Antipsychotic-like activity of noni (Morinda citrifolia Linn.) in mice.
BACKGROUND
Noni fruit is widely consumed in tropical regions of Indonesia to the Hawaiian Islands. The noni plant has a long history of use as a medicinal plant to treat a wide variety of ailments including CNS disorders. The present investigation was designed to evaluate the antipsychotic effect of noni fruits (Morinda citrifolia Linn.) using mouse models of apomorphine-induced climbing behaviour and methamphetamine-induced stereotypy (licking, biting, gnawing and sniffing).


METHODS
In acute study, the methanolic extract of Morinda citrifolia (MMC) at different doses 1, 3, 5, 10 g/kg was administered orally one hour prior to apomorphine (5 mg/kg, i.p) and methamphetamine (5 mg/kg, i.p) injection respectively in Swiss albino mice. In chronic studies, (TAHITIAN NONI® Juice, TNJ) was made available freely in daily drinking water at 30, 50 and 100% v/v for 7 days; 30 and 50% v/v for 21 days respectively. On the test day, an equivalent average daily divided dose of TNJ was administered by oral gavage one hour prior to apomorphine treatment. Immediately after apomorphine/ methamphetamine administration, the animals were placed in the cylindrical metal cages and observed for climbing behaviour/ stereotypy and climbing time.


RESULTS
The acute treatment of MMC (1, 3, 5, 10 g/kg, p.o) significantly decreased the apomorphine-induced cage climbing behaviour and climbing time in mice in a dose dependent manner. The MMC also significantly inhibited methamphetamine-induced stereotypy behaviour and climbing time in mice dose-dependently. The 7 and 21 days treatment of TNJ in drinking water at 50 and 100%v/v significantly alleviated the apomorphine-induced climbing behaviour and climbing time in mice.


CONCLUSIONS
The present study results demonstrated the antidopaminergic effect of Morinda citrifolia Linn. in mice, suggesting that noni has antipsychotic-like activity which can be utilized in the treatment of psychiatric disorders. However further studies are warranted to identify the active principles responsible for the antipsychotic activity of noni.
Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. pandiphd@gmail.com
Vijayapandi
V
Pandy
Megala
M
Narasingam
Zahurin
Z
Mohamed
D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage*; D001522:Behavior, Animal / Q000187:drug effects; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007214:Indonesia; D008297:Male; D051379:Mice; D032066:Morinda / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage*; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000523:psychology
D014150:Antipsychotic Agents; D010936:Plant Extracts