Gymnemagenin Research Articles

Radio-protective efficacy of Gymnema sylvestre on Pangasius sutchi against gamma (60Co) irradiation

ABSTRACT Purpose Freshwater fish Pangasius sutchi was used in this study as a vertebrate model. We evaluated the induction of certain antioxidant enzymes in various vital organs. The radioprotective efficacy of Gymnema sylvestre leaves extract (GS) [25mg/kg Body Weight (B.W)] and its bioactive compound Gymnemagenin (GG) [0.3mg/kg B.W] was compared with Amifostine (Ami), the only radioprotector clinically approved by the US-FDA [Ami- 83.3mg/kg B.W] against different doses of gamma radiation – 60Co (Lethal Dose: LD30-9.2Gy, LD50-10.2Gy and LD70-11.4Gy). Materials and Methods This study was done via stress marker enzymes, cell cycle analysis (CCA) and DNA damage assay prediction with molecular docking, which are reported here for the first time. The results indicate an elevated LPO level and decreased level of CAT, SOD and GSH due to oxidative stress initiation by 60Co Ionizing Radiation (IR) on 4th day and slightly reduced on 32nd day while the reverse observed when the fishes were pre-treated with Ami, GS and GG. Similarly, CCA and dead/live cells counts were conducted with pre-treatment of Ami, GS and GG against 60Co IR dose (LD50-10.2Gy). Results In CCA, G0/G1 phase was observed to be the highest in Ami and lowest in GG, against 60Co IR doses 10.2Gy which was 51.76 ± 7.55. The dead cells range observed in pre-treated group of Ami, GS and GG was lowest in Ami and highest in GG and live cells (highest in Ami and lowest in GG) as compared to 60Co IR group (86.43 ± 3.42 and 8.77 ± 5.95). Thus, antioxidant profile improvement by oxidative stress reduction and gradual progression of different phases of cell cycle except the apoptotic phase along with the live cells counts indicates that the radio-protective efficacy of GS is similar to Ami. Conclusion Predictive assessment was carried out by docking of Ami, various components of GS with p53, NF-κβ cells and Rad51 proteins structures responsible for CCA, apoptosis and repair mechanism. These structural proteins were docked with other structural proteins like USP7, TNF-α and partner and localizer of BRCA2 associated (PALB2/BRCA2) complex which made us perform these systemic efforts to find the functional activity of these known radio-protectants.

Radio-protective dosimetry of Pangasius sutchi as a biomarker, against gamma radiation dosages perceived by genotoxic assays

Exposure to ionizing radiation is harmful to any living organism. It may cause varying levels of genetic mutation or ultimately death. Synthetic compounds have been used to counteract the hazardous effect of radiation on the live cells, but the possibility of these synthetic compounds being harmful to the organism being treated also exists. Herbal formulations are thus being explored as a possible alternative for the synthetic radioprotectant. Induction of DNA damage in fishes caused by ionizing radiation and its protection by phytocompounds is a hardly studied topic. In this study, we analyzed the radioprotective effect of Gymnema sylvestre leaves extract (GS) and its active compound gymnemagenin (GG) against different doses of gamma radiation (60Co) on the freshwater fish Pangasius sutchi. The radioprotective efficacy was assessed by micronuclei and alkaline comet assays. The freshwater fish P. sutchi was pre-treated with intramuscular injection (IM) of amifostine (83.3 mg/kg of B.W.), GS (25 mg/kg of B.W.) and GG (0.3 mg/kg of B.W.), 1 h prior to the gamma radiation. The fishes were exposed to LD30, LD50 and LD70 of gamma radiation and the protection activities were assessed by analyzing the number of micronuclei (MN) and erythrocytic abnormalities in the blood after 2, 4, 8, 16 and 32 days after exposure. Compared to the irradiated fishes, frequency of erythrocytic abnormalities were decreased in response to the radio-protection in the amifostine treated groups for all three doses of gamma radiation (LD70 – 77.62%), (LD50 – 80.11%) and (LD30 – 82.30%); GS (LD70 – 62.66%), (LD50 – 69.74%) and (LD30 – 70.81%); and GG (LD70 – 49.42%), (LD50 – 53.43%) and (LD30 – 58.42%). Similarly, a significant radio-protective effect in terms of decremented DNA damage was observed using the comet assay after post exposure. The percentage of protection noted for amifostine was (LD70 – 58.68%), (LD50 – 64.52%) and (LD30 – 74.40%); GS (LD70 – 53.84%), (LD50 – 59.02%) and (LD30 – 65.97%); GG (LD70 – 49.85%), (LD50 – 52.56%) and (LD30 – 64.30%). From the current study, we can conclude that the radioprotective efficacy of the GS is similar to the synthetic compound (amifostine) and also greater than the bioactive compound (GG). The synergetic effect of the plant extract which leads to a better protection than the bioactive compound must be further studied. MN and Comet assays can easily identify the damage due to radiation exposure and thus can be used as predictive biomarkers for aquatic organisms exposed to radiation.

Effects of Gymnema sylvestre extract on the pharmacokinetics and pharmacodynamics of glimepiride in streptozotocin induced diabetic rats

Gymnema sylvestre, important Indian traditional herbal medicine has been used for diabetes from several years and marketed as single or multi-herb formulations globally. People are consuming G.sylvestre along with conventional hypoglycemic drugs. Therefore, there is need of evidence based assessment of risk versus benefits when G.sylvestre co-administered with conventional oral hypoglycemic drugs. In present investigation, pharmacodynamics and pharmacokinetic interactions with oral hypoglycemic drug, glimepiride (GLM) was studied in streptozotocin (STZ) induced diabetic rats. A specific and rapid HPLC-ESI-MS/MS method was established for simultaneous quantification of GLM and gymnemagenin (GMG) in rat plasma. Pharmacokinetic and pharmacodynamic interaction studies were carried out in STZ induced diabetic rats after concomitant administration of 400mg/kg of G.sylvestre extract and 0.8mg/kg of GLM for 28 days. The developed HPLC-ESI-MS/MS method was rapid, specific, and precise. Con-comitant oral administration of G.sylvestre extract (400mg/kg) and GLM (0.8mg/kg) in diabetic rats for 28 days showed beneficial pharmacodynamic interactions whereas no major alterations in the pharmacokinetics parameters of GLM and GMG were observed. This interaction demonstrated in animal model implies that significant clinical outcome might occur during concomitant administration of G.sylvestre extract and GLM especially in diabetic patients and warrants further studies in the same set up.

Determination of gymnemagenin in rat plasma using high‐performance liquid chromatography–tandem mass spectrometry: application to pharmacokinetics after oral administration of Gymnema sylvestre extract

A sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed and validated for the determination of gymnemagenin (GMG), a triterpene sapogenin from Gymnema sylvestre, in rat plasma using withaferin A as the internal standard (IS). Plasma samples were simply extracted using liquid-liquid extraction with tetra-butyl methyl ether. Chromatographic separation was performed on Luna C(18) column using gradient elution of water and methanol (with 0.1% formic acid and 0.3% ammonia) at a flow rate of 0.8 mL/min. GMG and IS were eluted at 4.64 and 4.36 min, ionized in negative and positive mode, respectively, and quantitatively estimated using multiple reaction monitoring (MRM) mode. Two MRM transitions were selected at m/z 505.70 → 455.5 and m/z 471.50 → 281.3 for GMG and IS, respectively. The assay was linear over the concentration range of 5.280-300.920 ng/mL. The mean plasma extraction recoveries for GMG and IS were found to be 80.92 ± 8.70 and 55.63 ± 0.76%, respectively. The method was successfully applied for the determination of pharmacokinetic parameters of GMG after oral administration of G. sylvestre extract.