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.

Kalanchoe pinnata (KP) is popularly used for treating inflammatory diseases. This study investigated the antinociceptive, antiedematogenic, and anti-inflammatory potential of the subcutaneous administration of KP flower aqueous extract (KPFE), its ethyl acetate (EtOAcF) and butanol (BuOHF) fractions, and the main KP flavonoid [quercetin 3-O-α-L-arabinopyranosyl (1 → 2) α-L-rhamnopyranoside] (KPFV) in mice, as well as its possible mechanisms of action. KPFE (30–300 mg/kg) and KPFV (1–10 mg/kg) inhibited the acetic acid-induced writhing (ID50 = 164.8 and 9.4 mg/kg, resp.). KPFE (300 mg/kg), EtOAcF (12 mg/kg), BuOHF (15 mg/kg), or KPFV (0.3–3.0 mg/kg) reduced leukocyte migration on carrageenan-induced pleurisy (ID50 = 2.0 mg/kg for KPFV). KPFE (3–30 mg/kg) and KPFV (0.3–3.0 mg/kg) reduced the croton oil-induced ear edema (ID50 = 4.3 and 0.76 mg/kg, resp.). KPFE and KPFV reduced the TNF-α concentration in the pleural exudates on carrageenan-induced pleurisy test. Moreover, KPFV inhibited COX-1 (IC50 = 22.1 μg/mL) and COX-2 (IC50 > 50 μg/mL). The selectivity index (COX-1IC50/COX-2IC50) was <0.44. These results indicate that KPFE and KPFV produced antinociceptive, antiedematogenic, and anti-inflammatory activities through COX inhibition and TNF-α reduction, revealing that the main flavonoid in KP flowers and leaves plays an important role in the ethnomedicinal use of the plant.

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--D-glucuronopyranoside and quercetin 3-O--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.

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.

Abstract:The inflammatory process, involved in several pathologies, is the natural response of the organism to an infection or to tissue injury. It comprises basically two defense mechanisms: an unspecific response (innate response), responsible for common characteristics of inflammation (redness, edema, a sense of heat, pain and loss of function) and an immunological response that involves the production of specific antibodies against an aggressor agent. The inflammatory response is not always sufficient and the process can progress to a state of chronic inflammation.Non-steroidal anti-inflammatory drugs (NSAIDs) are nowadays the main family of medicaments used to treat inflammation but they frequently show gastric and cardiovascular side effects. This situation is an incentive towards a search for new molecules for the treatment of inflammation.Many Brazilian plants are popularly used against inflammatory processes, and are therefore potential sources of new bioactive molecules. Among the different chemical classes of bioactive natural products, flavonoids -a group of polyphenolic compounds -show special promise. Flavonoids are widely distributed throughout the plant kingdom and are pharmacologically important, particularly for their action on inflammation and the immune system.In this paper different aspects of the inflammatory process and its treatment are described, with a special focus on the anti-inflammatory activity of flavonoids. A brief evaluation of the structure-activity relationship is presented.

The optimized process is faster and spends less energy than the previous one (water; 30 min at 55°C); therefore is greener and more attractive for industrial purposes. This is the first report of extraction optimization of this bioactive flavonoid. Copyright © 2018 John Wiley & Sons, Ltd.

Leaves of Kalanchoe pinnata are used worldwide for healing skin wounds. This study aimed to develop and compare two creams containing a leaf aqueous extract of K. pinnata (KP; 6 %) and its major flavonoid [quercetin 3-O-α-L-arabinopyranosyl-(1→2)α-L-rhamnopyranoside] (0.15 %). Both creams were topically evaluated in a rat excision model for 15 days. On the 12 th day, groups treated with KP leaf-extract and KP major flavonoid creams exhibited 95.3  1.2 % and 97.5  0.8 % of healing, respectively (positive control = 96.7  0.8 %; negative control = 76.1  3.8 %). Both resulted in better re-epithelialization and denser collagen fibres. Flavonol glycosides are the main phenolics in KP leaf-extract according to HPLC-ESI-MS/MS analysis. KP major flavonoid plays a fundamental role in the wound healing. The similar results found for both creams indicate that the use of KP crude extract should be more profitable than the isolated compound.

RESUMO.-[Eficácia do extrato de Kalanchoe gastonis--bonnieri no controle do biofilme bacteriano e cálculo dentário em cães.] Um extrato aquoso de folhas da espé-cie medicinal Kalanchoe gastonis-bonnieri (aqui denominado como KGB) foi efetivo como um agente antimicrobiano contra as bactérias da cavidade oral de cães em testes in vitro. Neste estudo, investigou-se o efeito da administração oral tópica de KGB sobre o desenvolvimento do biofilme dental em cães da raça Beagle. Os experimentos foram realizados com um grupo experimental (0,2% de extrato de KGB), um grupo controle negativo (0,9% de solução salina) e um grupo controle positivo (0,12% de gluconato de clorexidina). Cada tratamento foi aplicado no interior da ca- An aqueous leaf extract of the medicinal species Kalanchoe gastonis-bonnieri (here denominated KGB) has been found to be effective as an antimicrobial agent against canine oral cavity bacteria in in vitro assays. In this study, we investigated the effect of topic oral administration of KGB on the development of dental biofilm in Beagle dogs. The experiments were performed with an experimental group (0.2% of KGB extract), a negative control group (0.9% of saline solution) and a positive control group (0.12% chlorhexidine). Each treatment was sprayed into the oral cavity daily for 28 days. Thirty Beagle dogs with similar characteristics and kept under the same management and diet were used. The measurement of dental plaque and calculus was performed using a computerized analytical method. The phenolic profile of KGB extract was analyzed by HPLC-DAD. KGB extract at 0.2% showed efficacy in controlling the formation of plaque compared to the negative control group, and dental calculus in relation to the negative and positive control groups. A significant difference was observed among these three groups. Peaks attributed to flavonoids and phenolic acids were identified in the HPLC-DAD chromatogram of the KGB extract. The presence of these substances could be related to the activity observed. Our findings demonstrate that treatment with KGB is effective in controlling periodontal disease in dogs, providing new insights into the medicinal properties of this plant. KGB extract has a potential use as a supplemental agent in pharmaceutical products for the prevention of periodontal disease. Efficacy of aINDEX TERMS: Kalanchoe gastonis-bonnieri, plant extract, bacterial biofilm, dental calculus, dogs, periodontal disease, dental plaque, flavonoids. TERMOS DE INDEXAÇÃO:Kalanchoe gastonis-bonnieri, extrato de plantas, biofilme bacteriano, cálculo dentário, cães, doença periodontal, cálculos dentários, placa bacteriana, flavonoides.