Somatic embryogenesis and plant regeneration in Wedelia calendulacea Less. an endangered medicinal plant

In this work, plant regeneration via somatic embryogenesis was achieved from leaf and internode derived callus of Wedelia calendulacea, an endangered medicinal plant. Primary callus was induced by culturing leaf disc and internode explant on Murashige and Skoog medium supplemented with 2.0 mg L-1 of 2,4-D under light condition. Transfer of embryogenic callus on a reduced concentration of 2,4-D facilitated somatic embryo development while calluses remained unorganized at the same 2,4-D level. A histological analysis confirmed somatic embryo by revealing the presence of a closed vascular system in the developing embryos and lack of a vascularconnection with surrounding callus tissues. Somatic embryos germinated into plantlets upon transfer on MS medium containing 1.0 mg L-1 BAP plus 0.5 mg L-1 GA3. Plantlets were acclimatized successfully and survived under soil condition. This is the first on somatic embryogenesis of W.calendulacea. This result could facilitate genetic transformation of this important medicinal plant.

Antioxidant mediated defense role of Wedelia calendulacea herbal extract against CCl4 induced toxic hepatitis.

Liver,the most complex metabolic organ in human body is continuously exposed to various pathogenic oraganisms, xenobiotic agents,drugs and subjected to metabolic stresses. Being the organ of metabolism of xenobiotics and sources of free radicals, it becomes more vulnerable to toxic metabolites and free radical mediated disorders.The present study focuses on the antioxidant mediated protective effect of a popular medicinal herb Wedelia calendulacea against carbon tetrachloride induced oxidative stress in the liver of rats.Rats divided into four groups were administered with CCl4 and CCl4 along with methanol extract of leaves of Wedelia herb (200 and 400 mg/kg b.wt) for three weeks.At the end of treatment, rats were anaesthetized and blood samples were collected for serum separation.Biochemical analysis such as alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),lactate dehydrogenase(LDH) and total bilirubin(TB) were done in serum.Liver tissue was used for glutathione(GSH),lipid peroxidation(LPO),gluatathione peroxidase (GPx),glutathione Stransferase( GST) ,superoxide dismutase (SOD)and catalase(CAT) analysis.CCl 4 administration caused significant elevation of the serum enzymes and total bilirubin content.Antioxidant enzymes were drastically inhibited with significant reduction of glutathione and increased lipid peroxidation in CCl4 treated rats.W.calendulacea extracts administrated rats ,however did not show much changes in marker enzyme level.Antioxidant enzyme status was also not affected and found nearer to the control levels.Increased gluatathione level and reduced lipid peroxidation was also evident in W.calendulacea treated rats .The findings show that W.calendulacea extract offers better protection against the free radical toxicity of CCl4 .

Preliminary: Studies on Chemical Composition of Wedelia calen-dulacea Less. (Asteraceae)

Wedelia calen-dulacea Less. (Asteraceae) is well known for its antibacterial, demulcent and antifebrile properties, it is a traditional medicine which wild growing in many areas in Viet Nam. The researchers firstly study its chemical composition. Results of the chemical analysis show that: The plant contains flavonoid, alcaloids, coumarin, triterpenoid saponins, tanin, sugars, fat, sterols and carotenoid. The content of total flavonoids is about 1% (on dry basis), at least 11 spots on chromatogram. The content of total saponins is about 12% (on dry basis). The analysis with 3 different solvent systems revealed at least 15 spots on chromatogram. Some of the spots can be shown with both flavonoid and coumarin reagents, these are tentatively called coumestan components.

Evaluation of hepatoprotective effect of wedelia calendulacea lees

The 1:1 fluid extract of Wedelia calendulacea Less. aerial part was used for the evaluation of the plant hepatoprotective effect. The results of the pharmacological studies included: (1) Oxidative activity: 83.1% (in vitro), (2) Decrease of malonyl dialdehyde in mouse liver: 25.1%, (3) Decrease of the serum glutamate pyruvic transaminase level: 34.1%, (4) Decrease of the concentration of bilirubin in mouse serum: 10.4%, (5) Increase of the bile flow in mice: 88.8%. Conclusion: W. calendulacea had a good hepatoprotective effect in mouse model.

Studies on the Hepatoprotective Activity of Oleanolic Acid from Wedelia calendulacea Less

The Wedelia calendulacea Less. in Van Dien area, Ha Noi, rats of the body weight of 20-22g were divided into 3 groups. In order to use Wedelia calendulacea Less. in treating liver diseases, fractions from the plant have been studied pharmacologically. This paper presents the method of extraction of oleanolic acid and results of its anti-oxidative effect. The studies have revealed that amount of liver MDA of the treated mice decreased by 44.8%, and that of serum GPT decreased by 26.3%. These results show that oleanolic acid do take part in the hepatoprotective activity of the plant