Pharmacological investigation of analgesic and antipyretic activities of methanol extract of the whole part of Aeginetia indica.

ETHNOPHARMACOLOGICAL RELEVANCE

Aeginetia indica (Linn.), commonly known as aankuri bankuri, guan-jen-huang, forest ghost flower, dok din daeng, dapong tubo; is a root parasitic plant of the Orobanchaceae family native to South and South-East Asian region. Different parts of the plant are traditionally used to treat fever, pain, inflammation, arthritis, cough, diabetes, and chronic liver disease. Local practitioners often recommend this plant as a folk remedy for dermal swelling, painful menstrual periods, wounds, and knee pain. However, the antipyretic and analgesic activity of A. indica have never been investigated.

AIM OF THE STUDY

The present study was aimed to evaluate the analgesic and antipyretic potential of Aeginetia indica plant extract to verify its effectiveness as reported in traditional uses.

MATERIALS AND METHODS

Preliminary phytochemical analysis of Aeginetia indica crude extract was performed using previously established methods and antioxidant capacity was determined by phosphomolybdenum assay. In vivo analgesic activity of Aeginetia indica methanol extract (AiME) was evaluated by acetic acid-induced writhing test, formalin-induced paw licking test, and hot plate test model. The antipyretic activity was studied in Baker's yeast induced pyrexia model.

RESULTS

Phytochemicals screening revealed cardiac glycosides, saponins, phenols, tannins, and flavonoids in the crude extract of Aeginetia indica. Total phenolic and flavonoid content were recorded as 101 ± 1.1 mg GAE/g of the extract and 35 ± 0.8 mg QE/g of the extract, respectively. The total antioxidant capacity observed in phosphomolybdenum assay was 68.3 ± 1.3 mg ascorbic acid equivalent per gram of the extract. AiME showed significant dose-dependent analgesic activity against acetic acid-induced writhing, formalin-induced paw licking, and hot plate pain model. A higher dose of A. indica (200 mg/kg) produced significant (P < 0.001) inhibition of writhing by 69% whereas, standard aspirin showed maximum 85.6% inhibition. AiME at all doses showed a significant (P < 0.001) decrease of paw licking time in both early neurogenic and late inflammatory pain phase of formalin-induced licking test. In the hot plate test, AiME at a 200 mg/kg dose produced antinociceptive activity (55.18%) higher than the standard ketorolac (49.88%) at 1 h. However, after 2 h, ketorolac showed a maximum effect of 62.66% and AiME 200 mg/kg showed a 60.24% effect. A significant (P < 0.001) reduction of rectal temperature (4.54 °F↓) was recorded for AiME 200 mg/kg, which was higher than the standard paracetamol (3.86 F°↓) after 24 h of treatment.

CONCLUSION

The in vivo investigational studies' results demonstrated promising analgesic and antipyretic activities of A. indica, which supported the claim of its folk uses.