Investigations on biological activity of Vetiveria zizanioides L. Nash, a palingenesis of some important findings in miracle grass

Vetiveria zizanioides L. Nash synonymously known as Chrysopogon zizanioides L. Roberty (Family: Poaceae/Graminae), widely cultivated in the tropical regions of the world, is a miraculous grass native to India first developed for soil and water conservation by the World Bank during mid 1980s. Popularly known as ‘KHUS’, it is the major source of the well-known oil of vetiver, which is used in medicine, cosmetics and in perfumery making agarbattis, soaps, soft drinks, pan masala. Being a major constituent of ‘Rasayana’ in Ayurveda, different parts of the vetiver plant have traditionally been used by the Indian tribes for treating various ailments, diseases and disorders including boils, burns, epilepsy, fever, scorpion sting, snakebite, sores in the mouth, headache, toothache, weakness, lumbago, sprain, rheumatism, urinary tract infection, malarial fever, acidity relief and as an anti-helmintic. It has also been used in traditional medicine of Asia and Africa, particularly ancient Tamil literature mentions the use of vetiver for medical purposes. The essential oil of vetiver has extensive applications in toiletries and cosmetics, possesses sedative property and has traditionally been used in aromatherapy for relieving stress, anxiety, nervous tension and insomnia. Root is also important in traditional medicine as a carminative, stimulant and diaphoretic. Besides these medicinal properties of the plant, the dried culms of the plant are used as brooms and to thatch roofs. Pulp of the plant is used to prepare straw boards and paper. In India, the roots have been used for making screens, mats, hand fans, and baskets. Formulations containing oil and/or extracts of vetiver have been reported to treat inflammatory bowel disease, urinary tract infection, and in making insect repellents. Research on various aspects of vetiver make it an excellent plant describing many characteristics including phytoremediation, water purification, leachate and effluent disposal, utilizing wastewater, removing nitrogen and phosphorus etc. It is one of the most promising aromatic plants known to possess antimicrobial, antioxidant and termicidal properties. However, the plant has not been studied exclusively for other pharmacological activities and there is a lack of scientific evidence to prove these effects. We are studying bioactivity of vetiver root as a part of our effort to discover plant-based biologically active molecules since last many years using molecular and cell target based assays. In our published reports, we showed potent antibacterial, drug-resistant modifying, hydroxyl radical scavenging, anticancer, antihepatotoxic and antioxidant activity in intact and spent root of vetiver. In view of our findings, the present paper recapitulates some important findings on the bioactivity of Vetiveria zizanioides L. Nash and a palingenesis has been made for this miracle grass

Ferric reducing antioxidant power and free radical scavenging activity of Moringa oleifera: Relevance in oxidative stress

Moringa oleifera of family Moringaceae, commonly known as Horseradish-tree or the Ben-oil tree is an exceptionally nutritious vegetable tree with a variety of medicinal uses, distributed in tropical and subtropical regions of the world. The tree's bark, roots, fruit (pod), flowers, leaves, seeds and gum are used as an antiseptic, anticancer, anti-inflammatory, hepatoprotective and in treating rheumatism, venomous bites and other conditions. The immature green pods, called ‘drumsticks’ are probably the most valued and widely used part of the tree for water purification (e.g. desalination of ocean salt water). The leaves are highly nutritious, being a significant source of beta-carotene, vitamin C, protein, iron and potassium used in soups and sauces. The present study focuses on concentration-dependent ferric reducing antioxidant power (FRAP), free radical scavenging (DPPH), total phenolics (TP), total antioxidant capacity (TAC) and reducing power (RP) of moringa leaf and fruit (pod) extract compared with standard antioxidant. A strong positive co-relation was observed between FRAP, DPPH, TP and RP activity. Comparatively, the antioxidant potential of fruit extract was more pronounced than the leaf extract and ethanolic extract showed better activity than aqueous. On the basis of our observations, we hypothesize that moringa fruit (pod) and leaves can be a potential source of natural antioxidants due to their marked antioxidant activity

Protective effect of (-) α-bisabolol on markers of oxidative stress in erythrocytes subjected to oxidative insult

(-)-α-bisabolol is a sesquiterpene alcohol found as a major component of essential oil of chamomile (Matricaria recutita L., Chamomilla recutita L., Matricaria chamomilla L.; Family Asteraceae). Chamomile, one of the most ancient and widely recognized herbs to mankind, has been used traditionally for centuries as an anti-inflammatory, antispasmodic, carminative, mild astringent and healing medicine. It is also known to be very helpful as an external agent for encouraging the rapid healing of ulcers and burns without infection, as well as persistent skin problems such as eczema and psoriasis. Since clinical trials and human studies are limited, we have investigated the effect of (-)-α-bisabolol on markers of oxidative stress in human erythrocytes by incubating with hydrogen peroxide (2mM) and tert-butyl hydroperoxide (10 µM). Subjecting erythrocyte to oxidative stress caused a significant alteration in reduced glutathione GSH), malondialdehyde (MDA) concentration as well as superoxide dismutase and catalase activity compare to control. Presence of (-)-α-bisabolol as low as 0.1µM in incubation medium protected the erythrocytes from oxidative stress and helps to maintain the basal level of GSH and MDA. The activity of superoxide dismutase and catalase were also restored in a concentration-dependent manner (0.01-100µM). The effect was also compared with L-Ascorbic acid, quercetin and BHT. Our findings provide evidence for the protection of oxidative stress in erythrocytes by (-)-α-bisabolol that could be considered for further studies

Ornithine decarboxylase activity, a clinical biomarker for evaluating cancer chemopreventive efficacy of phytomolecules

Biomarkers of cancer have made a strong traipse in predicting the disease pattern and contributed significantly to the understanding of tumour state, progression, characteristics and response to therapies. Polyamines such as putrescine, spermine and spermidine are cationic biomolecules essential for the cell cycle function and serve as excellent biomarkers of tumour progression. The polyamine biosynthesis is tightly regulated by ornithine decarboxylase, a highly inducible enzyme specific to pH, temperature, time and substrate concentration. The expression of this enzyme is very high during cell transformation and tumour progression leading to elevated level of polyamines. To measure the activity of ornithine decarboxylase an improved, easy, simple, reliable and cost-effective method has been developed utilizing small quantity of chemicals. The methodology is based on the cognizance that enzyme transforms L-ornithine hydrochloride substrate to a yellow coloured product putrescine soluble in pentanol, the absorbance of which was measured spectrophotometrically. The procedure is being utilized for evaluating cancer chemopreventive efficacy of phytomolecules. We have analyzed hundreds of molecules belonging to flavonoid, terpenes and alkaloid groups and very few were found to inhibit enzyme activity in a concentration dependent manner (0.4-50µg/mL). In addition, the molecules were also tested for their radical scavenging properties. Our results depict that molecules having phenolic groups and lactone rings in their structure are better inhibitors than their counterparts. The comparative analysis of the groups reassures flavonoids as better scavengers of radical formation and a positive correlation was observed among the nitric oxide and 2, 2-diphenyl-1-picrylhydrazyl inhibition (p<0.01). Further evaluation and augmentation may reveal novel ornthine decarboxylase inhibitors and cancer chemopreventive agents from plants

Weight matrix based identification of terpene synthases conserved motifs in Arabidopsis thaliana proteome

Terpenes comprise the most diverse collection of natural products. Out of more than 30,000 individual terpenoids identified, at least half are synthesized by plants. A relatively small, but quantitatively significant, number of terpenoids are involved in primary plant metabolism. However, the vast majorities are classified as secondary metabolites; compounds not required for plant growth and development but presumed to have an ecological function in communication or defense and are widely used in industrial applications. Terpene hydrocarbon scaffolds are generated by the action of the mechanistically intriguing family of mono-, sesqui-, and diterpene synthases collectively termed as terpene synthases, that catalyze multistep reactions with diphosphorylated substrates of 10 (geranyl diphosphate), 15 (farnesyl diphosphate) or 20 (geranylgeranyl diphosphate) carbons. In the studied work, we performed a computational study on proteome wide identification of terpene synthase motifs in Arabidopsis thaliana proteome on the basis of weight matrix approach. We have developed an optimal weight matrix for the identification of terpene synthase motifs in the plant’s proteome. Weight matrix was constructed by aligning orthologous sequences of known terpene synthases originated from diverse plant species viz., Abies grandis, Nicotiana tobaccum etc. Sequences of detected domains & motifs were retrieved through SwissProtKB/NCBI on the basis of specific conservation IDs of Prosite, Pfam, Interpro, Prodom, COG, TIGR databases, while position specific scoring matrices were made through MEME, MotifSampler, PossuMsearch tools. Weight matrix based search of conserved motifs in the proteome of A. thaliana was done through ESA, Lahead and Simple algorithm based search tools of PossuMsearch biosuite in Linux system. Prediction was first validated by using positive control data set and optimized the method to reach prediction accuracy upto >90%. After tool performance evaluation, prediction was made on whole proteome at specific threshold/score value. Significant results were found in A. thaliana with motif similarity ranges from 80% to 100%. This proteome wide search model paves the path to identify more terpene synthases genes in A. thaliana, as well as in other plant systems

Structure Prediction and Functional Characterization of ERG Proteins Involved in Ergosterol Biosynthetic Pathway of Candida albicans

The ERG proteins and enzymes of the ergosterol biosynthetic pathway has been the subject of intensive investigation as a target for several classes of antifungal agents used to treat C. albicans infection. Over the past few decades, a number of drugs and inhibitors with wide spectrum of activity, low toxicity and defined targets have been introduced. Several lines of evidence suggest that allylamines targets squalene epoxidase (ERG1), morpholines affects sterol C8-C7 isomerase (ERG2) and sterol reductase (ERG24), azoles inhibits a cytochrome P450 (ERG11) responsible for the 14 α-demethylation of lanosterol and C-5 sterol desaturase (ERG3) and polyenes binds to ergosterol that leads to the damage of cell plasma membrane, ensuing in leakage of intracellular ions. However, little information about the experimental structure (X-ray and NMR) of proteins from ergosterol biosynthetic pathway is available in RCSB Protein Databank (PDB). Since ERG proteins play a key role in metabolic pathway of ergosterol, their 3D structures are essential to determine most of their functions. Homology modeling approach was employed for comparative modeling. Modeller 9v7 and I-Tasser programs were utilized to serve our purpose. The modeled proteins were further validated by Procheck, Verify-3D, ERRAT and PROVE servers. Expasy’s Prot-param server and Cys_rec tool was used for physico-chemical and functional characterization of these proteins. Studies of secondary structure of these proteins were carried out using computational program, Profunc. Swiss-pdb viewer was used to visualize and analyze homology derived structures. The modeled structures of 12 ERG proteins have been submitted and are available in Protein Model Database (PMDB) so that they become accessible to other users for further studies

Anticancer efficacy of phenolics based structurally related compounds and their radical scavenging action

Cancer, one of the leading causes of death worldwide, is an abnormal cell proliferation that fails to respond to the normal signals. In an effort to eradicate the growing menace of cancer, a clear understanding of fundamental biology and molecular mechanism of carcinogenesis is essential for targeted therapies. Among the devised strategies in use for cancer treatment, the one that is of immense interest is the development of plant based novel anticancer agents. Due to their tremendous availability, biological activity and efficacy, the phytochemicals deemed a gibbous future in chemoprevention. In the present study, several phenolics based structurally related compounds of steroidal and non-steroidal skeleton were synthesized and tested for their modulatory effect on ornithine decarboxylase activity, an enzyme highly upregulated in cancer. Additionally, these compounds were also examined for radical scavenging extent to establish a correlation with the anticancer property. Our result suggests that the tested compounds possessed radical scavenging activity, for being the inherent property of the phenolics. 3-(3’,4’5’-trimethoxyphenyl)-4,5,6-trimethoxyindan-1-one oxime exhibited highest inhibition of enzyme activity (91%) followed by 1-(2,4-dibromophenyl)-3-[3-methoxyestra 1,3,5(10)-trien-17-acetate,2-yl]-2-propen-1-one (85%), 2-Hydroxy, 3-(3’,4’,5’-trimethoxy phenyl)-4,5,6-trimethoxy ind-2-en-1-one (80%), 1-(3,4-methylenedioxyphenyl)-3-(3,4,5-trimethoxyphenyl)-2-propen-1-one (74%) and 1-(3,-methoxy, 4-hydroxyphenyl)-3-[3-methoxyestra 1,3,5(10)-trien-17-acetate, 2-yl]-2-propen-1-one (67%). Furthermore, it was observed that 1-(3-Methoxy, 4- hydroxyphenyl)-3-[3-methoxyestra 1,3,5 (10)-trien-17-acetate, 2-yl]-2-propen-1-one showed the highest scavenging effect (67%) in nitric oxide assay, whereas 1-(3-methylphenyl)-3-[3-methoxy, 17-hydroxyestra 1,3,5(10)-trien, 2-yl]-2-propen-1-one showed maximum inhibition of radical formation in 2,2-diphenyl-1-picrylhydrazyl analysis. Most of these compounds possessed a 3,4,5-trimethoxyphenyl unit which might be inducing enzyme inhibition and scavenging radical formation. Further investigations are on the way to establish the structure-activity relationship, so that these compounds can be developed as anticancer agents

Suppression of 12-O-tetradecanoylphorbol-13-acetate-induced ornithine decarboxylase activity by resveratrol derivatives

As demonstrated previously, resveratrol (3,4',5-trihydroxy-trans-stilbene) inhibits 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ornithine decarboxylase (ODC), the key rate limiting enzyme in mammalian polyamine synthesis. Using human bladder epithelial carcinoma HTB-24 cells in culture where resveratrol inhibits induction with an IC50 of 8.8 µM, we now report potential metabolites demonstrate greater activity [tetrabutylammonium (E)-4-(3,5-dihydroxystyryl)phenyl sulfate (IC50 1.2 µM), resveratrol tripotassium 3,5,4'-trisulfate (IC50 1.8 µM), resveratrol tripotassium 3,4'-disulfate (IC50 1.8 µM), and resveratrol tripotassium 3,5-disulfate (IC50 2.3 µM)]. Based on RT-PCR studies, ODC inhibition occurs at the transcriptional level, but this was not due to direct inhibition of protein kinase C (e.g., resveratrol IC50, 79 µM; resveratrol tripotassium 3,5-disulfate IC50, 49 µM). Additional work is underway to more fully investigate this potentially important observation. [This work was supported by program project P01 CA48112 awarded by the National Cancer Institute. SL acknowledges Indo-US Science and Technology Forum (IUSSTF), New Delhi for a Research Fellowship]

Bioconversion of eugenol into food flavouring agent vanillin

Microorganisms have the ability to chemically modify a wide variety of organic compounds by a process referred to as biological or microbial transformation, or in general, bioconversion. The microbial cells and their catalytic machinery (enzymes) accept a wide array of complex molecules as substrates, yielding products with unparallel chiral (enantio-), positional (region-) and chemical (chemo-) selectivity through various biochemical reactions. The present study was formulated on the objective of the conversion of abundantly available phytomolecules eugenol into vanillin, a compound of industrial importance, using microorganisms Aspergillus flavus, Aspergillus niger and Pseudomonas aeruginosa. These microbes were found to be capable of converting eugenol to industrially important cost-effective products, vanillin (used as flavouring agent). The results were analyzed using thin layer and gas chromatographic techniques. Our results demonstrated that A. flavus, A. niger and P. aerouginosa were able to transform eugenol to vanillin. Our findings may provide a novel approach for the production of cost-effective vanillin using microorganisms