Coleus vettiveroides ethanolic root extract induces cytotoxicity by intrinsic apoptosis in HepG2 cells.

Hepatocellular carcinoma (HCC) contributes to more than 80% of all primary cancers globally and ranks fourth in cancer-related deaths, due to the lack of an effective, definite therapeutic drug. Coleus vettiveroides (CV) has been used in Indian traditional medicine to treat diabetes, liver ailments, skin diseases, leukoderma, and leprosy. This study investigates the anticancer effect of CV ethanolic root extract in HepG2 cells. HepG2 cells were treated with CV extract, and its cytotoxicity was analyzed by MTT assay. AO/EB staining, propidium iodide staining, DCFH-DA assay, phalloidine staining, flow cytometry, and qPCR studies were performed for ROS expression, apoptosis and cell cycle analysis. The phytochemical analysis confirmed the presence of quercetin and galangin in CV root extract. The results showed that CV inhibited the proliferation of HepG2 cells, with altered cellular and nuclear morphology. CV was also found to increase intracellular ROS levels and oxidative stress markers in HepG2 cells. CV significantly altered the actin microfilament distribution in HepG2 cells and caused cell cycle arrest at the sub G0 -G1 phase. CV also induced mitochondria-mediated apoptosis, as evidenced by increased expression of p53, Bax, cytochrome C, Apaf-1, PARP, caspase-3 and caspase-9, and downregulated Bcl-2 expression. Therefore, CV exerts its anticancer effect by inducing mitochondrial dysfunction, oxidative stress, cytoskeletal disorganization, cell cycle arrest, and mitochondria-mediated apoptosis, and it could be a potent therapeutic option for HCC.

Antibacterial, antifungal, antidiabetic, and antioxidant activities potential of Coleus aromaticus synthesized titanium dioxide nanoparticles.

The nanoparticles based drug delivery and treatment related research has been increased significantly in the recent years. Hence, the antibacterial, antifungal, and antioxidant activity potential of pre synthesized and characterized Titanium dioxide nanoparticles (TiO2 NPs) were investigated in this study through respective standard protocols. Interestingly, the obtained results revealed that TiO2 NPs have concentration dependent antibacterial activity against bacterial pathogens such as E. coli, P.mirabilis, V. cholerae, P. aeruginosa, S. typhimurium, and S. aureus at 100 µg mL-1 concentration. Furthermore, these TiO2 NPs showed remarkable antifungal activity against aspergillosis causing fungal pathogens such as A. niger, A. fumigatus, A. nidulans, and A. flavus at 100 µg mL-1 concentration. α-glucosidase. This TiO2 NPs also effectively inhibit the α-amylase (17%) and α-Glucosidase (37%) enzyme activity at 100 µg mL-1 dosage. The DPPH assay revealed that TiO2 NPs effectively scavenge DPPH free radicals by up to 89% at 100 µg mL-1 concentration, which was comparable to butylated hydroxytoluene (96%). These results suggest that the plant-based TiO2 NPs have remarkable in-vitro antibacterial, antifungal, and antioxidant activity. These may be considered for additional in-vitro and in-vivo experiments to assess their potential biomedical applications.

Isolation, cloning, and functional analysis of a putative constitutive promoter of E3 ubiquitin-protein ligase RF4 from Coleus amboinicus Lour.

A promoter is a region in the genome sequence located upstream of the transcription start site comprising cis acting elements that initiates and regulates the transcription of an associated genes and restriction endonucleases. As the need for genetically engineered plants has widened, the requirement to develop methods to optimize the control of transgene expression has also increased. Therefore, analyzing the functionality of the promoter is very important in understanding the target gene expression. The widespread use of viral constitutive promoters (cauliflower mosaic virus, CaMV35) has raised concerns about the safety and containment of transgene in the environment. Hence isolation and characterization of novel promoters using fast and efficient genetic engineering tools is the need of the hour. The present study, for the first time, describes the isolation and characterization of a novel constitutive promoter driving ubiquitin E3 ligase from the plant Coleus amboinicus, a perennial herb, of the Lamiaceae family. The functionality of the isolated promoter was demonstrated using the ß -glucuronidase as a reporter in tobacco var Petit havana. The development of blue color in the tobacco leaves indicated the presence of a functional promoter.

Quantitative dissection of color patterning in the foliar ornamental coleus.

Coleus (Coleus scutellarioides) is a popular ornamental plant that exhibits a diverse array of foliar color patterns. New cultivars are currently hand selected by both amateur and experienced plant breeders. In this study, we reimagine breeding for color patterning using a quantitative color analysis framework. Despite impressive advances in high-throughput data collection and processing, complex color patterns remain challenging to extract from image datasets. Using a phenotyping approach called "ColourQuant," we extract and analyze pigmentation patterns from one of the largest coleus breeding populations in the world. Working with this massive dataset, we can analyze quantitative relationships between maternal plants and their progeny, identify features that underlie breeder-selections, and collect and compare public input on trait preferences. This study is one of the most comprehensive explorations into complex color patterning in plant biology and provides insights and tools for exploring the color pallet of the plant kingdom.

Differences in diterpenoid diversity reveal new evidence for separating the genus Coleus from Plectranthus.

Covering: up to 2019The large and medicinally important tropical plant genus Plectranthus (Lamiaceae) was recently split into three separate genera on the basis of molecular and morphological evidence; Plectranthus sensu stricto, Coleus and Equilabium. We found striking differences between the diterpenoids which strongly support this taxonomic split. Coleus is characterised by abietanes oxygenated at C-14 such as royleanones, spirocoleons and acylhydroquinones, which could be useful chemotaxonomic markers to distinguish this genus from Plectranthus s.s. In contrast, the abietanes in Plectranthus s.s. lack C-14 oxygenation, but are often acylated with unusual acids. Equilabium species do not seem to produce diterpenoids. The structures of the nearly 240 abietanes so far reported from Coleus and Plectranthus and their distribution are presented. The aim of this Highlight is to provide an overview of the differences in diterpenoid diversity between these newly defined genera, which are relevant to predict which previously understudied species could hold untapped potential for their medicinal and other economic uses, and to underpin future research on how these plants have evolved to synthesise distinct abietane types.

Synthesis and characterization of TiO2 NPs by aqueous leaf extract of Coleus aromaticus and assess their antibacterial, larvicidal, and anticancer potential.

The frequent applications of synthetic chemical insecticides and drugs create resistance among insects and microbes, creating a new threat to human and environmental welfare. This investigation focused on evaluating the possibilities of fabricating and characterizing the titanium dioxide nanoparticles (TiO2 NPs) from titanium dioxide (TiO2) through the aqueous leaf extract of Coleus aromaticus. Their biological applications were studied against the larvae of Aedes aegypti human pathogenic bacteria, and cancer cell line. The results revealed that the aqueous leaf extract had the metal reducing proficiency to produce nanoparticles from TiO2. The synthesized TiO2 NPs were initially confirmed by visible color changes and Ultraviolet-Visible Spectrophotometer analysis that showed a predominant peak at 332 nm. Furthermore, the nanocrystals, structural alignment, functional groups and elemental compositions were studied by following standard operating protocol in XRD (X-ray Powder Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy), and EDX (Energy-Dispersive X-ray Spectroscopy) techniques, respectively. The results attained from these techniques confirmed that the plant mediated and fabricated particles were in the nanoscale range (12-33 nm) with a hexagonal shape. The synthesized TiO2 NPs had an outstanding (1000 µg mL-1) larvicidal activity against the four stages of instars larvae of Ae. aegypti at 1000 µg mL-1. It also had an excellent antibacterial potential against E. faecalis (33 mm), followed by S. boydii (30 mm) at 30 mg L-1 concentration. The green fabricated TiO2 NPs had a fabulous (92.37%) cytotoxic activity on the HeLa cell line at 100 µg mL-1 dosage within one day of exposure. The entire results concluded that the C. aromaticus mediated TiO2 NPs have excellent biological applications and thus, could be considered for the welfare of human beings.

Phytochemical Profile and Antioxidant Activities of Coleus amboinicus Lour. Cultivated in Indonesia and Poland.

Coleus amboinicus Lour., Lamiaceae, is a perennial herb that is native to Indonesia and also cultivated in Africa, Asia and Australia. The major phytochemicals responsible for its bioactivity are rosmarinic acid (RA) and its analogues, flavonoids and abietane diterpenoids. The possibility of cultivation in a colder climate would extend the use of this herb and provide new opportunities to herb growers and livestock farmers. Our study to compare feed value and phytochemical composition of C. amboinicus plants cultivated in its original region, Indonesia, and in Poland. The crude protein content was significantly higher in plants cultivated in Indonesia compared to those cultivated in Poland-21% and 13% of dry matter, respectively. The higher ADF contents were detected in C. amboinicus cultivated in Indonesia, 38-41%, in comparison to 34% in plants cultivated in Poland. The phytochemical composition was also significantly influenced by the cultivation location. Polish samples were higher in polyphenols (RA and its analogues), and also had 1.5-2-fold higher antioxidant potential, as measured by DPPH scavenging, phosphomolybdenum reduction and Fenton reaction driven lipid peroxidation. The Indonesian samples contained more diterpenoid compounds, such as dihydroxyroyleanone, and the sum of terpenoids was ca. 10 times higher than in samples from Poland (15.59-23.64 vs. 1.87 µg/g of extracts). In conclusion, C. amboinicus is suitable for cultivation in non-optimal climatic conditions but some nutritional properties and bioactivity are significantly affected.

In vivo diagnostics of early abiotic plant stress response via Raman spectroscopy.

Development of a phenotyping platform capable of noninvasive biochemical sensing could offer researchers, breeders, and producers a tool for precise response detection. In particular, the ability to measure plant stress in vivo responses is becoming increasingly important. In this work, a Raman spectroscopic technique is developed for high-throughput stress phenotyping of plants. We show the early (within 48 h) in vivo detection of plant stress responses. Coleus (Plectranthus scutellarioides) plants were subjected to four common abiotic stress conditions individually: high soil salinity, drought, chilling exposure, and light saturation. Plants were examined poststress induction in vivo, and changes in the concentration levels of the reactive oxygen-scavenging pigments were observed by Raman microscopic and remote spectroscopic systems. The molecular concentration changes were further validated by commonly accepted chemical extraction (destructive) methods. Raman spectroscopy also allows simultaneous interrogation of various pigments in plants. For example, we found a unique negative correlation in concentration levels of anthocyanins and carotenoids, which clearly indicates that plant stress response is fine-tuned to protect against stress-induced damages. This precision spectroscopic technique holds promise for the future development of high-throughput screening for plant phenotyping and the quantification of biologically or commercially relevant molecules, such as antioxidants and pigments.

Manoyl oxide (13R), the biosynthetic precursor of forskolin, is synthesized in specialized root cork cells in Coleus forskohlii.

Forskolin, a complex labdane diterpenoid found in the root of Coleus forskohlii (Lamiaceae), has received attention for its broad range of pharmacological activities, yet the biosynthesis has not been elucidated. We detected forskolin in the root cork of C. forskohlii in a specialized cell type containing characteristic structures with histochemical properties consistent with oil bodies. Organelle purification and chemical analysis confirmed the localization of forskolin and of its simplest diterpene precursor backbone, (13R) manoyl oxide, to the oil bodies. The labdane diterpene backbone is typically synthesized by two successive reactions catalyzed by two distinct classes of diterpene synthases. We have recently described the identification of a small gene family of diterpene synthase candidates (CfTPSs) in C. forskohlii. Here, we report the functional characterization of four CfTPSs using in vitro and in planta assays. CfTPS2, which synthesizes the intermediate copal-8-ol diphosphate, in combination with CfTPS3 resulted in the stereospecific formation of (13R) manoyl oxide, while the combination of CfTPS1 and CfTPS3 or CfTPS4 led to formation of miltiradiene, precursor of abietane diterpenoids in C. forskohlii. Expression profiling and phylogenetic analysis of the CfTPS family further support the functional diversification and distinct roles of the individual diterpene synthases and the involvement of CfTPS1 to CfTPS4 in specialized metabolism and of CfTPS14 and CfTPS15 in general metabolism. Our findings pave the way toward the discovery of the remaining components of the pathway to forskolin, likely localized in this specialized cell type, and support a role of oil bodies as storage organelles for lipophilic bioactive metabolites.

Examining the photoprotection hypothesis for adaxial foliar anthocyanin accumulation by revisiting comparisons of green- and red-leafed varieties of coleus (Solenostemon scutellarioides).

Although plants rely on light to drive energy production via photosynthesis, excess light can be harmful. Plants have evolved photoprotective mechanisms to mitigate this threat, including thermal energy dissipation, the most common form of which involves de-epoxidized constituents of the xanthophyll cycle facilitating the conversion of excess excitation energy to heat. A role in photoprotection has also been proposed for red anthocyanins when they accumulate near the adaxial leaf surface. Here, we compared the response to experimental light stress of a red-leafed (anthocyanin rich) and a green-leafed variety of coleus [Solenostemon scutellarioides (L.) Codd], examining chlorophyll fluorescence emission and pigment composition. After experimentally imposed intense white light, red- and green-leafed coleus exhibited manifestations of light stress (decreased photosystem II quantum efficiency) of a similar magnitude. This, considered alone, could be interpreted as evidence that anthocyanins do not serve a photoprotective role. However, during excess light exposure, the green-leafed variety employed a greater level of thermal energy dissipation and possessed correspondingly higher xanthophyll cycle pool sizes and de-epoxidation states. During exposure to red light, which anthocyanins absorb very poorly, levels of thermal energy dissipation did not differ between coleus varieties. Taken together, our findings suggest that adaxial anthocyanins minimize stress associated with excess light absorption and that the green-leafed variety of coleus compensated for its much lower levels of adaxial anthocyanins by invoking higher levels of energy dissipation. Thus, anthocyanin accumulation should be considered alongside the suite of photoprotective mechanisms employed by photosynthetic tissues.

Changes in the spectral pattern of selenium accumulation in Coleus blumei and the effects of chelation.

Chemically enhanced phytoremediation has been proposed as an effective approach to remove heavy metals from contaminated soil through the use of high biomass production plants. This study investigated changes in the spectral pattern of selenium (Se) accumulation in Coleus blumei Benth. (coleus) plants grown in hydroponics with 1.0 mg/l sodium selenite (Na2SeO3) and the effects of (S,S)-ethylenediamine disuccinic acid (EDDS) thereon through X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDXS) and Fourier transform infrared (FTIR) spectroscopy analyses. When EDDS concentrations were in the range of 0-1.0 mmol/l, Se content increased significantly; however, at EDDS concentrations above this range, the symptoms of Se toxicity were alleviated in coleus leaves. Application of EDDS over 1.0 mmol/l significantly decreased total Se uptake in the leaves and roots of the plants. The powder diffraction patterns of the roots and leaves displayed sharp crystalline peaks, which were characteristic of an organic molecule with crystallinity. Our results revealed the presence of high amounts of C, O, Mg, Al, Si, K and Ca in the roots and leaves under Se-induced stress with different concentrations of EDDS. There were no changes in the chemical compositions of the roots and leaves, but the contents were influenced by Se-induced stress and EDDS treatment. This study demonstrated the importance of applying XRD, EDXS and FTIR methods toward a more comprehensive understanding of the mechanisms of EDDS-induced Se accumulation in plants.

Isolation and Functional Characterization of a Phenylalanine Ammonia-Lyase Gene (SsPAL1) from Coleus (Solenostemon scutellarioides (L.) Codd).

Phenylalanine ammonia-lyase (PAL) is the first enzyme involved in the phenylpropanoid pathway and plays important roles in the secondary metabolisms, development and defense of plants. To study the molecular function of PAL in anthocyanin synthesis of Coleus (Solenostemon scutellarioides (L.) Codd), a Coleus PAL gene designated as SsPAL1 was cloned and characterized using a degenerate oligonucleotide primer PCR and RACE method. The full-length SsPAL1 was 2450 bp in size and consisted of one intron and two exons encoding a polypeptide of 711 amino acids. The deduced SsPAL1 protein showed high identities and structural similarities with other functional plant PAL proteins. A series of putative cis-acting elements involved in transcriptional regulation, light and stress responsiveness were found in the upstream regulatory sequence of SsPAL1. Transcription pattern analysis indicated that SsPAL1 was constitutively expressed in all tissues examined and was enhanced by light and different abiotic factors. The recombinant SsPAL1 protein exhibited high PAL activity, at optimal conditions of 60 °C and pH 8.2. Although the levels of total PAL activity and total anthocyanin concentration have a similar variation trend in different Coleus cultivars, there was no significant correlation between them (r = 0.7529, p > 0.1), suggesting that PAL was not the rate-limiting enzyme for the downstream anthocyanin biosynthetic branch in Coleus. This study enables us to further understand the role of SsPAL1 in the phenylpropanoid (flavonoids, anthocyanins) biosynthesis in Coleus at the molecular level.

In vitro plant development and root colonization of Coleus forskohlii by Piriformospora indica.

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.

The influence of cultivation conditions on the formation of psychoactive salvinorin A, salvinorin B, rosmarinic acid and caffeic acid in Coleus scutellarioides.

Coleus scutellarioides (L.) Benh. is a popular species in the world, known for its characteristic magnificent colourful leaves. The study has revealed that the contents of rosmarinic acid and caffeic acid are significantly higher in the plant tissues cultivated in vivo than when under in vitro conditions. The performed qualitative and quantitative analyses confirmed the presence (whose averaged content) of salvinorin A (6.65 µg/1 g of fresh plant) and salvinorin B (50.46 µg/1 g of fresh plant) in tissues of Coleus scutellarioides (L.) Benh. of 'Electric lime' variety. The greatest quantities of these compounds were recorded for plants cultivated in vitro on the MS medium enriched with NAA (naphthyl-1-acetic acid) at a concentration of 0.5 mg∙ dm-3. The research detected differences in the amounts of compounds between plants grown in vivo and those cultivated in vitro. Addition of plant growth regulators into the breeding medium under in vitro conditions was found affecting the amounts of compounds in plant tissues.

Dietary Coleus forskohlii extract generates dose-related hepatotoxicity in mice.

Coleus forskohlii root extract (CFE) represented by its bioactive constituent 'forskolin' is popularly used as a natural weight-lowering product, but the association of its use with liver-related risks is very limited. In the present study, the effect of standardized CFE with 10% forskolin on liver function of mice was examined. Mice were given 0-5% CFE in an AIN93G-based diet for 3-5 weeks. Food intake, body weights, relative organ weights and liver marker enzymes [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP)] combined with histophatological analysis were assessed. CFE (0-0.5%) only had minimal effects on food intake and body weight whereas a significant difference was observed in mice receiving the highest dose (5% CFE). The extract 0.05-5% dose-dependently decreased visceral fat weight by between 16% and 63%, and a dose-dependent several folds increase was observed in liver weights and plasma AST, ALT and ALP activities with quick onset apparent after only 1 week of 0.5% CFE intake. The hepatic effect persisted throughout the 3-weeks course but was restored towards normalization within 1 week after withdrawal of treatment. Liver histology of mice fed 0.5% CFE for 3 weeks showed hepatocyte hypertrophy and fat deposition. In contrast, none of the hepatic responses measured were altered when mice were given a diet containing pure forskolin alone at the dose corresponding to its content in 0.5% CFE. The present study clearly indicated that forskolin was not involved in the CFE-induced hepatotoxicity and was caused by other unidentified constituents in CFE which warrants further studies.

Mosquito larvicidal activity of thymol from essential oil of Coleus aromaticus Benth. against Culex tritaeniorhynchus, Aedes albopictus, and Anopheles subpictus (Diptera: Culicidae).

Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have a worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. However, the indiscriminate use of conventional insecticides is fostering multifarious problems like widespread development of insecticide resistance, toxic hazards to mammals, undesirable effects on nontarget organisms, and environmental pollution. The aim of this research was to evaluate the toxicity of mosquito larvicidal activity of essential oil from Coleus aromaticus and its pure isolated constituent thymol against larvae of Culex tritaeniorhynchus, Aedes albopictus, and Anopheles subpictus. The chemical composition of the essential oil was analyzed using gas chromatography-mass spectroscopy. A total of 14 components of the essential oil of C. aromaticus were identified. The major chemical components identified were thymol (82.68%), terpinen-4-ol (3.2%), and trans-Caryophyllene (3.18%). Twenty-five early third instar larvae of C. tritaeniorhynchus, A. albopictus, and A. subpictus were exposed and assayed in the laboratory. Thymol and essential oil were tested in concentrations of 10, 20, 30, 40, and 50 and 30, 60, 90, 120, and 150 ppm, respectively. The larval mortality was observed after 24 h of treatment. The thymol had a significant toxic effect against early third-stage larvae of C. tritaeniorhynchus, A. albopictus, and A. subpictus with an LC50 values of 28.19, 24.83, and 22.06 µg/mL respectively, whereas the essential oil of C. aromaticus had an LC50 values of 72.70, 67.98, and 60.31 µg/mL, respectively. No mortality was observed in controls. The Chi-square values were significant at p < 0.05 level. The result indicated that the essential oil of C. aromaticus and the isolated constituent have a potential for use in control of C. tritaeniorhynchus, A. albopictus, and A. subpictus larvae and could be useful in search of newer, safer, and more effective natural compounds as larvicides.

Synergy between Glomus fasciculatum and a beneficial Pseudomonas in reducing root diseases and improving yield and forskolin content in Coleus forskohlii Briq. under organic field conditions.

Root rot and wilt, caused by a complex involving Fusarium chlamydosporum (Frag. and Cif.) and Ralstonia solanacearum (Smith), are serious diseases affecting the cultivation of Coleus forskohlii, a crop with economic potential as a source of the medicinal compound forskolin. The present 2-year field experiments were conducted with two bioinoculants (a native Pseudomonas monteilii strain and the exotic arbuscular mycorrhizal (AM) fungus Glomus fasciculatum) alone and in combination under organic field conditions in order to evaluate their potential in controlling root rot and wilt. Combined inoculation of P. monteilii with G. fasciculatum significantly increased plant height, plant spread, and number of branches; reduced disease incidence; and increased tuber dry mass of C. forskohlii, compared to vermicompost controls not receiving any bioinoculants. Increase in tuber yields was accompanied by an increase in plant N, P, and K uptake. Co-inoculation of P. monteilii with G. fasciculatum significantly improved the percent AM root colonization and spore numbers retrieved from soil. This suggests P. monteilii to be a mycorrhiza helper bacterium which could be useful in organic agriculture. The forskolin content of tubers was significantly increased by the inoculation treatments of P. monteilii, G. fasciculatum, and P. monteilii + G. fasciculatum.

Protective effect of Coleus aromaticus Benth (Lamiaceae) against naphthalene-induced hepatotoxicity.

OBJECTIVE: To investigate protective effect of Coleus aromaticus leaf extract against naphthalene induced hepatotoxicity in rats. METHODS: Eighteen male rats were divided into three groups. Group I rats were treated as control. Group II rats were intraperitoneally administered with naphthalene (435 mg/kg b.wt) dissolved in corn oil once a day for a period of 30 days. Group III rats were treated with leaf extract (100 mg/kg b.wt) dissolved in 0.9% saline and naphthalene (435 mg/kg b.wt) dissolved in corn oil once a day for a period of 30 days. RESULTS: Significant protective effect was observed against naphthalene induced liver damage, which appeared evident from the response levels of marker enzymes (aspartate transaminase, alanine transaminase, acid phosphatase, alkaline phosphatase and lactate dehydrogenase). The biochemical components viz. triglycerides, free fatty acids, cholesterol acyl transferase, high-density lipoprotein, low-density lipoprotein, cholesterol and bilirubin were found to be increased in liver and serum of naphthalene stressed rats when compared to control. CONCLUSION: Treatment of naphthalene intoxicated rats with plant extract reversed these distorted parameters to near normal levels. Liver histology showed supportive evidence regarding the protective nature of plant extract against fatty changes induced by naphthalene. The present study provides a scientific rationale for using C. aromaticus in the management of liver disorders.

Matrix solid-phase dispersion extraction for chromatographic analysis of labdane diterpenoids in Coleus forskohlii.

INTRODUCTION: The quality of Coleus forskohlii is often evaluated by high performance liquid chromatography (HPLC), using bioactive labdane diterpenoids as chemical markers. However, the existing sample preparation methods for the analysis of diterpenoids in C. forskohlii are generally labour-intensive, time-consuming and require large volumes of solvents. OBJECTIVE: To establish an efficient matrix solid-phase dispersion (MSPD) extraction method for the simultaneous analysis of five bioactive diterpenoids in C. forskohlii by HPLC. METHODOLOGY: Herbal samples were prepared by an optimised MSPD procedure using C(18) as the sorbent. The quantification of the diterpenoids was achieved by HPLC with evaporative light scattering detector (ELSD), and the identification of the five compounds was performed by HPLC with tandem mass detector (MS/MS). The efficiency of the MSPD method was also compared with other extraction techniques including Soxhlet extraction, heat reflux extraction, ultrasonic-assisted extraction and microwave-assisted extraction. RESULTS: The MSPD extracted five diterpenoids with satisfactory recoveries ranging from 98.36% to 102.08%. Compared with other extraction methods, the proposed MSPD method had the advantages of combining extraction and clean-up into a single step, consuming less time and requiring lower solvent volumes. CONCLUSION: The MSPD method is simple, rapid and efficient for the extraction of labdane diterpenoids from C. forskohlii. The MSPD procedure coupled with HPLC-ELSD or HPLC-MS/MS is suitable for the quantification and identification of the diterpenoids in C. forskohlii.

[In vitro metabolism of forscolin isolated from Coleus forskohlii].

This paper is to report the study of the metabolism of forscolin in plasma and liver microsomes for guiding clinical therapy. Forscolin was quantified by HPLC-MS/MS. The metabolic stability of forscolin in rat, Beagle dog, monkey and human plasma and liver microsomes, mediated enzymes of forscolin and its inhibition on cytochrome P450 isoforms in human liver microsomes were studied. Results showed that forscolin was not metabolized in plasma of the four species but metabolized in liver microsomes of the four species. The t1/2 of forscolin in rat, Beagle dog, monkey and human liver microsomes were (52.0 +/- 15.0), (51.2 +/- 5.9), (6.0 +/- 0.2) and (11.9 +/- 1.8) min; CL(int) were (75.6 +/- 18.7), (60.9 +/- 6.8), (513.8 +/- 14.3) and (176.2 +/- 25.6) mL x min(-1) x kg(-1); CL were (34.8 +/- 4.5), (23.3 +/- 1.0), (40.3 +/- 0.5) and (17.9 +/- 0.3) mL x min(-1) x kg(-1), respectively. Forscolin was metabolized by CYP3A4 in human liver microsomes. There was definite inhibition on CYP3A4 at the concentrations of forscolin between 0.1 ng x mL(-1) and 5 microg x mL(-1). Therefore, forscolin is rapidly excreted from liver microsomes. Attention should be paid to the drug interaction when forscolin was used along with other drugs metabolized by CYP3A4 in clinics.