Anti-inflammatory and analgesic activities of mature fresh leaves of Vitex negundo.
This study confirmed the oral anti-inflammatory, analgesic and antihistamine properties of mature fresh leaves (MFL) of Vitex negundo L. (Verbenaceae) claimed in the Ayurveda medicine by orally treating a water extract of the leaves to rats. The early phase (2h) of carrageenan-induced rat paw oedema was significantly (P<0.01) suppressed in an inversely does-dependent (r(2)=1, P<0.01) manner by MFL. The EC(50) was 2g/kg of MFL. In the formaldehyde-induced rat paw oedema test, the 2.5 and 5g/kg leaves significantly (P<0.05) suppressed the inflammation on days 4-6 of the test. In the hot plate test, 2.5 and 5g/kg of MFL showed a significant (P<0.05) and directly dose-dependent analgesic activity at 1h of treatment while the activity was absent in the tail flick test in rats. The EC(50) for the analgesic activity was 4.1g/kg. In the formalin test, 1.25, 2.5 and 5g/kg of MFL significantly (P<0.05) suppressed the pain in both the phases of the test like aspirin. The leaves showed an inversely dose-dependent in vivo antihistamine and in vitro prostaglandin (PG) synthesis inhibition, membrane stabilising and antioxidant activities. Naloxone did not abolish the analgesic activity in the hot plate test. A 5g/kg of MFL did not impair muscle strength and co-ordination and did not induce sedation. The treatment of 5g/kg of MFL did not show signs of acute toxicity or stress. Fourteen-day oral treatment of 5g/kg of MFL significantly increased the serum activity of AST. Flowering of the tree did not abolish the analgesic and anti-inflammatory activities of the leaves. These observations revealed that the fresh leaves of Vitex negundo have anti-inflammatory and pain suppressing activities possibly mediated via PG synthesis inhibition, antihistamine, membrane stabilising and antioxidant activities. The antihistamine activity can produce the anti-itching effect claimed in Ayurveda medicine.
Dharmasiri
M G
MG
Department of Zoology, University of Colombo, 3, Colombo, Sri Lanka.
Jayakody
J R A C
JR
Galhena
G
G
Liyanage
S S P
SS
Ratnasooriya
W D
WD
D000700:Analgesics / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002351:Carrageenan; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy; D005260:Female; D005557:Formaldehyde; D006634:Histamine H1 Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D007249:Inflammation / Q000188:drug therapy; D008297:Male; D008515:Medicine, Ayurvedic; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D018515:Plant Leaves / Q000009:adverse effects / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D020950:Vitex / Q000009:adverse effects / Q000737:chemistry*
D000700:Analgesics; D000893:Anti-Inflammatory Agents; D006634:Histamine H1 Antagonists; D010936:Plant Extracts; D005557:Formaldehyde; D002351:Carrageenan