Cassia auriculata L. (CA) is profoundly used as a tonic, astringent, anti-diabetic, conjunctivitis and opthalmia in Ayurvedic medicine (Subhadradevi et al., 2011). It is one of the principle constituent of Avaarai panchaga chooranam; an Indian herbal formulation used in the treatment of diabetes to control the blood sugar level (Berman et al., 2001). Cassia species, are rich sources of polyphenols, anthraquinone derviatives, flavanoids, polysaccrides, saponins, tannins and steroids (Singh et al., 1980; Yen et al., 1998; Ayo et al., 2004), flavanoids, sterols/terpenoids and phenolic acids are known to be antidiabetic bioactive principles. Flavanoids are known to regenerate the damaged β cells in alloxan induced diabetic rats (Yasir M et al., 2012).
Diabetes mellitus, caused by an absolute or relative deficiency of insulin or its function, lead to number of complications, it is emerging as the factor responsible for chronic disability and even death. Most of the secondary failures are observed with monotherapy and devastating long term consequence of poor glycemic control. Also it is always beneficial to switch over the patient on combination therapy. A reasonable goal of treatment is to maintain good glycemic control through combination therapy to keep the blood glucose level to near normal to particular patient. (Kuchake V. G, et al. 2009).
The first choice of biguanide for the recently diagnosed diabetic patients is MT (MT). It acts by reducing hepatic glucose production and improving insulin sensitivity. Studies have suggested that administration of MT with phytoconstituents / herbal products presumably enhanced therapeutic effects (Dey et al., 2002), however sufficient data is lacking with respect to their potential Pharmacodynamic (PD) and Pharmacokinetic (PK) interaction. Added exploration on their interaction between CA and MT at PK-PD levels will provide conceivable interest in administering in combination for the treatment of diabetes.
A dependable and effective analytical method was required for the assessment of PK Studies. We developed a simple, rapid and precise RP-HPLC-UV method. The method was validated and engaged to a PK study were CA and MT was co-administered to normal rats to investigate the potential PK interaction.
2. Materials and methods
2.1. Chemicals and reagents
Cassia auriculata extract (CA) was purchased from Green Chem Herbal Extracts and Formulation Ltd., (Bangalore, India). MT (MT) and Pioglitazone (IS) was purchased from Cipla Pharmaceuticals (Mumbai, India). HPLC grade acetonitrile, and potassium dihydrogen phosphate from E. Merck (Mumbai, India). Streptozotocin from Hi Media Laboratories Pvt. Ltd., (Mumbai, India). MilliQ Water for HPLC was procured from In-house MilliQ RO water purification system.
2.2. HPLC instrumentation and analytical conditions
The RP-HPLC comprised of a dual plunger pump (LC-10ATVP, Shimadzu, Kyoto, Japan), a UV-VIS detector (SPD 10AVP, Shimadzu) equipped with...