Tea saponin

It is well known that dietary fat is not absorbed from the intestine unless it has been subjected to the action of pancreatic lipase [1], Previously, we found that basic proteins such as protamines, histones and purothionine inhibited the hydrolysis of triolein emulsified with phosphatidylcholine [2], The inhibition of hydrolysis of dietary fat may cause a decrease or delay in the intestinal absorption of fat and reduce blood chylomicron levels, an excess of which is known to induce obesity [3], Therefore, there was a possibility that inhibitory substances toward pancreatic lipase activity may prevent the onset of obesity induced by feeding a high fat diet to mice. Recently, we found that natural products such as tea saponin, platycodi radix saponin, chitin-chitosan and chondroitin sulfate inhibited the pancreatic lipase activity. In the following section, the anti-obesity effects of these natural products will be described in detail. 

Table 2. Effects of tea saponin on parametrial adipose weight and the diameter of adipose cells of mice fed a high-fat diet for 11 weeks.

Fig. (3) Effects of tea saponin on pancreatic lipase activity. Results are expressed as means- s.e.m. offour experiments.

It was demonstrated that the anti-obesity effects of oolong tea in high-fat diet-treated mice might be partly due to the inhibitory actions of the saponin fraction in oolong tea on pancreatic lipase activity. In this study, tea saponin prevented the high-fat diet-induced increases in body and parametrial adipose tissue weights by inhibiting the intestinal absorption of dietary fat via inhibition of pancreatic lipase activity, Fig. (5). 

Fig. (5) Effects of tea saponin on rat plasma triacylglycerol levels after oral administration of a lipid emulsion. Each point represents the mean s.e.m. of four rats. p<0.05, significantly different from lipid emulsion only-...

Yazicioglu, T., Karaali, A. and Gokcen, J. (1977) Turkish tea seed oil and tea saponin. Fette Seifen Anstrichm. 79, 115-120. 

Kyung KH, Lee YC (2001) Antimicrobial activities of sulfur compounds derived from S-alk (en) yl-L-cysteine sulfoxides in Allium and Brassica. Food Rev Int 17 183-198 Lee YS, Kang OH, Choi JG, Oh YC, Keum JH, Kim SB, Jeong GS, Kim YC, Shin DW, Kwon DY (2010) Synergistic effect of emodin in combination with ampicillin or oxacillin against methicUlin-resistant Staphylococcus aureus. Pharm Biol 48 1285-1290 Li Y, Du Y, Zou C (2009) Effects of pH on antioxidant and antimicrobial properties of tea saponins. Eur Food Res Technol 228 1023-1028... 

Protozoal numbers (13-16%) Ammonia production (19%) Methane production (12.7-14%) No effect on total VFA production Interactions between tea saponin and protozoa were mostly weak No effect on total VFA, ammonia, propionate... 

From the rumen, the bacteria and protozoa flow to duodenum could be observed by measuring the markers, Nitrogen and phosphatidylcholine (PC) in the rumen and duodenal digesta (Ivan et al. 2006). Not only the microbial protein synthesis, but also the flow of microbial protein to duodenum was enhanced by Sapindus saponaria (Abreu et al. 2004) and tea saponin (Mao et al. 2010 Zhou et al. 2010). These positive effects on the microbial protein synthesis, efficiency microbial protein synthesis, the microbial N flow and Non Ammonia Nitrogen (NAN) may help to improve dietary N utilization by ruminants (Busquet et al. 2005). 

Mao HL, Wang JK, Zhou YY et al (2010) Effects of addition of tea saponins and soybean oil on methane production, fermentation and microbial population in the rumen of growing lambs. Livest Sci 129 56-62... 

Zhou YY, Mao HL, Jiang F et til (2010) Tea saponins reduce ruminal methane emission through the inhibitory effect on protozoa in Hu sheep. In Presented in greenhouse gas emimal agriculture conference IV, Alberta-Ctmada, 4-8 Oct 2010... 

In an in vivo experiment in sheep with tea saponins it has been reported that saponins inhibit protozoa, methane emission and improved rumen fermentation, where the reduction of methane emission was mediated through inhibitory effect on protozoa (Zhou et al. 2010). 

---