Biological Activities and Chemical Profiles of Kalanchoe fedtschenkoi Extracts

Abstract

In this study, the leaves of Kalanchoe fedtschenkoi were consecutively macerated with hexane, chloroform, and methanol. These extracts were used to assess the bioactivities of the plant. The antimicrobial activity was tested against a panel of Gram-positive and -negative pathogenic bacterial and fungal strains using the microdilution method. The cytotoxicity of K. fedtschenkoi extracts was investigated using human-derived macrophage THP-1 cells through the MTT assay. Finally, the anti-inflammatory activity of extracts was studied using the same cell line by measuring the secretion of IL-10 and IL-6. The phytoconstituents of hexane and chloroform extracts were evaluated using gas chromatography-mass spectrometry (GC/MS). In addition, high-performance liquid chromatography (HPLC) was used to study the phytochemical content of methanol extract. The total flavonoid content (TFC) of methanol extract is also reported. The chemical composition of K. fedtschenkoi extracts was evaluated using Fourier-transform infrared spectroscopy (FTIR). Results revealed that the chloroform extract inhibited the growth of Pseudomonas aeruginosa at 150 μg/mL. At the same concentration, methanol extract inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA). Regarding their cytotoxicity, the three extracts were highly cytotoxic against the tested cell line at IC₅₀ < 3 μg/mL. In addition, the chloroform extract significantly stimulated the secretion of IL-10 at 50 μg/mL (p < 0.01). GC/MS analyses revealed that hexane and chloroform extracts contain fatty acids, sterols, vitamin E, and triterpenes. The HPLC analysis demonstrated that methanol extract was constituted by quercetin and kaempferol derivatives. This is the first report in which the bioactivities and chemical profiles of K. fedtschenkoi are assessed for non-polar and polar extracts.

Keywords: Crassulaceae; Kalanchoe fedtschenkoi; anti-inflammatory properties; antimicrobial; bioactivities; cytotoxicity; traditional medicine.

Figure 1

Viability of human-derived THP-1 cells against treatment with 50 (C1), 100 (C2), 150 (C3), and 200 (C4) μg/mL of K. fedtschenkoi using U, untreated cells, chloroform (Cl), hexane (H), and methanol (M) extracts using the MTT assay. PS, positive control (2% Tween-20); OD, optical density. Shown is the mean ± S.D. of three independent experiments. * Represents p-values significantly below to <0.0001 evaluated with Tukey’s test.

Figure 2

Immunological response of K. fedtschenkoi hexane (H), chloroform (Cl), and methanol (M) extracts on human-derived THP-1 cells using ELISA for (A) IL-6 and (B) IL-10. LPS, lipopolysaccharide (positive control for inflammation), untreated cells (U), and prednisone (Pr, anti-inflammatory, positive control). Shown is the mean ± S.D. of three independent experiments. ** Represents p-values significantly below <0.01 evaluated with Tukey’s test. *** Represents p-values significantly below <0.001 evaluated with Tukey’s test.

Figure 3

FTIR analysis of K. fedtschenkoi hexane (blue line), chloroform (yellow line), and methanol (green line).