as AD are characterised by reduced cholinergic activity in brain (Nunes-Tavares et al. 2012).
Downloaded by [University of Otago] at 09:13 20 July 2015
Natural Product Research
3
The enzymes AchE and BchE cause hydrolysis of ACh; therefore, inhibition of these enzymes plays a key role in enhancing cholinergic activity. Besides reduced cholinergic activity, oxidative stress has also been recognised as a key factor in the pathogenesis of AD (Lee et al. 2012). Oxidation is an integral process in the cellular metabolism. Generally, the free radicals generated during metabolic processes have unpaired electrons (Pietta 2000), are highly reactive and produce cellular injury by causing membrane lipid peroxidation and damage to enzymes and DNA (Rafat Husain et al. 1987). The cell injury and multiple hazardous effects of free radicals may lead to several nervous disorders and eventually may cause neuronal death. In this context, huge investigational studies demonstrate the efficacy of phenolic antioxidants from plant origin to reduce or block neuronal death occurring in the pathophysiology of AD. Flavonoids being a group of polyphenolic compounds have been reported to be responsible for antioxidant activity, as they can effectively scavenge the free radicals and protects the body cells especially the neuronal cells from injurious effect of free radicals (Valko et al. 2006). Furthermore, the hydrogen donating substituent (hydroxyl groups) attached to the aromatic ring structures of flavonoids enable them to undergo a redox reaction, which in turn, helps them scavenge free radicals (Robards et al. 1999). Similarly, another group of secondary metabolite, i.e. the saponins have also been reported to possess antioxidant and anticholinesterase potentials (Gülçin et al. 2004). Bacopa monniera and Ginkgo biloba have been traditionally used in dementia and cognitive disorders and as reported earlier that these plants are rich in saponins and possess strong anticholinesterase potentials (Das et al. 2002). In this study, we observed that Ig.Cf and Ig.Cr showed the highest phenolic contents which were 89.11 ± 1.07 mg and 83.46 ± 2.40 mg GAE/g, respectively. Whereas, Ig.Cf and Ig.Cr showed the highest flavonoids contents which were 100.27 ± 2.65 mg and 67.12 ± 2.37 mg RTE/g, respectively. Further, flavonoids, phenolics, saponins and fractions rich with these compounds exhibited high antioxidant and anticholinesterase activities. In AChE inhibitory assay, we found Ig.Fl, Ig.Sp, Ig.Chf and Ig.EtAc were most potent presenting IC50 of < 0.1, 5.64, 19 and 43 μg/mL, respectively (Table S1). Likewise in BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Chf, Ig.EtAc and Ig.Cr were found most effective fractions with IC50 values of
