Staff Profile

Roles and Responsibilities

Director, North East Universities Medicinal Plant Research Group

Member Board of Examiners, BSc Food and Human Nutrition/ Food Marketing and Nutrition 

Member Board of Studies, BSc Food and Human Nutrition/ Food Marketing and Nutrition 

Member, Curriculum Committee, BSc Food and Human Nutrition/ Food Marketing and Nutrition 

Qualifications

BSc (Hons.), MSc., PhD

Memberships

Society for Medicinal Plant and Natural Product Research
North East Dementias & Neurodegenerative Diseases Network (DeNDRoN)
UK Biobank Enhancement Subgroup (brain imaging) Network
Member of the North East Bionet Bioactive Chemistry Working Group

Academic member American Botanical Council

North East Universities Medicinal Plant Research Group 

Franco-British Natural Products Research Network

Alzheimer Research UK Network

Newcastle University BAME Advisory Group

Research Interests

Medicinal plants and natural product pharmacognosy/ pharmacology
Drug Discovery
Dementia, Alzheimer’s disease and related issue
Phyto-chemicals and neurophysiological/ pharmacological effects
Food Quality & Health
Phytochemistry and Mechanistic enzymology
Medical and veterinary applications of natural plant products

Current Work

The isolation and chemical characterization of novel active components from natural products, particularly medicinal plants, and screening for key bioactivities in disease mechanisms – particularly those associated with dementia of the Alzheimer’s type -such as neuromodulation, neurotransmitter function, neuroprotection (antioxidants, anti-inflammatory, anxiolytics and anti-amyloidal agents) and enzyme inhibition (cholinesterases, BACE) with a view to developing new strategies for the prevention of and/ or treatment of Alzheimer’s disease.

Research Roles

In addition to conduction my own research and supervising postgraduate (MSc and PhD) students, I am also Director of the North East Universities Medicinal Plant Research Group (MPRG). The MPRC) was founded in 1996. It is a research partnership between the Universities of Newcastle, Northumbria and Durham, in the North East of England (UK). Our mission is to develop a ‘centre of research excellence’ for interdisciplinary research in the pharmacology of medicinal plants and to apply the advances in knowledge that emanate from this to develop novel plant based bioactives for health and disease, particularly in areas of neuroscience, clinical brain ageing, psychology, oncology, diabetes and ageing and health.

I am also a member of the Institute of Neuroscience Natural Products Pharmacology research group: www.ncl.ac.uk/ion/research/themes/neuropharmacology/natural.htm.

Member, Franco-British Natural Products Research Network

Postgraduate Supervision

I am currently co-supervising  5 PhD students. Two other PhD’s to commence September 2011.

Esteem Indicators

Selected Invited Lectures
First International Conference about Pharmacology of natural Products and BLACPMA, Varadero, Cuba, 20-24 Novermber 2006

The 10th Shangai Internatiobnal Forum on Biotechnology and Pharmaceutical Industry (Bio-Forum) & 13th Annual Conference of Chinese Biopharmaceutical Association, 20-30th May 2008

The British Psychological Society Annual Conference, Brighton 1-3 April 2009

Vitafoods International Conference (Symposium Chair and Speaker), Geneva, 5-7 May 2009

Second International Symposium on Pharmacology of Natural Products, (FAPRONATURA) “OASIS VARADERO 1920” Hotel, Varadero Beach, Matanzas, Cuba. June 3-7, 2009

Brain Ageing and Dementia in Newcastle: Past, Present and Future. Medical School, Newcastle University, 19th May 2010

International Congress of Applied Psychology, 11-16 July, 2010, Melbourne Australia

Brain Ageing and Dementia in Developing Countries, 4-7 December, 2012, Nairobi, Kenya 

PhD thesis adjudicator, Vellore Institute of Technology, Tamilnadu, India (2010)

PhD thesis External Examiner, University of Fort Hare, South Africa (2011).

PhD thesis External Examiner, St. Joseph’s College (Autonomous), Tiruchirappalli 620002, TN, India. (2013)

External assessor of the research activities of a candidate applying for promotion to Associate Professor – University of Malta (2014).

Reviewer of Academic Manuscript for:
Pharmacology, Biochemistry and Behavior
Journal of the Science of Food and Agriculture
Marine Biotechnology
Phytochemistry
Phytotherapy Research
Journal of the American College of Nutrition
European Journal of Neuroscience

Journal of Medicinal Food 

Human Psychopharmacology

Journal of Alternative and  Complementary Medicine

African Journal of Biotechnology 

Editorships

Associate editor, European Journal of Medicnal Plants

Guest Editor, Evidence-Based Complementary and Alternative Medicine

Other invitations

External Examiner, MSc in Medicinal Natural Products and Phytochemistry, UCL (from 2019)
PhD External Examiner, School of Biological & Biomedical Sciences, Durham University; Teesside University (UK), Sunderland University (UK).
Independent assessor on a report for an application for transfer from MPhil to PhD – School of Science & Engineering, Teesside University.

Invited as an International Expert Panel Member by the Medical Council of South Africa to review and assess the progress and status of their Indigenous Knowledge System Unit (Cape Town) against its 5 year research mandate: September 2011.

National Research Foundation, South Africa - Blue Skies funding call Assessor (2010)

Peer Reviewer, Medical Research Council (UK) - Grant Reference: MR/L001330/1 (2013)

External Reviewer for a postdoctoral research project for the German Academic Exchange Service (DAAD – P.R.I.M.E program (2014)

Public Interviews
Dissemination of knowledge/ research to general public (National TV interviews, International/national / local radio interviews; International and Nations/ local newspaper articles – featuring my research on tea consumption and prevention of dementia (2006)

Funding

Norvatis, Rington’s Tea Company, Mental Health Foundation, Royal Society, DEFRA, KTP with Citrox Limited, Wellcome Trust Summer Studentship, BBSRC CASE Studentship,Wirz Herbs

Undergraduate Teaching

NUT1001 Academic and Professional Skills

NU 2004 Academic and professional Skills 2 (Module Leader) 

ACE 1018 Introduction to Nutrition, Food Science and the Food Industry

Postgraduate Teaching

Degree Programme Director, MSc Medicinal Plants and Functional Foods (2008-2017)

• ACE 8051 Production of herbal medicines and functional foods (Module Leader)
• ACE 8052 Traditional use of plants (including ethno-pharmacology) (Module Leader)
• ACE 8053 Functional foods in nutrition and health
• ACE8106 Effective Communication Skills for Postgraduate Research (Module Leader)

• Okello EJ, Mather J. Comparative Kinetics of Acetyl- and Butyryl-Cholinesterase Inhibition by Green Tea Catechins|Relevance to the Symptomatic Treatment of Alzheimer’s Disease. Nutrients 2020, 12(4), 1090.
• Babateen AM, Rubele S, Shannon O, Okello E, Smith E, McMahon N, O'Brien G, Wightman E, Kennedy D, Mathers JC, Siervo M. Protocol and recruitment results from a 13-week randomized controlled trial comparing the effects of different doses of nitrate-rich beetroot juice on cognition, cerebral blood flow and peripheral vascular function in overweight and obese older people. Contemporary Clinical Trials Communications 2020, 18, 100571.
• Babateen AM, Rubele S, Shannon O, Okello E, Smith E, Mcmahon N, O'Brien G, Wighman E, Kennedy D, Mathers JC, Siervo M. Protocol and recruitment results from a 13-week randomized controlled trial comparing the effects of different doses of nitrate-rich beetroot juice on cognition, cerebral blood flow and peripheral vascular function in overweight and obese older people. Contemporary Clinical Trials Communications 2020.
• Watson AW, Okello EJ, Brooker H, Lester S, McDougall GJ, Wesnes KA. The impact of blackcurrant juice on attention, mood and brain wave spectral activity in young healthy volunteers. Nutritional Neuroscience 2019, 22(8), 596-606.
• Neto HL, Okello E. In vitro Fermentation Method as a Tool to Assess the Effects of Secondary Metabolites on Rumen Fermentation—A Brief Review. Journal of Agricultural Science 2018, 10(6), 28-32.
• Okello EJ, Howes MJR. Essential oils and aromas that affect mood and cognition. In: Murphy PN, ed. Routledge International Handbook of Psychobiology. London and New York: Routledge, 2018, pp.195-208.
• Zakaria NNA, Okello EJ, Idowu OC. Evaluation of the antioxidant efficacy of extracts/ ingredients used in skin care products. International Journal of Phytocosmetics and Natural Ingredients 2018, 5, 7.
• Zakaria NNA, Okello EJ, Howes M-J, Birch-Machin MA, Bowman A. In vitro protective effects of an aqueous extract of Clitoria ternatea L. flower against hydrogen peroxide-induced cytotoxicity and UV-induced mtDNA damage in human keratinocytes. Phytotherapy Research 2018, 32(6), 955-1144.
• Kennedy D, Okello E, Chazot P, Howes M-J, Ohiomokhare J, Haskell-Ramsay C, Khan J, Forster J, Wightman E. Volatile Terpenes and Brain Function: Investigation of the Cognitive and Mood Effects of Mentha x Piperita L. Essential Oil with In Vitro Properties Relevant to Central Nervous System Function. Nutrients 2018, 10(8), 1029.
• Ohiomokhare SO, Ladagu A, Olapade J, Okello E, Chazot PL. Chronic exposure to low dose vanadium exacerbates the motor deficits in the Drosophila melanogaster PINK1 mutant model of Parkinson’s disease. In: BNA 2017 Festival of Neuroscience. 2017, Birmingham International Conference Centre: British Neuroscience Association.
• Haskell-Ramsay CF, Stuart RC, Okello EJ, Watson AW. Cognitive and mood improvements following acute supplementation with purple grape juice in healthy young adults. European Journal of Nutrition 2017, 56(8), 2621–2631.
• Wesnes KA, Brooker H, Watson AW, Bal W, Okello E. Effects of the Red Bull Energy Drink on cognitive function and mood in healthy young volunteers. Journal of Psychopharmacology 2017, 31(2), 211-221.
• Haskell-Ramsay CF, Stuart RC, Okello EJ, Watson AW. Erratum to: Cognitive and mood improvements following acute supplementation with purple grape juice in healthy young adults. European Journal of Nutrition 2017, 56(8), 2633–2633.
• Okello EJ, Abadi AM, Abadi SA. Effects of green and black tea consumption on brain wave activities in healthy volunteers as measured by a simplified Electroencephalogram (EEG): A feasibility study. Nutritional Neuroscience 2016, 19(5), 196-205.
• Okello EJ. Traditional Herbal Medicines Research Methods: Identification,Analysis, Bioassay, and Pharmaceutical and Clinical Studies,Willow J.H. Liu, John Wiley & Sons (2011). Hardback pp. 466,ISBN: 978-0470149362. £105. Journal of Herbal Medicine 2016, 6(3), 160-161.
• Chattuwatthana T, Okello E. Anti-collagenase, anti-elastase and antioxidant activities of Pueraria candollei var. mirifica root extract and Coccinia grandis fruit juice extract: An In vitro study. European Journal of Medicinal Plants 2015, 5(4), 318-327.
• Lam YS, Okello EJ. Determination of Lovastatin, β-glucan, Total Polyphenols, and Antioxidant Activity in Raw and Processed Oyster Culinary-Medicinal Mushroom, Pleurotus ostreatus (Higher Basidiomycetes). International Journal of Medicinal Mushrooms 2015, 17(2), 117-128.
• Okello EJ, Coleman A, Seal CJ. In-vitro anti-cholinesterase activities by piperine, an alkaloid from the spice family Piperaceae. International Journal of Pharmaceutical Sciences and Research 2015, 6(9), 3726-3732.
• Sparagano O, George D, Finn R, Dinesh R, Rashed A, Graham K, Okello E, Maurer V. Potential of essential oils in medical and veterinary pest management: efficacy and modes of action. In: 13th International Congress of the European Association for Veterinary Pharmacology and Toxicology (EAVPT 2015). 2015, Nantes, France: Wiley-Blackwell.
• Dinesh R, George D, Okello E, Daoud-Bouattour A, Ghrabi-Gammar Z, Sparagano O. Does AChE inhibition explain acaricidal activity of plant essential oils against the poultry red mite Dermanyssus gallinae, and can such inhibition be considered selective?. In: 8th International TTP and 12th Biennial STVM Conference. 2014, Cape Town, South Africa.
• Jansen RLM, Brogan B, Whitworth AJ, Okello EJ. Effects of five Ayurvedic herbs on locomotor behaviour in a Drosophila melanogaster Parkinson's disease model. Phytotherapy Research 2014, 28(12), 1789-1795.
• Lima-Neto HR, Okello E, Rowlinson P. Effects of Solanum lycocarpum on ruminal fermentation-In vitro study. LAP Lambert Academic Publishing, 2013.
• Asim M, Liu OH, Okello E, Birch-Machin M, Foltz M, Lietz G. The anti-oxidant capacity of green tea polyphenols in the oral cavity. In: Nutrition Society Annual Summer Meeting. 2013, Newcastle, UK: Cambridge University Press.
• Kumar S, Harris RJ, Seal CJ, Okello EJ. An aqueous extract of Withania somnifera root inhibits amyloid-B fibril formation in vitro. Phytotherapy Research 2012, 26(1), 113-117.
• Ayissi Mbomo R, Gartside SE, Ngo Bum E, Njikam N, Okello E, McQuade R. Effect of Mimosa pudica (Linn.) extract on anxiety behaviour and GABAergic regulation of 5-HT neuronal activity in the mouse. Journal of Psychopharmacology 2012, 26(4), 575-583.
• Kumar S, Okello EJ, Harris JR. Experimental Inhibition of Fibrillogenesis and Neurotoxicity by amyloid-beta (Aβ) and Other Disease-Related Peptides/Proteins by Plant Extracts and Herbal Compounds. In: Robin, H.J, ed. Protein Aggregation and Fibrillogenesis in Cerebral and Systemic Amyloid Disease. London: Springer, 2012, pp.295-328.
• Okello EJ, Leylabi R, McDougall GJ. Inhibition of acetylcholinesterase by green and white tea and their simulated intestinal metabolites. Food & Function 2012, 3, 651-661.
• Okello EJ, McDougall GJ, Kumar S, Seal CJ. In vitro protective effects of colon-available extract of Camellia sinensis (tea) against hydrogen peroxide and beta-amyloid (Aβ_(1–42)) induced cytotoxicity indifferentiated PC12 cells. Phytomedicine 2011, 18(8-9), 691-696.
• Kumar S, Seal CJ, Okello EJ. Kinetics of acetylcholinesterase inhibition by an aqueous extract of Withania somnifera roots. International Journal of Pharmaceutical Sciences and Research 2011, 2(5), 1188-1192.
• Kennedy DO, Dodd FL, Robertson CB, Okello EJ, Reay JL, Scholey AB, Haskell CF. Monoterpenoid extract of sage (Salvia lavandulaefolia) with cholinesterase inhibiting properties improves cognitive performance and mood in healthy adults. Journal of Psychopharmacology 2011, 25(8), 1088-1100.
• Kumar S, Seal CJ, Howes MJ, Kite GC, Okello EJ. In vitro protective effects of Withania somnifera (L.) dunal root extract against hydrogen peroxide and beta-amyloid_(1-42)-induced cytotoxicity in differentialted PC12 cells. Phytotherapy Research 2010, 24(10), 1567-1574.
• Kennedy DO, Wightman EL, Reay JL, Lietz G, Okello EJ, Wilde A, Haskell CF. Effects of resveratrol on cerebral blood flow variables and cognitive performance in humans: a double-blind, placebo-controlled, crossover investigation. American Journal of Clinical Nutrition 2010, 91(6), 1590-1597.
• George DR, Sparagano OAE, Port G, Okello E, Shiel RS, Guy JH. Environmental interactions with the toxicity of plant essential oils to the poultry red mite Dermanyssus gallinae. Medical and Veterinary Entomology 2010, 24(1), 1-8.
• Kennedy DO, Wightman E, Okello EJ. Medicinal plants, phytochemicals and Alzheimer's disease. In: Martinez, A, ed. Emerging Drugs and Targets for Alzheimer's Disease: Neuronal Plasticity, Neuronal Protection and Other Miscellaneous Strategies. London, UK: Royal Society of Chemistry, 2010, pp.269-290.
• George DR, Sparagano OAE, Port G, Okello E, Shiel RS, Guy JH. The effect of essential oils showing acaricidal activity against the poultry red mite (Dermanyssus gallinae) on aspects of welfare and production of laying hens. Animal Welfare 2010, 19(3), 265-273.
• George DR, Sparagano OAE, Port G, Okello E, Shiel RS, Guy JH. Toxicity of plant essential oils to different life stages of the poultry red mite, Dermanyssus gallinae, and non-target invertebrates. Medical and Veterinary Entomology 2010, 24(1), 9-15.
• Crowch CM, Okello EJ. Kinetics of acetylcholinesterase inhibitory activities by aqueous extracts of Acacia nilotica (L.) and Rhamnus prinoides (L'Her.). African Journal of Pharmacy and Pharmacology 2009, 3(10), 469-475.
• Perry E, Okello E, Howes MJR, Chazot P. Phytopharmaceuticals for dementia therapy. PLANTA MEDICA 2009, 75(9), 880-881.
• George DR, Sparagano OAE, Port G, Okello E, Shiel RS, Guy JH. Repellence of plant essential oils to Dermanyssus gallinae and toxicity to the non-target invertebrate Tenebrio molitor. Veterinary Parasitology 2009, 162(1-2), 129-134.
• Tasker A, Ballard CG, Joachim C, Warden DR, Okello EJ, Perry RH, Khan N, Smith AD, Lehmann DJ, Perry EK. Butyrylcholinesterase K variant associated with higher enzyme activity in the temporal cortex of elderly patients. Neuroscience Letters 2008, 442(3), 297-299.
• Okello EJ, Dimaki C, Howes MJR, Houghton PJ, Perry EK. In vitro inhibition of human acetyl- and butyryl-cholinesterase by Narcissus poeticus L. (Amaryllidaceae) flower absolute. International Journal of Essential Oil Therapeutics 2008, 2(3), 105-110.
• George DR, Guy JH, Arkle S, Harrington D, De Luna C, Okello EJ, Shiel RS, Port G, Sparagano OAE. Use of Plant-derived Products to Control Arthropods of Veterinary Importance: A Review. Animal Biodiversity and Emerging Diseases: Annals of the New York Academy of Sciences 2008, 1149, 23-26.
• Kennedy DO, Pace S, Haskell C, Okello EJ, Milne A, Scholey AB. Effects of cholinesterase inhibiting sage (Salvia officinalis) on mood, anxiety and performance on a psychological stressor battery. Neuropsychopharmacology 2006, 31(4), 845-852.
• Kennedy DO, Pace S, Milne A, Okello E, Scholey AB. Anxiolytic effects of single doses of sage (Salvia officinalis) in healthy volunteers. In: Journal of Psychopharmacology: Summer Meeting of the British Association for Psychopharmacology. 2005, Harrogate, UK: Sage Publications Ltd.
• Hasegawa T, Okello E, Yamada T. Protective effect of Japanese green tea against cognitive impairment in the elderly, a two-years follow-up observation . Alzheimer's and Dementia 2005, 1(1), S100.
• Savelev SU, Okello EJ, Perry EK. Butyryl- and Acetyl-cholinesterase Inhibitory Activities in Essential Oils of Salvia Species and Their Constituents. Phytotherapy Research 2004, 18(4), 315-324.
• Okello EJ, Savelev SU, Perry EK. In vitro anti-β-secretase and dual anti-cholinesterase activities of Camellia sinensis L. (tea) relevant to treatment of dementia. Phytotherapy Research 2004, 18(8), 624-627.
• Okello EJ. The benefits to memory of biological activities in tea. 2004. Available at: http://www.nutritionreview.co.uk.
• Pitcairn CER, Fowler D, Leith ID, Sheppard LJ, Sutton MA, Kennedy V, Okello E. Bioindicators of enhanced nitrogen deposition. Environmental Pollution 2003, 126(3), 353-361.
• Savelev S, Okello E, Perry NSL, Wilkins RM, Perry EK. Synergistic and antagonistic interactions of anticholinesterase terpenoids in Salvia lavandulaefolia essential oil. Pharmacology Biochemistry and Behavior 2003, 75(3), 661-668.
• Okello-Ekochu EJ, Wilkins RM. Influence of some maize cultivars/lines (Zea mays L.) on biological characters of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae). International Journal of Pest Management 1996, 42(2), 81-87.