Table 2 Summarized experimental studies and anti-cancer mechanisms of action of SLs

Guaianolides (Cynara scolymus) Cynaropicrin

leukocyte cancer cells in vitro

↓invasion

↓migration

↓metastasis

[150]

U937 cells in vitro

↑apoptosis

↑cell cycle stall at the G1/S stage

[151]

DU145

human prostate cancer cells

in vitro

↑anti-apoptotic genes

↑Bcl-2, ↓IL-6, ↓STAT3

↓intracellular GSH

[152]

Keratinocytes cells

in vitro

↓TrxR

↓NF-κB

[132]

Pseudoguaianolides

(Arnica montana)

Helenalin

A2780 human ovarian cancer cells

RKO colon carcinoma cancer cells

MCF-7 breast adenocarcinoma cancer cells

in vitro

↑autophagic cell death

↑caspase activity

[153]

Eudesmanolide

(Spilanthes acmella and

Taraxacum officinale)

MCF-7 breast cancer cells

in vitro

↓ metastasis

↓colony formation

[154]

HEP-2

HT-29

liver cancer cells

in vitro

↓ROS

↑apoptosis

↓cancer cells growth

[155]

DLA Dalton’s lymphoma ascites cells

V79 Chinese hamster lung carcinoma

in vitro

↑DNA damage

↓ROS

[156]

MCF-7AZ breast cancer cells

LNCap prostate cancer cells

in vitro

↓cancer cells growth

↓PI3K/AKT

[157]

[141]

A375 human melanoma cells

in vitro

↑apoptosis

↑caspase-8

[144]

SH-SY5Y neuroblastoma cells

in vitro

↑cytotoxic activity

mice

in vivo

↓tumor size

[157]

Melampodinin A

(Melampodium spp.)

PC-3

DU145

Hela

in vitro

seizure of the cell cycle at the G2/M stage

↑abnormal mitotic spindle cycle

↑cytotoxicity

[145]

Germacrene

(Solidago spp.)

germacrene D

Hepg2 liver carcinoma cells breast MCF7 carcinoma cells cervix

Hela carcinoma cells

in vitro

↑cytotoxic activity

[147]

SMMC- 7721

SGC-7901

Hela

in vitro

↑cytotoxic activity

[158]