Objective:

2

To examine the effect of the aqueous extract of

Ligustrum robustum

on tumor growth

in vitro

and

in vivo

and explore the possible molecular mechanisms.

Methods:

2

In

in vitro

study

cell viabilities of human cervical carcinoma cells (HeLa)

human breast cancer cells (MCF-7)

human prostate cancer cells (PC-3)

human hepatoma cells (7721) and human colon carcinoma cells (SW480) were evaluated with cell counting kit-8. For

L. robustum

-treated Hela cells

early or late apoptosis were evaluated by annexin V/PI staining. Mitochondrial membrane potential was measured by staining cells with JC-1. Apoptosis was monitored by nuclear morphology based on chromatin condensation and fragmentation by 4'

6-diamidino-2-phenylinole (DAPI) staining. Caspase-3 and -8 activity levels were measured by a colorimetric assay.

In vivo

to evaluate the possible mechanism of

L. robustum

-mediated antitumor effect

nude mouse xenograft study was also conducted.

Results:

2

In

in vitro

study

L. robustum

was found to be toxic to HeLa

MCF-7

PC-3

7721

SW480

with an half maximal inhibitory concentration value of 2–5 mg/mL (

P

<

0.05). Moreover

externalization of phosphatidylserine

loss of mitochondrial membrane potential

DNA fragmentation and activation of caspase-3 and -8 were detected in

L. robustum

-treated Hela cells. Using a nude mouse model bearing Hela xenografts

we found that

L. robustum

reduced tumor volume and tumor weight (

P

<

0.05)

but had no effect on body weight and histological damage of important organs. Intraperitoneal injection of

L. robustum

caused a significant reduction in serum aspartate transaminase and alanine transaminase levels (

P

<

0.05). Furthermore

cleaved caspase-3-positive and terminal nucleotidyl transferase-mediated nick end labeling (TUNEL)-positive cells were observed in

L. robustum

-treated tumor tissues.

Conclusions:

2

L. robustum

inhibits tumor cell growth both

in vitro

and

in vivo

by inducing apoptosis in a caspasedependent way without apparent hepatic toxicity and histological damage

which may offer partial scientific support for the ethnopharmacological claims of

L. robustum

as a herbal tea for its antitumor activity.