Immunochemical identification of the mammalian peptide hormone obestatin from tea plant (Camellia sinensis).

This study determines obestatin-like substances from the young shoots of the tea plant [Camellia sinensis (L.) O. Kuntze (Theaceae)]. Proteins were extracted from the vegetative tea leaves using the QB (Quick Buffer) buffer as an extraction buffer. Obestatin-like substances in tea extract were investigated using an indirect home-made enzyme-linked immunosorbent assay (ELISA). Human obestatin-like immunoreactive substances from tea extract were isolated and characterized by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (tricine-SDS-PAGE) and immunoblotting techniques. Immunochemical results showed that there are strong human obestatin-like immunoreactive substances (0.048±0.0064ng/mg protein) in vegetative tea leaves. This finding was completely unexpected since this hormone was considered to be present solely in animals. Furthermore, a single obestatin-like immunoreactive protein band of 13kDa was identified by tricine-SDS-PAGE and Western blotting of extract of vegetative tea leaf proteins. Present investigation is the first report of presence of obestatin-like immunoreactive substances in plants. It is concluded that obestatin-like bioactive peptides derived from plants can affect gastrointestinal tract structures as endogenous obestatin does and hence play a role in appetite regulation and body weight gain.

Effect of alpha lipoic acid on smoking-induced skin damage.

OBJECTIVE: Exposed to cigarette leads to the formation of reactive oxygen species and the generation of bioactive molecules that can damage skin cells. This investigation was carried out to study possible effects of Alpha Lipoic Acid (ALA) on smoking-induced rat skin injury. MATERIALS AND METHODS: 28 Spraque-Dawley female rats were allocated into three groups: control group (n = 8), smoking group (n = 10; 12 cigarettes/day, 8 weeks) and smoking + ALA group (n = 10; 12 cigarettes/day + 100 mg/kg, 8 weeks). Experiment group animals were sacrificed under anaesthesia with 10%ketamine + 2%xylasine at the end of second mounts and then skin examples were taken from the epigastric area. Histochemical (Haematoxylin-Eosin and Masson's trichrome, immunohistochemical (TNF-α) and biochemical analysis (CAT, MDA and protein carbonylation) were performed on these skin tissues. RESULTS: Histologically, skin was distinguished normal structure in the control group. In the smoking group, collagen bundles and hair follicle degradation/reduction, sweat gland degeneration, mononuclear cell infiltration in dermis were encountered. In ALA-treated group, all of these changes were improved (p < 0.05). Collagen bundles structures were appearance more regular than the smoking group . Immunohistologically, intense staining was observed in the smoking group, while very weak staining was observed in control group, weak staining was observed in the ALA-treated group. Biochemically; The CAT activity compared to cigarette group with control was raised high and in ALA group was higher compared to both groups, but not significant (p > 0.05). MDA; which is indicator of lipid peroxidation was significantly higher in cigarette group than in control group (p < 0.05) and was significantly lower in ALA group than cigarette (p < 0.05). Protein carbonylation was higher in cigarette group than the control group but not in the non-significant (p > 0.05). In the ALA it was significantly lower compared to the control group and cigarette (p < 0.05). CONCLUSIONS: Based on biochemical and histopathological determinations, the study showed that cigarette smoke can cause degenerative effects on skin tissues in rats. However, ALA has a curative effect on cigarette-induced injuries on the skin tissues by anti-oxidative and anti-inflammatory effects.