Dr. Alok Lehri

Chief Scientist

Research Interests

Natural Product Chemistry

Dr. Alok Lehri

Chief Scientist

Research Summary

Aromatic oils and chemicals

A: Safety and antiageing studies of essential oils

Antioxidant and anti-aging potential of Juniper berry (Juniperus communis L.) essential oil in Caenorhabditis elegans model system

Plant and plant products including essential oils are globally acclaimed for their medicinal and therapeutic values. It’s an age-old practice, owing to their safety and protective effects against reactive oxygen species (ROS)/oxidative stresses. Aging is a global challenge and needs proper attention to check on its causative factors. The increased ROS production/oxidative stress is one of the major contributing factors endorses aging and age-related disorders. To this end, the present study was designed to explore the in vivo-antioxidant and anti-aging potentials of Juniper berry essential oil (JBEO) by using Caenorhabditis elegans as a model organism. Present work investigated the impact of different doses (0, 10, 50, 100 ppm) on lifespan and healthspan of C. elegans. The present study revealed that lower dose (10 ppm) was highly effective and enhanced the lifespan of C. elegans by 18.54% as compared to the control. Similarly, same concentration, i.e. 10 ppm was also showing potential against various oxidative and thermal stresses. The JBEO treated worms showed 30.40% more survival under thermal stress as compared to control. Besides the increased survival percent of worms, the elevated expression of SOD-3 (39.49%) and GST-4 (25.13%) was also observed, indicating oxidative stress resistance in worms. The screening studies on mutants of C. elegans for prediction of mechanism demonstrated the involvement of major conserved transcription factors (DAF-16, SKN-1, and HSF-1) which coordinates in the stress-induced transcription and extends longevity. Overall, here we unrevealed potentials of JBEO in anti-stressor activities and lifespan extension in C. elegans. Thus, in future, more studies on JBEO will pave paths for commercialization of essential oils in the formulations of antiaging products.

B: Detection of adulteration in essential oils

Ratio Mass Spectrometry Study for Differentiation Between Natural and Adulterated Essential Oils of Lemongrass (Cymbopogon flexuosus) and Palmarosa (Cymbopogon martinii)

Natural and adulterated essential oils of lemongrass (Cymbopogon flexuosus) and palmarosa (Cymbopogon martinii) were differentiated and identified on the basis of their carbon isotope composition (13C/12C) using Isotopic-Ratio Mass Spectrometry (IRMS) technique. This technique differentiates the natural oils (lemongrass and palmarosa oils) with adulterated oils by showing decrease in their carbon isotopic composition as blending of synthetic compounds viz. geraniol, citral, polyethylene glycol (PEG), dioctyl phthalate (DOP) and diethyl phthalate (DEP) of these adulterants with increasing order (5 % to 50 %).

C. Effect of Geographical Climatic Conditions on Yield, Chemical Composition and Carbon Isotope Composition of Nagarmotha (Cyperus scariosus R. Br.) Essential Oil, Using TD-NMR/hydro-distillation, GCMS and IRMS

Nagarmotha (Cyperus scariosus) rhizomes collected from 13 locations in India were characterized for oil content using hydro-distillation method. The oil yield analysed by using hydro-distillation varied from 0.20% Padampur (Orissa) to 0.58% Tilakgram (M.P.). The major compounds present in essential oil of nagarmotha rhizomes were identified as cyperene, longifolin, caryophylline oxide and longiverbenone. The amount of cyperene varied from 5.77% (Tilakgram M.P.) to 24.17% (Raipur, Chhattisgarh), longifolin varied from 5.95% (Raipur, Chhattisgarh) to 20.43% (Panna, M.P.), caryophyllene oxide ranged from 2.42% (Padampur, Orissa) to 10.38% (Tilakgram M.P.) and longiverbenone ranged from 3.96% (Padampur, Orissa) to 12.71% (Badarpur, Orissa). The carbon isotope ratio of the oils varied from -11.15 (Ujjain MP) to –15.78 (Sitapur UP) per mil.

D: Aroma Mission

Leaf of developed superior variety of Curcuma longa L. (for leaf essential oil) var. Kesari was used for the distillation of essential oil. The major chemical constituents of essential oil were analysed by GCMS. The compounds present in essential oil are α–Phellandrenes (32%), terpinolene (26%), p-cymene 5.9%) and 1,8 cineole (6.5%).

Marketing of turmeric leaf oil of farmers with industries.

E: Preparation of Reference Materials (Aromatic)

Preparation of Reference Material (Aromatic). Geraniol, Citronellol, Citral, Nerol, Citronellal, Linalool, Limonene, Camphor, Menthol, Carvone

Analytical Method Development and Standardization.

A: Development and Validation of HPTLC Densitometric Method for Identification & Quantification of Geraniol in Palmarosa Oil

India is the main producer of palmarosa oil obtained from rosha grass (Cymbopogan martini var. motia) of family Graminae. The essential oil obtained from the grass is rich in geraniol content. The oil is commercially obtained by hydro-steam distillation of rosha grass. Oil of palmarosa and its separated fraction geraniol are widely used in perfumery industry. The palmarosa oil is valued due to geraniol and largely used as base for fine perfumery. In the present study a simple, rapid, cost-effective and accurate method using high performance thin layer chromatographic method (HPTLC) has been developed for separation, identification and quantification of geraniol in palmarosa oil. Separation and quantification of palmarosa is achieved by HPTLC using mobile phase of toluene:ethylacetate (92.5:7.5) followed by separation on precoated silica gel 60F₂₅₄ aluminium plates and densitometric determination carried out after derivatization with vanillin-sulphuric acid reagent at lmax, 400 nm, in absorption-reflectance mode. The calibration curves were linear in the range of (1-7 µg) and all the distinguished bands were observed at 400 nm. The method was also evaluated for different validation parameters; such as linearity, accuracy, precision, LOD, LOQ, specificity, selectivity and sample stability. The amount of geraniol varied from 78.3% to 78.9% by HPTLC and 78.2% to 78.7% by GC-FID method.

B: HPTLC-Mass spectrometry analysis for simultaneous quantification of four phenolic compounds in green, red and black fruits of Trapa natans var. bispinosa Roxb. (singhara).

The fruits of Trapa natans var. bispinosa Roxb. (singhara) of nutraceutical importance are commercially consumed in food commodities. It is nutritious while having several biological activities. In the present study, a simple, rapid, cost-effective, and sensitive highperformance thin-layer chromatography (HPTLC) method was developed for the simultaneous determination of four phenolic compounds viz. gallic (phenolic acid), caffeic acid (hydroxycinnamic acid), quercetin, and kaempferol (flavonols) in seeds and pericarp of green-, red-, and black-colored singhara fruits. The method is economical in terms of the time taken and the amount of solvent used for analysis. Simultaneous separation and quantification of compounds were achieved on HPTLC precoated silica gel 60 F254 aluminum plates using mobile phase of toluene–ethyl acetate–formic acid (13:11:2). Densitometric determination was carried out at λ λ max 282 nm. The calibration curves were linear ranging between 0.996 and 0.999; the limits of detection and quantification ranged between 86.8–135.0 ng μL–1 and 263.2–409.2 ng μL–1 and recovery ranged between 96.4% and 98.5%. The validated method was successively used to analyze the above compounds in fruit parts of singhara. The amount of phenolic compounds ranged from 0.04% kaempferol (green pericarp) to 2.11% gallic acid (red pericarp). The developed method may be used in the quality control and standardization of plant extracts as well as herbal drugs and formulations having polyphenols. As this study reveals the presence of specific phenolic compounds in green, red, and black pericarp of singhara, the agrowaste shall be a good source for isolation of the above compounds for industrial use.

C: Simultaneous quantification of six phenolic compounds in various parts of Moringa oleifera Lam using HPTLC.

Fresh pods of Moringa oleifera with nutraceutical importance are widely consumed in food commodities as vegetables. It is nutritious and it also has several biological activities. In the present study, a simple, rapid, cost-effective, and sensitive high-performance thin-layer chromatography (HPTLC) method was applied for the simultaneous determination of six phenolic compounds, viz., gallic (phenolic acid), p-coumaric, caffeic acid (hydroxycinnamic acid), chlorogenic acid (cinnamic acid derivative), quercetin and kaempferol (flavonols) in flowers, pods, leaves, twigs, and seeds of M. oleifera. Simultaneous separation and quantification of compounds were achieved on HPTLC pre-coated silica gel 60 F254 aluminum plates using the mobile phase toluene–ethyl acetate–formic acid (14:10:1). Densitometric determination was carried out at λmax 282 nm. The calibration curves were linear, ranged between 0.984 and 0.998; the limit of detection and quantification ranged between 110.8 ng mL−1 and 142.3 ng mL−1, and 301.6 ng µL−1 and 410.8 ng µL−1; and recovery ranged between 96.2% and 97.9%. The validated method was successively used to analyze the above compounds in the plant parts of M. oleifera. The amount of the total phenolic content and specific phenolic compounds ranged from 4.86 mg g−1 (gallic acid equivalent [GAE]) to 14.79 mg g−1 (GAE) and 0.007% quercetin (flower and flower with pods) to 0.099% gallic acid (pods of 15 days). This study reveals that the presence of specific phenolic compounds in M. oleifera shall be a good source for the isolation of the above-mentioned compounds for industrial use.

D: Biochemical composition of Betula utilis D. Don bark, collected from high altitudes of Indian Himalayas

Betula utilis (family Betulaceae) is an important medicinal plant that grows in high altitudes of Himalayan region of India. The present study is aimed to determine the biochemical composition in the bark of Betula utilis using HPLC, HPTLC and GCMS methods. The optimization of solvent system for maximum extraction yield has been carried out. Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Antioxidant Activity (AA) were estimated in various solvent extracts. Maximum extractive yield (14.56%), TPC (14.47 mg/g), TFC (20.10 mg/g) in 75% ethanol and scavenging activity (92.89%) were found in 50% ethanol. Pentacyclic triterpenoids (betulin, tupeol, oleanolic acid, beta-sitosterol) were characterized and quantified using HPLC, HPTLC and GCMS found close within limits. Betulin was found maximum in ethanol.

Medicinal Plants

A: Betula utilis extract prolongs life expectancy, protects against amyloid-β toxicity and reduces Alpha Synuclien in Caenorhabditis elegans via DAF-16 and SKN-1

Betula utilis (BU), an important medicinal plant that grows in high altitudes of the Himalayan region, has been utilized traditionally due to it’s antibacterial, hepatoprotective, and anti-tumor properties. It was studied for the longevity and amyloid-β toxicity attenuating activity of B. utilis ethanolic extract (BUE) in Caenorhabditis elegans. Lifespan of the worms was observed under both the standard laboratory and stress (oxidative and thermal) conditions. Eﬀect of BUE was also observed on the attenuation of age-dependent physiological parameters. Further, gene-speciﬁc mutants and green ﬂuorescent protein (GFP)-tagged strains were used to investigate the molecular mechanism underlying the beneﬁcial eﬀects mediated by BUE supplementation. Results showed that BUE (50μg/ml) extended the mean lifespan of C. elegans by 35.99% and increased its survival under stress conditions. The BUE also reduced the levels of intracellular reactive oxygen species (ROS) by 22.47%. A delayed amyloid-β induced paralyses was observed in CL4176 transgenic worms. Interestingly, the BUE supplementation was also able to reduce the α-synuclein aggregation in NL5901 transgenic strain. Gene-speciﬁc mutant studies suggested that the BUE-mediated lifespan extension was dependent on daf-16, hsf-1, and skn-1 but not on sir-2.1 gene. Furthermore, transgenic reporter gene expression assay showed that BUE treatment enhanced the expression of stress-protective genes such as sod-3 and gst-4. The ﬁndings suggested that ROS scavenging activity, together with multiple longevity mechanisms, were involved in BUE mediated lifespan extension. Thus, BUE might have potential to increase the lifespan and to attenuate neuro related disease progression.

B: NABL accreditation and Quality Assessment in terms of physico-chemical and instrumental analysis of essential oils, vegetable oils and herbal drugs

NBRI has been acccreditated / since 2008 as per the requirements of ISO-17025/ 2005 from NABL(National Accreditation Board for Calibration and Testing of Laboratories) Department of Science and Technologies (DST), Govt.of India, New Delhi. Services has been offered for the Quality Assessment in terms of physico-chemical and instrumental analysis of essential oils.

C: Monitoring of organochlorine pesticides (OCPs) status of river Ganga and its remediation measures at Kanpur, Uttar Pradesh, India

Under this project seasonal monitoring of Ganga river water, quality of river ganga at Kanpur was done. Samples were analysed for numbers of water quality parameters with prime thrust to determine organochlorine pesticides (OCPs) and metal concentration in the surface water at different location of river ganga at Kanpur, India. Alongwith this remediation techniques were also analysed with Velives and Pistia for such contaminated waters.

Dr. Alok Lehri

Chief Scientist

Publications

– Swapnil Pandey; Suresh Chandra Phulara; Shashank Mishra; Rajesh Bajpai; Anil Kumar; Abhishek Niranjan; Alok Lehri; Dalip Kumar Upreti. Betula utilis extract prolongs life expectancy, protects against amyloid-β toxicity and reduces Alpha Synuclien in Caenorhabditis elegans via DAF-16 and SKN-1. Comparative Biochemistry and Physiology, Part C. Accepted. 2019

– Swapnil Pandey, Sudeep Tiwari, Anil Kumar, Abhishek Niranjan, Jai Chand, Alok Lehri, Puneet Singh Chauhan. Antioxidant and anti-aging potential of Juniper berry (Juniperus communis L.) essential oil in Caenorhabditis elegans model system Industrial Crops & Products 120 (2018) 113-122

– Abhishek Niranjan, Nem Kumar Ngpoore, Naushi Anis, Anil Kumar, Alok Lehri, Pramod Arvind Shirke and Shri Krishna Tewari. Simultaneous quantification of six phenolic compounds in various parts of Moringa oleifera Lam using HPTLC Journal of Planer Chromatography 30 (2017) 6, 1–8

– Abhishek Niranjan, Alok Lehri and SK Tewari. Fatty acid composition of oil from seeds of Desmodium gangeticum. Journal of Lipid Science and Technology 48 (2017) 38-39

– Abhishek Niranjan, Alok Lehri, and S.K. Tewari. Essential Oil of Cinnamomum cassia for Pest Control in: Green Pesticides Handbook Essential Oils for Pest Control Edited by Leo M.L. Nollet & Hamir Singh Rathore CRC Press Taylor & Francis Group, Boca Raton (2017) 303-318

– Abhishek Niranjan, Alok Lehri, and S.K. Tewari. Essential Oil of Thymus vulgaris L. for Pest Control in Essential Oils for Pest Control Edited by Leo M.L. Nollet & Hamir Singh Rathore CRC Press Taylor & Francis Group, Boca Raton (2017) 319-331

– Ameena Siddiqui, Sudhir Shukla, Anu Rastogi, Atul Bhargava, Abhishek Niranjan and Alok Lehri. Relationship among phenotypic and quality traits in indigenous and exotic accessions of linseed. Pesq. agropec. bras., Brasília, 51, (2016) 1964-1972

– Anil Kumar, Abhishek Niranjan, Alok Lehri, SK Tewari and DK Upreti Biochemical composition of Betula utilis D. Don bark, collected from high altitudes of Indian Himalayas. Medicinal Plants Vol. 8 (1), March 2016, 33-3

– Anil Kumar, Abhishek Niranjan, Alok Lehri, Ramesh K. Srivastava, and SK Tewari. Effect of Geographical Climatic Conditions on Yield, Chemical Composition and Carbon Isotope Composition of Nagarmotha (Cyperus scariosus R. Br.) Essential Oil. Journal of Essential Oil Bearing Plants. Accepted, (2016)

– Reena Yadav, Meenakshi Mehrotra, Aditya K. Singh, Abhishek Niranjan, Rani Singh, Indraneel Sanyal, Alok Lehri, Veena Pande, D. V. Amla. Improvement in Agrobacterium-mediated transformation of chickpea (Cicer arietinum L.) by the inhibition of polyphenolics released during wounding of cotyledonary node explants. Protoplasma, DOI 10.1007/s00709-015-0940-0, 2016

– Abhishek Niranjan, SK Tewari, Alok Lehri and DV Amla. Extraction of polyphenols from Trewia nudiflora L. and its antioxidant activity. Medicinal Plants 7: 9-19, (2015)

– Anil Kumar, Abhishek Niranjan, Alok Lehri, Shri Krishna Tewari, Devendra Vijay Amla, Sri Krishna Raj, Ramesh Srivastava and Shakti Vijay Shukla. Isotopic Ratio Mass Spectrometry Study for Differentiation Between Natural and Adulterated Essential Oils of Lemongrass (Cymbopogon flexuosus) and Palmarosa (Cymbopogon martinii). Journal of Essential Oil Bearing Plants. 18: 368 – 373, (2015)

– R K Srivastava, A Singh, G P Srivastava, Alok Lehri, Abhishek Niranjan, S K Tewari, K Kumar and S Kumar. Chemical Constituents and Biological Activities of Promising Aromatic Plant Nagarmotha (Cyperus scariosus R.Br.): A Review. Proc Indian Natn Sci Acad 80: (525-536) 2014

– Abhishek Niranjan, Sandhya Mishra, Alok Lehri, Devindra V Amla, Ram Sanmukh Upadhyay, and Chandra Shekhar Nautiyal. Identification and quantification of heterologous compounds parthenin and organic acids in Parthenium hysterophorus L. using HPLC-PDA-MS-MS. Analytical Letters 46: 48–59, (2013)

– Abhishek Niranjan, Saurabh Verma, Alok Lehri and D.V. Amla. HPTLC-Mass spectrometry analysis for simultaneous quantification of four phenolic compounds in green, red and black fruits of Trapa natans var. bispinosa Roxb. (singhara). Journal of Planer Chromatography, 4: 316–321 (2013).

– Abhishek Niranjan, S.K.Tewari, Alok Lehri and D.V. Amla. Phytochemical constituents and free radical scavenging activity of four Terminalia species. Medicinal Plants 5: 206-213, (2013)