Skin exposure to ultraviolet (UV) rays in the sun causes premature ageing and may predispose to skin cancers. UV radiation generates excessive free radical species, resulting in oxidative stress, which is responsible for cellular and DNA damage. There is growing evidence that phytonutrients such as flavonoids and carotenoids may impede oxidative stress and prevent photodamage. We conducted a systematic review of the literature to explore the effects of certain phytonutrients in preventing skin photodamage. We searched the electronic Medline (Ovid) and Pubmed databases for relevant studies published between 2002 and 2022. The main inclusion criteria were articles written in English, and studies reporting the effects of phytonutrient-containing plants of interest on the skin or skin cells exposed to UV radiation. We focused on tea, blueberries, lemon, carrot, tomato, and grapes, which are rich in flavonoids and/or carotenoids. Out of 434 articles retrieved, 40 were identified as potentially relevant. Based on our inclusion criteria, nine articles were included in the review. The review comprises three combined in vitro and animal studies, four human studies, one in vitro research, and one mixed in vitro and human study. All the studies reported positive effects of flavonoids and carotenoid-containing plant extract on UV-induced skin damage. This evidence-based review highlights the potential use of flavonoids and carotenoids found in plants in preventing the deleterious effects of UV radiation on the skin. These compounds may have a role in clinical and aesthetic applications for the prevention and treatment of sunburn and photoaging, and may potentially be used against UV-related skin cancers.

Osteoarthritis is a degenerative joint disease which primarily affects the articular cartilage and subchondral bones. Since there is an underlying localized inflammatory component in the pathogenesis of osteoarthritis, compounds like tocotrienol with anti-inflammatory properties may be able to retard its progression. This study aimed to determine the effects of oral tocotrienol supplementation on the articular cartilage and subchondral bone in a rat model of osteoarthritis induced by monosodium iodoacetate (MIA). Thirty male Sprague-Dawley rats (three-month-old) were randomized into five groups. Four groups were induced with osteoarthritis (single injection of MIA at week 0) and another served as the sham group. Three of the four groups with osteoarthritis were supplemented with annatto tocotrienol at 50, 100 and 150 mg/kg/day orally for five weeks. At week 5, all rats were sacrificed, and their tibial-femoral joints were harvested for analysis. The results indicated that the groups which received annatto tocotrienol at 100 and 150 mg/kg/day had lower histological scores and cartilage remodeling markers. Annatto tocotrienol at 150 mg/kg/day significantly lowered the osteocalcin levels and osteoclast surface of subchondral bone. In conclusion, annatto tocotrienol may potentially retard the progression of osteoarthritis. Future studies to confirm its mechanism of joint protection should be performed.

Metabolic syndrome (MetS) refers to the simultaneous presence of hypertension, hyperglycemia, dyslipidemia and/or visceral obesity, which predisposes a person to cardiovascular diseases and diabetes. Evidence suggesting the presence of direct and indirect associations between MetS and osteoporosis is growing. Many studies have reported the beneficial effects of polyphenols in alleviating MetS in in vivo and in vitro models through their antioxidant and anti-inflammation actions. This review aims to summarize the effects of honey (based on unifloral and multi-floral nectar sources) on bone metabolism and each component of MetS. A literature search was performed using the PubMed and Scopus databases using specific search strings. Original studies related to components of MetS and bone, and the effects of honey on components of MetS and bone were included. Honey polyphenols could act synergistically in alleviating MetS by preventing oxidative damage and inflammation. Honey intake is shown to reduce blood glucose levels and prevent excessive weight gain. It also improves lipid metabolism by reducing total cholesterol, triglycerides and low-density lipoprotein, as well as increasing high-density lipoprotein. Honey can prevent bone loss by reducing the adverse effects of MetS on bone homeostasis, apart from its direct action on the skeletal system. In conclusion, honey supplementation could be integrated into the management of MetS and MetS-induced bone loss as a preventive and adjunct therapeutic agent.

Glucocorticoid-induced osteogenic dysfunction is the main pathologyical mechanism underlying the development of glucocorticoid-induced osteoporosis. Glucocorticoids promote adipogenic differentiation and osteoblast apoptosis through various pathways. Various ongoing studies are exploring the potential of natural products in preventing glucocorticoid-induced osteoporosis. Preclinical studies have consistently shown the bone protective effects of tocotrienol through its antioxidant and anabolic effects. This review aims to summarise the potential mechanisms of tocotrienol in preventing glucocorticoid-induced osteoporosis based on existing in vivo and in vitro evidence. The current literature showed that tocotrienol prevents oxidative damage on osteoblasts exposed to high levels of glucocorticoids. Tocotrienol reduces lipid peroxidation and increases oxidative stress enzyme activities. The reduction in oxidative stress protects the osteoblasts and preserves the bone microstructure and biomechanical strength of glucocorticoid-treated animals. In other animal models, tocotrienol has been shown to activate the Wnt/β-catenin pathway and lower the RANKL/OPG ratio, which are the targets of glucocorticoids. In conclusion, tocotrienol enhances osteogenic differentiation and bone formation in glucocorticoid-treated osteoblasts while improving structural integrity in glucocorticoid-treated rats. This is achieved by preventing oxidative stress and osteoblast apoptosis. However, these preclinical results should be validated in a randomised controlled trial.

Extensive knowledge related to medicinal characteristics of plants by living in forest or semi-forest habitats and close observations of indigenous communities have led to the discoveries of the genus Lepisanthes and its traditional uses. The genus Lepisanthes is a member of the Sapindaceae family and is found in various regions of the world. Six species of Lepisanthes such as L. alata, L. amoena, L. fruticosa, L. senegalensis, L. rubiginosa, and L. tetraphylla are widely utilized in traditional and folk medicinal systems. They have been used for centuries for the treatment of ailments or symptoms such as pain, dizziness, high fever, frequent passing of watery stool (diarrhea), abscess, and healing of cuts and wounds. Various methodological approaches, mainly in vitro studies, have been employed to further explore the roles of the genus Lepisanthes. The studies identified that the genus Lepisanthes exerts beneficial effects such as antioxidant, antimicrobial, antihyperglycemic, antimalarial, analgesic, and antidiarrheal. However, the summary of the available literature remains inconclusive. This review aims to comprehensively address the botany, traditional uses, phytochemistry, methods, and pharmacological properties of the six commonly used Lepisanthes species. Hence, our review provides a scientific consensus that may be essential in translating the pharmacological properties of the genus Lepisanthes into future novel cost-effective medicines.

Obesity and hyperlipidemia are metabolic dysregulations that arise from poor lifestyle and unhealthy dietary intakes. These co-morbidity conditions are risk factors for vascular diseases. Piper sarmentosum (PS) is a nutritious plant that has been shown to pose various phytochemicals and pharmacological actions. This study aimed to investigate the effect of PS on obesity and hyperlipidemia in an animal model. Forty male Wistar rats were randomly divided into five experimental groups. The groups were as follows: UG—Untreated group; CTRL—control; FDW—olive oil + 20% fructose; FDW-PS—PS (125 mg/kg) + 20% fructose; FDW-NGN—naringin (100 mg/kg) + 20% fructose. Fructose drinking water was administered daily for 12 weeks ad libitum to induce metabolic abnormality. Treatment was administered at week 8 for four weeks via oral gavage. The rats were sacrificed with anesthesia at the end of the experimental period. Blood, liver, and visceral fat were collected for further analysis. The consumption of 20% fructose water by Wistar rats for eight weeks displayed a tremendous increment in body weight, fat mass, percentage fat, LDL, TG, TC, HMG-CoA reductase, leptin, and reduced the levels of HDL and adiponectin as well as adipocyte hypertrophy. Following the treatment period, FDW-PS and FDW-NGN showed a significant reduction in body weight, fat mass, percentage fat, LDL, TG, TC, HMG-CoA reductase, and leptin with an increment in the levels of HDL and adiponectin compared to the FDW group. FDW-PS and FDW-NGN also showed adipocyte hypotrophy compared to the FDW group. In conclusion, oral administration of 125 mg/kg PS methanolic extract to fructose-induced obese rats led to significant amelioration of obesity and hyperlipidemia through suppressing the adipocytes and inhibiting HMG-CoA reductase. PS has the potential to be used as an alternative or adjunct therapy for obesity and hyperlipidemia.