Challenges in natural health product research: The importance of standardization.

Before there can be acceptance of natural health products (NHPs) or "phytomedicines" by the Western medical community, questions related to active ingredients, mechanisms of action, toxicology, and drug interactions will need to be satisfactorily addressed. Since NHPs are generally manufactured from highly variable raw materials, identifying the therapeutically active ingredients can be challenging. Standardization according to all known bioactive components is critical to ensure consistent pharmacological and clinical results. CV Technologies, Inc. has made great strides in resolving these challenges through the patented technology, ChemBioPrint. During early ChemBioPrint product development, the optimal active components of a natural extract are identified and characterized chemically (chemical fingerprinting) and pharmacologically through a variety of activity assays (biological fingerprinting). Subsequent manufacturing steps ensure each batch is standardized accordingly and has consistent composition and efficacy. Case studies will be presented on two commercially available ChemBioPrint products: COLD-fX (an immune-modulator) and REMEMBER-fX (a neuro-modulator). Unique and important structure-function relationships exist between the major classes of bioactive molecules from the shared source material of these two products, Panax quinquefolius. Through numerous published and ongoing clinical trials and pharmacological studies, these ChemBioPrint products have been shown to be consistent, safe and effective. The future directions of NHP research will be discussed, including the requirements for accurate reporting of study results related to ingredient and standardization descriptions.

Regulation of parathyroid hypertensive factor secretion by Ca2+ in spontaneously hypertensive rat parathyroid cells.

BACKGROUND: Elevated parathyroid hypertensive factor (PHF) has been suggested to play a causal role in the pathogenesis of hypertension. Previous studies have indicated that PHF secretion is stimulated by low extracellular (EC) Ca2+. Therefore, we hypothesized that the calcium-sensing receptor (CaR) is involved in regulation of PHF release. METHODS: Parathyroid gland (PTG) organ and cell cultures derived from spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats were exposed to low and normal EC Ca2+ and PHF release measured by ELISA. Expression of CaR protein was assessed by Western blot. RESULTS: Low EC Ca2+ stimulated both SHR and WKY PTG organ cultures to secrete more PHF, first observable after 60 min incubation. After 4 h, PHF secretion was stimulated (66-fold v 24-fold stimulation for SHR and WKY, respectively). Cultured SHR and WKY parathyroid cells were also stimulated, but to a lesser extent (2.63-fold v 3.75-fold stimulation for SHR and WKY respectively). After 24 h the stimulation by low EC Ca2+ was no longer apparent. Expression of CaR is elevated in the SHR relative to WKY PTG. In both strains expression is higher under conditions of normal (1.5 mmol/L) EC Ca2+ and it increases with incubation time. The apparent suppression of PHF release by normal (1.5 mmol/L) EC Ca2+ is blocked by pre-exposure of the PTG cells to anti-CaR antibody. CONCLUSIONS: Low EC Ca2+ stimulated rapid PHF release from both SHR and WKY PTG. Changes in CaR expression may account for different sensitivity to EC Ca2+ of the two strains and over time.

Protein kinase C masks nitric oxide synthase activity in vascular smooth muscle under basal conditions.

Under basal conditions there is no observable nitric oxide synthase (NOS) activity in vascular smooth muscle (VSM). Pretreatment of endothelium-denuded aortic rings from Sprague-Dawley rats with 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), (0.1 micromol/L) significantly attenuated phenylephrine (PE)-induced contractile responses in a dose-dependent manner. In the presence of 10 micromol/L Nomega-nitro-L-arginine (L-NNA) or 0.1 mmol/L aminoguanidine (AG), the inhibition of contractions at 10 nmol/L PE by H-7 was blocked by 88% or 52%, respectively. The blockade by antagonists was completely reversed by l-arginine but not by d-arginine, and alone they did not significantly alter PE-induced contraction of endothelium-denuded aorta. Methylene blue (MB, 50 micromol/L) also inhibited the action of H-7. The inhibitory effect of H-7 occurred after 5 minutes and was reversible. PE-induced contraction was also inhibited by the selective protein kinase C inhibitors calphostin C (10 micromol/L), and bisindolylmaleimide IV (Bis-IV, 10 micromol/L), but not by the selective protein kinase A inhibitor H-89 (0.1 micromol/L). These results indicate protein kinase C inhibits NOS activity in VSM under basal conditions. Incubation of tissues with either H-7 or calphostin C stimulates NO production, and immunocytochemical studies reveal the presence of NOS in VSM under basal conditions.