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Pterostilbene has dermal medicinal benefits such as anti-inflammatory, antioxidative effects and photoprotective properties against UVB radiation. The purpose of this study was to evaluate the dermal toxicity of pterostilbene via skin irritation and sensitisation. A skin irritation test was done according to the Organization Economic Co-operation and Development 404 guideline with the scoring of irritation based on erythema and oedema in 5 albino rabbits were observed up to 14 days. The sensitisation test using the Buehler Test in accordance with the ISO 10993-10 guideline was used to study the sensitisation effect of pterostilbene on the skin surface of albino guinea pigs. According to the primary dermal irritation index (PDII), the positive control group was classified with severe irritation (scorings of 7.71). No irritation was observed for the negative control and the 5% pterostilbene treated groups. But, a slight irritation reaction with PDII scorings of 0.86 was observed in the 10% pterostilbene treated group. The sensitisation study indicated that pterostilbene did not produce any sensitisation signs, thus classified as a non-sensitiser agent according to the Magnusson & Kligman classification. Pterostilbene-treated skin also did not indicate any signs of irritation and sensitisation. In conclusion, pterostilbene did not cause dermal toxicity upon application on the skin.

Background: Personalised nutrition and medicine are the future of healthcare. In relation to cancer, public and healthcare professionals often seek dietary recommendations for cancer prevention. Among the important cancers that can be prevented by diet and lifestyle is colorectal cancer (CRC). CRC is one of the commonest cancers globally, and is a major health concern in Malaysia as it presents with high mortality and morbidity rates, causing a significant socioeconomic burden to the country. While extensive research has been conducted on the treatment and mechanisms of cancer, there have been no reports on the associations between metabolites, novel biomarkers of cancer, and dietary patterns in the context of cancer prevention in the Malaysian multiethnic population. Methods: A case control study will be conducted in Malaysia, involving patients diagnosed with CRC, colorectal adenoma and a group of healthy participants. Multiple endpoints will be analyzed, namely metabolomic signatures, epigenetic marks, inflammatory markers and relationship with dietary patterns will be established. Multiple machine learning models will then be used to develop personalised risk stratification algorithms. Recruitment began in July 2019 and is ongoing due to COVID-19 pandemic. Discussion: This study will be the first to identify alterations in metabolites, inflammatory markers and epigenetic marks associated with dietary patterns and CRC risk in Malaysia. Understanding on how dietary patterns influence CRC risk in the multi-ethnic Malaysian population and identification of novel oncometabolites for CRC risk, will allow for development of personalised evidence-based recommendations in reducing individual risks of CRC.

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Curcumin has demonstrated potential cytotoxicity across various cell lines despite its poor bioavailability and rapid metabolism. Therefore, our group have synthesized curcuminoid analogues with piperidone derivatives, FLDP-5 and FLDP-8 to overcome these limitations. In this study, the analogues were assessed on human glioblastoma LN-18 cells in comparison to curcumin. Results from cytotoxicity assessment showed that FLDP-5 and FLDP-8 curcuminoid analogues caused death in LN-18 cells in a concentration-dependent manner after 24-h treatment with much lower IC50 values of 2.5 µM and 4 µM respectively, which were more potent compared to curcumin with IC50 of 31 µM. Moreover, a significant increase (p<0.05) in the level of superoxide anion and hydrogen peroxide upon 2-h and 6-h treatment confirmed the oxidative stress involvement in the cell death process induced by these analogues. These analogues also showed potent anti-migratory effects through inhibition of LN-18 cells’ migration and invasion. In addition, cell cycle analysis showed that these analogues are capable of inducing S-phase cell cycle arrest during the 24-hour treatment, which explained the reduced proliferation indicated by MTT assay. In conclusion, these curcuminoid analogues exhibit potent anti-cancer effects with anti-proliferative and anti-migratory properties towards LN-18 cells as compared to curcumin.