Biologically active constituents of hot red peppers and their properties

Spices and herbs such as oregano, garlic, thyme, rosemary, black pepper, hot red pepper and sage are listed among the most commonly researched phytobiotics in broiler nutrition. This classification as phytobiotics is not only in terms of medicinal plants or their respective essential oil extracts but also as blended combinations of multiple phytogenic products because of the large number of their bioactive compounds. Spices and herbs represent an important part of the current literature on phytobiotic applications in broiler nutrition (Horosova et al., Reference HOROSOVA, BUJNAKOVA and KMET2006; Cross et al., Reference CROSS, MCDEVITH, HILLMAN and ACAMOVIC2007; Al-Kassie et al., Reference AL-KASSIE, AL-NASRAWI and AJEENA2011; Reference AL-KASSIE, GHASSAN, BUTRIS and AJEENA2012, Kostadinović et al., Reference KOSTADINOVIĆ, LEVIĆ, GALONJA-COGHILL and RUŽIČIĆ2012; Puvača et al., Reference PUVAČA, STANAĆEV, GLAMOČIĆ, LEVIĆ, PERIĆ, STANAĆEV and MILIĆ2013; Reference PUVAČA, LJUBOJEVIĆ, LUKAČ, KOSTADINOVIĆ, STANAĆEV, POPOVIĆ, ŽIVKOV BALOŠ and NIKOLOVA2014; Reference PUVAČA, KOSTADINOVIĆ, LJUBOJEVIĆ, LUKAČ, LEVIĆ, POPOVIĆ, NOVAKOV, VIDOVIĆ and ĐURAGIĆ2015).

Biologically active constituents of plants are mostly secondary metabolites, such as terpenoids, phenolic, glycosides and alkaloids. Composition and concentrations of these biological chemicals in plants vary due to biological factors, manufacturing and storage conditions. Approximately 48% of the active substances in capsaicinoids are capsaicin (8-methyl-N-vanillyl-6-nonemide; Carol et al., 1996), which is an important alkaloid due to its neurotonic and antimicrobial activity (Tellez et al., Reference TELLEZ, JAEGER, DEAN, CORRIER, DELOACH, WILLIAMS and HARGIS1993; McElroy et al., Reference McELROY, MANNING, JAEGER, TAUB, WILLIAMS and HARGIS1994; Fadile and Elife, Reference FADILE and ELIFE2005), and its potential to decrease lipid peroxidation (Kentaro et al., Reference KENTARO, SATORU, MIKI, MINA, KAZUTOYO, CHIE, HIRONORI, TAKENORI and HIROSHI2002; Oboh et al., Reference OBOH, PUNTEL and ROCHA2006; Conforti et al., Reference CONFORTI, STATTI and MENICHINI2007). Research has proven that Capsicum annuum is the only plant that produces alkaloid capsaicinoids, which are responsible for their hot taste. Capsaicinoids are alkaloids that are important in the pharmaceutical industry for their neurological benefits (Hayman and Kam, 2008). Previous reports on the phytochemical properties of capsaicinoids have shown many biochemical and pharmacological properties which includes antioxidant, anti-inflammatory, antiallergenic and anti-carcinogenic activities (Lee et al., Reference LEE, CROSBY, PIKE, YOO and LESCOBAR2005), and may reduce the risk of cancer (Nishino et al., Reference NISHINO, MURAKOSH, TOKUDA and SATOMI2009). Kentaro et al. (Reference KENTARO, SATORU, MIKI, MINA, KAZUTOYO, CHIE, HIRONORI, TAKENORI and HIROSHI2002) and Luqman and Razvi (Reference LUQMAN and RAZVI2006) reported that capsicum is more effective than vitamin E in inhibiting lipid peroxidation. Capsaicin can potentiate the activities of pancreatic and intestinal enzymes (Platel and Srinivasan, Reference PLATEL and SRINIVASAN2004), increase bile acid secretion (Abdel Salam et al., Reference ABDEL SALAM, HEIKAL and EL-SHENAWY2005), and increase body weight gain in broiler chickens (Galib et al., Reference GALIB, AL-KASSIE, AL-NASRAWI and SABA2011; Puvača et al., Reference PUVAČA, LJUBOJEVIĆ, LUKAČ, KOSTADINOVIĆ, STANAĆEV, POPOVIĆ, ŽIVKOV BALOŠ and NIKOLOVA2014; Reference PUVAČA, KOSTADINOVIĆ, LJUBOJEVIĆ, LUKAČ, LEVIĆ, POPOVIĆ, NOVAKOV, VIDOVIĆ and ĐURAGIĆ2015). Approximately 85% of capsaicin is absorbed by passive diffusion mainly in jejunum (Kawada et al., Reference KAWADA, TETSUYA, MASAHIRO and KAZUO1984; Iwai et al., Reference IWAI, YAZAWA and WATANABE2003).

Hot red pepper (Capsicum annuum L.) as a diet supplement in poultry

The poultry do not sense the effect of hot spices, either because of the lack of receptors specific for capsaicin binding (Mason and Maruniak, Reference MASON and MARUNIAK1983; Geisthovel et al., Reference GEISTHOVEL, LUDWIG and SIMON1986) or the lack of receptors that are sensitive to capsaicin (Szolcsangi, Reference SZOLCSANGI1976). On the other hand, capsaicin increases appetite in poultry, so the addition of hot red pepper to the diet influences feed consumption of the broiler (Yoshioka et al., Reference YOSHIOKA, ST-PIERRE, DRAPEAU, DIONNE, DOUCET, SUZUKI and TREMBLAY1999). Effective compounds in hot peppers are cupsaeesin, cupsisin and cupsantine. Recent studies monitoring poultry performance showed that blends of the active compounds of hot red pepper resulted in chemo-preventive and chemo-therapeutic benefits. As seen for red chilli peppers, capsaicin is the main active compound responsible for the pungent effects of various species of the hot red peppers (Jancso et al., Reference JANCSO, KIRALY and JANSCO-GABOR1997) and the main component including hot taste. Capsaicin has been shown to have a protective function in the gastric mucosa as a stimulant of afferent nerve endings. Hencken (Reference HENCKEN1991) and Yoshioka et al. (Reference YOSHIOKA, DOUCET, DRAPEAU, DIONNE and and TREMBLAY2001) explained that hot red pepper is rich in vitamin C, which has a considerable impact in improving production through contributing to the reduction of heat stress. Although it is well known that plant extracts improve the digestibility of feeds in broilers, Hernandez et al. (Reference HERNANDEZ, MADRID, GARCIA, ORENGO and MEGIAS2004) reported that such ingredients only slightly improved performance, and these differences were not significant.

Capsinoids are a family of compounds that are analogues of capsaicin, which is the pungent component in hot red peppers. Capsinoids are widely present at low levels in hot red peppers, including capsiate, dihydrocapsiate (Kobata et al., Reference KOBATA, TODO, YAZAWA, IWA and WATANABE1999) which is thought to stimulate certain healing processes in the body.

Effects of red chilli peppers on production performances and blood lipid status of broiler chickens

Al-Kassie et al. (Reference AL-KASSIE, GHASSAN, BUTRIS and AJEENA2012) investigates the efficiency of utilisation of broiler feed supplemented with red chilli peppers on productive performance. A total of 300 one day old chicks were divided into five groups of 60 birds each and were allocated to five feeding treatments, including a control group free from any additions, and groups with addition of 0.25, 0.5, 0.75 and 1% hot red pepper, respectively. The results showed a highly significant (P<0.05) increase in live weight gain, feed consumption, improved feed conversion ratio and dressing percentage, but no significant difference in the weight of edible giblets. Diets containing 0.75 and 1.0% of hot red pepper showed a decrease in blood cholesterol concentration. It was concluded that using a mixture as feed additive at levels of 0.75 and 1% in feed enhanced the overall performance of broilers, and improved haematological traits. Shahverdi et al. (Reference SHAHVERDI, KHEIRI, FAGHANI, RAHIMIAN and RAFIEE2013) conducted a study to determine the effect of use of red pepper, black pepper and their mixtures on performance of broilers. Chicks were fed a basal diet as the control, and treatments of 0.02% red pepper, 0.02% black pepper and with the mixture of these two products. Feed intake, body weight gain and FCR were determined. Cholesterol, triglyceride, glucose levels and antibody titre against Newcastle Disease vaccine were investigated. The results revealed that the inclusion of red and black pepper in broilers diet improved weight gain, feed intake and FCR. In addition, use of red and black pepper decreased the cholesterol, triglyceride, glucose concentration and heterophil and lymphocyte ratio in blood (P<0.05). Data from the same study showed that use of red and black pepper powders in broiler diets caused an increase in total diameter of small intestines (P<0.05). It was concluded that the use of red and black pepper as feed additive at 1% level in feed enhanced the overall performance of broilers.

In an earlier study Al-Kassie et al. (Reference AL-KASSIE, AL-NASRAWI and AJEENA2011) determined the performance of Ros 308 broilers fed diets containing red chilli peppers (Capsicum annuum L.). Four levels of red chilli pepper (0.25, 0.50, 0.75 and 1.0%) were incorporated into the basal diet for six weeks. The results showed that the inclusion of hot red pepper at levels of 0.50%, 0.75% and 1.0% in the diets improved body weight gain and conversion ratio. At the same time the red chilli pepper levels at 0.25%, 0.75% and 1.0% decreased the total blood cholesterol concentration. From such data, it appears that red chilli pepper as a feed supplement in certain quantities enhances the overall performance of broiler chicks.

Goncalves et al. (Reference GONCALVES, ZANINI, FEITOSA, GONCALVES and COLNAGO2012) investigated the effects of Brazilian red pepper meal (BRPM) on liver function and performance of broilers. At 21 days of age there were elevated levels of aspartate aminotransferase and decreased alanine aminotransferase in broilers supplemented with BRPM, which was associated with higher levels of antibiotic activity compared to the control (P<0.05). There was no effect (P>0.05) of treatments on broilers weight and relative liver weight at 43 days of age. The supplementation of Brazilian red pepper with or without antibiotics improved feed conversion at 43 days of age. It was concluded that the inclusion of BRPM did not affect liver function but the addition of high levels of antibiotics associated with the BRPM resulted in alteration of hepatic enzymes.

Puvača et al. (Reference PUVAČA, KOSTADINOVIĆ, LJUBOJEVIĆ, LUKAČ, LEVIĆ, POPOVIĆ, NOVAKOV, VIDOVIĆ and ĐURAGIĆ2015) conducted experiments to investigate the effect of various spice herbs such as garlic (Allium sativum L.), black pepper (Piper nigrum L.) and hot red pepper (Capsicum annuum L.) in broiler chicken nutrition on productive performance and blood lipid profile. Experimental treatments were fed with the same basal diet as the control but with the addition of garlic, black pepper, hot red pepper and their mixture in amount of 0.5 and 1%. Chicken in the experimental treatments with two levels of hot red pepper achieved statistically significant higher final body weight compared to the control group and other treatments. The highest amounts of triglycerides, total cholesterol, low density lipoprotein (LDL) and non high density lipoprotein (non HDL) in chicken blood in the control birds was statistically different compared to the treatments. The lowest statistical levels of high-density lipoprotein (HDL) were seen in the control group. Puvača et al. (Reference PUVAČA, KOSTADINOVIĆ, LJUBOJEVIĆ, LUKAČ, LEVIĆ, POPOVIĆ, NOVAKOV, VIDOVIĆ and ĐURAGIĆ2015) concluded that the chicken fed diets containing spices achieved better production results and lipid profile status compared with those on unsupplemented feed.

Acknowledgements

This paper is a part of the project III 46012, which is financed by Ministry of Education, Science and Technological development of the Republic of Serbia.