An Insight Into the Anxiolytic Effects of Lignans (Phyllanthin and Hypophyllanthin) and Tannin (Corilagin) Rich Extracts of Phyllanthus amarus : An In-Silico and In-vivo approaches.

The extracts and the compounds isolated from Phyllanthus amarus Schumm and Thonn (Family: Euphorbiaceae) have shown a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective, nephroprotective and diurectic properties. BACKGROUND: This investigation was aimed at exploring the anxiolytic potential of Phyllanthus amarus standardized extracts and predict probable role of marker phyto constitutents. OBJECTIVE AND METHODS: Three standardized extracts of Phyllanthus amarus plant viz. standardized aqueous extract of Phyllanthus amarus whole plant (PAAE), standardized methanolic extract of P. amarus leaf (PAME) and the standardized hydro-methanolic extract of P. amarus leaf (PAHME) were tested in the classical animal models of anxiety: Elevated plus-maze model and Light & Dark Exploration test. RESULTS: The lower doses of the tannin rich extract (PAHME) of the P. amarus possess significant anxiolytic activity compared to lignin rich (PAME) and aqueous extracts (PAAE), while at a higher dose (400mg/kg) the results of all three extracts appears to be potentially sedative. While the molecular docking studies support these probable anxiolytic, the sedative effects of the Phyllanthus amarus extracts could be due to the interaction of tannins and lignans with the GABAbenzodiazepine receptor complex. CONCLUSION: The results of the present study indicate that the tannin-rich extract of the P. amarus may have potential clinical applications in the management of anxiety. It can be further studied for optimum dosage to be used as a future of anti-anxiety drug development or as a standardized Phytomedicine.

Pharmacological characterization of carrageenan induced heat muscle hyperalgesia in rats using non-selective, preferential and selective COX-2 inhibitors.

BACKGROUND: Previous studies have shown that unilateral injection of carrageenan into the gastrocnemius muscle produces chronic thermal and mechanical hyperalgesia. AIM: In the present study, we have characterized this model of muscoskeletal inflammatory pain, by evaluating the antihyperalgesic effects of selective and non-selective COX-2 inhibitors after systemic administration. MATERIALS AND METHODS: Rats were injected with 3% carrageenan in the left gastrocnemius muscle and hyperalgesia to heat stimuli (measured as decreased withdrawal latency) to paws was assessed before and at varying times after injection, till end of 2nd week. Histological changes and the determination of prostaglandin E2 (PGE2) concentration were performed after the completion of drug treatment protocol. RESULTS: Intraperitoneal administrations of the selective COX-2 inhibitor celecoxib (7 mg/kg) as well as preferential COX-2 inhibitors like nimisulide (5mg/kg) and aceclofenac (5mg/kg) attenuated hyperalgesia whereas non-COX-2 selective inhibitors like ibuprofen (40 mg/kg) and indomethacin (10mg/kg) did not. Also the histopathological evidence suggests the beneficial effects of COX-2 selective inhibitors. The data suggest that selective inhibition of COX-2 produce good anti-inflammatory, analgesic and antihyperalgesic effects on Carrageenan-induced thermal inflammatory hyperalgesia. CONCLUSION: In the present carrageenan induced chronic pain model we have determined the role of analgesics in the reversal and inhibition of the state of chronic hyperalgesia. While considering the characterization of the present model our observations suggest the importance of a spinal COX-2 mechanism, a spinal action of systemically delivered drugs in the face of peripheral inflammation.

Cardioprotective effect of methanolic extract of Ixora coccinea Linn. leaves on doxorubicin-induced cardiac toxicity in rats.

OBJECTIVES: To investigate the effect of methanolic extract of Ixora coccinea Linn. (MEIC) leaves against doxorubicin-induced cardiac toxicity in rats. MATERIAL AND METHODS: Albino Wistar rats were pretreated with the methanolic extract of Ixora coccinea Linn. leaves (200 and 400 mg/kg, orally) for 1 week followed with the simultaneous treatment with doxorubicin (cumulative dose of 15 mg/kg in six divided doses for 2 weeks) along with the extracts for the next 14 days. On the 22(nd) day hemodynamic parameters such as blood pressure and ECG were recorded. Biochemical study including biomarkers like creatine kinase - MB (CK - MB), lactate dehydrogenase (LDH), SGOT and SGPT, tissue antioxidant markers viz. catalase (CAT), superoxide dismutase (SOD) and extent of lipid peroxidation viz. malondialdehyde (MDA) was estimated. Histopathology of heart was also done to assess the cardioprotective effect. RESULTS: Pretreatment with MEIC significantly reduced (P<0.01) the ST segment elevation and also maintained the BP (P<0.01) close to normal. The MEIC significantly reduced the elevated level of biomarkers like CK - MB, LDH, SGOT, SGPT (P<0.01) near to normal, the MEIC also increased the tissue antioxidant markers viz. CAT, SOD and decreased the level of MDA (P<0.01) in cardiac tissue by dose-dependant manner. The histopathology of heart also further confirmed the cardioprotection provided by the methanolic extract of Ixora coccinea Linn. leaves. CONCLUSION: The results suggest a cardioprotective effect of Ixora coccinea Linn. leaves due to its antioxidant properties.