Effects of Opuntia Ficus-indica Supplementation on Antioxidant Status and Inflammation Levels

Study Design

This open-label, single-arm, prospective study involved a supplementation period of three months. The research was conducted in full compliance with the Declaration of Helsinki and the criteria outlined in Malaysian guidelines for Good Clinical Practice [76]. Participant eligibility was confirmed according to the protocol checklist, and written informed consent was obtained from all participants. The study received approval from the Institutional Ethics Committee, UCSI University, Malaysia, approval code is IEC-2022-FMHS-082.

Participants Selection

Participants were recruited through off-campus advertisements, and the study was conducted at UCSI University in Kuala Lumpur, Malaysia. The inclusion criteria were as follows: (1) generally healthy individually; (2) aged 18 years and above; (3) capable of understanding the study protocol and information; and (4) willing to provide informed consent. Exclusion criteria included: (1) currently undergoing supplementation aimed at enhancing antioxidant status, (2) having undergone major surgical procedures within six months before study entry and (3) pregnant or lactating woman. All participants were provided a participant information sheet and received a thorough explanation from the investigator. Written informed consent was obtained from each participant. Potential risks, including food allergies, were communicated to participants during the consent process.

Supplementation

Demographic characteristics and participants' medical histories were collected during the baseline visit. Afterwards, participants began daily oral supplementation of OFi fine powder packaged in individual sachets (LifeGreenTM, LifeTree Asia, Selangor, Malaysia) at the dosage of 1500 mg once daily for 3 months. The recommended intake dosage was communicated to participants upon their enrollment in the study. Participants prepared the beverages by mixing the contents of each sachet with 150 mL of lukewarm water and were instructed to consume it before meals. Three monthly follow-up visits were conducted. During each visit at weeks 0, 4, 8 and 12, a case report form (CRF) was utilized to gather information on vital signs, self-perceived general well-being and saliva samples for laboratory investigations. Participants were instructed to inform the research team immediately if they experienced adverse reactions to the tested supplement.

Laboratory Examinations Unstimulated saliva samples were collected using a sterile 2.0-mL vial. Participants uncapped the vial, placed the straw into the vial, and passively drooled down the straw for 90 secs. All samples were assayed for different parameters in duplicates. Total antioxidant capacity was assayed using Elabsciecne total T-AOC colourimetric assay kit (Elabscience Biotechnology Co. Ltd, Texas, United States), MDA as lipid peroxidation biomarker was assayed using Elabsciecne MDA colourimetric assay Kit (Elabscience Biotechnology Co. Ltd, Texas, United States), 3-NT as a biomarker of oxidative stress-derived protein damage was assayed using Elabsciecne 3-NT ELISA Kit (Elabscience Biotechnology Co. Ltd, Texas, United States) and 8-OHdG as a biomarker of oxidative stress-derived DNA damage was assayed using Elabsciecne 8-OHdG ELISA Kit (Elabscience Biotechnology Co. Ltd, Texas, United States). Inflammation levels were measured via IL-1beta, IL-6 and IL-10 biomarkers, using Elabsciecne ELISA Kit (Elabscience Biotechnology Co. Ltd, Texas, United States).

Vital Signs and General Wellbeing

Blood pressure and heart rate were measured using the Omron automatic blood pressure monitor HEM 7120 (Omron Healthcare, Kyoto, Japan). Temperature was measured using a Braun forehead infrared thermometer NTF 3000 (Braun GmbH, Kronberg, Germany). Visual Analogue Scale (VAS) was incorporated to self-evaluate their well-being. VAS is a psychometric instrument designed for participants to subjectively assess disease-related symptoms' severity or general well-being. It is a validated tool with demonstrated good validity and excellent reliability in evaluating general well-being and quality of life [35]. During the assessment, participants rated their condition on a 10-cm long horizontal VAS scale, where 0 points indicated the least healthy condition and 10 points indicated the most healthy condition.

Inclusion criteria

• generally healthy individually
• aged 18 years and above
• capable of understanding the study protocol and information
• willing to provide informed consent.

Exclusion criteria

• currently undergoing supplementation aimed at enhancing antioxidant status
• having undergone major surgical procedures within six months before study entry
• pregnant or lactating woman.