Antioxidant and toxicity studies of 50% methanolic extract of Orthosiphon stamineus Benth.
The present study evaluated the antioxidant activity and potential toxicity of 50% methanolic extract of Orthosiphon stamineus (Lamiaceae) leaves (MEOS) after acute and subchronic administration in rats. Superoxide radical scavenging, hydroxyl radical scavenging, and ferrous ion chelating methods were used to evaluate the antioxidant properties of the extract. In acute toxicity study, single dose of MEOS, 5000 mg/kg, was administered to rats by oral gavage, and the treated rats were monitored for 14 days. While in the subchronic toxicity study, MEOS was administered orally, at doses of 1250, 2500, and 5000 mg/kg/day for 28 days. From the results, MEOS showed good superoxide radical scavenging, hydroxyl radical scavenging, ferrous ion chelating, and antilipid peroxidation activities. There was no mortality detected or any signs of toxicity in acute and subchronic toxicity studies. Furthermore, there was no significant difference in bodyweight, relative organ weight, and haematological and biochemical parameters between both male and female treated rats in any doses tested. No abnormality of internal organs was observed between treatment and control groups. The oral lethal dose determined was more than 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of MEOS for both male and female rats is considered to be 5000 mg/kg per day.
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Pulau Penang, Malaysia.
Mun Fei
MF
Yam
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Pulau Penang, Malaysia.
Chung Pin
CP
Lim
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Pulau Penang, Malaysia.
Lee
L
Fung Ang
Faculty of Computer Science and Information Technology, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Lip Yee
LY
Por
International Medical University, Jalan Jalil Perkasa 19, Taman Esplanade, 57000 Kuala Lumpur, Malaysia.
Siew Tung
ST
Wong
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Pulau Penang, Malaysia.
Mohd Zaini
MZ
Asmawi
Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Rusliza
R
Basir
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Pulau Penang, Malaysia.
Mariam
M
Ahmad
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D016166:Free Radical Scavengers / Q000378:metabolism; D008297:Male; D000432:Methanol / Q000737:chemistry; D009929:Organ Size / Q000187:drug effects; D031342:Orthosiphon / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats
D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D000432:Methanol