Search

Camptothetin (CPT) is a quinoline alkaloid originally isolated from the Chinese tree, Camptotheca acuminata Decne. CPT was found to have anticancerous and antiviral properties. Derivatives of natural CPT, including topothecan and irinotecan are used clinically to treat a variety of cancers. Apart from Camptotheca acuminata Decne, CPT production was also found in the perennial plant Ophiorrhiza mungos. In this study we attempted the immobilization of the tissue culture grown callus of Ophiorrhiza mungos for the continuous production of a higher concentration of CPT. As evident from previous studies about the antiviral effects of CPT, we wanted to bioinformatically analyze the binding potential of CPT towards two important proteins of SARS-CoV-2, protease (Mpro) and RNA dependent RNA polymerase (RdRp). Further docking analysis of the CPT against the exterior spike glycoprotein of SARS-CoV-2 was also done to determine their potential interaction. The immobilized callus of Ophiorrhiza mungos produced CPT at a concentration of 420 µg/l by the end of 12 days of growth. The HPLC analysis was done to determine the purity of the CPT synthesized by the immobilization technique. The bioinformatic analysis revealed a higher binding efficiency of CPT and its derivatives, toptecan and irinotecan against Mpro and RdRp. The docking analysis of CPT against the spike glycoprotein of SARS-CoV-2 showed hydrogen bonding with the amino acids at K466 with a bond distance of 2.56A° and K355 with a bond distance of 2.40A°. This finding was of particular importance that other compounds including hydroxychloroquine sulphate, lopinavir and ivermectin could bind with the spike protein only by weak Vander wall bonds and no hydrogen bond formation was noticed. Our studies hence evaluate the efficiency of CPT against SARS-CoV-2, by potentially blocking the interaction of the spike glycoprotein with the angiotensin-converting enzyme 2 (ACE2) receptor found on host cells.

In the study, endophytic fungi isolated from Ophiorrhiza mungos were screened for camptothecin (CPT) biosynthetic potential by high performance liquid chromatography (HPLC). Among the 16 fungi screened, OmF3, OmF4, and OmF6 were identified to synthesize CPT. Further LC-MS analysis also showed the presence of CPT specific m/z of 349 for the extracts from OmF3, OmF4, and OmF6. However, the fragmentation masses with m/z of 320, 305, 277 and 220 specific to the CPT could be identified only for the OmF3 and OmF4. These CPT producing fungi were further identified as Meyerozyma sp. OmF3 and Talaromyces sp. OmF4. The cultures of these two fungi were then supplemented with nanoparticles and analyzed for the quantitative enhancement of CPT production by LC-MS/MS. From the result, Meyerozyma sp. OmF3 was found to produce 947.3 ± 12.66 μg/L CPT, when supplemented with 1 μg/mL zinc oxide nanoparticles and the same for uninduced parental strain OmF3 was only 1.77 ± 0.13 μg/L. At the same time, Talaromyces sp. OmF4 showed the highest production of 28.97 ± 0.37 μg/L of CPT when cultured with 10 μg/mL silver nanoparticles and the same for uninduced strain was 1.19 ± 0.24 μg/L. The observed quantitative enhancement of fungal CPT production is highly interesting as it is a rapid and cost effective method. The study is remarkable due to the identification of novel fungal sources for CPT production and its enhancement by nanoparticle supplementation.

Ophiorrhiza mungose var. angustifolia (Thwaites) Hook. f (Family- Rubiaceae) is a recently identified plant from Ophiorrhiza species in Western Ghats of Kerala. The plant is a promising candidate for the production of camptothecin (CPT) - a high value anticancer compound. Preliminary screening of hexane and methanol extract revealed the presence of phenolics, flavonoids, caumarins, steroids, terpeanoids, saponins, carbohydrates and alkaloids. Camptothecin was estimated from methanol extract using high performance liquid chromatography and the level of CPT was 297.94 ± 2.27 µg/g dry weight. The in vitro antioxidant assay revealed both extract showed moderate level of total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, ferric chloride reducing power assay, phospho-molybdate assay of total anti-oxidant capacity and nitric oxide scavenging activity assay. Antimicrobial study reveals that only hexane extract inhibits pathogenic bacteria and fungus. Overall these findings will lead to isolation of active compounds other than camptothecin, elucidate them against wider range of bioactivity studies to find new therapeutic principles.

A number of plant natural products are of commercial interest for pharmacy, medicine, agriculture, or nutrition. A challenge for biotechnology is the production of such compounds in vitro. Whereas callus and suspension cultures of plants mostly fail as production systems, differentiated root cultures provide a better platform. We established normal and transformed root cultures of Ophiorrhiza mungos, which produce the anticancer drug camptothecin in yields, which are similar to differentiated plants.

Camptothecin (CPT), a cytotoxic quinoline indole alkaloid, is an anticancer compound. Its two major semi synthetic derivatives, topotecan and irinotecan, are Food and Drug Administration (FDA) approved drugs effectively used for treating different cancer types and sold under the trade names Hycamtin and Camptosar. Among the Ophiorrhiza species, Ophiorrhiza mungos contains the highest CPT level (0.02 % g dw). CPT level was determined in plants before flowering (0.074 ± 0.003 % g dw) and at flowering (0.052 ± 0.002 % g dw). Multiple shoot cultures were induced on seedling-derived explants of O. mungos in half strength MS solid media supplemented with 1.0 mg/L BAP to obtain 12.00 ± 1.22 shoots in 20 days. Repeated subcultures at 20 days interval yielded 20.00 ± 3.71 shoots/subculture of shoot clusters. After elongation, rooting and transplanting, the growth of shoot clusters were studied in both in vitro and same aged naturally grown seedlings. Highest biomass (4.62 ± 0.158 g fw) was obtained in in vitro-derived shoot clusters. CPT increased according to biomass and the maximum CPT was recorded in in vitro rooted shoot clusters after 15 days (0.031 ± 0.001 % g dw). Hence, in vitro-derived rooted shoot clusters of O. mungos cultivated in net-pots for 60 days under shade net house conditions found to be a sustainable source for CPT.

Camptothetin (CPT) is a quinoline alkaloid originally isolated from the Chinese tree, Camptotheca acuminata Decne. CPT was found to have anticancerous and antiviral properties. Derivatives of natural CPT, including topothecan and irinotecan are used clinically to treat a variety of cancers. Apart from Camptotheca acuminata Decne, CPT production was also found in the perennial plant Ophiorrhiza mungos. In this study we attempted the immobilization of the tissue culture grown callus of Ophiorrhiza mungos for the continuous production of a higher concentration of CPT. As evident from previous studies about the antiviral effects of CPT, we wanted to bioinformatically analyze the binding potential of CPT towards two important proteins of SARS-CoV-2, protease (Mpro) and RNA dependent RNA polymerase (RdRp). Further docking analysis of the CPT against the exterior spike glycoprotein of SARS-CoV-2 was also done to determine their potential interaction. The immobilized callus of Ophiorrhiza mungos produced CPT at a concentration of 420 µg/l by the end of 12 days of growth. The HPLC analysis was done to determine the purity of the CPT synthesized by the immobilization technique. The bioinformatic analysis revealed a higher binding efficiency of CPT and its derivatives, toptecan and irinotecan against Mpro and RdRp. The docking analysis of CPT against the spike glycoprotein of SARS-CoV-2 showed hydrogen bonding with the amino acids at K466 with a bond distance of 2.56A° and K355 with a bond distance of 2.40A°. This finding was of particular importance that other compounds including hydroxychloroquine sulphate, lopinavir and ivermectin could bind with the spike protein only by weak Vander wall bonds and no hydrogen bond formation was noticed. Our studies hence evaluate the efficiency of CPT against SARS-CoV-2, by potentially blocking the interaction of the spike glycoprotein with the angiotensin-converting enzyme 2 (ACE2) receptor found on host cells.

The gastroprotective effect of luteolin-7-O-glucoside (LUT7G) on different ulcer models using rats including the indomethacin model, the ethanol-induced gastric ulcer model and the Shay ulcer model was examined. The ethanol-induced ulcer group showed significant increases in MPO, NO, iNOS, MMP-2, MMP-9, caspase-3, apoptosis, IL-6, TNF-α, IKK, NF-κB p65, and ICAM-1 and declines in PGE2, arginase, SOD, GSH, mucin, IL-10, eNOS, COX-1, HSP-70, and IκBα levels. However, LUT7G (25 mg/kg) pretreatment significantly reverted the pathophysiological levels of these biomarkers to near normal levels. The gastroprotective activity of LUT7G was abolished by pretreatment with SC560, rofecoxib, and L-NAME, demonstrating the participation of COX and NOS in LUT7G-facilitated gastroprotection against ethanol-induced ulcers. Convincingly, LUT7G (25 mg/kg) provided protective effects in the rat gastric mucosa against ethanol-induced gastric injury at least in part to antisecretory, anti-inflammatory, antioxidative, and antiapoptotic activity, and augmentation of PGE2, mucin and HSP-70 synthesis.

High-performance liquid chromatography is the prevalent method used to estimate Camptothecin quantitatively. In the present study thin layer chromatography and UV spectrophotometric method was established as a sensitive, economical and accurate method of detection and estimation of Camptothecin. The method was developed on TLC aluminum plates (60F254 from E-Merck Ltd.) precoated with silica gel using solvent system ethyl acetate: methanol (7.5:2.5, v/v) which gives a dark blue spot of Camptothecin at 254 nm (Rf value 0.46 cm). Spectrometric analysis of Camptothecin was carried out at the absorbance of 254 nm. Leaves and stems of Nothapodytes foetida and Ophiorrhiza mungos were extracted, subjected to TLC and UV spectrophotometric analysis and maximum absorption of CPT in ethyl acetate was observed at 254 nm. The quantification by this method was comparable to data obtained by HPLC. The optimized method was simple, repeatable, precise and cost effective, useful when there is large number of crude samples. In the present study this method was used to screen high yielding lines of CPT producing plants.

Camptothecin (CPT) content in 44 accessions belonging to nine Ophiorrhiza species and three varieties collected from their natural habitats in the Kerala region of Western Ghats were estimated by HPTLC-densitometry. Ophiorrhiza mungos 170.11–503.15 (μg/g, dr. wt.) and O. mungos var. angustifolia 127.86–476.89 (μg/g, dr. wt.) accessions showed the highest CPT contents. O. trichocarpon (19.50–28.31 μg/g) and O. pectinata (0.28–38.65 μg/g) showed moderate contents of CPT. Among the nine Ophiorrhiza species and three varieties screened O. barberi , O. caudata , O. nairii and O. rugosa var. decumbens showed zero or non-detectable levels of CPT. O. grandiflora (1.07–1.34 μg/g), O. eriantha (0.00–0.30 μg/g), O. rugosa var. prostrata (0.16 μg/g) and O. shendurunii (0.05 μg/g) showed only very low contents of CPT. O. mungos var. angustifolia is an established variant and is a small herb which could be relatively easily cultivated or multiplied by tissue culture compared to O. mungos . Significant variations in CPT contents were found between the ecotypes/genotypes of the same Ophiorrhiza species or variety collected from different geographic locations. This revealed the importance of choosing high CPT yielding Ophiorrhiza genotypes or ecotypes for commercial purposes.

Ophiorrhiza mungos was reported from China by several authors. Examining the relevant specimens reveals that it is a misidentification of O. rosea. Here we also lectotypify the name O. rosea.

Vivipary, the precocious germination of seeds within the parent plant, is a specialised feature of evolutionary and biological importance that ensures survival of a plant. Reports on vivipary in angiosperms are rare, accounting for

Ophiorrhiza mungos Linnaeus, Species Plantarum 1: 150. 1753. "Habitat in India orientali." RCN: 1188. Lectotype (Verdcourt in Jarvis & al., Regnum Veg. 127: 71. 1993): Herb. Hermann 3: 50, No. 402 (BM-000594692). Generitype of Ophiorrhiza Linnaeus (vide Hitchcock, Prop. Brit. Bot.: 129. 1929). Current name: Ophiorrhiza mungos L. (Rubiaceae)., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part O), pp. 696-717 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on page 703, DOI: 10.5281/zenodo.291971

Camptothecin is an anticancer quinoline alkaloid effective against colon cancer. It acts by inhibition of the enzyme DNA topoisomerase I. A comparative study of camptothecin from the indigenous plants namely Nothapodytes foetida, Ophiorrhiza mungos and Ophiorrhiza rugosa indicated highest yields of camptothecin and 9-methoxy camptothecin in N. foetida. The other two plants O. mungos and O. rugosa contained low levels of alkaloids.

In Ophiorrhiza mungos L. the first division of the microspore nucleus gives rise to a large vegetative nucleus and a smaller generative nucleus. The vegetative nucleus subsequently fragments into a number of irregularly sized particles. These vegetative nuclear bodies move to and flow out of the three germ pores to form three spherical buds on the developing pollen grains. The 'pollen buds' are shed off from the pollen proper before dehiscence. The uninucleate grains readily germinate in vitro, and the single generative nucleus undergoes normal division to give rise to two sperm nuclei.

Ophiorrhiza mungos, spec. nov. 1. Ophiorrhiza foliis lanceolato-ovatis. Ophiorrhiza. Fl. zeyl. 402. Mat. med. 79. t.1. Amoen. acad. 2. p.118. Habitat in India orientali. ��� Conf. Limonium mauritanicum, flore minimo, caule folioso. Pet. gaz. 66. t.41. f.12., Published as part of Linnaeus, Carolus, 1753, Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas, Stockholm :Laurentius Salvius on page 150, DOI: 10.5281/zenodo.3931989