Evaluating the Efficacy of Lotion Containing Black Rice Bran (Oryza sativa L. indica) Extract as Skin Brightening Agent: A Clinical Trial

Background: Ultraviolet exposure is an extrinsic factor to initiate melanogenesis, the process of melanin formation in the skin. Nowadays, natural ingredients tend to be more prevalent in cosmetic formulations due to consumers’ concern about synthetic ingredients and the risks they may represent for human health. Rice bran, the outer layer of a rice grain, can be utilized as a skin-lightening agent. Objectives: This study aimed to determine the efficacy of a lotion containing black rice bran (Oryza sativa L. indica) ethanolic extract as a skin lightening agent. Methods: The black rice bran ethanolic extract was formulated into oil in water (o/w) lotion. In this study, 34 women applied the lotion at one side of the forearm and base placebo lotion as control at the other side of forearm. The results were tested with a paired t-test by GraphPad Prism 8.3.0 software. Results: There was a significant decrease in the melanin index and erythema index in the forearm with a lotion containing black rice bran extract (P-value < 0.0001). Conclusions: The lotion containing 10% black rice bran extract was effective as a skin lightener because it effectively reduced skin melanin production when applied topically.

Gastroprotective Activities of Ethanol Extract of Black Rice Bran (Oryza sativa L.) in Rats

Black rice is a type of rice in the Oryza sativa L. species. There are numerous reports regarding the pharmacological actions of black rice bran, but scientific evidence on its gastroprotection is limited. This study aimed to evaluate the gastroprotective activities of black rice bran ethanol extract (BRB) from the Thai black rice variety Hom Nil (O. sativa L. indica) as well as its mechanisms of action, acute oral toxicity in rats, and phytochemical screening. Rat models of gastric ulcers induced by acidified ethanol, indomethacin, and restraint water immersion stress were used. After pretreatment with 200, 400, and 800 mg/kg of BRB in test groups, BRB at 800 mg/kg significantly inhibited the formation of gastric ulcers in all gastric ulcer models, and this inhibition seemed to be dose dependent in an indomethacin-induced gastric ulcer model. BRB could not normalize the amount of gastric wall mucus, reduce gastric volume and total acidity, or increase gastric pH. Although BRB could not increase NO levels in gastric tissue, the tissue MDA levels could be normalized with DPPH radical scavenging activity. These results confirm the gastroprotective activities of BRB with a possible mechanism of action via antioxidant activity. The major phytochemical components of BRB comprise carotenoid derivatives with the presence of phenolic compounds. These components may be responsible for the gastroprotective activities of BRB. The 2000 mg/kg dose of oral BRB showed no acute toxicity in rats and confirmed, in part, the safe uses of BRB.

Effect Effect of Black Rice Bran on the Pharmacokinetics Profile of Glibenclamide in Hyperglycemic Rats

Black rice bran (BBH) which contains anthocyanins has the ability to lower blood sugar. In therapy diabetes mellitus (DM) it is possible that BBH is used together with the oral antidiabetic Glibenclamide (Gli). Glibenclamide, a weak acid, is well absorbed in the gastrointestinal tract. The absorption of BBH is also good under acidic conditions. So, it is necessary to study the pharmacokinetic interactions between Gli and BBH. The study was designed using a one-way completely randomized design of ten (10) hyperglycemic rats, divided into two groups. Group I rats received Gli 5 mg / kgBW treatment, and group II received Gli 5 mg/kgBW along with BBH 50 mg / kgBW. Sampling was carried out at 1, 2, 4,6, 8 and 24 hours after treatment. Gli levels in the blood were determined by Liquid Chromatography/Mass Spectroscopy (LC/MS). The results showed that in the absorption phase, giving BBH with Gli did not affect the Gli profile in terms of parameters Tmax, Cmax and AUC0-inf. Likewise, in the distribution and elimination phases in terms of parameters VD, ClT and elimination half-time (t1/2). So that the provision of BBH does not affect the pharmacokinetic parameters of Gli in hyperglycemic rats.