Melatonin and nitric oxide enhance cadmium tolerance and phytoremediation efficiency in Catharanthus roseus (L.) G. Don

In this study, a pot experiment was performed to evaluate the effects of foliar spray with sodium nitroprusside (200 μM SNP) and melatonin (100 μM) singly and in combination on tolerance and accumulation of cadmium (Cd) in Catharanthus roseus (L.) G. Don plants exposed to different levels of cadmium (0, 50, 100, and 200 mg Cd kg^-1 soil). The results showed that 50 mg kg^-1 Cd had no significant effect on the fresh and dry weight of roots and shoots and content of chlorophyll (Chl) a and b, but the higher levels of Cd (100 and 200 mg kg^-1) significantly reduced these attributes and induced an increase in the level of leaf electrolyte leakage and disrupted nutrient homeostasis. The activities of catalase (CAT) and peroxidase (POD) in leaves were increased under lower Cd concentrations (50 and 100 mg kg^-1) but decreased under 200 mg kg^-1 Cd. However, foliar spray with melatonin and/or SNP increased shoot biomass and the content of Chl a and b, augmented activities of POD and CAT, lowered electrolyte leakage (EL), and improved essential cations homeostasis in leaves. Cadmium content in shoots of C. roseus was less than roots and TF (transfer factor) was < 1. Interestingly, foliar spray with SNP and/or melatonin increased Cd accumulation and bioconcentration factor (BCF) in both roots and shoots and elevated the Cd transport from roots to shoot, as TF values increased in these treatments. The co-application of melatonin and SNP further than their separate usage augmented Cd tolerance through increasing activities of antioxidant enzymes and regulating mineral homeostasis in C. roseus. Furthermore, co-treatment of SNP and melatonin increased Cd phytoremediation efficiency in C. roseus through increasing biomass and elevating uptake and translocation of Cd from root to shoot.

1α, 25-dihydroxy Vitamin D3 containing fractions of Catharanthus roseus leaf aqueous extract inhibit preadipocyte differentiation and induce lipolysis in 3T3-L1 cells

BACKGROUND

To investigate the potential of Catharanthus roseus leaf aqueous crude extract (CRACE) as a regulator of adipocyte development and function.

METHODS

3T3-L1 adipogenesis model was used to investigate the effect of CRACE on adipogenesis. 3T3-L1 preadipocytes (for adipogenic differentiation) and mature 3T3-L1 adipocytes (for adipocyte function) were treated with non-toxic doses of CRACE. The outcomes were corroborated by intracellular lipid accumulation, expression of pro-and anti-adipogenic effector molecules. To investigate CRACE mediated lipolysis, cAMP accumulation, glycerol release and phosphorylation of key effector molecules were tested in treated mature adipocytes. Finally, the extract was fractionated to identify the active molecule/s in the extract.

RESULTS

CRACE significantly reduced adipocyte differentiation by modulating PPARγ expression. At early stage CRACE directly targeted Lipin1 expression and consequently impacted KLF7, subsequently expression of GATA2, CEBPα, SREBP1c were targeted, with PPARγ expression, particularly curtailed. While CRACE significantly reduced several lipogenic genes like FAS and GPD1 in mature adipocytes, concomitantly, it greatly increased lipolysis resulting in decreased lipid accumulation in mature adipocytes. The increase in lipolysis was due to decreased Akt activation, increased cAMP level, and PKA activity. The fractionation of CRACE allowed identification of two fractions with potent anti-adipogenic activity. Both the fractions contained 1α, 25-dihydroxy Vitamin D3 as major component.

CONCLUSIONS

1α, 25-dihydroxy Vitamin D3 containing CRACE can be developed into an effective anti-obesity formulation that decreases adipogenesis and increases lipid catabolism.

Role of Burkholderia cepacia CS8 in Cd-stress alleviation and phytoremediation by Catharanthus roseus

The current study was performed to assess the effect of Burkholderia cepacia CS8 on the phytoremediation of cadmium (Cd) by Catharanthus roseus grown in Cd-contaminated soil. The plants cultivated in Cd amended soil showed reduced growth, dry mass, gas-exchange capacity, and chlorophyll contents. Furthermore, the plants exhibited elevated levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) under Cd stress. The bacterized plants showed higher shoot length, root length; fresh and dry weight. The improved stress tolerance in inoculated plants was attributed to the reduced quantity of MDA and H₂O₂, enhanced synthesis of protein, proline, phenols, flavonoids, and improved activity of antioxidant enzymes including peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase. Similarly, the 1-aminocyclopropane-1-carboxylate deaminase activity, phosphate solubilization, auxin, and siderophore production capability of B. cepacia CS8 improved growth and stress alleviation in treated plants. The bacterial inoculation enhanced the amount of water extractable Cd from soil. Furthermore, the inoculated plants showed higher bioconcentration factor and translocation factor. The current study exhibits that B. cepacia CS8 improves stress alleviation and phytoextraction potential of C. roseus plants growing under Cd stress.

Application of Bacillus megaterium MCR-8 improved phytoextraction and stress alleviation of nickel in Vinca rosea

The current research was performed to evaluate the effect of Bacillus megaterium MCR-8 on mitigation of nickel (Ni) stress in Vinca rosea grown on Ni-contaminated soil (50, 100, and 200 mg Ni kg^-1 soil). The treated plants exhibited reduced growth, biomass, gas exchange capacity, and chlorophyll (Chl) content under Ni stress. The inoculated plants growing in Ni-contaminated media exhibited relatively higher growth, total soluble protein, and proline contents. Similarly, bacterial inoculation improved the activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) under Ni stress. The Ni stress alleviation in inoculated plants was attributed to the reduced level of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), enhanced synthesis of protein, proline, phenols, and flavonides in conjunction with improved activity of antioxidant enzymes. The growth-promoting characteristics of microbe such as 1-aminocyclopropane-1-carboxylate deaminase (ACCD) and phosphate solubilization activity, siderophore, and auxin production capability also improved the growth and stress mitigation in inoculated plants. Furthermore, the inoculated plants exhibited higher value for bioconcentration factor (BCF), translocation factor (TF), and resulted in higher loss of Ni content from soil. The current results exhibited the beneficial role of B. megaterium MCR-8 regarding stress alleviation and Ni phytoextraction by V. rosea.

Anti-diabetic potential of Catharanthus roseus Linn. and its effect on the glucose transport gene (GLUT-2 and GLUT-4) in streptozotocin induced diabetic wistar rats

BACKGROUND

Catharanthus roseus is an important Ayurvedic medication in traditional medicine. It is potentially used in countries like India, South Africa, China and Malaysia for the healing of diabetes mellitus. Although, the molecular mechanisms behind this effect are yet to be exclusively explored. Due to the great antidiabetic and hyperlipidemic potential of c. roseus, we hypothesized that the insulin mimetic effect of ethanolic extract of c. roseus might add to glucose uptake through improvement in the expression of genes of the glucose transporter (GLUT) family messenger RNA (mRNA) in liver.

METHODS

STZ-induced diabetic rats treated by ethanolic extract of c. roseus 100 mg/kg and 200 mg/kg; and one group treated with Metformin (100 mg/kg). After final administration of treatment of 4 weeks, blood samples were collected under fasting conditions, and the body weights (BWs) were measured. Total RNA from liver was extracted with the Qiagen RNEasy Micro kit (GERMANY) as described in the manufacturer's instructions. First-strand complementary DNA (cDNA) was synthesized at 40 °C by priming with oligo-dT12-18 (Invitrogen, USA) and using Super ScriptII reverse transcriptase according to the protocol provided by the manufacturer (Invitrogen, USA). Real-time polymerase chain reaction (PCR) amplifications for GLUT-4 (gene ID: 25139) were conducted using Light-Cycler 480 (Roche, USA) with the SyBr® I nucleic acid stain (Invitrogen, USA) according to the manufacturer's instructions. Polymerase chain reaction products of β-actin primer gene were used as an internal standard.

RESULTS

The proposed study was framed to look at the antidiabetic efficacy of ethanolic extract of c. roseus and an expression of GLUT-2 and GLUT-4 gene in streptozotocin induced diabetic wistar rats. The doses were administered orally at a rate of 100 and 200 mg/kg and detrain the glucose transport system in liver for 4 weeks. The observed results showed a good positive correlation between intracellular calcium and insulin release levels in isolated islets of Langerhans. The supplementation of ethanolic extract of c. roseus significantly amplified the expression of GLUT gene mRNA by Real Time PCR in liver of diabetic rats.

CONCLUSIONS

We conclude that the observed antidiabetic effect of c. roseus on STZ induced diabetes was a result of complex mechanisms of GLUT gene mRNA expression. The findings are very encouraging and greatly advocate its candidature for the design of a novel herbal drug to cure deadly diabetes.

Antimicrobial potentials of Catharanthus roseus by disc diffusion assay

The present research work investigates the in vitro antimicrobial activity of different solvent extracted samples from the aerial parts (stem, leaf, fruit and flower) of C. roseus against different microbial species using disc diffusion assay at two different concentrations of 1 and 2 mg disc-1. Hexane extracted samples inhibited the growth of all tested microbial strains except S. typhi. Similarly, ethyl acetate extracted samples was effective to control the activity of all the tested microbial strains. E. coli and S. typhi showed resistance to chloroform extracted samples and the remaining eight microbial strains were susceptible to the same extract. Butanol extracted samples did not inhibit the growth of K. pneumonia and S. typhi at low concentration, however, at higher concentration the same extract reduced the growth of different microbes. Methanol extracted samples effectively controlled the growth of all tested microbes at both concentrations except for S. typhi. Water extracted samples did not inhibit the growth at low concentration except E. coli, K. pneumonia and S. aureus and were ineffective against P. aeroginosa at both concentration. C. albicans, showed resistance against chloroform and water extracted samples at low concentration and susceptible to other solvent extracted samples at both concentration. All fractions were effective against plant pathogens i.e. E. carotovora and A. tumefaciens.

Evaluation of antimicrobial activity of extracts of in vivo and in vitro grown Vinca rosea L. (Catharanthus roseus) against pathogens

The antimicrobial activity of Vinca rosea was evaluated against pathogenic bacterial strains (Bacillus subtilis, B. licheniformis and Azotobacter sp.) and fungal strains (Asprgillus niger, Alternaria solani and Rhizopus oryzae) using agar well diffusion method. Methanolic extracts of in vivo leaf, in vitro leaf, in vitro calluses of leaf, nodal and fruit explants were used and exhibited antimicrobial activity as indicated by minimum inhibitory concentration (MIC). In vitro extracts showed better results as compared to the in vivo extracts for both the antibacterial as well as the antifungal activity. Among all the extracts, maximum zone of inhibition (30.3 mm ± 0.58(a)) was formed by in vitro leaf callus extract concentration of 2.0mg/ml against B. licheniformis. Similarly in case of antifungal activity, maximum zone of inhibition (34.6mm ± 0.57(a)) was formed by in vitro leaf callus extract and MIC value is 6.0mg/ml against A. niger. Hence these results clearly depicts that V. rosea possess a great strength to fight against the microbial activity and can be used against various infections.

Evaluation of hypolipidemic activity of leaf juice of Catharanthus roseus (Linn.) G. Donn. in guinea pigs

Our aim of the study was to evaluate the hypolipidemic activity of leaf juice of Catharanthus roseus (Linn.) G. Donn. in guinea pigs. Adult guinea pigs of either sex were divided into seven groups: group 1 - normal diet; group 2 - high fat diet; group 3 and 4 - normal diet plus leaf juice of Catharanthus roseus (Linn.) G. Donn. in the dose of 0.5 and 1 mL/kg, respectively; group 5 and 6- high fat diet with leaf juice of Catharanthus roseus (Linn.) G. Donn. in the dose of 0.5 and 1 mL/kg, respectively; group 7 - high fat diet plus atorvastatin (3 mg/kg). Above diet treatment was given for six weeks and drug was given during last three weeks. Serum lipid profile (total cholesterol, triglycerides, LDL-c, VLDL-c, HDL-c) was performed in each group of animals before and at the end of six weeks. Histological study of aorta, liver and kidney was done in group 1, 2, 6 and 7 and blood cell count was done in animals that were treated juice of C. roseus (Linn.) G. Donn. before and after juice administration. Simultaneous administration of leaf juice of C. roseus (Linn.) G. Donn. in the dose of 0.5 mL/kg prevents the rise of serum lipid parameters and decreases the fatty changes in the tissue induced by high fat diet, whereas in the dose of 1 mL/kg not only counteracts the elevation, but also significantly (p < 0.05) reduces the serum level LDL-c and the ratio of total cholesterol and HDL-c. Leaf juice of C. roseus (Linn.) G. Donn. possesses significant lipid lowering and anti atherosclerotic activity.

Evaluation of wound-healing potential of Catharanthus roseus leaf extract in rats

Rats treated with 100 mg /kg/day of the Catharanthus roseus ethanol extract had high rate of wound contraction significantly decreased epithelization period, significant increase in dry weight and hydroxyproline content of the granulation tissue when compared with the controls. Wound contraction together with increased tensile strength and hydroxyproline content support the use of C. roseus in the management of wound healing.

Hypoglycemic effect of Catharanthus roseus in normal and streptozotocin-induced diabetic rats

The effects of crude juice (at 0.5 and 1 ml/kg b.w.) and aqueous extract (at 0.30 and 0.45 gm/kg b.w.) of leaves of Catharanthus roseus on serum glucose level in streptozotocin induced diabetic rats were examined at 8 hours, 12 hours and 24 hours following single oral administration. The administration of crude juice at 1 ml/kg b.w. continued for another 9 doses (total 10 single morning doses given) and its effect was examined on the 4th and 11th day. The rats were made diabetic by single intraperitoneal injection of streptozotocin at 45 mg/kg b.w. Glibenclamide was used in the study for comparison. The crude leaf juice at 0.5 and 1 ml/kg b.w. reduced the serum glucose level in streptozotocin induced diabetic rats throughout the 24-hour period significantly (P varies between 0.05 and 0.001 at different times). The aqueous extract at 0.30 and 0.45 gm/kg reduced the serum glucose level in streptozotocin diabetic rats at 8 and 12 hour significantly (P varies between 0.05 to 0.01 at different times) but not at the 24 hour. Glibenclamide, at 500 mug/kg, also reduced the serum glucose level in streptozotocin induced diabetic rats throughout the 24-hour period (P<0.001). The crude leaf juice at 1 ml/kg also significantly reduced the serum glucose level in the streptozotocin induced diabetic rats on the 4th and 11th day (P<0.001 on both occasions). The effect of crude leaf juice at 1 ml/kg b.w administered daily orally over a 10 day period was also examined on a group of normal rats at different times. The study showed significant reduction at 8 hr (P<0.05), 12 hr, 24 hr and on the 4th day (P<0.01 on these 3 occasions) and also on the 11th day (P<0.001).

Catharanthus roseus flower extract has wound-healing activity in Sprague Dawley rats

BACKGROUND

Catharanthus roseus L (C. roseus) has been used to treat a wide assortment of diseases including diabetes. The objective of our study was to evaluate the antimicrobial and wound healing activity of the flower extract of Catharanthus in rats.

METHODS

Wound healing activity was determined in rats, after administration (100 mg kg-1 day-1) of the ethanol extract of C. roseus flower, using excision, incision and dead space wounds models. The animals were divided into two groups of 6 each in all the models. In the excision model, group 1 animals were topically treated with carboxymethyl cellulose as placebo control and group 2 received topical application of the ethanol extract of C. roseus at a dose of 100 mg/kg body weight/day. In an incision and dead space model group 1 animals were given normal saline and group 2 received the extract orally at a dose of 100 mg kg-1 day-1. Healing was assessed by the rate of wound contraction, period of epithelization, tensile strength (skin breaking strength), granulation tissue weight, and hydoxyproline content. Antimicrobial activity of the flower extract against four microorganisms was also assessed

RESULTS

The extract of C. roseus significantly increased the wound breaking strength in the incision wound model compared with controls (P < 0.001). The extract-treated wounds were found to epithelialize faster, and the rate of wound contraction was significantly increased in comparison to control wounds (P < 0.001), Wet and dry granulation tissue weights, and hydroxyproline content in a dead space wound model increased significantly (p < 0.05). Pseudomonas aeruginosa and Staphylococcus aureus demonstrated sensitivity to C. roseus

CONCLUSION

Increased wound contraction and tensile strength, augmented hydroxyproline content along with antimicrobial activity support the use of C. roseus in the topical management of wound healing.

Cloning, characterization and localization of three novel class III peroxidases in lignifying xylem of Norway spruce (Picea abies)

Plant class III peroxidases (POXs) take part in the formation of lignin and maturation of plant cell walls. However, only a few examples of such peroxidases from gymnosperm tree species with highly lignified xylem tracheids have been implicated so far. We report here cDNA cloning of three xylem-expressed class III peroxidase encoding genes from Norway spruce (Picea abies). The translated proteins, PX1, PX2 and PX3, contain the conserved amino acids required for heme-binding and peroxidase catalysis. They all begin with putative secretion signal propeptide sequences but diverge substantially at phylogenetic level, grouping to two subclusters when aligned with other class III plant peroxidases. In situ hybridization analysis on expression of the three POXs in Norway spruce seedlings showed that mRNA coding for PX1 and PX2 accumulated in the cytoplasm of young, developing tracheids within the current growth ring where lignification is occurring. Function of the putative N-terminal secretion signal peptides for PX1, PX2 and PX3 was confirmed by constructing chimeric fusions with EGFP (enhanced green fluorescent protein) and expressing them in tobacco protoplasts. Full-length coding region of px1 was also heterologously expressed in Catharanthus roseus hairy root cultures. Thus, at least the spruce PX1 peroxidase is processed via the endoplasmic reticulum (ER) most likely for secretion to the cell wall. Thereby, PX1 displays correct spatiotemporal localization for participation in the maturation of the spruce tracheid secondary cell wall.

Protective effects of Piper nigrum and Vinca rosea in alloxan induced diabetic rats

In the present study aqueous extract of Piper nigrum seeds and Vinca rosea flowers were administered orally to alloxan induced diabetic rats once a day for 4 weeks. These treatments lead to significant lowering of blood sugar level and reduction in serum lipids. The levels of antioxidant enzymes, catalase and glutathione peroxidase decreased in alloxan induced diabetic rats however these levels returned to normal in insulin, P. nigrum and V. rosea treated rats. There was no significant difference in superoxide dismutase activity in all groups compared to controls. Lipid peroxidation levels were significantly higher in diabetic rats and it was slightly increased in insulin, P. nigrum and V. rosea treated rats as compared to control rat. These results suggest that oxidative stress plays a key role in diabetes, and treatment with P. nigrum and V. rosea are useful in controlling not only the glucose and lipid levels but these components may also be helpful in strengthening the antioxidants potential.

Cytochrome P450 2D6 (CYP2D6) Inhibitory Constituents of Catharanthus roseus

The MeOH-soluble fraction of the water extract of Catharanthus roseus from Indonesia, having shown potent inhibitory activity on the metabolism mediated by CYP2D6, was subjected to activity-guided isolation to yield two triterpenes, ursolic acid (1) and oleanolic acid (2), and three alkaloids, vindoline (3), ajmalicine (4), and serpentine (5). The isolated compounds were tested for their inhibitory activity on the metabolism mediated by CYP3A4 or CYP2D6 using [N-methyl-14C]erythromycin or [O-methyl-14C]dextromethorphan as a substrate, respectively. Ajmalicine (4) and serpentine (5) showed very potent inhibitory activity against CYP2D6 with IC50 values of 0.0023 and 3.51 microM, respectively. All isolated compounds showed weak or no inhibition against CYP3A4. On time-, concentration-, and NADPH-dependent assay, serpentine (5) appear to be the mechanism-based inhibitor for CYP2D6 enzyme in which the inhibition was irreversible and driven by catalytic process. K(I) and k(inact) values for serpentine (5) were 0.148 microM and 0.090 min-1, respectively. On the other hand, ajmalicine (4) showed no time-dependent inhibition or reversible inhibition, and thus appear to be not mechanism-based inhibitor.

The juice of fresh leaves of Catharanthus roseus Linn. reduces blood glucose in normal and alloxan diabetic rabbits

BACKGROUND

The leaf juice or water decoction of Catharanthus roseus L. (Apocyanaceae) is used as a folk medicine for the treatment of diabetes all over the world. In the present investigation, the leaf juice of C. roseus has been evaluated for its hypoglycemic activity in normal and alloxan-induced diabetic rabbits.

METHODS

The blood glucose lowering activity of the leaf juice was studied in normal and alloxan-induced (100 mg/kg, i.v.) diabetic rabbits, after oral administration at doses of 0.5, 0.75 and 1.0 ml/kg body weight. Blood samples were collected from the marginal ear vein before and also at 4, 6, 8, 10, 12, 16, 18, 20 & 24 h after drug administration and blood glucose was analyzed by Nelson-Somogyi's method using a visible spectrophotometer. The data was compared statistically by using Student's t-test.

RESULTS

The leaf juice of C. roseus produced dose-dependent reduction in blood glucose of both normal and diabetic rabbits and comparable with that of the standard drug, glibenclamide. The results indicate a prolonged action in reduction of blood glucose by C. roseus and the mode of action of the active compound(s) of C. roseus is probably mediated through enhance secretion of insulin from the beta-cells of Langerhans or through extrapancreatic mechanism.

CONCLUSIONS

The present study clearly indicated a significant antidiabetic activity with the leaf juice of Catharanthus roseus and supports the traditional usage of the fresh leaves by Ayurvedic physicians for the control of diabetes.

Biotransformation of 2alpha,5alpha,10beta,14beta-tetraacetoxy-4(20),11-taxadiene by cell suspension cultures of Catharanthus roseus

Catharanthus roseus cell suspension cultures were employed for the biotransformation of 2alpha,5alpha,10beta,14beta-tetraacetoxy-4(20),11-taxadiene ( 1), and four metabolites were obtained. Based on their physical and chemical data, the structures of the four metabolites were respectively elucidated as 10beta-hydroxy-2alpha,5alpha,14beta-triacetoxy-4(20),11-taxadiene (2), 5alpha-hydroxy-2alpha,10beta, 14beta-triacetoxy-4(20),11-taxadiene (3), 6alpha,10beta-dihydroxy-2alpha,5alpha,14beta-triacetoxy-4(20),11-taxadiene (4), and 6alpha,9alpha,10beta-trihydroxy-2alpha,5alpha,14beta-triacetoxy-4(20),11-taxadiene (5), among which 3 and 5 were characterized as new taxoids. The effects of the stages of substrate addition on the biotransformation were also investigated. The results revealed that the biotransformation rate for 1 reached 85.3 % and the yield of 2 70 % when 1 was administered during the mid-linear phase (9 - 12 th day) of the cell growth cycle. On the other hand, the yield for 4 reached the highest level of 11.8 % when 1 was added in the early linear phase (6 th day).