Tylophora Indica Research Articles

Inhibition of cellular immune responses by Tylophora indica in experimental models.

Tylophora alkaloids have been shown to have antiasthmatic, antiinflammatory and antianaphylactic properties. Since all these disorders are a consequence of altered immunological status, the effect of these alkaloids on model immune reactions were studied. Crude extract of the leaves of Tylophora indica inhibited delayed hypersensitivity reaction to sheep red blood cells in rats when the alkaloid mixture was administered before and after immunization with these cells. The alkaloid mixture also inhibited contact sensitivity to dinitro-fluorobenzene in mice when given prior to or after contact sensitization. Lymphocytes taken from contact sensitized mice, when treated with tylophora alkaloid in vitro and transferred into naive syngeneic hosts, could suppress the transfer of delayed type hypersensitivity (DTH) response. However, the tylophora alkaloids could not suppress primary humoral (IgM) immune response to SRBC in mice at the same dose. These studies suggest that tylophora alkaloids suppress cellular immune responses when administered at any stage during the immune response.

Immunomodulatory effect of Tylophora indica on Con A induced lymphoproliferation.

Our preliminary studies with tylophora alkaloids had shown that they inhibit cellular immune responses like contact sensitivity to dinitro-flurobenzene and delayed hypersensitivity to sheep red blood cells, in vivo. Investigations were hence carried out to determine the cellular targets of tylophora alkaloids in in vitro systems. Con A induced proliferation of splenocytes was used as a model system to study the effect of the alkaloids on cellular immune responses. The alkaloid mixture was found to inhibit proliferation of splenocytes at higher concentrations and augment the same at lower concentrations. Both macrophages and T cells were found to be vulnerable to tylophora alkaloids. The alkaloid mixture suppressed IL-2 production in Con A stimulated splenocytes at the inhibitory or higher concentrations and enhanced production at the lower concentrations. IL-1 production by activated macrophages on the contrary was doubled in the presence of inhibitory concentrations of tylophora. These studies indicate that tylophora alkaloids have a concentration dependent biphasic effect on Con A induced mitogenesis. At lower concentrations they augment Con A induced lymphoproliferation by enhancing IL-2 production. Inhibition of proliferation at higher concentrations of the alkaloid is due to inhibition of IL-2 production and activation of macrophages, which have a cytostatic effect.

Allozyme and RAPD polymorphism in Tylophora indica (Burm.f.) Merr.

Tylophora indica (Burm.f.) Merr (syn. T. asthmatica), is being indiscriminately collected for medicinal use which is not sustainable. Conservation of the species requires information on existing genetic content and its distribution in different populations. In the present study, polymorphism in allozyme and RAPD profiles of five populations were analysed using six enzyme systems and ten random primers. Genetic content in terms of allozymes and RAPDs as revealed by Shannon-Weiner index was more or less same in all the populations. Evenness as calculated from observed diversity (Shannon-Weiner index, H’) and the maximum expected diversity (Hmax) for the allozymes and RAPDs was high for individual populations indicating that the distribution of genetic content was fairly uniform. From the results, it was concluded that collection of few genotypes from geographically distinct locations rather than intensive collection within one or two locations would be representative of the genetic variability present in this species.

Effects of ascorbic acid on axillary shoot induction in Tylophora indica (Burm. f.) Merrill.

A procedure for rapid in vitro multiplication of Tylophora indica (Burm. f.) Merrill., an important indigenous medicinal plant, has been developed. Addition of ascorbic acid was essential to induce sprouting of axillary buds. Optimum multiplication was observed on MS medium containing 6-benzylamino purine (5.0 mg l−1), α-naphathalene-acetic acid (0.5 mg l−1) and ascorbic acid (100 mg l−1). Rooting of in vitro produced shoots was readily achieved with indole-3-acetic acid alone (1.0 mg l−1) in MS. The plantlets thus obtained were successfully transferred to pots in large numbers which grew normally.

Alkaloids from Tylophora indica

Seven rare and four known alkaloids have been isolated from two varieties of Tylophora indica. The new alkaloids include tyloindicines A-E, (+)- 14-hydroxyisotylocrebrine and 4,6-desdimethylisotylocrebrine. Tylophorine, 6-desmethyltylophorine, tylophorinidine and 5-hydroxy- O-methyltylophorinidine were the known alkaloids. Structural studies indicate that apart from tyloindicine B all alkaloids possess the dibenzo-[ f, h] pyrrolo [ 1 2 b] isoquinoline skeleton but differ in the number, nature and distribution of the oxygen-bearing substituents, in the presence or absence of C-13a or benzylic hydroxyls and an angular methyl function. Tyloindicine B possesses a cleaved substituted phenanthrene moiety nucleus and an angular methyl group on the indolizidine portion.

Immunomodulating agents of plant origin. I: Preliminary screening

The immunobiological activity was investigated of certain medicinal plants widely used in the Ayurvedic and Unani systems of medicine for treatment of chronic infections and immunological disorders. The effect of an ethanolic extract of each drug was studied on delayed type hypersensitivity, humoral responses to sheep red blood cells, skin allograft rejection, and phagocytic activity of the reticuloendothelial system in mice. Picrorhiza kurroa was found to be a potent immunostimulant, stimulating both cell-mediated and humoral immunity. Tylophora indica, Aconitum heterophyllum and Holarrhena antidysenterica appeared to stimulate phagocytic function while inhibiting the humoral component of the immune system. Tinospora cordifolia and Ocimum gratissimum appeared to improve the phagocytic function without affecting the humoral or cell-mediated immune system. Hemidesmus indicus suppressed both the cell-mediated and humoral components of the immune system.

Plant Regeneration in Protoplast Cultures of Tylophora indica

Protoplasts isolated from callus tissue derived from freshly cultured stem segments of Tylophora indica (Asclepiadaceae) rapidly divided and resulted in callus. Subsequent embryoid/ shoot bud differentiation in callus was observed on MS medium supplemented with auxins and cytokinins. The embryoids/shoot buds on transfer to appropriate basal medium without growth substances grew into plantlets. Protoplasts isolated from callus tissue maintained for over five years showed divisions and subsequent callus formation but failed to regenerate plants.

Alkaloid Synthesis in Tissue Cultures and Regenerated Plants of Tylophora indica MERR. (Asclepiadaceae)

Summary Tissue cultures were established from leaf, stem and root segments of the plant Tylophora indica on a chemically defined medium. Distinct differences were observed in the morphogenetic responses of the tissues derived from different organs of the plant under the stimuli of various growth regulators. Regenerants derived from stem callus were transferred to pots and reared to mature plants under field conditions. Callus cultures failed to synthesize phenanthroindolizidine alkaloids in quantities comparable to the mature plant. While the alkaloid profile of the tissue cultures, regenerated shoot buds and roots was similar, the seedlings (10 leaf stage) showed a tendency to acquire the metabolic status of the mature plant. The alkaloid profile and concentration of the regenerated flowering plants were similar to that of the vegetatively propagated field grown plants (normal plant).

Effect of gamma irradiation on biosynthetic potential of callus cultures of Tylophora indica.

The irradiation of callus cultures of Tylophora indica with gamma rays at different doses viz. 140, 280, 560, 840 and 2240r at dose rate of 140r per hour failed to induce alkaloid synthesis in vitro. The number of lignified elements increased due to radiation which resulted in the formation of a phenolic flavonoid namely quercetin in case of the tissue irradiated at higher dose of 2240r. The synthesis of terpenoidal and steroidal constituents in the tissue decreased with increasing dose of radiation.

Incorporation of cinnamic acid-2-[ 14C] into tylophorine

Tylophora indica plants have been shown to contain phenanthroindolizidine alkaloids of the tylophorine type. Cinnamic acid-[2- 14C]was incorporated efficiently into these alkaloids supporting the hypothesis that ring A and C-10 and C-6 $ ́ of tylophorine are derived from phenylalanine.

Botany of Tylophora indica (Burm. f.) Merr

Tylophora indica (Burm. f.) Merr. is gaining importance in India, due to its anti-asthmatic properties. A short history of its introduction as an anti-asthmatic drug with important bibliography and citations, cultural trial and the botany of the cultured plants and the distribution are included. It is established that T. indica could easily be propogated by stem cutting and grown in the northern part of India.

Morphogenetic Investigations in Callus Cultures of Tylophora indica

AbstractCallus cultures derived from stem explants of Tylophora indica (Fam. Asclepiadaceae) show a broad spectrum of tissue differentiation and regenerative potentialities over a wide range of nutrient conditions resulting in the production of roots, shoots, bipolar embryos and plantlets. This has been investigated and interpreted on a histological basis. Studies on the morphogenesis of embryos have shown that only such embryonal cells which were deeply embedded with in the callus parenchyma showed an ontogenic development reminiscent of ovular embryogeny whereas in those organized in the superficial layer of the callus the sequence of embryogeny was entirely different. Free cells growing in agitated liquid media first developed into filamentous structures and eventually, by repeated intercalary divisions, organized into bipolar embryos. Development of accessory embryos through cleavage and budding in the callus, differentiation of amphicribral vascular nodules, and meristematic colonies organized into spheres of parenchyma were also observed. These alternative morphogenetic events probably reflect the biochemical subtleties occurring within the callus as a result of an inadequacy or an imbalance of the various constituents in the culture medium.

Alkaloids of Tylophora III: New Alkaloids of Tylophora indica (Burm) Merrill and Tylophora dalzellii Hook. f

During a reexamination of the alkaloidal constituents of Tylophora indica, three new alkaloids (designated A, B, and C) were isolated. Analytical and spectral data indicate that these alkaloids are related to tylophorine and tylophorinine, which are also present in the plant. Alkaloid B is shown to be a desmethyl‐tylophorine, and Alkaloid C is shown to be a desmethyltylophorinine. T. dalzellii has a relatively low alkaloid content, and desmethyl‐tylophorinine is the major constituent. A brief description of the antileukemic activity of desmethyltylophorinine is presented.

Differentiation ex ovulo of Embryos and Plantlets in Stem Tissue Cultures of Tylophora indica

Abstract Tylophora indica callus tissue repeatedly subcultured every month on a series of different nutrient media in sequence regenerated roots, shoots and typical, bipolar embryos in vitro from unorganized callus parenchyma. The embryo‐like structures developed from somatic cells grew into normal plantlets when isolated and cultured on appropriate milieu of nutrients and hormones bypassing the normal sexual method of reproduction. Likewise, free cells in suspension also passed through embryonic stages reminiscent of development from fertilized egg.

Biochemical assessment of <i>in vitro</i> and <i>in vivo</i> culture of <i>Tylophora indica</i> (Burm. F.) Merr

Tylophora indica (Burm. F.) Merr is an endangered plant which can be protected from extinction by its large scale production. Nodal segments of healthy plants are used as explants and cultured on MS Basal medium fortified with different growth regulators. Optimum shoot induction conditions from explants were established. In vitro and in vivo phytochemical test were done by using standard methods for chlorophyll, carbohydrates, proteins, lipids and starch. 3mg/l 2, 4 D showed maximum and success full callus production. Shoot initiation started in 7 days and best shoot regeneration reported with 3 mg/ml BAP in Basal medium. Combination of IBA and NAA in concentration 2 and 4 mg/l respectively proved to be best for root initiation. Concentration of chlorophyll, protein, lipid, carbohydrate, and starch in vitro and in vivo culture are investigated. DOI: 10.3126/kuset.v6i2.4005Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.1-5

A crossover double-blind study on Tylophora indica in the treatment of asthma and allergic rhinitis

Results of a crossover double-blind trial on 110 bronchial asthma patients with leaves of Tylophora indica and of spinach (placebo) are presented. The dose was one leaf daily for 6 days to be chewed and swallowed early in the morning. A 12 week follow-up was done. At the end of one week, 62 per cent of the Tylophora group had complete to moderate relief in symptoms, as compared with 28 per cent of the placebo group. At 4 weeks, the respective figures were 37 per cent and 11 per cent; at 8 weeks, 30 per cent and 7.4 per cent; and at 12 weeks, 16 per cent and zero per cent. The incidence of side effects, such as sore mouth, loss of taste for salt, and/or morning nausea and vomiting was 53 per cent in the Tylophora group and 9 per cent in the placebo group. There appeared to be a correlation between the incidence of side effects and degree of improvement. After crossover at the end of one week, 50 per cent of the Tylophora group had complete to moderate relief as compared with 11 per cent of the placebo group. The authors are not aware of any other drug which, when administered in a small dose once a day for 6 days only, will suppress the symptoms of allergic rhinitis and/or asthma for 8 to 12 weeks in a significant number of patients. It is postulated that irritative effects of the juice of the Tylophora leaf on the mucous membranes of the mouth, tongue, and stomach somehow suppress or diminish the response of the nasobronchial tissue to an inhalant allergen through some reflex mechanism.