Repair function of essential oil from Crocodylus Siamensis (Schneider, 1801) on the burn wound healing via up-regulated growth factor expression and anti-inflammatory effect.

ETHNOPHARMACOLOGICAL RELEVANCE: Crocodile oil has been used by traditional physicians around the world to treat wound healing and inflammation. However, the scientific rationale and mechanism behind its use in vivo has not been fully researched. AIMS OF THE STUDY: We mainly investigated the mechanism during crocodile oil treatment of up-regulated growth factor expression and anti-inflammatory on burn wound healing in rats. MATERIALS AND METHODS: The moisture and nitric oxide (NO) levels in the skin of rats were analyzed in the first 14 days after burn and the changes of the structure of the skin tissues in the wound healing were studied by hematoxylin-eosin (H.E.) staining within 21 days after scald. The inflammatory factor on burn wound healing in rats was dected by ELISA kits and Q-PCR. the expression of a variety of growth factors (TGF-ß1, VEGE-α, EGF) and PCNA in the skin tissue after burns was evaluated using immunohistochemistry. The down-regulated phosphorylation of p38 MAPK in the wound healing was confirmed by Western-blot analysis. In addition, TEM was used to observe the ultrastructure of scalded skin. RESULTS: This study showed that crocodile oil could significantly reduce the protein and mRNA levels of TNF-α, IL-1ß and IL-6. And it was found that the phosphorylation of p38 MAPK was down-regulated in the wound healing (p < 0.05). Meanwhile, crocodile oil can promote the expression of a variety of growth factors (TGF-ß1, VEGE-α, EGF) and PCNA in the skin tissue after burns, and promote the repair of collagen fibers in the dermis, preventing the production of melanin and maintain the appearance of repaired skin.

EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT.

BACKGROUND: Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. MATERIALS AND METHODS: The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment - (1% wt/wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. RESULTS: COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) (P<0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). CONCLUSIONS: COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns. Abbreviations: COBO, crocodile oil burn ointment; SSD, silver sulfadiazine; MEBO, moist exposed burn ointment; TCM, traditional Chinese medicine; CHM, Chinese herbal medicine; GC-MS, gas chromatography-mass spectrometry.

Crocodile oil enhances cutaneous burn wound healing and reduces scar formation in rats.

OBJECTIVES: This study was performed to evaluate the burn wound-healing efficacy of crocodile oil from Crocodylus siamensis by employing deep second-degree burns in a Wistar rat model. METHODS: Twenty-four rats were assigned equally into four groups using a random-number table, and two burns were created on the dorsum of each animal except for the sham group. The three treatment groups received with saline solution (12 burns, served as negative control), silver sulfadiazine (12 burns, served as positive control), or crocodile oil (12 burns). Silver sulfadiazine cream was used as standard care, and the treatments were repeated twice daily for 28 days. After day 28 the animals were euthanized and the wounds were removed for quantitative real-time polymerase chain reaction, histologic, and immunohistochemical study. RESULTS: Crocodile oil accelerated the wound-healing process as indicated by a significant decrease in wound closure time in comparison to the burn control and silver sulfadiazine treatment groups. Histologic results showed well-organized and distributed skin structure and collagen deposition in the animals treated with crocodile oil. Transforming growth factor-ß1 (TGF-ß1), a key cytokine promoting scarring, was also observed to play a role in the burn wound healing. Immunohistochemical staining results showed the negative expression of TGF-ß1 and Smad3 in the 28-days-postburn skin of crocodile oil group versus positive in the epidermis of burn controls. Compared to the burn control group, expressions of TGF-ß1 and Smad3 mRNA decreased significantly (p < 0.01) in the 28-days-postburn skin of the crocodile oil group. CONCLUSIONS: Our results showed that crocodile oil could enhance cutaneous burn wound healing and reduce scar formation in rats, which might be related to TGF-ß1/Smad3 signaling.

Apoptosis of human cholangiocarcinoma cells induced by ESC-3 from Crocodylus siamensis bile.

AIM: To investigate the effects of ESC-3 isolated from crocodile bile on the growth and apoptosis induction of human cholangiocarcinoma cells. METHODS: ESC-3 was isolated from crocodile bile by Sephadex LH-20 and RP-18 reversed-phase column. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was conducted to determine the effects of ESC-3 on the proliferation of human cholangiocarcinoma cell lines (QBC939, Sk-ChA-1 and MZ-ChA-1). Giemsa staining, Hoechst 33258 and acridine orange/ethidium bromide staining showed the morphological changes of Mz-ChA-1 cells exposed to ESC-3 at different concentrations. Flow cytometry with regular propidium iodide (PI) staining was performed to analyze the cell cycle distribution of Mz-ChA-1 cells and to assess apoptosis by annexin v-fluorescein isothiocyanate (V-FITC)/PI staining. Rh123 staining was used to detect the alteration of mitochondrial membrane potential (ΔΨm). The protein levels of Bax, Bcl-2, Cdk2, cytochrome c and caspase-3 were further confirmed by Western blotting. RESULTS: ESC-3 significantly inhibited the growth of three human cholangiocarcinoma cell lines and arrested Mz-ChA-1 cell cycle at G0/G1 phase. Mz-ChA-1 cells showed typical apoptotic morphological changes after treated with ESC-3 (10 µg/mL) for 48 h. Cell death assay indicated that Mz-ChA-1 cells underwent apoptosis in a dose-dependent manner induced by ESC-3. In addition, ESC-3 treatment could downregulate the protein level of Bcl-2 and upregulate the Bax, leading to the increase in the ratio of Bax to Bcl-2 in Mz-ChA-1 cells. Meanwhile, cytochrome c was released from the mitochondria into the cytosol, which subsequently initiated the activation of caspase-3. All these events were associated with the collapse of the mitochondrial membrane potential. CONCLUSION: ESC-3, the active ingredient of crocodile bile, induced apoptosis in Mz-ChA-1 cells through the mitochondria-dependent pathway and may be a potential chemotherapeutic drug for the treatment of cholangiocarcinoma.

Apoptosis mechanism of human cholangiocarcinoma cells induced by bile extract from crocodile.

Animal bile is popularly used as a traditional medicine in China, and bile acids are their major bioactive constituents. In the present study, effects of bile extract from crocodile gallbladder on QBC939 cell growth, cell cycle, and apoptosis were investigated by MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, scanning electron microscopy, PI single- and FITC/PI double-staining flow cytometry, and western blotting. Our data have revealed that bile extract inhibited cells growth significantly, and the cell cycle was arrested in G1 phase. Bile extract induced QBC939 cell apoptosis, which was associated with collapse of the mitochondrial membrane potential and increase of ROS. In bile extract-treated cells, it was observed that the expression of bcl-2 decreased and cytochrome c released to cytosol, but the expression of bax remained unchanged. The data indicated that mitochondrial pathway might play an important role in bile extract-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of bile extract on cholangiocarcinoma cells.