Secondary metabolites from rhizome of Curcuma caesia Roxb. (Zingiberaceae)

Cytotoxic potential of Curcuma caesia rhizome extract and derived gold nanoparticles in targeting breast cancer cell lines

Among all types of cancer, breast cancer is the most aggressive, as it is responsible for most of the cancer related death of women. Though several medical therapies are available, the scenario of curing such disease is not favorable. Therefore, there is an urgent need to find alternatives to deal with it. The knowledge of ethnopharmacy might give some better solution to mitigate such deadly diseases. Here, we are using the rhizome of Curcuma caesia Roxb. (Black turmeric), as well as gold nanoparticles (GNPs) synthesized with it to check their specific cytotoxic potentiality against breast cancer cell lines. In our study, ethanolic extract was used to evaluate the cytotoxic effect of the rhizome. GNPs were synthesized by using the same extract and characterized by UV-Vis spectroscopy (UV-Vis), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Thermo gravimetric analysis (TGA). The TEM, XRD, FTIR and TGA results revealed the successful synthesis and capping of GNPs. The UV-Vis Spectrum showed a sharp and narrow absorption peak at 550 nm and HRTEM confirmed both the stability and successful synthesis of the nanoparticles. The MTT assay of the crude extract revealed strong cytotoxicity against breast cancer cell lines viz. MCF-7 (ER+) and MDA MB-231 (Triple Negative Breast Cancer, TNBC) by showing IC50 values as 15.70 ± 0.029 and 21.57 ± 0.031 μg/mL respectively. For extract mediated GNPs, the IC50 values were found to be 6.44 ± 0.045 and 5.87 ± 0.031μg/mL respectively in both breast cancer cell lines. As the IC50 value for GNPs was found to be much lower than that of crude extract, it indicates a higher efficiency of the GNP. However, both the rhizome extract and its mediated GNPs showed more toxicity towards MDA MB-231 (TNBC) cell lines. It was also observed that the GNPs showed more toxicity towards TNBC cell lines compared to the rhizome extract. No toxicity was found in case of other cell lines such as L 929 and HeLa for both crude extract as well as for GNPs. These observations suggests that both the crude rhizome extract and its derived GNPs exhibit selective cytotoxic potential against breast cancer cell lines, which might be exploited for target specific treatment. Moreover, with an understanding of the mechanism behind the GNPs therapeutic efficiency, it can be developed as a personalized therapy to treat such type of cancers.

Small cardamom genome: development and utilization of microsatellite markers from a draft genome sequence of Elettaria cardamomum Maton

Small cardamom (Elettaria cardamomum Maton), the queen of spices, is the third most expensive spice in the world after saffron and vanilla, valued highly for its aroma and taste. This perennial herbaceous plant is a native of coastal parts of Southern India and displays a significant amount of morphological diversity. Its genetic potential has not been exploited due to lack of genomic resources limiting our understanding of the genome and important metabolic pathways which give it the economic advantage in the spice industry. Here, we report upon the de novo assembled, draft whole genome sequence of cardamom variety, Njallani Green Gold. We used a hybrid assembly strategy using the reads from the Oxford Nanopore, Illumina and 10x Genomics GemCode sequencing chemistries. The assembled genome length was 1.06 Gb (gigabases) which is close to the estimated genome size of cardamom. More than 75% of the genome was captured in 8000 scaffolds with a N50 of 0.15 Mb. The genome appears to have a high repeat content and 68055 gene models were predicted. The genome is close to Musa species and displays an expansion and contraction in different gene families. The draft assembly was used for in silico mining of simple sequence repeats (SSRs). A total of 2,50,571 SSRs were identified of which 2,18,270 were perfect SSRs and 32,301 were compound SSRs. Among the perfect SSRs, trinucleotides were most abundant (1,25,329) and hexanucleotide repeats appear least (2,380). From the 2,50,571 SSRs mined, 2,27,808 primer pairs were designed based on flanking sequence information. Wet lab validation was performed for 246 SSR loci and based on their amplification profiles, 60 SSR markers were used for diversity analysis of a set of 60 diverse cardamom accessions. The average number of alleles detected per locus were 14.57 with a minimum of 4 and maximum of 30 alleles. Population structure analysis revealed the presence of high degree of admixtures which could primarily be due to cross-pollination prevalent in this species. The SSR markers identified would help in the development of gene or trait-linked markers which can be subsequently used for marker-assisted breeding for crop improvement in cardamom. The information on utilization of the SSR loci for generation of markers has been developed into a public database, 'cardamomSSRdb' that is freely available for use by the cardamom community.

Bioactive chemical constituents from Curcuma caesia Roxb. rhizomes and inhibitory effect of curcuzederone on the migration of triple-negative breast cancer cell line MDA-MB-231

Rhizomes of Curcuma caesia are traditionally used to treat cancer in India. The aim is to isolate chemical constituents from C. caesia rhizomes through bioassay-guided fractionation. The extract, hexanes and chloroform fractions showed effect on MCF-7 and MDA-MB-231cells in cell viability assay. The chromatographic separation afforded germacrone (1), zerumbone (2), furanodienone (3), curzerenone (4), curcumenol (5), zederone (6), curcumenone (7), dehydrocurdione (8) from hexanes fraction and curcuminol G (9), curcuzederone (10), (1S, 10S), (4S,5S)-germacrone-1 (10), 4-diepoxide (11), wenyujinin B (12), alismoxide (13), aerugidiol (14), zedoarolide B (15), zedoalactone B (16), zedoarondiol (17), isozedoarondiol (18) from chloroform fraction. This is first report of compounds 2, 9-13, 15-18 from C. caesia. The study demonstrated compounds 1-4 and 10 are the bioactive compounds. The effect of curcuzederone (10) on MDA-MB-231 cell migration showed significant inhibition in scratch and Transwell migration assays. The results revealed that curcuzederone could be a promising drug to treat cancer.

De novo assembly of transcriptomes, mining, and development of novel EST-SSR markers in Curcuma alismatifolia (Zingiberaceae family) through Illumina sequencing

Curcuma alismatifolia widely used as an ornamental plant in Thailand and Cambodia. This species of herbaceous perennial from the Zingiberaceae family, includes cultivars with a wide range of colours and long postharvest life, and is used as an ornamental cut flower, as a potted plant, and in exterior landscapes. For further genetic improvement, however, little genomic information and no specific molecular markers are available. The present study used Illumina sequencing and de novo transcriptome assembly of two C. alismatifolia cvs, 'Chiang Mai Pink' and 'UB Snow 701', to develop simple sequence repeat markers for genetic diversity studies. After de novo assembly, 62,105 unigenes were generated and 48,813 (78.60%) showed significant similarities versus six functional protein databases. In addition, 9,351 expressed sequence tag-simple sequence repeats (EST-SSRs) were identified with a distribution frequency of 12.5% total unigenes. Out of 8,955 designed EST-SSR primers, 150 primers were selected for the development of potential molecular markers. Among these markers, 17 EST-SSR markers presented a moderate level of genetic diversity among three C. alismatifolia cultivars, one hybrid, three Curcuma, and two Zingiber species. Three different genetic groups within these species were revealed using EST-SSR markers, indicating that the markers developed in this study can be effectively applied to the population genetic analysis of Curcuma and Zingiber species. This report describes the first analysis of transcriptome data of an important ornamental ginger cultivars, also provides a valuable resource for gene discovery and marker development in the genus Curcuma.

Chemical constituents and biological research on plants in the genus Curcuma

Curcuma, a valuable genus in the family Zingiberaceae, includes approximately 110 species. These plants are native to Southeast Asia and are extensively cultivated in India, China, Sri Lanka, Indonesia, Peru, Australia, and the West Indies. The plants have long been used in folk medicine to treat stomach ailments, stimulate digestion, and protect the digestive organs, including the intestines, stomach, and liver. In recent years, substantial progress has been achieved in investigations regarding the chemical and pharmacological properties, as well as in clinical trials of certain Curcuma species. This review comprehensively summarizes the current knowledge on the chemistry and briefly discusses the biological activities of Curcuma species. A total of 720 compounds, including 102 diphenylalkanoids, 19 phenylpropene derivatives, 529 terpenoids, 15 flavonoids, 7 steroids, 3 alkaloids, and 44 compounds of other types isolated or identified from 32 species, have been phytochemically investigated. The biological activities of plant extracts and pure compounds are classified into 15 groups in detail, with emphasis on anti-inflammatory and antitumor activities.