Aspects of the taxonomy of the Kalanchoe daigremontiana species complex (Crassulaceae subfam. Kalanchooideae) and associated interspecific hybrids in southern Madagascar, with the description of a new nothospecies, K. ×descoingsii (=K. laetivirens × K. tubiflora)

Species included in Kalanchoe [subg. Bryophyllum] sect. Invasores (Crassulaceae subfam. Kalanchooideae), an infrageneric group naturally restricted to Madagascar, are, as the section name suggests, known to have several reproductive mechanisms that enable their successful establishment and spread in suitable climates in, and well away from, their natural habitats. Four species, which are particularly invasive, produce bulbils constitutively and copiously on dedicated pedestals that adorn their leaf margins or are concentrated towards the leaf tips, in the case of K. tubiflora. These species are: the predominantly pink-flowered K. daigremontiana, K. laetivirens, and K. sanctula, all with stem-peduncle transitions that give rise to distinct inflorescences, as well as K. tubiflora, which produces variously coloured inflorescences that indistinctly transition from the stem into a peduncle. Despite their apparent preferential, but not exclusive, reliance on asexual reproduction, several nothospecies involving these species have been described from southern Madagascar, and K. ×houghtonii, an artificially raised hybrid, has become naturalised on all continents bar Antarctica. Aspects of the taxonomy of these species and nothospecies are dealt with and arguments are presented in support of recognising K. laetivirens as a species, rather than as a nothospecies. The types of the names K. laetivirens and K. sanctula are no longer extant; both names are here neotypified. The geographical occurrence in Madagascar of K. laetivirens, and possibly K. ×houghtonii (=K. daigremontiana × K. tubiflora, known to have been artificially and independently produced in the USA and continental Europe), are discussed in detail. Kalanchoe ×descoingsii (=K. laetivirens × K. tubiflora) is described as a new nothospecies that was discovered in Madagascar where both parents grow sympatrically as a result of human activity.

Evaluation of Growth Parameters on Carpobrotus edulis, Kalanchoe daigremontiana and Kalanchoe tubiflora in Relation to Different Seaweed Liquid Fertilizer (SLF) as a Biostimulant

The aim of this research was to evaluate the biofertilization capacity of five different species of algae, representative of the three main groups of macroalgae selected from Lake Ganzirri in Messina, Venice Lagoon and Norwegian coasts. The experiments, started in January 2021, were conducted in the greenhouses of CREA-OF in Pescia (Pt), Tuscany, Italy (43°54′N 10°41′E) on Carpobrotus edulis, Kalanchoe daigremontiana and Kalanchoe tubiflora from seed. The test showed a significant increase in the agronomic parameters analysed in plants treated with algae extracts on succulents cultivated. The test also showed increased control of the pathogen Pythium debaryanum in seedlings where the algae extracts were introduced and also an increase in the percentage of seed germination and a reduction in the average germination time. This research work has shown that algal species have great potential for use in the development of biofertilisers in sustainable agriculture in terms of cost-effectiveness, ecological role, possible reduction of synthetic fertilisers and plant protection products, increased soil fertility and microbiological diversity.

In-Vitro Effect of Kalanchoe daigremontiana and Its Main Com-ponent, Quercetin against Entamoeba histolytica and Trichomo-nas vaginalis

Background: Parasitic infections represent one of the main public health problems in humans according to the WHO. Therefore, the need has arisen to find new treatments that can be used as an alternative cure to parasitosis. We aimed to investigate the in-vitro effects of the methanolic extract of Kalanchoe daigremontiana as well as its main component, quercetin against Entamoeba histolytica and Trichomonas vaginalis. Methods: For this purpose, the in-vitro activity of the methanol extract of K. daigremontiana also its main component, quercetin, against trophozoites of E. histolytica and T. vaginalis was evaluated, using the microassay technique. Furthermore, the antioxidant activity was determined. Finally, the cytotoxic and cytoprotective capacity was determined using the hemolysis technique. Results: The IC50 indicated that quercetin significantly (P < 0.05) inhibited the growth rate of the trophozoite stage of E. histolytica and T. vaginalis in comparison to the methanolic extract of K. daigremontiana (KalL). Also, quercetin significantly (P < 0.05) was a better antioxidant as compared with the positive control. In the evaluation of cytotoxicity effects, it could be observed that KalL as compared with quercetin exhibited more cytotoxicity against human erythrocytes. Quercetin significantly (P < 0.001) exhibited better cytoprotective activity compared to KalL. Conclusion: Both K. daigremontiana methanolic extract and quercetin alone demonstrated high antiparasitic activity against E. histolytica and T. vaginalis. However, the in-vivo efficacy of K. daigremontiana and quercetin also requires to be evaluated using an animal model.

Evaluation of the Leaf Extracts of Kalanchoe pinnata and Kalanchoe daigremontiana Chemistry, Antioxidant and Anti-inflammatory Activity

The aim of this study was to analyze the chemical components and evaluate the biological activity of the extracts from the leaves Kalanchoe pinnata and Kalanchoe daigremontiana, which are cultivated in the province of Chiriqui, Republic of Panama. Phytochemicals components, antioxidant and anti-inflammatory activities were studied. The composition of the obtained petroleum ether, ethanol and aqueous extracts was analyzed by phytochemical screening. The antioxidant activity of the extracts was studied using three in vitro model systems (DPPH radical scavenging assay, nitric oxide radical scavenging assay, and superoxide radical scavenging activity). The anti-inflammatory activity of these species was studied using an in vivo model (ʎ-carrageenan-induced paw edema in rats). Phytochemical analysis of the extracts showed the presence of alkaloids, steroids, triterpenes, flavonoids, phenolic compounds, saponins and glycosides. The greatest radical inhibitory effect was observed in the DPPH model where the ethanolic extracts of both species developed a concentration-dependent inhibitory effect, the K. pinnata extract reached a maximum inhibitory effect of 49.5 ± 5.6% (2000

Typification of the name Kalanchoe daigremontiana (Crassulaceae subfam. Kalanchooideae)

Several species and nothospecies of Kalanchoe Adanson (1763: 248) (Crassulaceae subfam. Kalanchooideae) that use multiple vegetative and reproductive methods of self-propagation have become weedy in especially mild-climate parts of the world (Garcês et al. 2007, Herrera & Nassar 2009, Smith 2019, Smith et al. 2019: 244–278). Some of these, including the nothospecies K. ×houghtonii Ward (2006: 94) (Smith 2019) and its two parent taxa, K. daigremontiana Raymond-Hamet & Perrier de la Bâthie (1914: 128) (Figs 1 & 2) and K. tubiflora (Harvey 1862: 380) Hamet (1912: 44), have taken on economic importance beyond being sold, in many instances unwisely, as ornamental plants in the horticultural trade, as their eradication from places where they have become established in vegetation well away from their natural habitats will require the investment of fiscal resources.

The Effect of Plant Extracts Kalanchoe daigremontiana and Aloe arborescens on the Metabolism of Human Multiple Myeloma Cells

The effect of plant extracts Kalanchoe daigremontiana, and Aloe arborescens on human multiple myeloma cells' viability was investigated. It was shown that plant extracts of kalanchoe and aloe reduced tumor cells' viability by 13 and 46%, respectively. The combination of plant extracts with doxorubicin showed an additive synergism of action, enhancing the antitumor effect. Treatment of multiple myeloma cells with plant extracts led to a decrease in intracellular reduced glutathione level. The intracellular glutathione level decreased by 25% under the action of kalanchoe extract and by 63% under the action of aloe extract. Extracts from kalanchoe and aloe decreased mitochondrial membrane potential by 19 and 53%, respectively. The results of the study showed that kalanchoe extract increased ATPase activity, but aloe extract did not affect the level of ATPase activity. The results showed that plant extracts of kalanchoe and aloe affect tumor cells' metabolism and contribute to their death. It was concluded that herbal extracts Kalanchoe daigremontiana and Aloe arborescens have antitumor activity, and aloe extract is more effective than kalanchoe.

Identification of Flavonoids and Bufadienolides and Cytotoxic Effects of Kalanchoe daigremontiana Extracts on Human Cancer Cell Lines

Kalanchoe species are well-known medicinal plants used in traditional medicine as anti-inflammatory and analgesic remedies. Recently, it has been reported that Kalanchoe plants have cytotoxic properties; however, data on traditional use of these plants in tumor treatment are extremely limited. Kalanchoe daigremontiana is one of the most popular species cultivated in Europe, and it is used, among other things, as a remedy in treating skin injuries and wounds. Studies on the biological activity of this species are scarce, and there is a lack of data on the cytotoxic activity of K. daigremontiana extracts on epithelial cancer cells in the literature. In our present study, we analyzed the phytochemical composition of K. daigremontiana ethanol extract and fractions–water and dichloromethane–by the HPLC-DAD-ESI-MS method and estimated cytotoxic activity of the extracts on human adenocarcinoma (HeLa), ovarian (SKOV-3), breast (MCF-7), and melanoma (A375) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, real-time cell analyzer (RTCA), and flow cytometry. We identified 6 bufadienolide compounds and 19 flavonoids, mostly kaempferol, quercetin, isorhamnetin, and myricetin glycosides, of which only 3 flavonoids have been identified in K. daigremontiana to date. Other flavonoids that were characterized in our study have not yet been found in this plant. The ethanol extract and water fraction of K. daigremontiana did not show significant cytotoxic activity on the tested cell lines. In contrast, the dichloromethane fraction showed the strongest activity against all cell lines with IC50 values of ≤ 10 µg/mL. The results indicated that this activity is mainly due to the presence of bersaldegenin-1,3,5-orthoacetate.

Vitamin C and aroma composition of fresh leaves from Kalanchoe pinnata and Kalanchoe daigremontiana

Species of kalanchoe are rich in bioactive compounds and are widely used in folk medicine; however, these plants are not well known from the point of view of aroma. Two species, Kalanchoe pinnata and Kalanchoe daigremontiana, were examined after six months and two years of growth and their vitamin C content, succulence, and aroma composition were determined. The efficiency of juice extraction was highest (72%) for the leaves of K. daigremontiana after six months of growth. The concentration of vitamin C was highest in juices from two-year-old plants and much higher in the juice of K. pinnata (81 mg/100 g). SPME/GC/MS analysis identified 32 aroma components, considering those with the spectrum similarity over 75%. The main components were furan-2-ethyl, hexanal, 2-hexenal, 2,4-hexadienal, 1-octen-3-ol, nonanal. The quantitative relations of these compounds were somewhat different in the two species. The most dominant component, 2-hexenal, is responsible for the green-like aroma noted by the sensory panel.