Increased antioxidant activity and changes in phenolic profile of Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) specimens grown under supplemental blue light

Antioxidant compounds protect plants against oxidative stress caused by environmental conditions. Different light qualities, such as UV-A radiation and blue light, have shown positive effects on the production of phenols in plants. Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) is used for treating wounds and inflammations. Some of these beneficial effects are attributed to the antioxidant activity of plant components. We investigated the effects of blue light and UV-A radiation supplementation on the total phenol content, antioxidant activity and chromatographic profile of aqueous extracts from leaves of K. pinnata. Monoclonal plants were grown under white light, white plus blue light and white plus UV-A radiation. Supplemental blue light improved the antioxidant activity and changed the phenolic profile of the extracts. Analysis by HPLC of supplemental blue-light plant extracts revealed a higher proportion of the major flavonoid quercetin 3-O-α-L-arabinopyranosyl (1→2) α-L-rhamnopyranoside, as well as the presence of a wide variety of other phenolic substances. These findings may explain the higher antioxidant activity observed for this extract. Blue light is proposed as a supplemental light source in the cultivation of K. pinnata, to improve its antioxidant activity.

Flavonoids in the therapy and prophylaxis of flu: a patent review

INTRODUCTION

Influenza viruses are common agents of flu outbreaks, epidemics, and pandemics that have occurred through the centuries. Prevention and control of flu are of great clinical importance, since they cause serious damage to health, with a consequent impact on quality of life and economy of a country. Resistance against the current drugs justifies the development of new anti-influenza molecules. Flavonoids exhibit significant activity against flu through their anti-inflammatory and antiviral properties. The profile of these molecules makes them particularly promising as therapeutic agents against flu.

AREAS COVERED

This review focus on the activity of flavonoids on different influenza virus targets as well as their use in patented pharmaceutical formulations. Twenty-one patents of these compounds for prophylaxis and treatment of influenza infection are discussed.

EXPERT OPINION

The H1N1 influenza pandemic in 2009 resulted in a significant increase in the number of patents claiming pharmaceutical formulations for prophylaxis and treatment of flu. The research advances on flavonoids showing anti-influenza activity and the efforts made by researchers and industries consolidate the interest on new alternatives for the therapy of an infectious disease that represents a serious public health problem throughout the world.

Flowers from Kalanchoe pinnata are a rich source of T cell-suppressive flavonoids

The chemical composition and immunosuppressive potential of the flowers from Kalanchoe pinnata (Crassulaceae) were investigated. We found that the aqueous flower extract was more active than the leaf extract in inhibiting murine T cell mitogenesis in vitro. Flavonoids isolated from the flower extract were identified and quantitated based on NMR and HPLC-DAD-MS analysis, respectively. Along with quercetin, four quercetin glycosyl conjugates were obtained, including quercetin 3-O-beta-D-glucuronopyranoside and quercetin 3-O-beta-D-glucopyranoside, which are described for the first time in K. pinnata. All flavonoids inhibited murine T cell mitogenesis and IL-2 and IL-4 production without cell toxicity. This is the first report on the pharmacological activity of flowers of a Kalanchoe species, which are not used for curative purposes. Our findings show that K. pinnata flowers are a rich source of T-suppressive flavonoids that may be therapeutically useful against inflammatory diseases.

Flowers from Kalanchoe pinnata are a Rich Source of T Cell-Suppressive Flavonoids

The chemical composition and immunosuppressive potential of the flowers from Kalanchoe pinnata (Crassulaceae) were investigated. We found that the aqueous flower extract was more active than the leaf extract in inhibiting murine T cell mitogenesis in vitro. Flavonoids isolated from the flower extract were identified and quantitated based on NMR and HPLC-DAD-MS analysis, respectively. Along with quercetin, four quercetin glycosyl conjugates were obtained, including quercetin 3-O-β-D-glucuronopyranoside and quercetin 3-O-β-D-glucopyranoside, which are described for the first time in K. pinnata. All flavonoids inhibited murine T cell mitogenesis and IL-2 and IL-4 production without cell toxicity. This is the first report on the pharmacological activity of flowers of a Kalanchoe species, which are not used for curative purposes. Our findings show that K. pinnata flowers are a rich source of T-suppressive flavonoids that may be therapeutically useful against inflammatory diseases.

Therapeutic Potential of Kalanchoe Species: Flavonoids and other Secondary Metabolites

The Kalanchoe genus (syn. Bryophyllum), family Crassulaceae, comprises 125 species, most of them native to Madagascar. The great importance of several of these species for the traditional medicine in several regions of the World, esspecially India, Africa, China and Brazil, stimulated research programs into these plants from both a pharmacological and chemical point of view. The present review focuses on the main results obtained during the last decade on the secondary metabolites isolated from these species – endowed or not with a specific biological profile – with emphasis on flavonoids. The distribution of these molecules in the genus will be summarized and special attention will be given to K. brasiliensis and K. pinnata, two species well-known for healing inflammatory and infectious processes. Ornamental Kalanchoe species are also discussed as a potential source of bioactive compounds. This review covers the period 1970–2008.