M. S. M. Rawat

Supramolecular phospholipids-polyphenolics interactions: the PHYTOSOME® strategy to improve the bioavailability of phytochemicals.

The poor and/or erratic oral bioavailability of polyphenolics can be improved using the PHYTOSOME delivery system, a strategy that enhances the rate and the extent of solubilization into aqueous intestinal fluids and the capacity to cross biomembranes. Phospholipids show affinity for polyphenolics, and form supramolecular adducts having a definite stoichiometry. This article reviews the preparation and characterization of PHYTOSOME complexes and their activity in various medicinal (cardiovascular, anti-inflammatory, hepatoprotective, anticancer) and cosmetic (skin aging) realms of application.

Lichens as a potential natural source of bioactive compounds: a review

Biological activity of material whether known in folk medicine or observed in planned screening program has been the starting point in the drug research. The general pattern is the isolation of active principles, elucidation their structures, followed by attempts for modulation of its activity potential by chemical modification. Lichens are valuable plant resources and are used as medicine, food, fodder, perfume, spice, dyes and for miscellaneous purposes throughout the world. Lichens are well known for the diversity of secondary metabolites that they produce. Compounds isolated from various lichen species have been reported to display diverse biological activities. Here we review the medicinal efficacy of lichen substances, which intends to explore the pharmaceutical potential of lichen substances.

Hair growth and rejuvenation: An overview

Abstract Hair has psychological and sociological importance throughout the ages in framing the personality and general appearance of an individual. Significant progress is being made on discovering an effective and safe drug for hair growth. Angiogenesis, androgen antagonism, vasodilation, potassium channel opening and 5-alpha reductase inhibition are the major non-surgical therapeutic strategies of hair growth promotion. In spite of a flood of drugs claiming to be useful as hair growth promoters, more rational strategies, which can target the problem areas or stages of the hair growth cycle effectively, are still awaited. This article highlights the developments in hair rejuvenation strategies and reviews the potential of herbal drugs as safer and effective alternatives.

Plant growth inhibitors (Proanthocyanidins) from Prunus armeniaca

Abstract A field survey in Prunus armeniaca growing areas of Garhwal Himalaya was conducted with reference to the germination and growth of some companion crops at various sites of different soil fertility. Retardation in germination, growth and yield were noted in nearby Triticum aestivum plants, particularly on those sites where the percentage of soil organic matter was low. It was also observed that the magnitude of interference gradually decreased as the distance from the tree increased. Aqueous and organic solvent extracts of the aerial parts of Prunus armeniaca were made and their residues were tested, after proper dilution, for their phytotoxic effect on germination and growth of the test crop. Residues of light petroleum and ethyl acetate extracts showed maximum inhibition in growth and germination of the test species. The isolated compounds were identified with the help of spectroscopic techniques and bioassays. β -Sito-sterol, 2,6-dihydroxy-4-methoxyacetophenone and kaempferol were isolated from a petroleum extract whereas aromadendrin, quercetin, β -sitosterol- β - d -glucoside, pleoside and tannins (four proanthocyanidins – A-type) were characterized from an ethyl acetate extract. Of these, proanthocyanidins showed maximum inhibition, whereas quercetin, aromadendrin, kaempferol and genin of pleoside inhibited to a lesser extent.

Antilithiatic effect of flowers of Jasminum Auriculatum Vahl.

The effect of oral administration of aqueous and alcohol extracts of Jasminum auriculatum Vahl (Oleaceae) flowers on calcium oxalate nephrolithiasis has been studied in male albino rats. Ethylene glycol feeding resulted in hyperoxaluria as well as increased renal excretion of calcium and phosphate. Supplementation with aqueous and alcohol extract of J. auriculatum flowers significantly reduced the elevated urinary oxalate, showing a regulatory action on endogenous oxalate synthesis. The increased deposition of stone forming constituents in the kidneys of calculogenic rats was significantly lowered by curative and preventive treatment using aqueous and alcohol extracts. The results indicate that the flowers of J. auriculatum are endowed with antiurolithiatic activity. Key words: Ethylene glycol, flowers, hyperoxaluria, Jasminum auriculatum, nephrolithiasis

Spirostanol glycoside from fruits of Asparagus officinalis

Abstract A spirostanol glycoside was isolated, together with some known compounds, from the methanolic extract of the fruits of Asparagus officinalis and characterized by chemical and spectral methods including 13 C NMR-DEPT and 2D-hetcor NMR spectra. The spirostanol glycoside caused 100% immobilization of human spermatozoa at 1.5% level.

Chemopreventive action of xanthone derivatives on photosensitized DNA damage.

Photosensitized DNA damage participates in solar‐UV carcinogenesis, photogenotoxicity and phototoxicity. A chemoprevention of photosensitized DNA damage is one of the most important methods for the above phototoxic effects. In this study, the chemopreventive action of xanthone (XAN) derivatives (bellidifolin [BEL], gentiacaulein [GEN], norswertianin [NOR] and swerchirin [SWE]) on DNA damage photosensitized by riboflavin was demonstrated using [32P]‐5′‐end‐labeled DNA fragments obtained from genes relevant to human cancer. GEN and NOR effectively inhibited the formation of piperidine‐labile products at consecutive G residues by photoexcited riboflavin, whereas BEL and SWE did not show significant inhibition of DNA damage. The four XAN derivatives decrease the formation of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine (8‐oxodGuo), an oxidative product of G, by photoexcited riboflavin. The preventive action for the 8‐oxodGuo formation of these XAN derivatives increased in the following order: GEN > NOR ≫ BEL > SWE. A fluorescence spectroscopic study and ab initio molecular orbital calculations suggested that the prevention of DNA photodamage is because of the quenching of the triplet excited state of riboflavin by XAN derivatives through electron transfer. This chemoprevention is based on neither antioxidation nor a physical sunscreen effect; rather, it is based on the quenching of a photosensitizer. In conclusion, XAN derivatives, especially GEN, may act as novel chemopreventive agents by the quenching mechanism of an excited photosensitizer.

Proanthocyanidins from Prunus armeniaca roots

Abstract Three isomeric A-type proanthocyanidins have been isolated from the root of Prunus armeniaca . They were identified as ent -epiafzelechin-(4α→8; 2α→O→7)-epiafzelechin (mahuannin A), ent -epiafzelechin-(4α→8; 2α→O→7)-(+)-afzelechin and ent -epiafzelechin-(4α→8; 2α→O→7)-(−)-afzelechin, by means of spectral studies.

A betulinic acid glycoside from Schefflera venulosa

Abstract A new betulinic acid glycoside, lup-20(29)-en-28-oic-3-O-β- d -glucopyranosyl (2→1)-O-β- d -glucopyranoside has been characterized from the leaves of Schefflera venulosa.

Baicalein-Phospholipid Complex: A Novel Drug Delivery Technology for Phytotherapeutics

Flavonoids are a group of low-molecular-weight polyphenolic compounds of plant origin. They exhibit a variety of biological activities such as anti-inflammatory, antioxidant, antiviral, and antitumor etc. Baicalein, is a bioactive flavone constituent of Scutellariae radix with a wide range of beneficial activities. But the poor solubility and dissolution rate limit its oral intestinal absorption and bioavailability. The aim of this study was to develop an amphiphilic phytophospholipid complex in order to enhance the delivery of poorly soluble drug (baicalein). The baicalein-phospholipid complex (Ba-PLc) was prepared and evaluated for various physico-chemical parameters like drug loading, infrared absorption (FT-IR), differential scanning calorimetry (DSC), X-ray powder diffractometry (X-RPD), scanning electron microscopy (SEM), aqueous/ n-octanol solubility and dissolution study. In the SEM, phospholipid complex (Ba-PLc) was found fluffy and porous with rough surface morphology. FT-IR, DSC and X-RPD data confirmed the formation of phospholipid complex. The water/ n-octanol solubility of baicalein was improved significantly in the complex. Improved dissolution was shown by the phospholipid complex. The results of the study concluded that the phospholipid complex may be considered as a promising drug delivery system for improving the absorption and overall bioavailability of the baicalein molecule.