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Coleus barbatus is a medicinal herb belonging to Lamiaceae. It is the only living organism known to produce forskolin, which is a labdane diterpene and is reported to activate adenylate cyclase. Microbes associated with plants play an important role in maintaining plant health. Recently, the targeted application of beneficial plant-associated microbes and their combinations in abiotic and biotic stress tolerance has gained momentum. In this work, we carried out the rhizosphere metagenome sequencing of C. barbatus at different developmental stages to understand how rhizosphere microflora are affected by and affect the metabolite content in plants. We found that the Kaistobacter genus was abundantly present in the rhizosphere of C. barbatus and its accumulation pattern appears to correlate with the quantities of forskolin in the roots at different developmental stages. Members of the Phoma genus, known for several pathogenic species, were in lower numbers in the C. barbatus rhizosphere in comparison with C. blumei. To our knowledge, this is the first metagenomic study of the rhizospheric microbiome of C. barbatus, which may help to explore and exploit the culturable and non-culturable microbial diversity present in the rhizosphere. [ABSTRACT FROM AUTHOR]

Coleus barbatus is a medicinal herb belonging to Lamiaceae. It is the only living organism known to produce forskolin, which is a labdane diterpene and is reported to activate adenylate cyclase. Microbes associated with plants play an important role in maintaining plant health. Recently, the targeted application of beneficial plant-associated microbes and their combinations in abiotic and biotic stress tolerance has gained momentum. In this work, we carried out the rhizosphere metagenome sequencing of C. barbatus at different developmental stages to understand how rhizosphere microflora are affected by and affect the metabolite content in plants. We found that the Kaistobacter genus was abundantly present in the rhizosphere of C. barbatus and its accumulation pattern appears to correlate with the quantities of forskolin in the roots at different developmental stages. Members of the Phoma genus, known for several pathogenic species, were in lower numbers in the C. barbatus rhizosphere in comparison with C. blumei. To our knowledge, this is the first metagenomic study of the rhizospheric microbiome of C. barbatus, which may help to explore and exploit the culturable and non-culturable microbial diversity present in the rhizosphere.

The effects of supplemental ultraviolet-B (s-UV-B; 3.6 kJ m day above ambient) radiation were investigated on plant metabolite profile, essential oil content and composition, and free radical scavenging capacities of methanolic extracts of Coleus forskohlii (an indigenous medicinal plant) grown under field conditions. Essential oil was isolated using hydrodistillation technique while alterations in metabolite profile and oil composition were determined via gas chromatography-mass spectroscopy (GC-MS). Leaf and root methanolic extracts were investigated via various in vitro assays for their DPPH radical-, superoxide radical-, hydrogen peroxide-, hydroxyl radical-, and nitric oxide radical scavenging activities, ferrous ion chelating activity, and reducing power. Phytochemical analysis revealed the presence of alkaloids, anthocyanins, coumarins, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids. Oil content was found to be reduced (by ∼7 %) in supplemental UV-B (s-UV-B) treated plants; the composition of the plant extracts as well as essential oil was also considerably altered. Methanolic extracts from treated plant organs showed more potency as free radical scavengers (their EC values being lower than their respective controls). Anomalies were observed in Fe chelating activity for both leaves and roots. The present study concludes that s-UV-B adversely affects oil content in C. forskohlii and also alters the composition and contents of metabolites in both plant extracts and oil. The results also denote that s-UV-B treated plant organs might be more effective in safeguarding against oxidative stress, though further studies are required to authenticate these findings. [ABSTRACT FROM AUTHOR]

Supplementary ultraviolet-B (ambient+3.6 kJ m −2 day −1 ) induced changes on morphological, physiological, and biochemical characteristics (specifically the defence strategies: UV-B protective compounds and antioxidants) of Coleus forskohlii were investigated under field conditions at 30, 60, and 90 days after transplantation. Levels of secondary metabolites increased under s-UV-B stress; flavonoids and phenolics (primary UV-B screening agents) were recorded to be higher in leaves which are directly exposed to s-UV-B. This was also verified by enhanced activities of phenylpropanoid pathway enzymes: phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), 4-coumarate-CoA ligase (4CL), chalcone–flavanone isomerase (CHI), and dihydroflavonol reductase (DFR). Antioxidants, both enzymatic (ascorbate peroxidase, catalase, glutathione reductase, peroxidase, polyphenol oxidase, and superoxide dismutase) and non-enzymatic (ascorbic acid and α-tocopherol) also increased in the treated organs of the test plant, higher contents being recorded in roots except for ascorbic acid. On the contrary, protein and chlorophyll content (directly implicated in regulating plant growth and development) declined under s-UV-B. These alterations in plant biochemistry led the plant to compromise on its photosynthate allocation towards growth and biomass production as evidenced by a reduction in its height and biomass. The study concludes that s-UV-B is a potent stimulating factor in increasing the concentrations of defense compounds and antioxidants in C. forskohlii to optimize its performance under stress. [ABSTRACT FROM AUTHOR]

The present study was conducted for optimization of in vitro substrates under aseptic conditions for interaction of Piriformospora indica with the medicinal plant Coleus forskohlii. It aims to test the effects of different substrates on P. indica colonization as well as growth parameters of the in vitro raised C. forskohlii. Interaction of in vitro C. forskohlii with root endophyte P. indica under aseptic condition resulted in increase in growth parameters in fungus colonized plants. It was observed that P. indica promoted the plant's growth in all irrespective of substrates used for co-culture study. The growth was found inferior in liquid compared to semisolid medium as well as there was problem of hyperhydricity in liquid medium. P. indica treated in vitro plantlets were better adapted for establishment under green house compared to the non treated plants due to fungal intervention. [ABSTRACT FROM AUTHOR]

Forskolin is the first pharmaceutical drug and product derived from a plant to be approved in India by the DCGI in 2006. Forskolin (7beta-acetoxy-8, 13-epoxy-1a, 6β, 9a-trihydroxy-labd-14-en-11-one) is a diterpenoid isolated from plant Coleus forskohlii (Lamiaceae). It is a lipid-soluble compound that can penetrate cell membranes and stimulates the enzyme adenylate cyclase which, in turn, stimulates ciliary epithelium to activate cyclic adenosine monophosphate, which decreases intraocular pressure (IOP) by reducing aqueous humor inflow. The topical application of forskolin is capable of reducing IOP in rabbits, monkeys, and humans. In its drug interactions, forskolin may act synergistically with epinephrine, ephedrine and pseudoephedrine. Whereas the effects of anti-clotting medications like warfarin, clopidogre, aspirin, anoxaparin, etc., may be enhanced by forskolin. Forskolin is contraindicated in the medications for people with ulcers as forskolin may increase acid level. Forskolin has a very good shelf-life of five years. Recently, its Ophthalmic inserts and in situ gels for sustained and delayed-release drug delivery systems were tested in New Zealand Albino Rabbits for its antiglaucoma efficacy. This drug review explains Forskolin as a drug, its antiglaucoma potential and recent findings of forskolin as an antiglaucoma agent. The literature search method used for this review was different databases and search engines like PubMed, International Pharmaceutical Abstracts, Google, Medicinal and Aromatic Plants (MAPA). [ABSTRACT FROM AUTHOR]

Medicinal plants growing in wild cannot ensure consistent quality due to genetic variability found in the natural populations, geographical variations and season of collection. Therefore, there is a need to cultivate medicinal plants using known varieties for extraction of high yields of active principles. This can be achieved only with organic farming practices and post harvest technologies. The research conducted by institutes like CIMAP and other CSIR institutes, ICAR and Universities has led to the release of a number of high yielding medicinal plant cultivars. Coleus forskohli is a herb with fleshy, fibrous roots that grows in wild in the warm, subtropical areas like in India, Burma, and Thailand. Coleus forskohlii is being grown in several parts of the country as a commercial crop. In the present investigation the effect of nitrogen, phosphorus, potassium (NPK) and farm yard manure amendments on the growth of roots and accumulation of forskolin was studied. The results revealed that 50% of NPK and 10 tonnes of farm yard manure per hectare at a harvesting time 150 days are ideal for maximum yield of forskolin. [ABSTRACT FROM AUTHOR]