Materials and Methods: Twenty-five ICR mice and 20 BALB/C mice were used where five animals as control and the rest were randomly divided into four time points at 5, 10, 24 and 48 hours post-dosing (hpd). They were induced with 500 mg/kg APAP intraperitoneally. Liver sections were processed for hematoxylin-eosin staining and histopathological changes were scored based on grading methods.

Results: Intense centrilobular damage was observed as early as 5 hpd in BALB/C as compared to ICR mice, which was observed at 10 hpd. The difference of liver injury between ICR and BALB/C mice is due to dissimilarity in the genetic line-up that related to different elimination pathways of APAP toxicity. However, at 24 hpd, the damage was markedly subsided and liver regeneration had taken place for both ICR and BALB/C groups with evidence of mitotic figures. This study showed that normal liver architecture was restored after the clearance of toxic insult.

AIM OF THE STUDY: To assess topical anti-inflammatory effect of Haruan cream on 12-0-tetradecanoylphorbol-13-acetate (TPA)-induced chronic-like dermatitis in mice.

MATERIALS AND METHODS: Male ICR mice were randomized into six groups of five mice each: acetone (vehicle), TPA alone (negative control), three Haruan treatment groups (Haruan 1%, Haruan 5% and Haruan 10%) and hydrocortisone 1% (positive control). Briefly, both surfaces of mouse ears were applied with TPA (2.5μg/20μl acetone) for five times on alternate days and with Haruan or hydrocortisone 1% cream for the last three days. Mouse ear thickness was measured 24h after final treatment with the cream and the ears were harvested for further histological analysis and gene expression studies of TNF-α by real-time reverse transcriptase-polymerase chain reaction (RT-qPCR).

RESULTS: Topical application of Haruan cream had reduced the mouse ear thickness 18.1-28%) with comparable effect to the positive control. In addition, histopathological comparison had shown evident reduction in various parameters of cutaneous inflammation including dermal oedema, inflammatory cells infiltration and proliferation of epidermal keratinocytes. Furthermore, TPA application had resulted in the up-regulation of TNF-α gene expression by 353-fold, which was subsequently down-regulated by the Haruan cream (34- to 112-fold).

METHODS: Mice were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 μL) followed by, in subsequent week, repeated promotion (twice weekly; 22 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 μL). Annonacin (85 nM) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application for 22 weeks. Upon termination, histopathological examination of skin, liver and kidney as well as genes and proteins expression analysis were conducted to elucidate the potential mechanism of annonacin.

RESULTS: With comparison to the carcinogen control, Annonacin significantly increased the tumor latency period and reduced the tumor incidence, tumor burden and tumor volume, respectively. In addition, it also suppressed tumorigenesis manifested by significant reduction of hyperkeratosis, dermal papillae and number of keratin pearls on skin tissues. Annonacin also appeared to be non-toxic to liver and kidney. Significant modulation of both AKT, ERK, mTOR, p38, PTEN and Src genes and proteins were also observed in annonacin-targeted signaling pathway(s) against tumorigenesis.