## 3 Encapsulation Techniques for Improving Phenolic Compounds Functionality
### Encapsulated Phenolic Compounds as Antidiabetic Agents
Proanthocyanidins are flavonoids found in many plants such as cranberries, blueberries, and grape seeds and have various pharmacological properties such as antioxidant, anticancer, antidiabetic, neuroprotective, and antimicrobial activities [112, 113]. A cinnamon extract rich in proanthocyanidins was encapsulated by complex coacervation combining gelatin and five different polysaccharides (gum arabic, pectin, cashew gum, carboxymethylcellulose, and K-carrageenan) [102]. The complex coacervation method successfully produced microparticles of cinnamon extract that exhibited high encapsulation efficiency and encapsulation yield [102]. Additionally, this encapsulation method protected the extract components, improving the antioxidant capacity and inhibiting the digestive enzymes \(\alpha\)-amylase and \(\alpha\)-glycosidase [102]. \begin{table}
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**Compound** & **Encapsulating** & **Type of Study/** & **Biological** & **Positive Effects** & **Refs** \\  & **Material/Technique** & **Dose** & **Parameters/Activities** & & \\ \hline Curcumin & Poly (gammabenzyl & _In vivo_/20 mg/kg & H\({}_{2}\)S and [Ca\({}^{2+}\)]\({}_{1}\) & Enhanced & [97] \\  & l-glutamate)-poly & administered to (ethylene glycol)-poly & Calcium-sensing receptor (CaSR) & drug solubility Improve & \\  & (gammabenzyl & rats for over 8 weeks & H\({}_{2}\)S generating enzymes (CSE) & Alleviated pathological morphological damage of myocardium & \\  & & encapsulated & Calmodulin (CaM) & Decreased blood glucose levels & \\  & digestive conditions & curcumin & & & \\ \hline Polyalkylcyanoacrylate microspheres & _In vivo_/4 mg/kg & Blood glucose, weight & Decreased blood glucose levels & [98] \\  & /Oil-in-water & (sublingual vein injection) to diabetic & Cytokines & Decreased mechanical and thermal & \\  & & rats in the 7 th & receptor (P2Y12) & hyperalgesia in diabetic rats & \\  & & and 8 th week & & & \\ \hline Gelatin microspheres into enzyme matrix & _In vitro_ using human & Antioxidative activity & Decreased ROS and increased GSH levels & [99] \\  & & normal skin fibroblast & after induced oxidation (H\({}_{2}\)O\({}_{2}\)) & Increased cellular & \\  & & & & & \\  & & human epidermal thermoresponsive & Cells/0.01, 0.1, or hydrogel/ & Cellular uptake(48-60\%) & compared to free \\  & & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \hline Nanigerin & Chitosan alginate core-shell nanoparticles/ & _In vivo_ using streptozotocin- & Blood glucose & Significant & [100] \\  & Ionotropic gelation & induced diabetic rats/50 mg/kg of & Serum cholesterol and triglyceride & hypoglycemic effect & \\  & & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \hline Berberin & Poly(lactic-co-glycolic acid)-poly (ethylene glycol)-Poly(lactic-co-glycolic acid) block copolymer nanoparticles/Nanoprecipitation & In vitro using Hep-G2 cells & PCSK-9, SREBP-1, LDL-r, HNF-1 alpha mRNAs and PCSK-9 protein expression & PCSK-9 modulation by & [101] \\  & & & & & improving Berberin \\  & & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \hline \hline \end{tabular}
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Table 2: Encapsulation technologies for different phenolic compounds and their positive effects observed in _in vitro_/_in vivo_ studies. Quercetin is a flavonoid found in citrus fruits and tea with antioxidant and anti-inflammatory properties [114]. It was reported to lower blood pressure, insulin resistance, and cholesterol levels [114]. In an _in vivo_ anti-diabetic study, focused on improving the the thermal conductivity of the cells. The results of the experiments are summarized in Table 2.