Ocimum sanctum leaf extract induces drought stress tolerance in rice.
ABSTRACT: Ocimum leaves are highly enriched in antioxidant components. Thus, its leaf extract, if applied in plants, is believed to efficiently scavenge ROS, thereby preventing oxidative damage under drought stress. Thus, the present study was performed in kharif 2013 and rabi 2014 season to evaluate the effect of aqueous leaf extract of Ocimum sanctum against drought stress in 2 rice genotype under glass house conditions. Here we show that various morpho- physiological (chlorophyll fluorescence, leaf rolling score, leaf tip burn, number of senesced leaves and total dry matter) and biochemical parameters (proline, malondialdehyde and superoxide dismutase content) were amended by Ocimum treatment in both the seasons. Application of Ocimum extract increased expression of dehydrin genes, while reducing expression of aquaporin genes in drought stressed rice plant. Thus, application of Ocimum leaf extract under drought stress can be suggested as a promising strategy to mitigate drought stress in economical, accessible and ecofriendly manner.
Project description:Holy basil (Ocimum sanctum L.) and sweet basil (Ocimum basilicum L.) are the most commonly grown basil species in India for essential oil production and biosynthesis of potentially volatile and non-volatile phytomolecules with commercial significance. The aroma, flavor and pharmaceutical value of Ocimum species is a significance of its essential oil, which contains most of the monoterpenes and sesquiterpenes. A large number of plants have been studied for characterization and identification of terpene synthase genes, involved in terpenoids biosynthesis. The goal of this study is to discover and identify the putative functional terpene synthase genes in O. sanctum. HMMER search was performed by using a set of 13 well sequenced and annotated plant genomes including the newly sequenced genome of O. sanctum with Pfam-A database locally, using HMMER 3.0 hmmsearch for the two Pfam domains (PF01397 and PF03936). Using this search method 81 putative terpene synthases genes (OsaTPS) were identified in O. sanctum; the study further reveals 47 OsaTPS were putatively functional genes, 19 partial OsaTPS, and 15 OsaTPS as probably pseudogenes. All these identified OsaTPS genes were compared with other plant species, and phylogenetic analysis reveals the subfamily classification of OsaTPS in TPS-a, -b, -c, -e, -f and TPS-g subfamilies clusters. This genome-wide identification of OsaTPS genes, their phylogenetic analysis and secondary metabolite pathway mapping predictions together provide a comprehensive understanding of the TPS gene family in Ocimum sanctum and offer opportunities for the characterization and functional validation of numbers of terpene synthase genes.
Project description:Ocimum sanctum Linn. (also known as Tulsi) is a sacred Indian plant, the beneficial role of which, in obesity and diabetes is described traditionally. This is a randomized, parallel group, open label pilot study to investigate the effect of O. sanctum on metabolic and biochemical parameters in thirty overweight/obese subjects, divided into two groups A and B. Group A (n = 16) received one 250 mg capsule of Tulsi (O. sanctum) extract twice daily in empty stomach for 8 weeks and group B (n = 14) received no intervention. Statistically significant improvements in the values of serum triglycerides (p = 0.019); low density lipoprotein (p = 0.001); high density lipoprotein (p = 0.001); very low density lipoprotein (p = 0.019); Body Mass Index, BMI (p = 0.005); plasma insulin (p = 0.021) and insulin resistance (p = 0.049) were observed after 8 weeks in the O. sanctum intervention group. The improvement in HDL-C in the intervention group when compared to the control group was also statistically significant (p = 0.037). There was no significant alteration of the liver enzymes SGOT and SGPT in both the intervention (p = 0.141; p = 0.074) and control arms (p = 0.102; p = 0.055) respectively. These observations clearly indicate the beneficial effects of O. sanctum on various biochemical parameters in young overweight/obese subjects.
Project description:This study aimed to develop nanodelivery systems for enhancing the Ocimum sanctum Linn. extract delivery into the skin. Rosmarinic acid (RA) was used as a marker for the quantitative determination of the extract by high-performance liquid chromatography. Nanostructured lipid carriers (NLC), nanoemulsion, liposome, and niosome, were developed and characterized for internal droplet size, polydispersity index (PDI), and zeta potential using photon correlation spectroscopy. Irritation properties of each formulations were investigated by hen's egg test on the chorioallantoic membrane. In vitro release, skin permeation, and skin retention are determined. NLC was suggested as the most suitable system since it enhances the dermal delivery of RA with the significant skin retention amount of 27.1 ± 1.8% (p < 0.05). Its internal droplet size, PDI, and zeta potential were 261.0 ± 5.3 nm, 0.216 ± 0.042, and -45.4 ± 2.4 mV, respectively. RA released from NLC with a sustained release pattern with the release amount of 1.29 ± 0.15% after 24 h. NLC induced no irritation and did not permeate through the skin. Therefore, NLC containing O. sanctum extract was an attractive dermal delivery system that was safe and enhanced dermal delivery of RA. It was suggested for further used as topical anti-ageing products.
Project description:Endophytic mycopopulation isolated from India's Queen of herbs Tulsi (Ocimum sanctum) were explored and investigated for their diversity and antiphytopathogenic activity against widespread plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani and Fusarium oxysporum. 90 fungal isolates, representing 17 genera were recovered from 313 disease-free and surface sterilised plant segments (leaf and stem tissues) from three different geographic locations (Delhi, Hyderabad and Mukteshwar) during distinct sampling times in consequent years 2010 and 2011 in India. Fungal endophytes were subjected to molecular identification based on rDNA ITS sequence analysis. Plant pathogens such as F. verticillioides, B. maydis, C. coarctatum, R. bataticola, Hypoxylon sp., Diaporthe phaseolorum, Alternaria tenuissima and A. alternata have occurred as endophyte only during second sampling (second sampling in 2011) in the present study. Bi-plot generated by principal component analysis suggested tissue specificity of certain fungal endophytes. Dendrogram revealed species abundance as a function of mean temperature of the location at the time of sampling. Shannon diversity in the first collection is highest in Hyderabad leaf tissues (H' = 1.907) whereas in second collection it was highest from leaf tissues of Delhi (H' = 1.846). Mukteshwar (altitude: 7500 feet) reported least isolation rate in second collection. Nearly 23% of the total fungal isolates were considered as potent biocontrol agent. Hexane extract of M. phaseolina recovered from Hyderabad in first collection demonstrated highest activity against S. sclerotiorum with IC50 value of 0.38 mg/ml. Additionally, its components 2H-pyran-2-one, 5,6-dihydro-6-pentyl and palmitic acid, methyl ester as reported by GC-MS Chromatogram upon evaluation for their antiphytopathogenic activity exhibited IC50 value of 1.002 and 0.662 against respectively S. sclerotiorum indicating their significant role in antiphytopathogenic activity of hexane extract. The production of 2H-pyran-2-one, 5,6-dihydro-6-pentyl from M. phaseolina, an endophytic fungus is being reported for the first time.
Project description:There is an urgent need to develop alternative therapies against lethal pancreatic cancer (PC). Ocimum sanctum ("Holy Basil") has been used for thousands of years in traditional Indian medicine, but its anti-tumorigenic effect remains largely unexplored. Here, we show that extracts of O. sanctum leaves inhibit the proliferation, migration, invasion, and induce apoptosis of PC cells in vitro. The expression of genes that promote the proliferation, migration and invasion of PC cells including activated ERK-1/2, FAK, and p65 (subunit of NF-?B), was downregulated in PC cells after O. sanctum treatment. Intraperitoneal injections of the aqueous extract significantly inhibited the growth of orthotopically transplanted PC cells in vivo (p<0.05). Genes that inhibit metastasis (E-cadherin) and induce apoptosis (BAD) were significantly upregulated in tumors isolated from mice treated with O. sanctum extracts, while genes that promote survival (Bcl-2 and Bcl-xL) and chemo/radiation resistance (AURKA, Chk1 and Survivin) were downregulated. Overall, our study suggests that leaves of O. sanctum could be a potential source of novel anticancer compounds in the future.
Project description:The role of silver nanoparticles (AgNps) is an attractive proposition for advancing modern diabetes therapies and applied science. Stable AgNps with a size range of 3-25 nm were synthesized using aqueous leaf extracts from <i>Ocimum basilicum</i>, <i>Ocimum sanctum</i>, and in combination. The concentration of the extracts facilitated the reduction of silver nitrate that led to the rapid formation of AgNps at room temperature, indicating a higher reaction rate as opposed to harsh chemical methods, and high conversion energy usually involved in the synthesis. The size, shape and elemental analysis were carried out using UV-Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), dynamic light scattering (DLS), and zeta potential whilst, Fourier transform infrared (FTIR) supported by gas chromatography mass spectroscopy (GC-MS) was used to identify the type of capping agents. Inhibition of ?-amylase and ?-glucosidase enzymes retards the rate of carbohydrate digestion, thereby provides an alternative and a less evasive strategy of reducing postprandial hyperglycaemia in diabetic patients. The AgNps derived from <i>O. sanctum</i> and <i>O. basilicum</i>, respectively displayed an inhibitory effect at 89.31 ± 5.32%, and 79.74 ± 9.51%, respectively, against <i>Bacillus stearothermophilus</i> ?-glucosidase enzyme model, indicating an enhanced biocatalytic potential compared to their respective crude extracts and the control. Furthermore, the emerging rate of infections in diabetic patients validates the need for the discovery of dual diabetes therapies. As a result, the bioderived AgNps displayed antimicrobial activity against bacterial species <i>Staphylococcus aureus</i>, <i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i>, <i>Bacillus subtilis</i>, and <i>Salmonella</i> species.
Project description:Background: Ocimum sanctum L. (holy basil; Tulsi in Hindi) is an important medicinal plant, traditionally used in India. Methods: The phytochemical study of the nonpolar (dichloromethane 100%) and polar (methanol:water; 7:3) extracts yielded fourteen compounds. Compounds 6, 7, 9, 11, 12, and 13, along with the methanol:water extract were evaluated for their cytotoxicity against the human cancer cell lines MCF-7, SKBR3, and HCT-116, and normal peripheral blood mononuclear cells (PBMCs). Results: Five terpenoids, namely, ursolic acid (1), oleanolic acid (2), betulinic acid (3), stigmasterol (4), and β-caryophyllene oxide (5); two lignans, i.e., (-)-rabdosiin (6) and shimobashiric acid C (7); three flavonoids, luteolin (8), its 7-O-β-D-glucuronide (9), apigenin 7-O-β-D-glucuronide (10); and four phenolics, (E)-p-coumaroyl 4-O-β-D-glucoside (11), 3-(3,4-dihydroxyphenyl) lactic acid (12), protocatechuic acid (13), and vanillic acid (14) were isolated. Compound 6 was the most cytotoxic against the human cancer lines assessed and showed very low cytotoxicity against PBMCs. Conclusions: Based on these results, the structure of compound 6 shows some promise as a selective anticancer drug scaffold.
Project description:BACKGROUND: Ocimum L. of family Lamiaceae is a well known genus for its ethnobotanical, medicinal and aromatic properties, which are attributed to innumerable phenylpropanoid and terpenoid compounds produced by the plant. To enrich genomic resources for understanding various pathways, de novo transcriptome sequencing of two important species, O. sanctum and O. basilicum, was carried out by Illumina paired-end sequencing. RESULTS: The sequence assembly resulted in 69117 and 130043 transcripts with an average length of 1646 ± 1210.1 bp and 1363 ± 1139.3 bp for O. sanctum and O. basilicum, respectively. Out of the total transcripts, 59648 (86.30%) and 105470 (81.10%) from O. sanctum and O. basilicum, and respectively were annotated by uniprot blastx against Arabidopsis, rice and lamiaceae. KEGG analysis identified 501 and 952 transcripts from O. sanctum and O. basilicum, respectively, related to secondary metabolism with higher percentage of transcripts for biosynthesis of terpenoids in O. sanctum and phenylpropanoids in O. basilicum. Higher digital gene expression in O. basilicum was validated through qPCR and correlated to higher essential oil content and chromosome number (O. sanctum, 2n = 16; and O. basilicum, 2n = 48). Several CYP450 (26) and TF (40) families were identified having probable roles in primary and secondary metabolism. Also SSR and SNP markers were identified in the transcriptomes of both species with many SSRs linked to phenylpropanoid and terpenoid pathway genes. CONCLUSION: This is the first report of a comparative transcriptome analysis of Ocimum species and can be utilized to characterize genes related to secondary metabolism, their regulation, and breeding special chemotypes with unique essential oil composition in Ocimum.
Project description:Ocimum is one of the most revered medicinally useful plants which have various species. Each of the species is distinct in terms of metabolite composition as well as the medicinal property. Some basil types are used more often as an aromatic and flavoring ingredient. It would be informative to know relatedness among the species which though belong to the same genera while exclusively different in terms of metabolic composition and the operating pathways. In the present investigation the similar effort has been made in order to differentiate three commonly occurring Ocimum species having the high medicinal value, these are Ocimum sanctum, O. gratissimum and O. kilimandscharicum. The parameters for the comparative analysis of these three Ocimum species comprised of temporal changes in number leaf trichomes, essential oil composition, phenylpropanoid pathway genes expression and the activity of important enzymes. O. gratissimum was found to be richest in phenylpropanoid accumulation as well as their gene expression when compared to O. sanctum while O. kilimandscharicum was found to be accumulating terpenoid. In order to get an overview of this qualitative and quantitative regulation of terpenes and phenylpropenes, the expression pattern of some important transcription factors involved in secondary metabolism were also studied.
Project description:CONSTANS (CO)-like genes have been intensively investigated for their roles in the regulation of photoperiodic flowering, but very limited information has been reported on their functions in other biological processes. Here, we found that a CO-like gene, Ghd2 (Grain number, plant height, and heading date2), which can increase the yield potential under normal growth condition just like its homologue Ghd7, is involved in the regulation of leaf senescence and drought resistance. Ghd2 is expressed mainly in the rice (Oryza sativa) leaf with the highest level detected at the grain-filling stage, and it is down-regulated by drought stress conditions. Overexpression of Ghd2 resulted in significantly reduced drought resistance, while its knockout mutant showed the opposite phenotype. The earlier senescence symptoms and the transcript up-regulation of many senescence-associated genes (SAGs) in Ghd2-overexpressing transgenic rice plants under drought stress conditions indicate that Ghd2 plays essential roles in accelerating drought-induced leaf senescence in rice. Moreover, developmental and dark-induced leaf senescence was accelerated in the Ghd2-overexpressing rice and delayed in the ghd2 mutant. Several SAGs were confirmed to be regulated by Ghd2 using a transient expression system in rice protoplasts. Ghd2 interacted with several regulatory proteins, including OsARID3, OsPUR?, and three 14-3-3 proteins. OsARID3 and OsPUR? showed expression patterns similar to Ghd2 in rice leaves, with the highest levels at the grain-filling stage, whereas OsARID3 and the 14-3-3 genes responded differently to drought stress conditions. These results indicate that Ghd2 functions as a regulator by integrating environmental signals with the senescence process into a developmental programme through interaction with different proteins.