The chemometrics analysis and integrated pharmacology approach to decipher the effect and mechanism between raw and processed cistanche tubulosa.

ETHNOPHARMACOLOGICAL RELEVANCE: Cistanche tubulosa (CT) is the dried fleshy stem with scaly leaves of Cistanche tubiflora (Schenk) Wight, which has the effects of tonifying the kidney-yang, benefiting the vital essence and blood, and moisturizing the intestines and laxatives. There are differences in the activity of CT before and after processing, but the mechanism of processing is not clear. AIM OF THE STUDY: The study aimed to compare the strength of action of CT before and after yellow-wine processing in the treatment of constipation and kidney yang deficiency and to identify the active ingredients responsible for the differences in activity before and after yellow-wine processing. MATERIALS AND METHODS: This study established the fingerprints of CT and PCT using HPLC to identify their shared components. Then efficacy of KYDS and FC were carried out to compare the differences between CT and PCT in terms of efficacy. Next, this study established the spectrum-effect relationship between the shared chemical components and the medical effects of CT and PCT using the gray correlation analysis and entropy methods. Ultimately, the activity of the analyzed chemical components was verified using the zebrafish model. RESULTS: CT was more effective than PCT in promoting intestinal peristalsis, regulating gastrointestinal hormone levels, and thus treating FC. PCT was more effective than CT in improving the level of hormone indexes of the hypothalamus-pituitary-target gland axis, replenishing blood, and enhancing immunity. Through the analysis of the spectrum-effect relationship, it was finally found that 5, 6, 12 (tubuloside A), and 13 (isoacteoside) might be more closely related to the activity of tonifying kidney yang, and peaks 9, 10, and 11 (acteoside) are more closely associated with the treatment of constipation, and peaks 3 (salidroside), 4, 1, 2 (geniposidic acid), and 8 (echinacoside) were associated with both kidney yang tonic and treatment of constipation. At the same time, an activity verification experiment showed that echinacoside, geniposidic acid, and salidroside were effective in the treatment of FC and KYDS, while acteoside was very effective in the treatment of FC, and tubuloside A was significant in supplementing the blood, which validated the spectrum-effect relationship analysis. CONCLUSION: This study proved that the raw CT had a better laxative effect, while the yellow-wine processed CT had a better kidney-yang tonic effect; moreover, spectrum-effect relationships were established to analyze the chemical components leading to changes in the activity of CT before and after yellow-wine processing.

Potent peptide agonists for human melanocortin 3 and 4 receptors derived from enzymatic cleavages of human beta-MSH(5-22) by dipeptidyl peptidase I and dipeptidyl peptidase IV.

Human beta-MSH(1-22) was first isolated from human pituitary as a 22-amino acid (aa) peptide derived from a precursor protein, pro-opiomelanocortin (POMC). However, Bertagna et al. demonstrated that a shorter human beta-MSH(5-22), (DEGPYRMEHFRWGSPPKD), is a true endogenous peptide produced in human hypothalamus. In this report, we demonstrated that in vitro enzymatic cleavage of native human beta-MSH(5-22) with two ubiquitous dipeptidyl peptidases (DPP), DPP-I and DPP-IV, generated two potent MC3/4R peptide analogues, beta-MSH(7-22) (GPYRMEHFRWGSPPKD) and beta-MSH(9-22) (YRMEHFRWGSPPKD). In fact, the MC4R binding affinity and functional potency of beta-MSH(7-22) (Ki=4.6 nM, EC50=0.6 nM) and beta-MSH(9-22) (Ki=5.7 nM, EC50=0.6 nM) are almost an order of magnitude greater than those of their parent peptide, beta-MSH(5-22) (MC4R, Ki=23 nM, EC50= 3nM). Furthermore, the DPP-I/DPP-IV cleaved peptide, beta-MSH(9-22), when administered intracerebroventricularly (ICV) at a dose of 3 nmol/rat, potently induced an acute negative energy balance in a diet-induced obese rat model, while its parent molecule, beta-MSH(5-22), administered at the same dose did not have any effect. These data suggest that DPP-I and DPP-IV may play a role in converting the endogenous beta-MSH(5-22) to more potent peptides that regulate energy homeostasis in the hypothalamus.