[www.ncbi.nlm.nih.gov]

Athletes use many nutritional supplements to improve their performance regardless of nutritional status.1 Therefore, interest in safer nutritional therapies and supplements for muscle building and performance enhancement is rising.

All performance enhancing supplements are regulated by the World Anti-Doping Code as defined by the World Anti-Doping Agency.2, 3, 4, 5 Many traditional herbal medicines are being investigated as safer alternatives for their nutritional benefits and performance enhancement.

Traditionally, fenugreek seeds have been reported to be useful in hormonal regulation, in particular for male impotence and as a galactagogue in lactating mothers.9 In India, ground fenugreek seeds mixed with jaggery are recommended for females after childbirth for their anabolic effects to develop and strengthen muscles.10 Recent studies on fenugreek seeds extracts support their effectiveness in promoting lean body mass, and lowering cholesterol.11

Increased testosterone levels are known to increase muscle size and strength in men14 with downstream benefits on body weight, body fat, muscle size, strength, libido, energy, and mood.15, 16 Increased total testosterone levels could potentially affect serum free/bioavailable testosterone concentrations, resulting in escalated delivery and use by muscle cells to enhance protein synthesis, thus positively influencing strength and body fat. However, direct evidence for the androgenic effects of fenugreek seeds extract or its components in clinical practice is lacking.

Fenugreek seeds are rich in steroidal compounds like glycosides and saponins including diosgenin, yamogenin, gitogenin, tigogenin, and neotigogens. Diosgenin is an important precursor for the synthesis of a number of sex hormones.17 Diosgenin, a steroidal sapogenin, is reported to augment overall weight and muscle growth in rats.18 Moreover, diosgenin is reported to improve glucose metabolism by promoting adipocyte differentiation and inhibiting inflammation in adipose tissues.19

The results of present clinical study demonstrated the efficacy of 8-week treatment of Fenu-FG offered beneficial effects in terms of repetitions to failure in leg press, free testosterone levels and serum creatinine as compared with placebo.

Testosterone can be measured as “free” (that is, bioavailable and unbound) or more commonly, “total” (including the percentage, which is chemically bound to SHBG and unavailable). The free and nonspecifically bound plasma hormone levels generally reflect the clinical situation more accurately than total plasma hormone levels.29 Two major enzymes involved in testosterone metabolism are 5a-dihydrotestosterone30 and aromatase (CYP19A1).31 In the present study, Fenu-FG supplementation was found to increase levels of free testosterone without reduction in total testosterone.

The relationship between serum testosterone levels and libido is well established.32 The recent double-blind randomized placebo-control study demonstrated beneficial effects of fenugreek seeds extract powder enhancing male libido in healthy adult males.33 In the present study, Fenu-FG supplementation was found to increase free serum testosterone levels as compared with placebo group. Testosterone plays a key role in the development of bone mass, increased bone density and strength, stimulation of linear growth and bone maturation. Increased levels of free testosterone was found to be correlated well with indirect measures of anabolic activity of Fenu-FG supplementation observed during the study.

Cycling, step machines, and sit-up tests are often used to measure muscular endurance. A fenugreek seeds extract is reported to enhance swimming endurance capacity in mice in vivo perhaps by utilization of fatty acids as an energy source and spares glycogen.12 In our study, increased number of repetitions to failure during resistance training was observed in subjects with Fenu-FG supplemented subjects whereas placebo supplemented subjects showed decrease. In addition, significant decrease in serum creatinine and BUN levels in Fenu-FG treated subjects is probable indicator of anabolic activity.

In the present study, significant reduction in body fat and skinfold thickness (thigh and tricep) was observed by 8 weeks of treatment of Fenu-FG with non-significant increase in muscle strength and significant increase in repetitions to failure. These physiological effects can be attributed to marker compounds, furostanol glycosides that are present in Fenu-FG supplementation.

The hypocholesterolaemic effect of diosgenin has been suggested to depend on its capacity to inhibit cholesterol absorption, increase biliary cholesterol secretion, increase faecal excretion of neutral sterols and thus to decrease liver cholesterol concentrations.37

The results of earlier studies on fenugreek seeds extract40 indicate that saponins present in fenugreek do not interact directly with cholesterol but have a strong inhibitory effect on bile salt absorption40 in a quantitative manner. Other reports41, 42 of increased faecal weight and excretion of bile acids by fenugreek enriched diets support the notion. The blood and hepatic cholesterol lowering may be due to a subsequent increase in the conversion of cholesterol to bile acids by the liver.

The active treatment product is capsules containing 300 mg of Fenu-FG supplied by manufacturer (Indus Biotech Private Ltd., Pune, India).

The subjects were instructed to consume 1 capsule with water twice a day (20 min before breakfast and 20 min before dinner).

The treatment period was 8 weeks