Microscopic images at 10X of A549 (A-F) and C-6 (G-J) cells treated for 24–48 h with 100 μg/mL of leaf and flower oils of C. citrinus (A) Control, no treatment after 24 h. (B) Control, no treatment after 48 h. (C) After 24 h treatment with flower oil. (D) After 48 h treatment with flower oil. (E) After 24 h treatment leaf oil. (F) After 48 h treatment with leaf oil. (G) Control, no treatment after 24 h. (H) Control, no treatment after 48 h. (I) After 24 h treatment with flower oil. (J) After 48 h of treatment with flower oil.

<p>Microscopic images at 10X of A549 (A-F) and C-6 (G-J) cells treated for 24–48 h with 100 μg/mL of leaf and flower oils of C. citrinus (A) Control, no treatment after 24 h. (B) Control, no treatment after 48 h. (C) After 24 h treatment with flower oil. (D) After 48 h treatment with flower oil. (E) After 24 h treatment leaf oil. (F) After 48 h treatment with leaf oil. (G) Control, no treatment after 24 h. (H) Control, no treatment after 48 h. (I) After 24 h treatment with flower oil. (J) After 48 h of treatment with flower oil.</p

(A) <i>C</i>. <i>citrinus</i> plant. (B) Flower of <i>C</i>. <i>citrinus</i>.

<p>(A) <i>C</i>. <i>citrinus</i> plant. (B) Flower of <i>C</i>. <i>citrinus</i>.</p

Activation of caspase 3, 7, 9, PARP and β-tubulin by western blot analysis after 36 h treatment with essential oils of (flowers and leaves) <i>C</i>. <i>citrinus</i>.

<p>Activation of caspase 3, 7, 9, PARP and β-tubulin by western blot analysis after 36 h treatment with essential oils of (flowers and leaves) <i>C</i>. <i>citrinus</i>.</p

IC₅₀ value against A549 & C-6 cells in μg/mL.

<p>IC₅₀ value against A549 & C-6 cells in μg/mL.</p

Induction of apoptosis on A549 and C-6 cells by leaf and flower oils at 20, 50 and 100 μg/mL assessed by flow cytometry.

<p>(A) A549 cells treated with flower oil for 12 h. (B) A549 cells treated with leaf oils for 12 h. (C) C-6 cells treated with flowers oil for 24 h.</p

<i>In vitro</i> cytotoxicity of leaf and flower oils against human PBMCs by MTT assay.

<p><i>In vitro</i> cytotoxicity of leaf and flower oils against human PBMCs by MTT assay.</p

<i>In vitro</i> cytotoxicity of <i>C</i>. <i>citrinus</i> oil against A549, C-6, Colo-205 and SiHa cells by SRB assay.

<p>(A) Flower oil. (B) Leaf oil.</p

Activation of CDK 2, 6, 7, 9, CDC 2 and β-tubulin by western blot analysis after 36 h treatment with essential oils of (flowers and leaves) <i>C</i>. <i>citrinus</i>.

<p>Activation of CDK 2, 6, 7, 9, CDC 2 and β-tubulin by western blot analysis after 36 h treatment with essential oils of (flowers and leaves) <i>C</i>. <i>citrinus</i>.</p

Chemical composition (%) of flower and leaf oils produced by hydrodistillation from Callistemon citrinus.

<p>¹ RRI, Relative Retention Indices on DB-5MS column were calculated from retention times relative to <i>n</i>-alkanes</p><p>² Absent</p><p>Chemical composition (%) of flower and leaf oils produced by hydrodistillation from Callistemon citrinus.</p

Effect of leaf and flower oils on cell cycle against A549 (A-F) and C-6 (G-I) cells after 24 h.

<p>(A) & (D) Control, no treatment. (B) Treated with flower oil at 20 μg/mL. (C) Treated with flower oil at 50 μg/mL. (E) Treated with leaf oil at 50 μg/mL. (F) Treated with leaf oil at 100 μg/mL. (G) Control, no treatment. (H) Treated with flower oil at 50 μg/mL. (I) Treated with flower oil at 100 μg/mL.</p