METHOD: Literature search was performed within the PubMed, ScienceDirect.com and Google Scholar.
RESULTS: The presence of proline at the C-terminal tripeptide of ACE inhibitor can competitively inhibit the ACE activity. The effects of other amino acids are less studied leading to difficulties in predicting potent peptide sequences. The broad specificity of the enzyme may be due to the dual active sites observed on the somatic ACE. The inhibitors may not necessarily competitively inhibit the enzyme which explains why some reported inhibitors do not have the common ACE inhibitor characteristics. Finally, the in vivo assay has to be carried out before the peptides as the antihypertensive agents can be claimed. The peptides must be absorbed into circulation without being degraded, which will affect their bioavailability and potency. Thus, peptides with strong in vitro IC50 values do not necessarily have the same effect in vivo and vice versa.
CONCLUSION: The relationship between peptide amino acid sequence and inhibitory activity, in vivo studies of the active peptides and bioavailability must be studied before the peptides as antihypertensive agents can be claimed.
METHODS: Cocoa pod extract (CPE) composition was accomplished using UHPLC. The antioxidant capacity were measured using scavenging assay of 1,2-diphenyl-2-picrylhydrazyl (DPPH), β-carotene bleaching assay (BCB) and ferric reducing antioxidant power (FRAP). Inhibiting effect on skin degradation enzymes was carried out using elastase and collagenase assays. The skin whitening effect of CPE was determined based on mushroom tyrosinase assay and sun screening effect (UV-absorbance at 200-400 nm wavelength).
RESULTS: LC-MS/MS data showed the presence of carboxylic acid, phenolic acid, fatty acid, flavonoids (flavonol and flavones), stilbenoids and terpenoids in CPE. Results for antioxidant activity exhibited that CPE possessed good antioxidant activity, based on the mechanism of the assays compared with ascorbic acid (AA) and standardized pine bark extract (PBE); DPPH: AA > CPE > PBE; FRAP: PBE > CPE > AA; and BCB: BHT > CPE > PBE. Cocoa pod extract showed better action against elastase and collagenase enzymes in comparison with PBE and AA. Higher inhibition towards tyrosinase enzyme was exhibited by CPE than kojic acid and AA, although lower than PBE. CPE induced proliferation when tested on human fibroblast cell at low concentration. CPE also exhibited a potential as UVB sunscreen despite its low performance as a UVA sunscreen agent.
CONCLUSIONS: Therefore, the CPE has high potential as a cosmetic ingredient due to its anti-wrinkle, skin whitening, and sunscreen effects.