A Literature-Based Update on Benincasa hispida (Thunb.) Cogn.: Traditional Uses, Nutraceutical, and Phytopharmacological Profiles

Benincasa hispida (Thunb.) Cogn. (Cucurbitaceae) is an annual climbing plant, native to Asia with multiple therapeutic uses in traditional medicine. This updated review is aimed at discussing the ethnopharmacological, phytochemical, pharmacological properties, and molecular mechanisms highlighted in preclinical experimental studies and toxicological safety to evaluate the therapeutic potential of this genus. The literature from PubMed, Google Scholar, Elsevier, Springer, Science Direct, and database was analyzed using the basic keyword “Benincasa hispida.” Other searching strategies, including online resources, books, and journals, were used. The taxonomy of the plant has been made by consulting “The Plant List”. The results showed that B. hispida has been used in traditional medicine to treat neurological diseases, kidney disease, fever, and cough accompanied by thick mucus and to fight intestinal worms. The main bioactive compounds contained in Benincasa hispida have cytotoxic, anti-inflammatory, and anticancer properties. Further safety and efficacy investigations are needed to confirm these beneficial therapeutic effects and also future human clinical studies.


Introduction
Food and food products are being used as medicines over centuries worldwide. Many species from the family Cucurbitaceae have been used as medicaments in various diseases in Ayurveda and ancient Chinese medicine. This family is also known as the gourd family. It provides approximately 5 to 6% of the total vegetables in the world. To date, 825 species from under 118 genera have been reported growing in temperate regions of the world [1]. It should be mentioned that the Cucurbit species can grow in diverse climatic conditions, including arid deserts, tropical, subtropical, and temperate regions. These various types of species are included in food systems and Indian traditional medicines. Generally, the gourd family vegetables provide vitamins, essential minerals, antioxidants, and soluble fibres [2].
The word "herb" derived from the Latin word "herba" and an old French word "herbe" refers to any part of the plant like fruit, seed, stem, bark, flower, leaf, stigma, or a root, as well as a non-woody plant. Many herbs are currently under-using as a source of foods, flavonoids, medicines, or perfumes as well as in certain spiritual activities. Ancient era literature including Unani manuscripts, Chinese writings, and Egyptian papyrus also depicted the use of herbs in various diseases. The Indian Vaids, Unani Hakims, and European and Mediterranean cultures are using herbs for more than 4000 years as medicines. Native people of Iran, Rome, Egypt, Africa, and America used medicinal herbs in healing habits. The Unani, Ayurveda, and Chinese Medicine are using herbal remedies systematically. These all are the potential sources of medicinal plant-based modern medicines. According to World Health Organization (WHO), about 80% of people in the world depend on herbal medicines to fulfil their basic health care needs, and around 21,000 species of plants have been identified as potential medicinal plants. In developed countries, around 25% of the total drugs come from plant origin, while in fast-developing countries as much as 80% [3].
Benincasa hispida (Thunb.) Cogn. (synonym: Benincasa cerifera Savi) (Cucurbitaceae) especially in Asian countries is considered as one of the famous crops under the Cucurbitaceae family that grows mainly for its fruits and well renowned for its nutritional and medicinal properties [4,5]. Scientific reports suggest that B. hispida possesses many important nutritious substances, including vitamins, natural sugars, amino acids, organic acids, and mineral elements [4,6,7]. This review is aimed at sketching an up-to-date scenario on the indigenous uses, nutraceutical, and phytochemical composition along with the pharmacological activities of B. hispida based on database reports.

Review Methodology
Using the PubMed database and the search engines Google scholar, Elsevier, Springer, Science Direct, research articles, and reviews related to B. hispida were analyzed. Abstracts and papers peer reviewed were selected according to the objectives of the research: the molecular pharmacological mechanisms of action proven by preclinical experimental studies [8] and which scientifically justify the traditional uses of B. hispida.
Other sources of "grey literature" information such as Web pages, book chapters, and specialized monographs were also analyzed to obtain maximum updated information on the biological properties of this plant. The keywords used were "Benincasa hispida" or "traditional uses" or "phytochemistry" of "pharmacological properties" or "biological activities" or "toxicology" or "safety" or "side effects." The scientific names of the plants were verified according to PlantList, and the chemical formulas were revised by consulting the PubChem database (https://scholar.google.com).
Inclusion criteria: the most relevant articles written in English on taxonomy, ethnopharmacology, phytochemistry, pharmacology, various biological activities, and toxicity of this plant were included and analyzed.
Exclusion criteria: the papers containing homoeopathic preparations, papers written in languages other than English, publications without pharmacological mechanisms of action.
There is a fine hairs fuzzy coating outer side of the young fruit and has solid thick white flesh of sweet in tastes. The mature fruit sheds its hairs and forms a waxy white coating, giving the name of "wax gourd." The gourd wax coating increases the storage facilities of it. It can grow of a length up to 80 cm and also have broad leaves and yellow flowers. The taste is rather bland. B. hispida is a native of South and Southeast Asia. However, it is commonly grown all over Asia, including Japan, Burma, Ceylon, Sri Lanka, Java, and Australia [10].

Traditional Uses and Ethnopharmacology.
In India, B. hispida is used as a winter season vegetable for a wide variety of diseases. Its medicinal properties have been also recognized in the Ayurvedic system of medicine, spiritual traditions of India and Yoga. In Vietnam, its soup (cooked with pork short ribs) is traditionally used by breastfeeding mothers. In north India and almost all regions in Bangladesh, it is added with pulses like as moong which usually crushed, along with wax gourd, makes a dish locally called bori, which after sun drying is used in curry dishes and eaten with rice or chapati [12]. To make wax gourd soup in China, it is used in stir-fries or added into pork or pork/beef bones, which often served in the scooped-out gourd, carved by 2 Oxidative Medicine and Cellular Longevity scraping off the waxy coating. It is also cut into pieces, candied and normally eaten during the time of New Year festivals, or used as filling in Sweetheart cake. For the Moon Festival, the Chinese and Taiwanese also used it in moon cakes as a base filling. It is candied by the people of the Philippines and is used as a pastry filling for bakpia. In some savoury soups and stir-fries, it also acts as an ingredient. In Nepal, India, and Bangladesh, the tendrils, shoots, and leaves of the plant are consumed as green vegetables [6]. B. hispida is widely used in Chinese medicine, in the treatment of fever, cough accompanied by thick mucus and urinary disorders, it is used especially in bark with a very good diuretic effect. The fruit is recommended for overweight people who want to follow diets. In Ayurvedic medicine, it is used in the treatment of epilepsy, cough, lung disease, hiccups, asthma, internal bleeding, and urinary retention. In India, a fruit compote called Petha Cubes is made from the pulp of the fruit, which is recommended for vegetarians [13].

Antioxidant Effects.
Oxidative stress is a term used for free radical diseases [51,52]. It is defined as the imbalance between free radicals and antioxidants, given that oxidants (free radicals) are more and have a destructive potential on the human body [53,54].
Polysaccharides of fruit extract showed DPPH free radicals scavenging activity with an EC 50 value of 0.98 mg/mL [50]. The seed oil also showed DPPH and ABTS radical scavenging capacity. However, the antioxidant activity was lower than the catechin and BHT at the same concentration (0.1 mg/mL) [44]. Petroleum ether and methanol fruit extracts increased in catalase (CAT) levels in gastric ulcer rats [58]. Hispidalin isolated from this herb also showed DPPH radical scavenging and inhibition of lipid peroxidation capacity [59]. The aqueous fruit extract significantly increased the antioxidant status as well as levels of vitamin C concentration in gastric juice or rats [60].
Antioxidant effects of various parts of B. hispida on various test models have been also observed by several authors [17,28,29,56,61]. Table 2 shows the antioxidant effects of various parts of B. hispida.
4.3. Antimicrobial, Antihelmintic, and Larvicidal Effects. Due to the excessive use of antibiotics that can lead to the development of antibiotic resistance of various strains of bacteria [63][64][65], attempts have been made to use natural antibiotic alternatives [66,67]. Most of these options include plants with antiviral and antibacterial properties that can be  Oxidative Medicine and Cellular Longevity effective against gram-negative and gram-negative germs, which are often difficult to eradicate [68,69]. The methanolic whole plant extract (500 μg/disc) was found to act against Pseudomonas aeruginosa and Vibrio parahaemolyticus [70].

Cytotoxic and Anticancer Effects.
Cancer is a term used to define malignancies in which abnormal cells multiply in an uncontrolled and continuous manner and can invade the surrounding healthy tissues [73,74]. Abnormal cells come from any tissue in the human body and can occur anywhere in the body [75][76][77]. Natural anticancer alternatives can have a direct effect on malignant cells, as well as by stimulating the body's immune capacity in the fight against the aggression of carcinogenic factors, internal or external [78,79]. The favourable effects of some medicinal plants are due to the main biochemical components: flavonoids-which inhibit the activity of carcinogens and prevent the metastasis of malignant cells; carotenoids-which protect the body against colon cancer; terpenes in essential oils-block the action of carcinogens, having a strong antioxidant action; β-carotene, a powerful antioxidant with anticancer protection and a recognized inhibitor of malignant cells; antioxidant vitamins C, E, and A, destroy free radicals, prevent cancer, and block the metastasis process [80][81][82][83].
The fruit, seed, and root proteins (10-1000 μg/mL) exerted a concentration-dependent cytotoxic effect on Artemia salina. The median lethal concentration (LC 50 ) values of fruit, seed, and root extract were 44, 41, and 50 μg/mL, respectively [24]. In this study, the root proteins inhibited the proliferation of HeLa and K-562 cells by 28.50 and 36.60%, respectively. Another study reveals that the whole plant methanolic extract (5-50 μg/mL) exerted a cytotoxic effect on A. salina (LC 50 : 45.187 μg/mL) [70]. Moreover, the aqueous seed extract (20-800 μg/mL) did not exert cytotoxic effects on HUVECs and normal fibroblast (NIH/3T3) cells. On male C57BL/6 mice, the extract showed a potent inhibitory effect on basic fibroblast growth factor-(bFGF-) induced angiogenesis [84]. The aqueous extract (1-20 μg/ mL) also reduced cell adhesion molecules activation by inhibiting monocyte adhesion, ROS, and nuclear factor kappalight-chain-enhancer of activated B cells (NF-κB) on high glucose (25 mM) induced HUVECs cells [57] (Figure 6). Table 4 shows the cytotoxic and anti-cancer effects of various parts of B. hispida, and Figure 1    methacin plus histamine displayed a dose-dependent antiulcerogenic effect in rats and mice [13]. The petroleum ether and methanol fruit extracts (300 mg/kg, p.o.) significantly (P < 0:05) reduced ulcer index, vascular permeability, and malondialdehyde (MDA) content, while an increase in CAT levels in comparison to   7 Oxidative Medicine and Cellular Longevity the control group in pylorus ligated (PL) gastric ulcers, ethanol-induced gastric mucosal damage, and cold restraint stress-(CRS-) induced gastric ulcer rat models [58]. The fruit extract (1 mL/kg, p.o.) also decreased ulcer index as well as MDA, superoxide dismutase (SOD), and vitamin C levels in indomethacin-induced gastric ulcer in rats [23].
The hydromethanol, ethyl acetate, and aqueous ripe fruit extracts (20 mg/kg, p.o./alternative days) were treated for 14 days in ranitidine (5 mg/kg, p.o.) induced hypochlorhydria in rats. The aqueous extract showed better effects on the test animals. It increased the antioxidant status as well as levels of pepsin, vitamin C, and gastric juice chloride concentration than the other extracts [60]. On the other hand, the extract of fruits with the whole plant of Fumaria vaillantii Loisel (1 : 1) (20 mg/kg, p.o.) was administrated in ranitidine (5 mg/kg) induced hypochlorhydria in rats as pre-and cotreatment manners. The extract significantly (P < 0:05) enhanced the concentration of pepsin, iron levels in serum, chloride level in gastric juice, and liver along with blood haemoglobin level in experimental animals [85].
A prospective pilot study on dyspeptic patients (n = 20) (baseline between 30 days and 45 days) aged between 18 and 45 years with only single dose of 200 mL fruit juice every morning in empty stomach for thirty days suggests that a significant improvement of pain, nausea, belching, retrosternal burning, and bowel habits among the patients [86]. Table 5 shows the gastrointestinal -protective effects of various parts of B. hispida.

Oxidative Medicine and Cellular Longevity
The B. hispida fruit methanolic extract displayed potential antidiarrheal activity on the castor oil-induced diarrheal rat model. It was also seen to inhibit induced PGE2, enter pooling, and reduce in the motility of gastro-intestine in charcoal meal rats [90]. The same extract also possessed a significant inhibitory activity against castor oil-induced diarrhoea and induced PGE2, enter pooling and gastrointestinal motility at 200, 400, and 600 mg/kg (p.o.) in castor oil, charcoal meal, and antienter pooling models in rats [90] ( Table 5).

Effects on Metabolic Diseases
4.6.1. Antidiabetic Effects. The methanolic stem extract (50,100, 200 mg/kg, p.o.) dose-dependently lowered the blood glucose level in alloxan-induced diabetic rats [37]. The chloroform fruit extract (250 and 500 mg/kg, p.o.) dose-dependently ameliorated the derangements in lipid metabolism in alloxan-induced diabetic albino rats after 14 days of treatment [91]. The study reveals that the methanol, ethanol, and aqueous peel extracts showed significant αamylase inhibition activity [17]. The ethanol and ethyl ethanoate leaf extracts lowered the blood glucose level of the diabetic mice in a dose-dependent manner [22]. Antidiabetic effects of various parts of B. hispida have been shown in Table 6. 4.6.2. Antiobesity and Lipid-Lowering Effect. Lipids are fatty organic substances that are the largest source of energy for the body. The vast majority of fats are stored in solid form in various organs or skin, and a small part circulates in the blood in liquid form [92,93]. Imbalances in lipid metabolism lead to pathophysiological changes and the appearance of chronic diseases such as cardiovascular disease, fatty liver, endocrine disorders, and diabetes [94,95]. Methanolic fruit extract (0.2-1 g/kg, i.p.) reduced food intake, suggesting anorectic activity in mice [96]. Hexane fraction from the aqueous fruit extract inhibited adipocyte differentiation by blocking leptin gene expression, peroxisome proliferatoractivated receptor gamma (PPARγ), and CCAAT enhancer-binding protein alpha (C/EBPα), resulting in the reduction of lipid accumulation, increased releasing of glycerol and intracellular triglycerides in 3T3-L1 cells [97].  [98]. On the other hand, the fruit peel methanolic extract exerted a dose-dependent (0.25-1.5 g/kg) anticonvulsant effect on pentylenetetrazol-induced convulsion in mouse models [62]. Ethanolic seed extract (250 and 500 mg/kg, p.o.) showed a dose-dependent anticonvulsant effect in anticonvulsant activity in Swiss albino mice [72].

Effects on Alzheimer's Disease.
Neurodegenerative diseases such as Alzheimer's disease are characterized by the presence of the central nervous system, protein aggregates, inflammation, and oxidative stress [99,100]. Several factors are involved in triggering neurodegenerative diseases, including the lifestyle that leads to the gradual deterioration of the health of the nervous system, with serious consequences on the quality of life of the patient with such a disease [101]. Although there are still no treatment solutions to restore nerve function in neurodegenerative diseases, more and more studies insist on several natural formulas that have been shown to have the effect of reducing symptoms and improving the quality of life of patients with neurodegenerative diseases [102,103]. Abbreviations: IC 50 : value concentration that inhibits cell growth by 50%; bFGF: basic fibroblast growth factor; ROS: reactive oxygen species; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; NNGH: N-isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid. 10 Oxidative Medicine and Cellular Longevity The fruit extract at a dose of 400 mg/kg (p.o.) showed a protective effect on colchicine-induced Alzheimer's disease rats, possibly through the presence of both vitamin E and β-carotene protecting rat neurons against oxidative stress. On the other hand, the aqueous fruit pulp extract (100-450 mg/kg, p.o.) dose-dependently increased SOD, CAT, and GSH, while reduced in LPO levels in the colchicineinduced Alzheimer's rat model [16].

Effects on Memory and Cognitive Behaviour.
Cognitive disorders are characterized by changes in brain structure and function that affect learning, orientation, judgment, memory, and intellectual abilities [104][105][106]. The methanolic fruit extract (200, 400, or 600 mg/kg, p.o.) showed a significant dose-dependent anticompulsive effect in marble-burying and motor coordination test models in mice [38]. The petroleum ether, methanolic, and aqueous fruit extracts (100,200, and 400 mg/kg, p.o.) showed a dose-dependent nootropic activity in the cognitive behaviour mouse model [107]. Kumar and Nirmala [108] also studied the possible nootropic effects of the fruit on experimental animals.

Antidepressant and Anxiolytic
Effects. Anxiety is defined as a diffuse fear, without a well-defined cause regarding various events of daily life [109]. Methanolic fruit extract (50, 100, and 200 mg/kg, p.o.) showed a dose-dependent   The development of morphine addiction prevented along with the suppression of opioid withdrawal symptoms [113] 12 Oxidative Medicine and Cellular Longevity antidepressant-like effect in TST and FST models possibly through GABAergic involvement in mice in Swiss mice [110]. Petroleum ether, methanolic, and aqueous fruit extracts (100,200, and 400 mg/kg, p.o.) confirmed a dose-dependent anxiolytic activity in mice [107]. Effects of various parts of B. hispida on the nervous system have been shown in Table 6.
4.9. Other Potential Biological Activities 4.9.1. Bronchodilatator Effect. Fruit methanol extract inhibited histamine release. In this study, two triterpenes, the triterpenes and sterols, multiflorenol and alnusenol exerted better inhibitory effects [33]. The methanolic extract (50,200, and 400 mg/kg, p.o.) of B. hispida exhibited significant protection in guinea pigs against the histamine and acetylcholine-induced bronchospasm [115]. The methanolic fruit extract (200-3000 mg/kg, p.o.) showed significant antihistaminic activity on experimental animals (e.g., rats, mice, and guinea pigs) [114]. dose-dependently lowered blood pressure, concentration-dependently showed relaxation of isolated rat aortic rings and produced nitric oxide (NO) from the cultured porcine aortic endothelial cells [116]. Polysaccharides of fruit extract showed an antiglycation effect [50]. 4.9.3. Nephroprotective Effects. Methanolic fruit extract (500 mg/kg/day, p.o.) for five days reduced the MDA content, while the increase in SOD, CAT, and GSH levels in renal ischemia/reperfusion injury in female Wistar albino rats [117]. The seed ethanolic extract (250 and 500 mg/kg, p.o.) for 35 days significantly lowered the increased urinary oxalate, presenting a regulatory action on endogenous oxalate synthesis; decreased in the urinary excretion and kidney retention levels of protein, oxalate, and calcium; and reduced the increased serum levels of sodium, calcium, phosphorus, and creatinine levels in ethylene glycol induced chronic hyperoxaluria in Wistar albino rat [118].
Effects of various parts of B. hispida on the kidney have been shown in Table 6.
4.9.4. Antiageing of Skin. A cream prepared from the dried fruit pulp extract (petroleum ether, chloroform, ethyl acetate, and methanol) showed a significant antiageing effect on the stratum corneum of human skin and dansyl chloride fluorescence models [12].

Toxicological Profile: Safety and Adverse Effects
The fresh juice (5% v/v) treatment for 3 months did not change the total white blood cells (WBC), red blood cells (RBC), haemoglobin (HB), mean corpuscular haemoglobin (MCH), hematocrit (HCT), mean corpuscular volume (MCV), sugar, and urea levels in rats and mice. The treatment also caused no behavioural changes in experimental animals [13]. The methanolic extract of fruit was nontoxic and did not cause the death of mice, rats, and guinea pigs in doses up to 3.0 g/kg [114]. Other studies, performed in female and male rats, concluded that the standardized hydroalcoholic (70% ethanol) extract of the fruit pulp of B. hispida administered orally was relatively safe when to female and male rats [119]. Up to oral dose (1000 mg/kg body weight/day) level, no-observe-adverse-effect-level (NOAEL) was obtained for the extract in the 90-days toxicity study. The ethanolic seed extract up to 5000 mg/kg (p.o.) did not exert toxicity in rats [26]. Di-2-Ethylhexyl phthalate (18.3-75.5 mg/kg), isolated from the fruit of this herb, is a popularly used plasticizer and is harmful to human health [36].

Conclusions and Future Perspectives
Benincasa hispida (Cucurbitaceae) is an annual plant, originating in Indonesia. The Chinese have been cultivating it for over 2000 years; its medicinal uses first appeared in the medical field of the Tang Dynasty. In Chinese medicine, the crust is used to treat urinary dysfunction, and the fruits are used to treat fever. In Ayurveda, the fruits are also used to treat epilepsy, lung diseases, asthma, cough, and urinary retention. Starting from these traditional uses, the present paper evaluated the latest in vivo and in vitro pharmacological studies that demonstrated the molecular mechanisms which confirmed ethnopharmacological uses. However, a limiting aspect of this paper is the lack of clinical trials in human subjects. In the future, they are needed to complete the pharmacological properties and to pave the way for new pharmaceutical forms based on natural compounds with proven therapeutic effects. Improvements in control standards are also needed for future pharmacological studies that include B. hispida. In our work, they are relative, phytochemical compounds being identified only by highperformance liquid chromatography (HPLC). Another limiting aspect is represented by the antioxidant action of this plant which has been researched only in vitro, which does not guarantee the same effect on in vivo experimental models. Also, in future studies, the bioavailability, pharmacokinetics, mechanism of action, and study of the activity relationship of the identified and isolated pure phytochemicals should be analyzed, to better understand the reported biological actions.
Although experimental toxicological studies in animals have not shown any adverse effects, no human clinical trials have been performed to demonstrate pharmacological properties or to systematically assess toxicity and safety in humans. These studies are very important for the evaluation of short-and long-term toxicity as well as clinical therapeutic efficacy. However, the results of the present study support the clinical use of B. hispida in modern medicine and can serve as a basis for further studies based on this plant. 14 Oxidative Medicine and Cellular Longevity Abbreviations ABTS: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid ALP: Alkaline phosphatase bFGF: Basic fibroblast growth factor CAT: Catalase C/EBPα: CCAAT enhancer-binding protein alpha DPPH: 2,2-diphenyl-1-picrylhydrazyl HPLC: High-performance liquid chromatography HUVECs: Human umbilical vein endothelial cells GSH: Reduced glutathione ICAM-1: Intercellular adhesion molecule IL-6: Interleukin 6 LC 50 : Median lethal concentration LPO: Lipid peroxidation MCV: Mean corpuscular volume MDA: Malondialdehyde NIH/3 T3: Normal fibroblast cells NO: Nitric oxide PGE2: Prostaglandin E2 PPARγ: Peroxisome proliferator-activated receptorgamma ROS: Reactive oxygen species SGOT: Serum glutamic oxaloacetic transaminase SGPT: Serum glutamic pyruvic transaminase SOD: Superoxidase dismutase STZ: Streptozotocin TPC: Total phenolic content TNF-α: Tumour necrosis factor-alpha.

Data Availability
The data supporting this review are from previously reported studies and datasets, which have been cited. The processed data are available from the corresponding author upon request.

Conflicts of Interest
The authors declare that they have no conflicts of interest.