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 ± 0.0064 ng/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 13 kDa 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.