Acute and long-term effects of alkaloid extract of Mitragyna speciosa on food and water intake and body weight in rats
Ekkasit Kumarnsita, Niwat Keawpradubb and Watcharin Nuankaewc aDepartment of Physiology, Faculty of Science, Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, PSU, Hat-Yai, Thailand.
20 August 2004

Abstract
Acute administration of Mitragyna speciosa (MS) extract (45 and 50 mg/kg) significantly resulted in dose-dependent decreases in food and water intakes (P < 0.05) in rats. Prolonged suppressing effects were observed following administration of the MS extract (40 mg/kg) for 60 consecutive days. Moreover, the long-term administration also significantly suppressed weight gaining.

EFFECT OF CAFFEINE AND CODEINE ON ANTINOCICEPTIVE ACTIVITY OF ALKALOID EXTRACT FROM LEAVES OF KRATOM (MITRAGYNA SPECIOSA KORTH.)
Ornchuma Botpiboon, Sathaporn Prutipanlai, Benjamas Janchawee,Sittipoom Thainchaiwattana.
Songkla University, Thailand
Regional Forensic Science Songkhla, Thailand
2007 

Abstract:
In this study, the effects of caffeine and codeine on antinociceptive activity of an alkaloid extract from leaves of M. speciosa using hot plate test were examined in rat model. The results were found that single oral administration of alkaloid extract at the dose of 100 mg/kg significantly increased latency of nociceptive response at 30, 60, 90 and 120 minutes in the heat induced pain in rats when compared with control vehicle group (p < 0.05).

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Antidepressant-like effect of mitragynine isolated from Mitragyna speciosa Korth in mice model of depression.
Idayu NF, Hidayat MT, Moklas MA, Sharida F, Raudzah AR, Shamima AR, Apryani E.
Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia.
(4-2011)

Mitragyna speciosa Korth. leaves have been used for decades as a traditional medicine to treat diarrhea, diabetes and to improve blood circulation by natives of Malaysia, Thailand and other regions of Southeast Asia. Mitragynine is the major active alkaloid in the plant. To date, the role of mitragynine in psychological disorders such as depression is not scientifically evaluated.

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Effect of Mitragyna speciosa aqueous extract on ethanol withdrawal symptoms in mice.
Ekkasit Kumarnsita, Niwat Keawpradubb and Watcharin Nuankaewc
Department of Physiology, Faculty of Science, Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, PSU, Hat-Yai, Thailand
27 October 2005

Abstract
Administration of the aqueous extract of Mitragyna speciosa at a dose of 300 mg/kg significantly inhibited ethanol withdrawal-induced behaviors that included rearing, displacement and head weaving. The results also showed that at doses of 100, 300 and 500 mg/kg M. speciosa showed antidepressant activity without effect on the spontaneous motor activity.

Source: Fitoterapia Volume 78, Issue 3, April 2007, Pages 182-185

Antinociception, tolerance and withdrawal symptoms induced by 7-hydroxymitragynine,
an alkaloid from the Thai medicinal herb Mitragyna speciosa
Kenjiro Matsumotoa, Syunji Horiea,Hiromitsu Takayamab, Hayato Ishikawab, Norio Aimib, Dhavadee Pongluxc, Toshihiko Murayamad and Kazuo Watanabed.
Laboratory of Pharmacolgy, Faculty of Pharmaceutical Sciences, Josai International University, Japan
Laboratory of Molecular Structure and Biological Function, Graduate School of Pharmaceutical Sciences, Chiba University, Japan. Faculty of Pharmaceutical Sciences, Chulalongkorn University, Thailand
19 June 2004

Abstract
7-Hydroxymitragynine is a potent opioid analgesic alkaloid isolated from the Thai medicinal herb Mitragyna speciosa. In the present study, we investigated the opioid receptor subtype responsible for the analgesic effect of this compound. In addition, we tested whether development of tolerance, cross-tolerance to morphine and naloxone-induced withdrawal signs were observed in chronically 7-hydroxymitragynine-treated mice.

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Evaluation of Antioxidant and Antibacterial Activities of Aqueous, Methanolic and Alkaloid Extracts from Mitragyna Speciosa (Rubiaceae Family) Leaves.
Suhanya Parthasarathy,Juzaili Bin Azizi, Surash Ramanathan, , Sabariah Ismail, Sreenivasan Sasidharan, Mohd Ikram Mohd. Said and Sharif Mahsufi Mansor.

Universiti Sains Malaysia, Penang, Malaysia
Institute for Research in Molecular Medicine, Malaysia
Universiti Kebangsaan Malaysia Selangor, Malaysia
2009

Abstract
 

Studies on the antioxidant and antimicrobial activities of Mitragyna speciosa leaf extracts are lacking. In this study the antioxidant properties of water, methanolic and alkaloid M. speciosa leaf extracts were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method. The amount of total phenolics and flavanoid contents were also estimated. The DPPH IC50 values of the aqueous, alkaloid and methanolic extracts were 213.4, 104.81 and 37.08 μg/mL, respectively. The total phenolic content of the aqueous, alkaloid and methanolic extracts were 66.0 mg, 88.4, 105.6 mg GAE/g, respectively, while the total flavanoid were 28.2, 20.0 and 91.1 mg CAE/g respectively. The antioxidant activities were correlated with the total phenolic content.

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