Narsimha Reddy

Antioxidant and anti-inflammatory activities of selected medicinal plants containing phenolic and flavonoid compounds

The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using Saccharomyces cerevisiae , whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely, Scutellaria baicalensis , Taxillus chinensis , Rheum officinale , and Sophora japonica , showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica, Mahonia fortunei , and Sophora flavescens ) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC(50) values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.

Antioxidant and anti-inflammatory activities of selected Chinese medicinal plants and their relation with antioxidant content

BackgroundThe main aim of this study is to evaluate the antioxidant and anti-inflammatory properties of forty four traditional Chinese medicinal herbal extracts and to examine these activities in relation to their antioxidant content.MethodsThe antioxidant activities were investigated using DPPH radical scavenging method and yeast model. The anti-inflammatory properties of the herbal extracts were evaluated by measuring their ability to inhibit the production of nitric oxide and TNF-α in RAW 264.7 macrophages activated by LPS and IFN- γ, respectively. The cytotoxic effects of the herbal extracts were determined by Alomar Blue assay by measuring cell viability. In order to understand the variation of antioxidant activities of herbal extracts with their antioxidant contents, the total phenolics, total flavonoids and trace metal (Mg, Mn, Cu, Zn, Se and Mo) quantities were estimated and a correlation analysis was carried out.ResultsResults of this study show that significant levels of phenolics, flavonoids and trace metal contents were found in Ligustrum lucidum, Paeonia suffuticosa, Salvia miltiorrhiza, Sanguisorba officinalis, Spatholobus suberectus, Tussilago farfara and Uncaria rhyncophylla, which correlated well with their antioxidant and anti-inflammatory activities. Some of the plants displayed high antioxidant and anti-inflammatory activities but contained low levels of phenolics and flavonoids. Interestingly, these plants contained significant levels of trace metals (such as Zn, Mg and Se) which are likely to be responsible for their activities.ConclusionsThe results indicate that the phenolics, flavonoids and trace metals play an important role in the antioxidant activities of medicinal plants. Many of the plants studied here have been identified as potential sources of new antioxidant compounds.

Antioxidant and immunomodulatory activities of polysaccharides from the roots of Sanguisorba officinalis

The roots of Sanguisorba officinalis are used in traditional Chinese medicine for the treatment of diseases such as inflammation and internal haemorrhage. Several scientific investigations involving extraction and pharmacological studies of terpenoids and triterpenoid glycosides from this herb have been carried out. However, little is known regarding the immunomodulatory and antioxidant properties of polysaccharides from S. officinalis. Hence the polysaccharides from this herb have been investigated here. The hot water extract of S. officinalis has been fractionated using size-exclusion chromatography to obtain four polysaccharide fractions designated as SOP-1, SOP-2, SOP-3 and SOP-4. The range of molecular masses of these fractions were from 280 Da to 2000 kDa, and their sugar compositions consisted mainly of fructose, glucose, xylose, arabinose, and rhamnose. The antioxidant activities of the crude polysaccharide fractions were evaluated in a biological assay using Saccharomyces cerevisiae, whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Analysis of the immunomodulatory activities of these polysaccharide fractions were measured by using mouse macrophages. Most of the polysaccharide fractions have stimulated the production of nitric oxide and tumour necrosis factor-α (TNF-α), and also displayed antioxidant activities. These results suggest that the roots of S. officinalis are likely to have therapeutic value for the treatment of cancer.

Anti-fungal and anti-bacterial activities of ethanol extracts of selected traditional Chinese medicinal herbs.

OBJECTIVEnTo evaluate in vitro antimicrobial activities of selected 58 ethno-medicinal plant extracts with a view to assess their therapeutic potential.nnnMETHODSnA total of 58 traditional Chinese medicinal plants were carefully selected based on the literature review and their traditional use. The antimicrobial activities of ethanol extracts of these medicinal plants were tested against fungi (Aspergillus fumigatus), yeast (Candida albicans), gram-negative (Acinetobacter baumannii and Pseudomonas aeruginosa) and gram-positive bacteria (Staphylococcus aureus). The activities were tested at three different concentrations of 1.00, 0.10 and 0.01 mg/mL. The data was analysed using Gene data Screener program.nnnRESULTSnThe measured antimicrobial activities indicated that out of the 58 plant extracts, 15 extracts showed anti-fungal activity and 23 extracts exhibited anti-bacterial activity. Eight plant extracts have exhibited both anti-bacterial and anti-fungal activities. For instance, Eucommia ulmoides, Polygonum cuspidatum, Poria cocos and Uncaria rhyncophylla showed activity against both bacterial and fungal strains, indicating their broad spectrum of activity.nnnCONCLUSIONSnThe results revealed that the ethanol extracts of 30 plants out of the selected 58 possess significant antimicrobial activities. It is interesting to note that the findings from the current study are consistent with the traditional use. A clear correlation has also been found between the antimicrobial activity and the flavonoid content of the plant extracts which is in agreement with the literature. Hence, the results presented here can be used to guide the selection of potential plant species for the isolation and structure elucidation of novel antimicrobial compounds in order to establish the structure-activity relationship. This in turn is expected to lead the way to the discovery of novel antimicrobial agents for therapeutic use.

Immunomodulatory activities of polysaccharides isolated from Taxillus chinensis and Uncaria rhyncophylla

Taxillus chinensis and Uncaria rhyncophylla are the herbs used in traditional Chinese anticancer formulations. During the past decade, research on plant polysaccharides has gained importance due to their therapeutic value and minimum side effects. In this study, hot water extraction method was employed to isolate polysaccharides from the stems of T. chinensis and stems with hooks of U. rhyncophylla. Size-exclusion chromatography was then used for further fractionation. Separated fractions from T. chinensis were designated as TCP-1, TCP-2 and TCP-3 and those from U. rhyncophylla were termed UC-1 and UC-2. Their sugar compositions were estimated using gas chromatography that revealed the presence fructose, glucose, xylose, arbinose, and rhamnose. Amino acid analysis of these fractions has indicated that they are protein-bound polysaccharides. The antioxidant activities were investigated using DPPH and yeast assays. The ability of these polysaccharide fractions to stimulate mouse macrophages was measured using Griess reagent and ELISA test. The results revealed that some of the isolated fractions (TCP-2, TCP-3, UC-1 and UC-2) displayed significant antioxidant activities and were also found to be effective immunomodulators in a concentration-dependent manner. Outcomes of this research strongly indicate that U. rhyncophylla and T. chinensis have therapeutic potential to be used for the treatment of cancer.

Hydrolysis of hedycaryol: the origin of the eudesmols in the Myrtaceae

The steam distillates of the family Myrtaceae are often found to contain the three isomeric sesquiterpene alcohols, β-, β- and γ-eudesmol. Associated with these alcohols but not steam-distilled with them are two hydrates of eudesmol, cryptomeridiol and 4-epicryptomeridiol, compounds which have not been previously reported in the Myrtaceae. These five alcohols are the major by-products of the hydrolysis of hedycaryol, which can occur during leaf ageing or distillation. The use of H218O during distillation implicated the presence of hedycaryol prior to distillation by trapping the eudesmyl-carbocation formed during the hydrolysis. Copyright

Origin of (+)-δ-cadinene and the cubenols in the essential oils of the Myrtaceae

The sesquiterpenoids (+)-δ-cadinene, epicubenol and cubenol in the essential oils of the Myrtaceae are by-products of the acid-solvolysis of the sesquiterpene alcohols cubebol and epicubebol. This solvolysis can occur during leaf ageing or steam distillation. Significant proportions of these compounds can be found in many members of the Myrtaceae, most notably commercial tea tree (Melaleuca alternifolia and M. linariifolia). Copyright

Isolation, characterization, and biological activities of polysaccharides from medicinal plants and mushrooms

Abstract Polysaccharides from medicinal plants and mushrooms form a major class of bioactive compounds with a wide range of pharmacological activities. Some of their biological activities include antioxidant, immunomodulatory, antitumor, gastrointestinal protection, antidiabetic, and hepatoprotective effects. Immunomodulatory and antitumor activities of polysaccharides, from medicinal plants and mushrooms, are of special interest in this review. The epidermal growth factor receptor molecules, such as HER family receptors, play a critical role in the formation and growth of cancer. Rational development of targeted therapeutic agents requires a clear understanding of cancer at the molecular level. This chapter therefore attempts to provide a molecular basis of cancer formation, development, and growth. This chapter then provides strategies for rational screening programs for the discovery of targeted cancer therapeutics. Major part of the plant-based polysaccharide research in biomedical arena has so far been on crude extracts or partially purified polysaccharides. To understand the precise function of plant/mushroom polysaccharides in immunomodulatory and antitumor mechanism, there is an urgent need for the development of improved separation and purification techniques that will allow a study of detailed structure–function relationship. A review of literature on separation methods is provided in this chapter, which is followed by suggestion for novel strategies for the purification of polysaccharides extracted from plant/mushroom sources. Methods for structural characterization of bioactive polysaccharides will then be highlighted after a brief discussion on structure–activity relationship. The mechanism of action of plant polysaccharides as anticancer agents is then briefly discussed. Finally, this chapter provides possible directions for future research in this important area.

Direct spectroscopic evidence for intramolecular π–π interactions in solutions of Λ-β1-[Co(R,R-picchxn)(aa)]n+ [picchxn=N,N′-di(2-picolyl)-1,2-diaminocyclohexane; aa=α-methyl-S-tryptophanato(1−), R-aminobenzylmalonato(1−)]

High-resolution NMR studies of Λ-β1-[Co(R,R-picchxn)(S-α-Me-trp)](ClO4)2 (picchxn=N,N′-di(2-picolyl)-1,2-diaminocyclohexane, α-Me-trpH=α-methyltryptophane), and Λ-β1-[Co(R,R-picchxn)(R-ABMA)]ClO4·1.5H2O (ABMAH2=2-amino-2-benzylpropandioic acid) dissolved in DMSO-d6 and D2O prove that significant intramolecular π–π interactions between a pyridyl ring of the tetradentate and pendant aromatic residues of the aminoacidates persist in solution. These non-classical bonding effects are accompanied by NH–π bonds involving an amine H atom of the coordinated aminoacidate, which lies in a hydrophobic region between the π-stacked aromatic rings. The intramolecular π–π interactions are stronger in D2O, in line with expectations associated with the hydrophobic effect, and significant charge transfer is evident between the indole and pyridyl rings in the methyltryptophane complex. The potential importance of such interactions in biochemical systems is highlighted.

Traditional Ayurvedic medicines: Pathway to develop anti-cancer drugs

Ayurveda, “life knowledge”, is an ancient Indian traditional medical system, which has been practiced for >5000 years and still in use with the same importance among many cultural tribes in Indian sub-continents. Ayurvedic medicine is a unique holistic approach to treatment where herbal medicines, special diets, yoga and relaxation methods, and lifestyle management are key strategies for curing various chronic diseases like diabetes, cancer, cardiovascular, neurological disorders and many other. Cancer is biologically complex disease, causing local damage and inflammation of cells due to lack of full response in a specific tissue that is responsible to maintain cellular differentiation, survival, proliferation and death. Studies have suggested that bioactive phytochemicals present in Ayurvedic plants (fruits, vegetables and herbs) mediate their effects by inhibiting some of the recently identified inflammatory pathways. Nevertheless, for successful implementation of Ayurvedic principles to drug discovery, major concerns relating to proportion, practicality, safety and drug interactions and possible side effects of newly developed Ayurvedic drugs and formulations need to be addressed. Systematic investigations of Ayurvedic drugs, employing contemporary scientific tools and methods, are expected to lead to the discoveries of major significance. Explorations involving studies of bioactive phytochemicals, their side effects, the specific potential targets and the mechanisms of action would transform this traditional therapeutic approach to standard Ayurvedic drug discovery which would be accepted and embraced by global populations. Current review focuses on the importance of anti-cancer drug discovery from Ayurvedic medicines in the modern context, ongoing improvements and major achievements in the field over the past decade or two.