*2.7.4 Antidiabetic activity*

Various animal model and human trial studies reported hypoglycemic effect of piperine. Administration of peiperine to hyperglycemic rats reported that it could reduce lipid peroxidation, hyperglycemic activities, and showed antioxidant activities. With Alloxan-induced diabetic rats it was reported piperine could reduce the blood glucose level [157]. Also, it was reported to enhance the serum cholesterol, serum liver cholesterol concentration, and hepatic cholesterol-7α-hydroxylase level after administration of piperine. Several research studies demonstrated that piperine could be used as bioavailability enhancer for other phytochemicals to receive better health beneficial properties. For examples, co-administration of curcumin with piperine was found to decrease the levels of total cholesterol (TC), triglyceride (TG) and *Bioaccessibility, Bioavailability, Antioxidant Activities and Health Beneficial Properties of Some… DOI: http://dx.doi.org/10.5772/intechopen.109774*

low-density lipoprotein cholesterol in the serum and liver in higher extent compared with administration of curcumin alone [158].

#### *2.7.5 Cardiovascular health*

Piperine played critical role on cardiovascular disease by mediating oxidation status, lipid metabolism, and inflammation [150]. Piperine inhibited development of lipid droplet, oxidized low density lipoprotein uptake in macrophages, retarded lipid peroxidation, induce cholesterol efflux from macrophages [159]. It has been reported to show antihypertensive, antithrombosis effect, and protect arterial stenosis through retarding vascular smooth muscle cell proliferation [150].

### **3. Bioaccebilities and bioavailabilities of bioactive compounds**

In order to receive optimum health benefits from the bioactive compounds of foods, they have to be released from the food matrix and be bioaccessible in the gastrointestinal tract, then undergo metabolism and reach the target tissue of action. Finally, this phenomenon determines the bioavailability of the biomolecules before showing its bioefficacy [11]. Bioavailability is a complex process that involves several different phases like liberation, absorption, distribution, metabolism, and elimination. There are several factors that could affect bioavailability of bioactive compounds such as nature of food matrices, molecular structures, metabolizing enzymes, type of food processing and cooking methods [160]. Improvement in the bioavailability of food component could enhance bioefficacy of bioactive compounds. Several technologies have been developed to improve the bioavailability such as structural modifications, colloidal systems, entrapped in liposome, inclusion complexation, nanoencapsulation polymer encapsulation, and emulsion [161].

As aforementioned curcumin has many potential health benefits such as antiinflammatory, antioxidant, anticancer, antiviral, and neurotrophic activity. However, due to its insolubility in water, the poor intestinal absorption, structural instability limits the potential therapeutic and nutritional benefits [24]. Therefore, efforts have been directed to develop curcumin formulations with greater bioavailability and systemic tissue distribution [162]. Among them modification of curcumin's chemical structure, conjugation of curcumin with lipid molecules, nanoparticle encapsulated curcumin, additive matrices with piperine are some of major approaches [162]. In a study polylactic-co-glycolic acid (PLGA) and PLGA-polyethylene glycol (PEG) (PLGA-PEG) blend nanoparticles containing curcumin in rats and it was found that compared to the curcumin aqueous suspension, the PLGA and PLGA-PEG nanoparticles increased the curcumin bioavailability by 15.6- and 55.4-fold, respectively [163]. Yu et al. [164] developed a food grade curcuminoid organogel using Span 20 and medium chain triacylglycerols with high bioaccessibility and high loading of curcumin. Among the biological active components of garlic, sulfur compounds especially allicin have antioxidant, anticancer and antibacterial functions and thus are considered as the main pharmacological active components in garlic. However, it was demonstrated it suffers from instability, low aqueous solubility, strong gastrointestinal irritation and low bioavailability. To circumvent this issue nanotechnology and other embedding technology have been used. The bioactive compounds extracted from garlic were incorporated into biodegradable and biocompatible nanoparticles such as liposomes, nano-emulsions, solid lipid nanoparticles (SLN),

micelles, nano-spheres and nano-capsules, protein-based nanoparticles, biopolymeric particles, and phyto-phospholipid complexes [165]. These techniques could enhance their stability, aqueous solubility, bioavailability, target specificity and circulation time. Garlic oil nanoemulsion generated with ultrasonic emulsification could improve efficacy and reduce toxicity in treating or preventing dyslipidemia [166]. Garlic Essential Oil (GEO) have been nanoencapsulated with chitosan and persian gum as wall materials which improved stability and dispersibility [167]. GEO have been embedded in liposomes formed by lecithin (LT) and *β*-sitosterol (*β*-S) and improved the bioavailability upto 51% [168]. [6]-gingerol is the key component of ginger that provides several health benefits. However due to its poor solubility in water coupled it results in low bioavailability. Several strategies such as gingerol incorporated nanoparticles, micelles, emulsions, solid dispersion, liposomes have been prepared to improve the bioavailability. The formulation of [6]-gingerol like proliposomes prepared through modified thin-film dispersion method, which were physicochemically stable with narrow size distribution and improved bioavailability and antitumor activity [169]. Another formulation was prepared by using solid dispersion of ginger extract with hydrophilic polymer, hydroxypropyl cellulose that improved 5 fold higher gingerol bioavailability [170, 171]. Quercetin, the major compound of onion also suffers low availability due to its poor solubility [172]. Several formulations been prepared to improve the poor solubility of quercetin. For example, *β*-cyclodextrin inclusion complex of quercetin, nano-system quercetin prepared using Eudragit®E and polyvinyl alcohol (PVA), solid lipid nanoparticles of quercetin using soybean lecithin, Tween 80, and PEG 400 increased the poor solubility and good dispersion of quercetin [173–176]. Similarly, capsaicin the major bioactive compounds of pepper suffer some limitations for the short half-life, low bioavailability, burning sensation and skin irritation etc. Several strategies have been applied to improve the delivery of capsaicin such as emerging micro and nanotechnologies to encapsulate capsaicin to liposomes eg: phosphatidylcholine (PC) liposomes, microemulsion, solid-lipid nanoparticle, polymeric carriers such as micelle (eg capsaicin with polyvinylpyrrolidone (PVP)/sodium cholate/phospholipid mixed micellar system, dendrimers (dendrimers formed from oleoyl chloride, Polyethylene glycol (PEG) 400, and triethylamine, and polymersome), Inorganic carriers (metal nanoparticles egcapsaicincapped silver nanoparticles, carbon spheres) [177–180].
