Anti-inflammatory and Analgesic Activities of Alpinia nigra Fruit Extract in Laboratory Animals.

Aim: This study was aimed to evaluate the possible anti-inflammatory and analgesic properties of the ethanol extract of fruit of Alpinia nigra (Zingiberaceae). Study Design: Assessment of anti-inflammatory and analgesic activity. Place and Duration of Study: Department of Pharmacy, North South University, Dhaka, Bangladesh, between June 2012 and February 2013. Methodology: The crude extract was investigated for anti-inflammatory effect on Long Evans rats using carrageenan induced paw edema method. For anti-inflammatory study, 20 rats were divided into 4 different groups each receiving either distilled water, standard drug or the extract at the doses of 250 and 500 mg/kg body weight. The analgesic activity was evaluated by hot plate; acetic acid induced writhing method in Swiss Albino mice divided into 4 different groups (control, standard diclofenac sodium and extract at two different doses of 250 and 500 mg/kg body weight). Results: The results of preliminary phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins, glycosides in significant amounts. The present study assessed anti-inflammatory activity of its fruit extracts at a dose of 250 mg/kg and 500 mg/kg against carrageenan induced paw edema in long Evans rats. Both the extracts were able to show a dose dependent anti-inflammatory activity as compared to diclofenac sodium used as a standard. The extract elicited a highly significant (p<0.001) analgesic activity in a dose dependent manner on hot plate and acetic acid induced writhing methods. Conclusion: The anti-inflammatory and analgesic effect of the ethanol fruit extract of A. nigra may be due to the presence of various chemical constituents especially flavonoids, tannins, alkaloids or terpenoids. These experimental findings would further establish the scientific basis of the traditional uses of the plant in the management of inflammatory conditions as well as control of pain.

Investigation of in vivo neuropharmacological effect of Alpinia nigra leaf extract

Objective: To analyze in vivo neuro-pharmacological effects of Alpinia nigra as anxiety is a particular form of behavioral inhibition that occurs in response to novel environmental events.Methods:In present study, the extract of Alpinia nigra was evaluated for its central nervous system depressant effect using mice behavioral models, such as hole cross, open field and thiopental sodium induced sleeping time tests for its sedative properties and an elevated plus-maze test for its anxiolytic potential, respectively.Results:In anxiolytic study, the extract displayed increased percentage of entry into open arm at the dose of 400 and 200 mg/kg. The extract produced a significant (P<0.01) increase in sleeping duration and reduction of onset of sleep compared to sodium thiopental at both doses (200 and 400 mg/kg). The extract (200 and 400 mg/kg) also showed a dose-dependent suppression of motor activity and exploratory activity of the mice in both open field and hole cross test.Conclusion:This study demonstrates that the treated extract has significant central nervous system depressant effect. Further studies on active constituent of the extract can provide approaches for therapeutic intervention.

Investigation of in vivo neuropharmacological effect of Alpinia nigra leaf extract

<p><b>OBJECTIVE</b>To analyze in vivo neuro-pharmacological effects of Alpinia nigra as anxiety is a particular form of behavioral inhibition that occurs in response to novel environmental events.</p><p><b>METHODS</b>In present study, the extract of Alpinia nigra was evaluated for its central nervous system depressant effect using mice behavioral models, such as hole cross, open field and thiopental sodium induced sleeping time tests for its sedative properties and an elevated plus-maze test for its anxiolytic potential, respectively.</p><p><b>RESULTS</b>In anxiolytic study, the extract displayed increased percentage of entry into open arm at the dose of 400 and 200 mg/kg. The extract produced a significant (P<0.01) increase in sleeping duration and reduction of onset of sleep compared to sodium thiopental at both doses (200 and 400 mg/kg). The extract (200 and 400 mg/kg) also showed a dose-dependent suppression of motor activity and exploratory activity of the mice in both open field and hole cross test.</p><p><b>CONCLUSION</b>This study demonstrates that the treated extract has significant central nervous system depressant effect. Further studies on active constituent of the extract can provide approaches for therapeutic intervention.</p>

Phytochemical investigation and in vitro antioxidant activity of an indigenous medicinal plant Alpinia nigra B.L. Burtt

Objective: To investigate antioxidant potential of methanol extract of Alpinia nigra leaves.Methods:picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), nitric oxide and hydrogen peroxide radical scavenging assays. Phytochemical constituents, total phenolic content and total flavonoid content of the extract at different concentrations (10-500 μg/mL) were determined.Results: Alpinia nigra leaves showed high free radical scavenging activity as evidenced by the low IC50 values in DPPH (64.51 μg/mL), in ABTS (28.32 μg/mL), in nitric oxide (80.02 μg/mL) and in H2O2 (77.45 μg/mL) scavenging assays. Furthermore the TPC and TFC of the extract were found to be 69.25 mg gallic acid equivalent per gram of extract and 78.84 mg quercetin equivalent per gram of extract respectively.Conclusions:The results of present comprehensive analysis demonstrated that Alpinia nigra The study was done by using various in vitro methods such as 1,1-diphenyl-2-leaves possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a viable source of natural antioxidants and might be exploited for functional foods and neutraceutical applications.