Khairiah Jusoh

Bio: Khairiah Jusoh is an academic researcher from National University of Malaysia. The author has contributed to research in topics: Germination & Radicle. The author has an hindex of 2, co-authored 4 publications receiving 152 citations.

Antioxidant Activity of Pink-Flesh Guava (Psidium guajava L.): Effect of Extraction Techniques and Solvents

Abstract: The effect of commonly used techniques and solvents in the antioxidant activities of pink-flesh guava fruit were studied. The extraction techniques compared were homogenization, shaking, sonication, magnetic stirring, and maceration for 1, 2, and 3 days. The solvent systems used were methanol, ethanol, and acetone at three different concentrations (50%, 70%, and 100%) and with 100% distilled water. The antioxidant activity of the fruit was evaluated using Folin–Ciocalteu index, ferric-reducing antioxidant power assay, and 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity. Ultrasonic and homogenization were the best techniques to extract the antioxidant from guava fruit. Homogenization technique was found to be the most convenient exhaustive and time-saving extraction technique. Results showed that the extracting solvent significantly (P < 0.05) altered the antioxidant property estimations of pink-flesh guava fruit. Pure solvents were inefficient extraction media for antioxidant. Enhanced extraction yields were obtained from solvent containing higher water concentrations and 50% acetone is a recommended solvent for extracting antioxidants compounds from pink-flesh guava fruit. High correlations between phenolic compositions and antioxidant activities of pink-flesh guava extracts were observed. High levels of antioxidant activities were detected in pink-flesh guava, indicating that the fruit may serve as an excellent dietary source of natural antioxidants.

Phytotoxicity assessment of nano-ZnO on groundnut (Arachis hypogaea) seed germination in MS medium

Abstract: Due to the increasing production and use of nanoparticles in various sectors such as electronic industries and healthcare, concerns about the unknown effects caused by the presence of these materials in the natural environment and agricultural systems were on the rise. Because of the growing trend of ZnO nanoparticles (nZnO) which is one of the most widely used nanoparticles being released into the environment, it has attracted the attention for more studies to be done on the effects of this nanoparticle on organisms. This study was carried out to investigate the phytotoxicity effect of nZnO on groundnut seedlings in Murashige and Skoog (MS) medium. The experimental treatments of this study include eight concentrations of nZnO (10, 30, 50, 100, 200, 400, 1000 & 2000 mg.L-1) added to MS medium and MS medium without nanoparticles have been used as control treatment. For the first 6 days after sowing, germination percent and germination rate index were calculated by counting the germinated seeds every day. Groundnut seedlings were incubated for 3 weeks in optimum condition and after that, seedling characteristics such as length, wet and dry weight of radicle and plumule were measured. The water content of radicle and plumule were also calculated. The results of this study showed that radicle and plumule length of groundnut seedlings were affected by nZnO exposure, in a way that length of radicles in 50 mg.L-1 nZnO and higher concentrations was significantly lower than that of control treatment and the shortest plumule length was observed in 2000 mg.L-1 nZnO concentration treatment. Both the radicle and plumule wet weight were also decreased as the nanoparticle concentration was increased. However, despite the decreasing in radicle and plumule dry weight with increasing in nZnO concentration, this increase was not significant. However radicle dry weight in 10 mg.L-1 nZnO was significantly higher than nZnO treatments with 200 mg.L-1 concentration and higher concentrations. Moreover, observations of this study did not show any significant difference between the water content of nZnO concentration treatments and control treatment.

Effects of zinc oxide nano-particles on groundnut (Arachis hypogaea) seedlings

Abstract: Along with the rapid growth of nanoparticle consumption in various industries, concerns about the unknown effects caused by the presence of these materials in the natural environment and agricultural systems are being highlighted. Due to the growing trend of Nano Zinc Oxide Nanoparticle (ZnO-np) which is one of the most widely used nanoparticles being released into the environment, it has attracted the attention for more studies to be done on the effects of this nanoparticle on organisms. This study was carried out to investigate the phytotoxicity effect of ZnO-np on peanut seedlings in Murashige and Skoog medium (MS medium). The experimental treatments of this study include nine concentrations of ZnO-np (0, 10, 30, 50, 100, 200, 400, 1000, 2000 ppm) added to MS medium. Peanut seedlings were incubated for 3 weeks in optimum condition and after that, seedling characteristics such as length, wet and dry weight of root and shoot were measured and the water content of root and shoot were calculated. Results o...

The phytochemistry and medicinal value of Psidium guajava (guava)

Abstract: Psidium guajava (guava) is well known tropic tree which is abundantly grown for fruit. Many countries have a long history of using guava for medicinal purposes. This plant finds applications for the treatment of diarrhea, dysentery, gastroenteritis, hypertension, diabetes, caries and pain relief and for improvement in locomotors coordination. Its leaf’s extract is being used as a medicine in cough, diarrhea, and oral ulcers and in some swollen gums wound. Its fruit is rich in vitamins A, C, iron, phosphorus and calcium and minerals. It contains high content of organic and inorganic compounds like secondary metabolites e.g. antioxidants, polyphenols, antiviral compounds, anti-inflammatory compounds. The phenolic compounds in guava help to cure cancerous cells and prevent skin aging before time. The presence of terpenes, caryophyllene oxide and p-selinene produces relaxation effects. Guava leaves contain many compounds which act as fungistatic and bacteriostatic agents. Guava has a high content of important antioxidants and has radio-protective ability. Quercetin is considered as most active antioxidant in the guava leaves and is responsible for its spasmolytic activity. Its ethyl acetate extract can stop the germ infection and thymus production. Guava possesses anti-viral, anti-inflammatory, anti-plaque and anti-mutagenic activities. Guava extract shows antinociceptive activity and is also effective in liver damage inflammation and serum production. Ethanolic extract of guava can increase the sperm quality as well as quantity and can be used for the treatment of infertile males.

Effect of extraction solvents on the phenolic content and antioxidant properties of two papaya cultivars

Abstract: In this study, three types of solvent extracts from two cultivars of papaya fruit (Hongkong and Eksotika) were used to examine the effects of extraction solvent on total phenolics content (TPC), total flavonoids content (TFC) and antioxidant activity by ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picryl hydrazyl radical scavenging (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) were determined spectrophotometrically Results showed that extraction solvent had significant effects on TPC, TFC, and antioxidant activity of methanol and acetone extract The highest content of TPC, TFC and antioxidant activity (FRAP, DPPH and ABTS) were found in 50% methanol and 50% acetone extracts The TPC varied for both cultivars (Hongkong and Eksotika) from 1635 to 4665, 6750 to 2338 mg gallic acid/100 g fresh weight, and TFC were between 1940 and 3617, 3981 and 2104 mg quercetin/100 g fresh weight and antioxidant activity (FRAP from 12484 to 9023, 19059 to 15998 mg Trolox equivalents/100 g fresh weight), DPPH were between 4782 and 2872%, 7456 and 3857%) and (ABTS from 5734 to 3149% and 6906 to 3484%), respectively The largest amount of TPC and TFC which leads to more effective radical scavenging effect was shown by 50% methanol extract Moreover, amount of phenolic compounds and antioxidant activities increased in methanol and acetone extract Therefore, a positive correlation occurred between antioxidant activity and phenolics compound Methanol 50% and acetone 50% solvent showed the greatest capability in extracting antioxidants and inhibiting the free radicals produced It was concluded that extraction solvent play important roles on the phenolics compounds and their antioxidant activity of papaya fruit extract Key words: Papaya, extraction solvent, antioxidant activity, phenolic compound