Key Findings
Sex hormones, such as the androgens testosterone and dihydrotestosterone (DHT), play an important role in the pathogenesis of benign Prostatic Hyperplasia (also known as benign prostatic hypertrophy (BPH). The primary androgen responsible for the pathogenesis of BPH is DHT, which is formed upon the conversion of testosterone by the enzyme 5a reductase leading to an increased level of DHT in the prostate. Due to the imbalance between testosterone and DHT in the circulation and/or prostate tissue linked to the enzyme 5a reductase, which excessively catalyzes DHT production from testosterone, DHT stimulates prostate tissue proliferation via binding with adrenergic receptors. The preventive effects of a lignan rich extract (LLE) from flaxseed hulls on BPH in male Wistar Unilever rats was demonstrated. LLE in the diet before the induction of BPH, significantly reduced the pathology in a dose to dependent manner inhibiting prostate growth and normalizing food consumption. Both average prostate weights and prostate weight ratios were significantly lower in rat fed LLE at both doses of 0.5 percent and 1.0 percent in comparison with positive control rats. The efficacy of LLE in preventing BPH was dose to dependent. Serum ENL concentrations determined at the end of the 5 week treatment period were 5 to 10 times higher in animals fed the LLE enriched diets. This action may involve an inhibition of 5a reductase by ENL. Further studies aimed at determining mechanisms of action of LLE to explore the preventive efficacy of lignans and their metabolites are recommended.
ABSTRACT
Consumption of diet rich in lignans may decrease the risk of some chronic hormonal conditions such as benign hyperplasia (BPH). This study investigated whether a lignan rich extract from flaxseed hulls, LinumLife EXTRA (LLE), could prevent BPH using the testosterone propionate (TP) induced BPH rat model. Male Wistar unilever rats were randomly divided into four groups of 12 rats each: a negative control group fed with control diet and receiving daily LLE (LLE 0.5) or 1.0 percent LLE (LLE 1.0) and receiving daily subcutaneous injections of TP in corn oil. Treatments with diets started 2 weeks before the induction of BPH and were carried out for 5 consecutive weeks. The influence of TP and LLE on body weight (BW), food and water consumptions, and enterolactone (ENL) levels in serum and urine of rats was examined at the end of the 5 week treatment period. TP significantly diminished the mean body weight gain (MBWG) of positive control rats and their food and water consumptions while LLE reduced, significantly this MBWG reduction in a dose to dependent manner. The lignan rich extract significantly inhibited TP induced prostate size ratio (prostate weight/rat BW) increase in comparison with positive controls. This effect was dose dependent. Higher serum and urine levels of ENL correlated well with the dose of extract provided to rats. It was concluded that the lignan rich flaxseed hull extract prevented the TP induced BPH indicating it might be beneficial in the prevention of BPH. (Authors abstract)
Link to Full Text